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1.Igneousrocksandprocesses1.1Hotspotsandintraplatemagmas:mantlesources,magmaticprocessesandmetasomatism.

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Theroleofsublithosphericmantlesourcesincontinentalfloodbasaltmagmatism:lessonslearnedfromtheKarooLIP

JussiS.Heinonen1,ArtoV.Luttinen2,TealR.Riley3andSanniTurunen21DepartmentofGeosciencesandGeography,UniversityofHelsinki,2FinnishMuseumofNaturalHistory,UniversityofHelsinki,3BritishAntarcticSurvey

The role of sublithospheric mantle sources iselusive in continental flood basalt (CFB)provinces. This is because on their way to thesurfaceoftheEarth,theparentalmagmasofCFBsinteract with thick continental lithosphere andmay lose their primary geochemicalcharacteristics. Several studies have alsosuggested that thepredominantmantle sourcesof continental flood basalts are within thecontinental lithosphere. Our studies in theAntarcticand,morerecently,AfricanpartsoftheEarly JurassicKarooLIPover thepast25yearshave revealed the existence of severalsublithospheric mantle-derived magma types.Theirsourcesrangefromdepleteduppermantle(DM)todifferentkindsofenrichedmantle(EM),and possibly even to ancient primordial plumesources originating from the core-mantleboundary. Whereas the recognized EM sourcesseem to be anomalous and had minorcontributions toKaroomagmatism, theDMandprimordial-like sources may have been veryimportantinthegenerationofvoluminousKaroomagmas. Energy-constrained assimilation‒fractional crystallizationmodeling has revealedthatonlya fewpercentofassimilationcanshiftthe CFB trace element and radiogenic isotope

signaturesclosetothoseoflithosphericwallrockmaterials. We suggest that, with the possibleexceptionofverystronglyenrichedmagmatypes,the continental lithosphere has in many casesacted as a ‘pepper mill’, only spicing up CFBmagmas otherwise predominantly generated inthesublithosphericmantle.

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MagmatismassociatedwithGondwanalandrifting:EvidencefromIraqZagrosSutureZone

SabahIsmail1andShaleerBurhan21Educationcollegeforpuresciences/KirkukUniversity/Iraq,2AppliedGeologyDepartment/KirkukUniversity/Iraq

The opening of the southern basin of the Neo-Tethys as a result of the breakup of Gondwanaduring Late Triassic was accompanied by theeruptionoffloodbasalts.Thisprocessledtothefragmentation of continental lithosphere andrifting of these fragments from the northernmargin of Gondwana and created deep trenchgrabens which were subsequently filled byradiolarite deposits. Such events are welldocumented in southern Turkey, northwesternSyria and southwestern Cyprus. Fragmentsrelated to these activities also exist as thrustnappesintheIraqiZagrosSutureZone(AvromanplatformlimestoneandQulqularadiolarite)Suchnappes also occur systematically beneath theobductedophiolitesfromGreecetoOman.IntheIraqi Zagros Suture Zone the Late TriassicAvroman nappe was thrusted over the EarlyCretaceous Qulqula radiolarite and both werethrustedovertheLateCretaceousophiolites.TheAvroman volcanics are lava flows consisting ofolivine-basalts, diabases, trachytes and tuffs.Previous K-Ar dating of a diabase rock gave anageof220Ma±20.Geochemicalanalysisoftheserocksindicatesthatthealkaliolivinebasaltsarestrongly enriched in light rare earth elementswithoutEuanomalies.Traceelementdataforthe

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most primitive mafic igneous rock samplessuggest that the tholeiitic basalts are derivedfrom an enriched mantle sourcewith OIBsignature formed within plate activity. Thisalkaline magmatism may have taken place ascontinentalfloodbasaltseruptedduringriftingofGondwana at Norian with evidences of mantleplume interaction in the early rifting phaserelatedtotheopeningoftheNeo-Tethys.

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Tracing of mantle heterogeneity inKaroo flood basalts using Nb-Zr-Ti-Yratios

ArtoLuttinen1,SanniTurunen1andJussiHeinonen21FinnishMuseumofNaturalHistory,P.O.Box44,00014UniversityofHelsinki,Finland,2DepartmentofGeosciencesandGeography,P.O.Box64,00014UniversityofHelsinki,Finland

Thestudyofmantlesourcesofcontinentalfloodbasaltprovincesisoftencompromisedbycrustalcontamination overprinting of the incompatibleelement and isotopic ratios of the predominantrock types. Geochemical tracers which areunaffectedbycontaminationhelpto:(1)identifyco-genetic types of flood basalts, (2) establishparent-daughter relationships between floodbasalt types and rare uncontaminated picrites,and (3) constrain mantle source heterogeneityeven when picrite types are unknown.Identificationofsuchtracershasturnedouttobedifficult,however.

WehaveexaminedvariationsofNb/Y,Nb/Zr,andNb/Ti at given Zr/Y (quantifiedusingΔNbY,ΔNbZr andΔNbTi) in geochemicallydiverse Karoo flood basalts. Importantly, thedelta-Nb values are only mildly affected bymelting, crystallisation, and contaminationprocesses and can be used as tracers ofmantlesourceheterogeneity.

In the Karoo province, the variationsinΔNbY,ΔNbZr, andΔNbTi and initial Nd and Srisotopicratioscallforatleastthreemantlesource

end-members: Two have Nb-depletedcompositions relative to primitive mantle, butmarkedly different depleted and enrichedisotopiccompositions.Thethirdend-member isNb-undepleted and shows isotopic affinity tobulksilicateEarth.ThreeKaroopicritesuitescanbeassociatedwiththeseend-members,whereasother picrites probably represent subordinatemantlecomponents.

IntheKarooprovince,thedelta-Nbtracerspavethe way for: (1) provincial scale mapping ofmantle heterogeneity using variablycontaminatedfloodbasaltsand(2)identificationof picrites best suited for geochemicalcharacterisation of the major mantlecomponents.

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Assessingprimaryvs.secondarygeochemicalfingerprintsofIcelandicbasaltsusinghigh-Fo#olivinecrystals

MajaB.Rasmussen1,SæmundurA.Halldórsson1,MartinJ.Whitehouse2,SallyA.Gibson3andDavidR.Hilton41NordicVolcanologicalCenter,UniversityofIceland,Reykjavik,Iceland,2SwedishMuseumofNaturalHistory,Stockholm,Sweden,3UniversityofCambridge,Cambridge,UK,4ScrippsInstitutionofOceanography,UCSD,LaJolla,USA

Oxygenisotoperatios(d18O)ofIcelandicbasaltsarenotablydistinctfromMORB-sourcedbasalts.Two prevailing hypotheses have been putforwardtoaccountforthis:interactionwithlow-d18Ocrustormantleheterogeneity[1].High-Fo#olivine crystals are widely used as a proxy forprimary melt composition prior to crustalmodification [2]. Therefore, their geochemicalcharacteristics can be useful to determine thesourceoflow-d18OinIcelandicbasalts.Wecouplein-situ d18O of high-Fo# (>80) olivine crystalsfromtheneovolcanicrift-andflankzonesaswellas older Tertiary units with major and traceelements using SIMS, EMPA and LA ICPMS astools to identify primary vs. secondary controls

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on some notable geochemical characteristics ofIcelandicbasalts.

The olivine crystals show limited intra-grainvariability but, collectively, they display avariationind18O(Ol)of>3‰acrossIceland,withmostvaluesfallingbelowtheexpecteddepletedmantle-value (~5.1 ±0.2‰ [3]). The lowestd18O(Ol)(+2.77‰),ismeasuredincrystalsfromcentralIceland,closetotheinferredplumehead[4].Traceelementratiosoftheseolivinecrystals(e.g.,Mn/Fe)suggestaperidotiticmantlesource,implying a shallow (likely crustal) origin of thelowd18O(Ol). Incontrast,crystals fromtheSouthIceland Volcanic Zone display trace elementratiosindicativeofgreateramountofpyroxenitein their source region while their d18O(Ol) varysignificantly (from +3.45 to +4.98 ‰). Theseresults, together with previously published3He/4Hevaluesforthesesamesamples[4],implya regional shift in the dominating mantlelithology and plumbing conditions beneathIceland.

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LuenhapicritesrevealaprimitivemantletypeplumesourceintheKaroolargeigneousprovince?

SanniTurunen1,ArtoLuttinen1andJussiHeinonen21FinnishMuseumofNaturalHistory,P.O.Box44,00014UniversityofHelsinki,Finland,2DepartmentofGeosciencesandGeography,P.O.Box64,00014UniversityofHelsinki,Finland

Two distinctive picrite suites have beenpreviously considered to represent importantparentalmagmatypesintheKaroolargeigneousprovince: (1) the Mwenezi picrites indicate anenriched mantle source (initialεNdca. -10) oflithospheric origin for enriched high-Ti basalts,whereas (2) theVestfjella ferropicrites reveal adepleted convective upper mantle source(εNd+8)forlow-Tibasalts.Bothpicritesuitesarecharacterised by negative ΔNb values (-0.9 to -0.1) indicative of relative Nb-depletion. Ourgeochemicaldataonrecentlydiscoveredpicritic

lavas in the Luenha river area, CentralMozambique, reveal a third significant mantlesourceforKaroobasalts.

The Luenha picrites differ from other KaroopicritesbasedontheirhighpositiveΔNbvalues(+0.5 to +0.6), low Ti contents, and low Zr/Y.Variable initial 87Sr/86Sr and incompatible traceelement ratios likely result from mild crustalcontamination. A single picrite sample lacksindications of contamination and indicates amantlesourcewith87Sr/86Srof0.7041andεNdof+2 and an overall geochemical affinity to aprimitiveormildlydepletedmantle.Wemaintainthat this magma source may represent thepreviouslyunknownmantlecomponentwhichisrequiredtoexplainthehighabundanceofKaroolow-TibasaltswithpositiveΔNb.Bearinginmindthatseverallargeigneousprovinces(e.g.OntongJava)havebeenrecentlyassociatedwithmeltingof geochemically primitive mantle type plumeheads,theLuenhapicritesmayprovideauniquegeochemical insight into a major plume sourcepreviously inferred from geophysical studies oftheKarooprovince.

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TheimportantdistinctionbetweenancientHIMUandyoungHIMU-likesourcesinintraplatemagmatism

QuintenvanderMeer1,TodWaight2,JamesScott3andCarstenMünker41NaturalHistoryMuseum,UniversityofCopenhagen,2DepartmentofGeosciencesandNaturalResourceManagement(GeologySection),CopenhagenUniversity,3DepartmentofGeology,UniversityofOtago,4InstitutfürgeologieundMineralogie,UniversitätzuKöln

Continental intraplate magmas with isotopicaffinities similar to HIMU are identifiedworldwide. Involvement of an asthenosphericHIMUorHIMU-likesource is contestedbecausethecharacteristicradiogenicPbcompositionsatunradiogenic Sr and moderate Nd and Hfcompositions can also result from in-situingrowth inmetasomatised lithosphericmantle.Sr-Nd-Pb-Hf isotopic composition of late

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Cretaceous lamprophyre dikes from Westland,New Zealand provide new insight into theformation of a HIMU-like alkaline intraplatemagmatic province under the ZealandiamicrocontinentandformercontiguousregionsofGondwana.Theoldest(102-100Ma)calc-alkalinelamprophyresarecompositionallysimilartothepreceding arc-magmatism and represent meltsoriginating from subduction-modifiedlithosphere. From ~98 Ma, alkaline intraplatemagmatism emerged throughout Zealandia thatwould remain active up to the present day.Webreak with the classical grouping of thismagmatism into a single suite and show thatdistinct ancient and young enriched sourcescontrolled melt isotopic compositions. Thedistribution of these sources in the Cretaceouswas strongly coupled to lithosphere terranestructure and emphasizes the influence ofenrichedmetasomesinthelithosphericmantleasameltsource.

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TracingpyroxeniteinthemantlesourceatHeardIslandintheIndianOcean

AbigailKBarker1,InêsGNobreSilva2,JaneBarling3andNaomiJSaunders31Mineralogy,Petrology,Tectonics,UppsalaUniversity,2MemorialUniversityofNewfoundland,3DepartmentofEarthSciences,UniversityofOxford

Heard Islandhosts the largest activevolcanooftheKerguelenOceanicPlateau,wherewholerockgeochemistrysuggestsanimportantcontributionfrom recycled ocean crust. We present minorelement compositions for olivine from HeardIsland,asatraceroftheinitialmagma,inordertoinvestigate the connection between sourcelithologyandmantlesourcecomponents.

Olivine crystals in the lavas from Heard Islandhave72.5to87.5Fomol%andformtwogroupsdistinguished by Ni and Mn compositions. ThemaingroupofolivinecrystalscontainNi*of540to870(Ni*=NixFeO/MgO;n=14of17samples)andMn*of90to110(Mn*=Mn/FeO),whichare

similartotheglobalarray.ThesecondgrouphashighNi*of1060to1820andhighMn*of150to175(n=3 of 17 samples), elevated in Ni* andMn*withrespecttotheglobalarray.Theolivinemineralchemistryis independentofwholerocktrace element and isotope geochemistry thatreflects mixing between the mantle sourcecomponents.

OlivinecrystalsfromHeardIslandthatplotalongthe global array are consistent with derivationfrom a pyroxenite rich source (60 to 90%).Furthermore,apyroxeniterichsourcelithologyisattributed to all geochemical end members.However, the wide range implies incompletehybridisationorheterogeneoussupplyofeclogiteinthemantlebelowHeardIsland.

TheolivinecrystalsthatdisplayelevatedNi*andMn* potentially reflect melting of the oceaniclithospheric mantle, which has previously beenmetasomatisedbymeltsgeneratedbythemantleplume.

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HydrothermalalterationoftheultramaficrocksattheKemiintrusion

FabianMauricioBotello1,HolgerPaulick1,TimoHuhtelin2andSariGrönholm31OuluMiningSchool,UniversityofOulu,Finland,2OutokumpuChromeOy,KemiMine,3GeologicalSurveyofFinland-GTK

TheKemichromitedepositislocatedclosetothetown of Tornio (northern Finland). Themineralization is hosted within the mafic-ultramafic Kemi intrusion that is part of theTornio–Näränkävääräbelt.Thisbelt consistofabout20individualintrusiveigneouscomplexeswithintheFennoscandianShieldthathavebeenemplacedat2.4to2.5Ga.TheKemiintrusionhasalenticularshapeandisabout15kmlongand2km wide in the middle section (Alapieti et al.,1989).Themainchromiteunitsarelocatedinthebasalpartof the intrusionandhaveanaveragethicknessof40m,butvaryfromafewmetersto

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160m. The chromitite units are enveloped andintercalatedwithvariablyalteredperidotiteandbronzites.

Hydrothermalalterationhaspervasivelyaffectedtheultramaficsequencemainlyinthelowerandupper segments, leaving the middle partlyunaltered(Alapietietal.,1989).Theselithologiescanstillbe identifiedduetothepreservationoftheirprimarytextures.Bronzitesandperidotitessurrounding the chromitite layers have beenalteredtoserpentine,talc,tremolite,chloriteandcarbonates(Gronhölm,1994).Alterationhasalsoaffectedchromitegraincompositionandtexture,finding some grains with inclusions of alteredsilicate minerals. The occurrence of thementioned alteration assemblages requires theinfluxoffluidsrichinSiO2aq(Paulicketal.,2006).Thestudyofthehydrothermalalterationpermitsinterpretationofitsoriginandmakesitpossibleto establish spatial distribution of the alteredassemblageaswell as associationswith theoreandpossibleexplorationvectors.

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Birthinganoceanislandrift:mantlefingersorlateralflow?

FrancesDeegan1,ValentinTroll1,HarriGeiger1,LinaBarke1,JuanCarlosCarracedo2andFranciscoJoséPerez-Torrado21UppsalaUniversity,Uppsala,Sweden,2UniversidaddeLasPalmasdeGranCanaria,GranCanaria,Spain

Rift zones play a key role in modulating thegrowth and destruction of ocean islands.However, it isnotalwaysclearwhethermagmafeedsintoriftsfromthemantleorfrombeneaththe island’s central complex before beingdivertedintoriftzones.Seismicmonitoringofthe2011-2012eruptiononElHierroshowedthatitwas fed by magma that underwent lateraltransport at the base of the ocean crust beforefinal ascent. If this is generally true for CanaryIslandrifts,thentheremaybelargeimplicationsfor rift zone magma evolution and thepreservation(orcrustalmodification)ofmantleisotope signatures. To test this concept, we

carried out mineral-melt thermobarometricmodelling on dykes of the Miocene-PlioceneNortheastRiftZone(NERZ)onTenerife,whichisasuperblyexposedexampleofafeedersystemtoa major ocean island volcanic rift. Our initialresultspointtosub-MOHOlevelcrystallizationoffeldspar and pyroxene, in stark contrast to thelatestrifteruptiononElHierro.Ourpreliminarydata thus support a model of rift growth onTenerifethroughinjectionofmantle-derivedhotfingers.Thisconclusionisinlinewithanisotropyof magnetic susceptibility (AMS) data, whichindicate non-unidirectional emplacement ofmagmaalongtherift.Moreover,themantlefingermodel is consistent with plume-like (HIMU)radiogenic isotope ratios preserved in many oftheNERZdykes.Oceanislandriftformationthusappears todifferbetween islands in theCanaryarchipelago, which must be taken intoconsideration when assessing mantle versuscrustalgeochemicalindices.

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GeochemicalcharacteristicsofanenrichedIcelandictholeiiticmagmasuite:thecaseoftheKverkfjöllvolcanicsystem

EemuRanta1,SæmundurA.Halldórsson1,Gu∂mundurH.Gu∂finsson1,EniköBali1,VesaNykänen2,KarlGrönvold1andRiinaKaikkonen31NordicVolcanologicalCenter,UniversityofIceland,Reykjavik,ICELAND,2GeologicalSurveyofFinland,Rovaniemi,FINLAND,3OuluMiningSchool,UniversityofOulu,FINLAND

The active Kverkfjöll central volcano and itsassociated fissure swarm are situated at thenorthern margin of the Vatnajökull glacier,Iceland.Thevolcanicsystemischaracterizedbysubglacial pillow basalt ridges and post-glaciallavaflows,eruptedonc.35kmthickcrustattheflankoftheNorthernRiftZone(NRZ).Publishedpetrochemical data from Kverkfjöll are verylimited, incontrast to itsneighboringvolcanoesBárdarbunga, Grímsvötn andAskja.We presentpreliminarygeochemicalandHf-Pbisotopedata

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largely acquired from subglacial pillow rimglasses, focusing further on their dissolvedvolatile contents (EPMA, FTIR) aswell as traceelements(LA-ICP-MS).

TheKverkfjöllbasaltsarenoticeablyenrichedinFeO (12-16 wt.%), with relatively uniformcompositions (MgO = 4-8 wt.%) compared toothertholeiiticmagmasuitesinIceland.Theyareanomalouslyenrichedinincompatibleelements,closelyresemblingtransitionalandalkalibasaltsfrom flank zone areas in Iceland. Suchenrichments are also evident in the dissolvedvolatilecontentsoftheKverkfjöllglasses,whicharesomeofthehighestinIcelandicbasalts(e.g.Cl=350ppm,H2O=0.9wt.%).Moreover,thePb-PbandPb-HfisotopicsignaturesofKverkfjöllfallsinbetween the well-defined trend of the NRZbasalts and the EM1-like compositions of theflank volcano Öræfajökull, unique amongIcelandicbasalts[1].

Theaimofthisin-progressstudyistoaddressifthe Kverkfjöll basalts sample a distinct,previously unrecognized component of theIcelandmantle,oriftheirvolatileenrichmentandatypical isotopicsignaturescanbeexplainedbyothermeans.

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AlkalineOIBsderivedbypyroxenite-meltingoflow-Tmantle

NinaSøager1,MaximPortnyagin2,PaulMartinHolm1andDieterGarbe-Schönberg31DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,2Geomar,HelmholtzCentreforOceanResearch,Kiel,Germany,3Christian-Albrechts-UniversitätzuKiel,Kiel,Germany

High precision microprobe and laser ablationanalyses of forsteritic olivine phenocrysts fromthealkalineEM1-typeoceanislandsofGoughandTristanhavehighratiosofFe/Mn,Zn/Fe,Ga/Scand Ni*FeO/MgO suggesting a large pyroxenitemelt component in the magmas. Crystallizationtemperatures calculated for the magmas rangebetween 1140 and 1227°C and overlap the

temperatures of MORBs confirming that themelts are derived from the asthenosphere.Applying correction along the olivine-liquidusslope to sub-lithospheric pressures suggests amantlesegregationtemperatureofmax.~1300-1350°Cwhich overlaps the range estimated forMORB. Therefore the high Fe/Mn andNi*FeO/MgOcannothavebeencausedbymeltingof very high temperature peridotitic mantle atlarge depths as has been suggested for someplume basalts by various authors. Results fortrace elementmodeling in theOBS1pyroxenitemeltingsimulator(Kimura&Kawabata,2015)onprimitivesamples fromGoughIslandreproduceexpectedpressuresandtemperaturesofmeltingand suggest 8-13% pyroxenite in the mantlesourceand~80%pyroxenitemeltinthemagmasinagreementwiththeolivinecompositions.Forcomparison,olivinecompositionsfromtwoCapeVerdeIslandsindicateaplumemeltend-memberderived by peridotite melting at temperaturescomparable to those for Gough Island despiteverysimilarpressuresandextentsofmeltingasindicatedbytheLa/SmandDy/Ybofthebasalts.ThisshowsthattheSobolevetal.(2007)olivinemodel is still viable for moderate temperatureOIBs.

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1.2.VolcanismintheNorthAtlantic,frombreakuptocurrenttime

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AnatomyoftheSørvágsfjördvolcaniccomplex:LatePalaeoceneexplosivebasalticvolcanismontheFaroeIslands

UniÁrting1,MortenS.Riishuus2,HansAmundsen3,TuridMadsen2andNicoleSchmitz1Jarðfeingi&UniversityoftheFaroeIslands,2Jarðfeingi,3VestfonnaGeophysical

Wereport on thebasaltic Sørvágsfjörd volcaniccomplex(SVC)atthebaseoftheMalinstindurFmintheFaroeIslandsBasaltGroup.This~1.5kmwideand~90mhighstructureisexposedinaseacliffonVágarIsland.Thestructurerestsonfluvio-lacustrine sediments of the Prestfjall Fm and itrepresents a positive paleo-relief onlapped byflood basalts. The SVC composite stratigraphicsequence includes from base to top: i)volcaniclastic sandstone grading into beddedtuffs, ii) agglomerates, iii) two ignimbrite units,iv) erosion surface, v) paleosol bed, in placesreplacedbylahar/debrisflow,vi)ignimbriteunit,vii) agglomerate, viii) two ignimbrite units, ix)erosion surface. The complex is faulted andintruded by stacked sills, dykes and irregularplugs.OnnearbyTindhólmurislet(1.5kmSSW)a paleo-valley incises the Prestfjall Fm, is filledwith lava flows and overlain by lahars andignimbrites.Anotheryoungeranddeeperpaleo-valleyincisesthelahar/ignimbritesequenceandissubsequentlyfilledbylavas,mega-breccia,andlahars(andre-incised).Bothvalleysareburiedbythe Malinstindur Fm. The SVC records asignificant explosive volcanic periodcharacterized by two phases that both includenear-vent agglomerates and pyroclastic densitycurrents.Theexplosivevolcanismwasprecededby regional uplift, faulting, erosion and valleyincision, followed by construction of positivevolcanicrelief,erosionandcontinuedupliftdueto intrusionactivity, erosionandvalley incisionpriortoburial.TheSVCisuniquewithintheNAIP

and important to the tectono-volcanicevolutionduring the transition from pre- to syn-breakupmagmatism.

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StructurallinksbetweentheJanMayenMicrocontinentandthecentralEastGreenlandcoastpriorto,during,andafterbreakup.

AnettBlischke1,ÖgmundurErlendsson2,PierpaoloGuarnieri3,BryndísBrandsdóttir4andCarmenGaina51IcelandGeoSurvey,BranchatAkureyri,Rangárvöllum,603Akureyri,Iceland,2IcelandGeoSurvey,Grensásvegi9,108Reykjavík,Iceland,3GeologicalSurveyofDenmarkandGreenland(GEUS),ØsterVoldgade10,DK1350CopenhagenK,Denmark,4InstituteofEarthScience,ScienceInstitute,UniversityofIceland,Askja,Sturlugata7,Reykjavik,5Dynamics(CEED),UniversityofOslo,SemSælandsvei24,P.O.Box1048,Blindern,Oslo,Norway

A detailed tectonostratigraphic frameworkmodeloftheJanMayenmicrocontinentareahasbeen correlated with its western conjugatemarginofcentralEastGreenland,spanningfromtheprimaryNorthAtlanticbreakup(~56-55Ma)to secondary local breakup processes (~49-21Ma). The reconstructions of the Jan Mayenmicrocontinentandsurroundingoceaniccrustalevolution demonstrate a clear correlation tocentral East Greenland, with respect to majorstructuralboundariesandunconformitieswithinthe stratigraphic record. Igneous stratigraphywascomparedspecificallyfortheplateaubasalts,the alignment to the Iceland Plateau riftsegments,andtotheIgtertivâFormationofKapDaltonwithintheBlossevilleKystarea.

The Jan Mayen microcontinent represents thenext adjacent graben system besides theLiverpool Land high domain and appears tofollow the northeast-southwest trending half-graben symmetryof theMesozoicperiodof theJameson Land Basin. These observations arebased on structural segmentation and trendsvisible in Paleozoic-Mesozoic stratigraphic

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thickness map series for both conjugate areas.TheBlossevilleKystadjacentareaofthesouthernextensionofthemicrocontinentindicatearapidthinningofthepre-break-upsectionbutincreaseinbreak-upandpostbreak-upvolcanicstrata.

For the first time we demonstrate that thewestern flank of the JanMayenmicrocontinentwas also a volcanicmargin, andwe reconstructthenewlymappedLateEocenetoEarlyOligocenesub-crop and volcano-facies maps of the JanMayen microcontinent aligned to a newlymapped volcano-facies and structural elementsmap of the Blosseville Kyst – Scoresby Sund –LiverpoolLandbasinmargin.

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FromIcelandtotheBightTransformFault.Evolutionof1000kmofVolcanicRiftingPlateBoundary

ArmannHoskuldsson1,RichardNHey2,FernandoMartinez3,AsdisBenediktsdottir1andSigvaldiThordarson41UniversityofIceland,2UniversityofHawaii,3UniversityofHawaii-SOEST/HIGP,4IcelandGeosurvey

IcelandisapartoftheNAIPandassuchformsalarge island in themiddle of the northAtlantic.With its continental shelf, Iceland covers about780 kkm3. The MAR plate boundary crossesthrough Iceland from south to north. In thispresentation, we present results from twomissions that cover the southern and northernpartof theReykjanesridge.WeshallshowhowtheReykjanesridgeplungesintotheabyssfromIcelandandfollowitsextentsome1000kmtothesouth,untilithitstheBightTransformfault.ThispartoftheMARsystemisslowspreadingwithanaverage separation of 2 cm per year. Due tounprecedented detailed multibeam mapping intheareafinestdetails involcanicstructurescanbeobserved.However,theactiveplateboundaryshowsremarkablediversityinoverallformsandindividual landforms as we extend away fromIceland.ClosetoIcelandshallowmagmastorageinthecrustisevident,withcalderasandevolvedmagma composition. At the termination of the

Reykjanes ridge AVR are observed at regularinterval. These ridges are formed in multipleeruptions and occupy the rift valley. However,towards the north rift valleys are absent oreshallow. In between the rift valleyswe observemonogenetic eruptive vents. Reorganization oftheplateboundaryisobservedinmagneticfabricof the seafloor and numerous oceanic corecomplexes seem to be related to suchreorganization. Off rift monogenetic eruptivevents are also more frequent as we go furtherawayfromIceland.

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Coast-paralleldoleritedykesalongSEGreenland:SouthernmostonshoreevidenceoftheTertiaryNorthAtlanticIgneousProvince?

MartinKlausen1,DominicLoreti1,ChristianTegner2,CharlesLesher2,ThomasUlrich2andThomasKokfelt31DepartmentofEarthSciences,StellenboschUniversity,PrivateBagX1,Matieland7602,SouthAfrica,2DepartmentofGeoscience,AarhusUniversity,Hoegh-GuldbergsGade2,DK-8000AarhusC,Denmark,3GeologicalSurveyofDenmarkandGreenland,GEUS,OesterVoldgade10,DK-1350CopenhagenK,Denmark

PristinedoleritedykesofpresumedTertiaryagehavepreviouslybeenmappedontheSEcoastofGreenland, south of where the coast-parallelTertiary East Greenland dyke swarm (EGDS)extends into the Atlantic Ocean (Klausen &Larsen, 2002). Between 64˚15’ and 65˚45’N,atotalofsixdykesconstitutingamorenortherlylocated and E-W trending segment are allcompositionallysimilartotheoldertholeiitesofEGDS (Hanghøj etal., 2003); whereas, twelvedykes constituting a more curved SW-NEtrending southern segment resemble youngertransitional-alkaline EGDS dolerites. TogetherwiththeirdistinctOIB-likebulkrockgeochemicalsignatures, these two southerly located swarmsegmentsmostlikelyformedatthesametimeasthemainEGDSandwereprimarilysourcedfroma~600kmsouthwarddisplacedproto-Icelandichot spot enriched mantle source. Compared to

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theIcelandicMantlearraybyFittonetal.(1997)and a petrogenetic REE-grid by Tegner et al.(1998),relativelyhighZr/Y,Nb/Yand(La/Sm)Nsuggestthatthesouthernsegment’stransitional-alkaline primary melts formed through ~ 5%partialmantlemeltingandsegregatedat~30kmdepth. Based on these results – albeit withoutsupporting absolute ages or cross cuttingrelationships – we tentatively propose that (1)early tholeiitic melts formed throughdecompressionmeltingalongaproto-AtlanticriftthatlinesupwiththeEGDS,butinjectedobliquelyinto the E-W trending northern dyke swarmsegment; and (2) a dextrally offset off-axis riftsystem allowed for the generation of morealkaline melts to feed more westerly locatedcoast-paralleldykeswithin thesouthernswarmsegment.

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NEAtlanticbreak-upandmagmatism

ErikLundin1,A.G.Doré2andR.Kyrkjebø1StatoilASA,ResearchCenter,ArkitektEbbelsvei10,7053Trondheim,NORWAY,2Statoil(UK)Ltd,OneKingdomStreet,LondonW26BD,UK

Northeast Atlantic (NEA) break-up in the EarlyEocene has generally been viewed as theculmination of a series of episodic rifts events,spanning from Carboniferous throughPaleocene.However, Paleocene rifting isconspicuously minor or absent. We proposedevelopment of a dextral Paleocene proto-NEATransformsystemthatallowedopeningwithoutfurtherrifting.Severalobservationssupportthisproposal:thelinear,althoughsegmented,lineofbreak-upcuttingobliquelyacrosstheCretaceoushyperextendedbasin;asteeplyterminatedoutermargin; shallowing basement and thickeningcontinental crust toward the margin; coevalcompression at Greenland's northern leadingedge,andsinistralmotionalongitswesternside.

The proto-NEA Transform linked with the DeGeer Transform and further with a transformalong the northern Barents and Kara Sea,effectively yielding a broken plate between

Greenland's southern tip and the LaptevSea.Opening of this c. 6000 km long segmentoccurred around a pole in the Laptev Sea,withhigher extension rates at the southern distalend.SDRs of the magma-rich NEA marginsdiminishnorthwardandareabsentintheEurasiaBasin. This architecture is well known and hastypicallybeenattributedtotheradiusofaplume.However, given that plates are approximatelyrigid, there isanotheroption– thatmagmatismreflects the rate of extension (and associateddecompressional melting). The NEA break-upmagmatism may therefore be rooted in platetectonics.

A relationshipbetweenextension rateandmeltgenerationisfurthersupportedbyevidencefromthe margins along the Aegir-Kolbeinsey Ridgepair,locatedoneithersideofJanMayen.

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TheevolutionofHeklavolcanointhe20thcentury:Integratingremotesensingdatafromthepast70years

GroB.M.Pedersen1,JoaquinM.C.Belart1,FadiKizel2,EyjolfurMagnusson1,OlgaK.Vilmundardóttir3,FriðþórS.Sigurmundsson3,GuðrunGisladóttir3andJónAtliBenidiktsson21InstituteofEarthSciences,UniversityofIceland,Sturlugata7,101Reykjavík,Iceland,,2FacultyofElectricalandComputerEngineering,UniversityofIceland,3InstituteofLifeandEnvironmentalsciences,UniversityofIceland

Heklavolcanoisoneofthemostactivevolcanicsystems in Iceland and has erupted ~23 timessince the settlement of Iceland in AD 874.Thehistorical Hekla eruptions have been studiedfrom written records and tephra chronology.Theseeruptionrecords indicateaveryconstantmagma production, which over the lastmillennium have produced a total of at least 7km3(DRE)oferuptivematerial.

Inthe20thcenturyHeklamountaineruptedfivetimes (1947-1948; 1970, 1980-1981, 1991,2000). These eruptions were well documented

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andithasbeenestimatedthat~80%ofthetotaleruptedvolumewaslava.However,thelavaflowthicknessesused in the volume calculations areuncertainduetocoarsesamplingatselectedlavathicknessprofilesoratflowfronts.Accuratelavavolumeestimatesarethereforecrucialinordertoassesthevolumeoferuptivematerialinthe20thcentury.

In the Hekla area, repeated aerial stereo-photographysurveyshavebeenconductedsince1945 allowing creation of Digital ElevationModels (DEMs) and ortho-photographs usingdigitalphotogrammetrictechniques.Weselectedseven photogrammetric surveys (1945, 1946,1960, 1979, 1984, 1987, 1992) to constructhistorical DEMs (5m/pixel) and ortho-photos(0.5-1m/pixel). Together with modern radar-basedDEMs(1998and2012-2013)anda lidar-basedDEM (2015) thesedata setsprovidepre-andpost-eruption topographyofHekla foreachof the five eruptions in the 20th century. TheseDEMs allow creation of thickness maps andthereby unprecedented estimation of lava flowthicknessandlavaflowvolume.

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Ahot,top-downmodelfortheformationoftheNorthAtlanticIgneousProvinceandtheIcelandhotspot

KenniDinesenPetersen1,ChristianSchiffer2andThorstenNagel11AarhusUniversity,2DurhamUniversity

TheGreenland-Iceland-FaroeRidge(GIFR) isanarea that has been magmatically hyperactivesincetheformationoftheNorthAtlanticIgneousProvince at ~55 Ma. The magmatic crustalthicknessand its compositions isdifferent fromtheaverageoceaniccrustinawaythatpossiblyrequires elevated temperature and enrichedcompositionofthemantlemeltsource.Apopularexplanation for this involves theconvectiveriseofhotplumes,oftenpostulatedtooriginateatthelowermantle with a different temperature and

composition than the upper mantle. However,sincetheGIFRinitiatedjustwheretheembryonicNorth Atlantic rift crossed older Caledoniansutures, alternative “top-down” models havebeenproposed,opposinga“bottom-up”modelinwhich an emerging deep mantle plume wouldexactlycoincidewiththelocationoflithosphericweaknesses. Here, we present a new top-downphysicalmodelwherelithosphericextensionledto delamination of a dense quasi-stable mantlelithosphere and lower crust. The delaminatedmaterialsankintothelowermantleandcausedaplume-like return flow of hot and primordialmaterial that reached the North Atlantic riftsystem and caused enhancedmelt productivity.Our model predicts melt volumes that are ofsimilarmagnitudeasthoseobservedintheNorthAtlantic, and explains why Iceland remainsmagmaticallyactiveatpresent.

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GeometryandtemporaldevelopmentoftheFaroeIslandsBasaltGroupintheFaroe-ShetlandBasin:Seismicmappingandwellcorrelationsbychemo/lithostratigraphy

MortenS.Riishuus1,UniÁrting1,HeriZiska1andJimáHorni11FaroeseGeologicalSurvey

The offshore distribution of the Faroe IslandsBasalt Group (FIBG) has received much debatesince the early 1980’s. We present newobservations and interpretations on the latePalaeocene-early Eocene volcanic history of theFaroe-Shetland Basin (FSB).These efforts arebasedonnovelintegrationofi)seismicmappingof the geometry of the pre- and syn-breakupvolcanic piles and volcanic facies with ii)chemo/litho-stratigraphy of the volcanicsequences in the nine exploration wells inFaroesesectorofFSBandiii)theknownonshorepetro-chemistryoftheFIBG.Contourmapsofthedepthtoi)thebaseofthevolcanicpile,ii)theA’-horizon, and iii) the top of the Palaeogenevolcanicsarepresentedalongwithisopachmaps

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of the thickness distribution of the respectivepre- and syn-breakup volcanics and associatedvolcanic foresets. We illustrate the offshoregeometry of the FIBG with generalizedgeoseismic sections and its temporaldevelopmentwithsequencestratigraphiccharts.Comparative analysis of volcanic thicknessdistributions and kinematic indicators reveal anumberofaspectsconcerning theemplacementoffloodvolcanismintoFSB;includingseeminglypersistent lava transport systems, south- andeastward progradational lava deltas, sub-basinsattimesactingasdepocentresforvolcanicswhilevolcanically starved at other times. A greatervolumeofvolcanicswasdeliveredtoFSBduringthepre-breakupvolcanismincomparisontothesyn-breakup phase. The syn-breakup volcanicdeposits are predominantly present in thenorthern part of FSB and along Fugloy ridge,likely reflecting eastwardmigration of volcanicsystems and proximity of the emerging Aegirridge.

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InteractionbetweenvolcanicandsedimentarytransportsystemsinthegreaterJuddBasinontheNorthEastAtlanticMargin

HeriZiska1,UniÁrting1andMortenS.Riishuus11Jarðfeingi(FaroeseGeologicalSurvey)

Understanding the transition from the volcanicunits of the North Atlantic Igneous Province tothe non-volcanic units in the Faroe ShetlandBasin,hasproventobeachallenge,partlyduetoinabilityofseismicdatatoresolvethedifferencein seismic response between volcanic and non-volcanic units, and partly due to lack of wellcontrol.

Published interpretation of well 6005/15-1 onSjúrður High suggested a thin extrusive basaltsectionintheearlyEoceneandintrusiveunitsinthe mid-Palaeocene section. A new integratedinterpretation of reprocessed seismic data andre-evaluationofwell-cuttingsdemonstratesthat

theintrusiveunitsoriginallyclassifiedasbasalticsills are predominantly pre-breakup extrusivebasaltsandhyaloclastites.Thisenabledmappingof discrete volcanic packages within thedominantlynon-volcanicsedimentarysectioninthegreaterJuddBasinarea.

Mappingofpre-andsyn-breakupvolcanicunitsaroundthegreaterJuddBasinarea,demonstratesa large variation in the interactionbetween thevolcanicandnon-volcanicsystems.Towardsthesouth volcanics were fed into the Judd basinduring mid-Palaeocene. Following a volcanicregression, basinal accommodation space wasfilledbysiliciclasticsedimentsprimarilysourcedfromthesoutheast.IntheearlyEocenevolcanicsagaintransgressedfarintotheJuddbasinbeforevolcanism eventually was restricted to thelocation of the incipient Northeast Atlanticfurthernorth-northwest.

Oneimplicationofmappingtheeventhorizonofanigneousprovinceusingseismicdataisthatwecannowachieveamoredetailedunderstandingofthetemporalandspatialevolutionofvolcanicandsedimentarydepositionalprocessesinbasin-hostedvolcanicprovinces.

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1.3.UnderstandingLargeIgneousProvincesandassociatedrapidenvironmentalchanges:fromtheNorthAtlanticIgneousProvinceandbeyond.

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ThePre-CaledonianMarginofBaltica:overviewandresearchinprogress

TorgeirB.Andersen1,JohannesJakob1,HansJørgenKjøll1,FernandoCorfu1,SverrePlanke1,ChristianTegner2,LoicLabrousse3,GeoffroyMohn4andTrondH.Torsvik11CEED,IG-UiO,Norway,2Geosciences,Univ.Århus,Denmark,3UPMCParis6,France,4Univ-Cergy-Pontoise,France

The Caledonian margin of Baltica formed bycontinental break-up of Rodinia in the LateProterozoic to Ediacaran.With exception of thedike-swarm near Egersund in SW Norway, theFennoscandian basement including theautochthonousbasementwindowsalongtheaxisof themountain beltwere little affected by themagmatism associated with the break-up. Thedistalparts,however,werestronglyattenuated,hyper-extended and a 1000 km long segment,intensivelyintrudedbyaLargeIgneousProvince(LIP),thePre-CaledonianLIP(PC-LIP).Here,weprovide glimpses of ourwork in progress fromthevestigesofthemargin.Moredetailsonseveralaspectsofthemarginevolutionarepresentedbyco-authors.Herewepresentaregionalmodelforthe pre-Caledonian margin suggesting it washighly complex and included micro-continentalsliver(s)andbothahyperextended,magma-poordomain with transition(s) to attenuatedembryonic oceanic and magma-rich margindomains. The break-up related PC-LIPmagmatism lasted from approximately 615 to570Ma,butthemostintenseactivityappearstohave been at ~600 Ma. Our ongoing worksuggeststhattheimpingementofamantleplumeon the Ediacaran continental lithosphere wasassociated with a temperature anomaly of~100oC, causing widespread melting of the

asthenosphere and dyke-intusion of thecontinental crust and sediments of the margin.Wesuggestthatthepre-CaledonianmarginoftheIapetuspreservedintheScandescomprisemostof the elements of passive continentalmargins,and that it probably represents one of the bestexposed field analogue for thedeeper and leastknownpartsofpassivemargins.

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ComparingthegeophysicalexpressionoftheSeilandIgneousProvincewiththeSWBarentsSeacrust–indicationsforaLIPduringopeningoftheIapetusocean?

ChristineFichler1,ZeudiaPastore1andSuzanneA.McEnroe11NorwegianUniversityofScienceandTechnology

The Seiland Igneous Province (SIP) in northernNorway isexpressedby largeoutcropsofmaficand ultramafic rocks of Neo-Proterozoic(Ediacaran)ageandishostedbytheCaledonianKalaknappe.TheSIPhasbeensuggestedtobetheplumbing system of a large igneous province.Unalteredultramaficrocksincrustalsettingsarecharacterized by low magnetization andexceptional high crustal densities, the latterformingacontrasttocommoncrustalrocks.Suchrock attributes have also been detected byintegratedinterpretationofgravity,magneticandseismic data on the continental shelf in thesouthwestern (SW) Barents Sea at Senja RidgeandVeslemøyHigh.Furthermore,ahighlydenserock unit of large lateral extension, has beenfoundbelow largeparts of the SWBarents Sea,either, at a lower crustal level, or in theuppermostmantle.Weinvestigateapossiblelinkbetween therockunitswithhighdensity in theSWBarentsSeaandtheSIP.Ifbothbelongtothesamemagmaticevent,theymaybecharacterizedasrelictsofaLIPwhichdevelopedatthetimeoftheopeningoftheIapetusOcean.Analternativescenariofortheoriginoftheoffshoreultramaficrocks at theVeslemøyHighhasbeenpublishedsuggesting exhumed mantle developed by

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hyperextensionduring theultraslowopeningoftheCretaceousBjørnøyBasin. Finally, obductedophiolitic crust containing mantle rocks isanotherpossibilitywhichwillbediscussed.

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KarooLIPthermogenicdegassinglessimportantthanpreviouslyestimated—newevidencefromthermo-hydro-mechanicalnumericalsimulations

ChristopheGalerne1andJörgHasenclever21GEOMARHelmholtzCentreforOceanResearchKiel,Germany,2InstituteforGeophysics,UniversityofHamburg,Germany

Thermogenic discharge into the atmosphereassociatedwiththeKarooLIPevent(183Ma)iscurrently estimated to asmuch as 12,600Gt ofmethane.Inordertoprecisethedegassingratesatthebasinfloor,weinvestigatetheinfluenceoftheKarooBasinstratigraphicphysicalproperties,including a realistic initial TOC profile. Usingstate-of-the-art numerical models ofhydrothermalfluidflowthroughporousrocksweinvestigate the formation and evolution ofhydrothermalsystemspoweredbysillintrusions.Wetakeintoaccounttheenergyconsumptionofthe dehydration reaction and the thermogeniccracking in the sediments as well as theincreasing pore space upon sedimentdehydration. Permeability depends on porosityand, in addition, a simple Mohr-Coulombrheologyisusedtosimulatehydrofracturing.Ourresultsindicatethatfluidflowcausedbyasinglesill intrusion emplaced in thedeeporganic-richformation is insufficient to rapidly transportthermogenicmethanetothebasinfloor.Insteadthemobilizedmethaneaccumulatesinshallowerparts of the basin, where it may be laterremobilized by shallower intrusions. Our newestimates suggest a reduction of one to twoorders of magnitude in the amount ofthermogenic gas emitted during the Karoo LIPevent.

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Large-scalesillemplacementinBrazilasatriggerfortheend-Triassiccrisis

TheaHatlenHeimdal1,HenrikHovlandSvensen1,JahandarRamezani2,KarthikIyer3,EgbertoPereira4,RenéRodrigues4,MorganThomasJones1andSaraCallegaro11CentreforEarthEvolutionandDynamics(CEED),UiO,2MassachusettsInstituteofTechnology(MIT),3GeoModellingSolutionsGmbH;GEOMAR,4RiodeJaneiroStateUniversity

It has long been postulated that the CentralAtlanticMagmaticProvince(CAMP)wasinvolvedin the end-Triassic extinction (ETE), one of thelargest mass extinctions of the Phanerozoic.Previous studies have mainly focused on theextrusive section of the province, howeverseveral lines of evidence point toward sillemplacement in Brazil being a key factorregarding the extinction. These sills haveintruded the Amazonas and Solimões basins,which include major deposits of evaporite,carbonateandorganic-richshale,andithasbeensuspected that contact metamorphism of theselithologies generated thermogenic gases thatwere released to the end-Triassic atmosphere.Untilnow,detailedstudies regarding theextentof the sill complex and estimates of sediment-derivedvolatileshavebeenabsent,likelybecauseoutcropsandsamplesareextremelylimited.Herewehaveaccess to samplesand logs fromsevendeep boreholes drilled in the Amazonas andSolimõesbasins.Thesillscompriseupto24%ofthestratigraphy,andthemajorityhaveintrudedevaporite-and carbonate dominated deposits.Thermalmodelingdemonstratesthatlargescalecarbon generation followed sill emplacement,including as much as 116 000 Gt CO2.We alsoprovide new constraints on the timing of sillemplacement by high precision U-Pb zircongeochronology. Our findings demonstratesynchronicitybetweenthesillsandtheETE,andwe suggest that venting of sediment-derivedvolatilessuchasC,SandClplayedamajorroleintheend-Triassiccrisis.

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EvidencefromDenmarkforNEAtlanticpre-PETMvolcanism

ClausHeilmann-Clausen1,BoPaghSchultz2,ClausBeyer3,HenrikFriis1,PetraL.Schoon4,ChristianTegner1andOleBjørslevNielsen11DepartmentofGeoscience,AarhusUniversity,Høegh-GuldbergsGade2,8000AarhusC,Denmark,2Muserum,DivisionofNaturalHistory,Havnevej14,7800Skive,Denmark,3CB-Magneto,Nørregade27,8670Låsby,Denmark,4DepartmentofGeology,LundUniversity,Sölvegatan12,22362Lund,Sweden

A new section on the Fur island in Denmarkincludestwoquadruplevolcanicashlayerswhichare older than the Paleocene-Eocene ThermalMaximum (PETM). The ash layers occurimmediatelybelowsedimentsdatedtothePETMinterval.Theash layersareofanormalbasaltictypeandolderthanhithertorecognizedvolcanicashlayersfromthePaleocene-Eocenetransitionin Denmark (i.e., the negative and positivenumbered ash series of Bøggild, 1918). Threeother Danish PETM sections (Ny Klitgård, Ølst-Hinge, Harre-1) show 1-3 volcanic ash layersclosely associated with the base of the PETMinterval. The ash layers point to a significantvolcanicepisodeandtheirstratigraphicpositionsupports previous evidence for NE AtlanticvolcanismasatriggerofthePETM(e.g.Svensenetal.,2004).All sectionsshowashift fromoxicsea-floor conditions (indicated by bioturbation)below the PETM interval, to anoxic conditions(indicatedby finely laminated sediment)withinthePETM interval.Thebasal layerof thePETMintervalatFurisa5cmthickdensityflowdepositoccurringimmediatelyabovetheashlayers.Thedensity flow deposit is not recognized in otherDanish sections and points to local sea-floorinstability.

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Thelithostratigraphyofahyperextendeddomaininthemagma-richtomagma-poortransitionzoneinthesouthernPre-CaledonianLIP,ScandinavianCaledonides,Norway

JohannesJakob1,GeoffroyMohn2,PierreClosset3andTorgeirB.Andersen11TheCentreforEarthEvolutionsandDynamics,DepartmentofGeosciences,UniversityofOslo,Norway,2DepartmentofGeosciencesandEnvironmentalSciences,UniversitédeCergy-Pontoise,France,3InstitutdePhysiqueduGlobedeStrasbourg,UMR7516CNRS,UniversitédeStrasbourg,France

RemnantsoftheancientriftedmarginofBalticaare preserved in the allochthons of theScandinavian Caledonides. The Baltica marginnappescompriseamagma-richsegment, i.e. thepre-Caledonian LIP (Tegner et al. 2016), and amagma-poor. (Andersenetal.2012; Jakobetal.2017).Thetransitionzonebetweenthemagma-rich and magma-poor domains correspondsapproximatelytothenorthernterminationoftheJotun Nappe Complex. Metaperidotites andmetamorphosed mafic rocks abound in themetasedimentsofthistransitionzone.

North of Lesja, an original lithostratigraphicsuccessionof theancientBalticahyperextendedmarginmaybepreserved.Atitsbaseisasheetofmetaperidotite that is locallycharacterizedbyapegmatitic texture, containing pseudomorphsafterdecimetre-sized,metamorphicolivine.Fewmafic dykes cutting themetaperidotite are alsoobserved.

Thetopofthemetaperidotitesheetisincontactwith metamorphosed mafic rocks or in astratigraphic contact with a monomicticmetaperidotite conglomerate. The latter gradesupwards into a polymictic conglomerate. Themetamorphicmaficrocksandtheconglomeratesabove the metaperidotites, but locally also theultramafic rocks, are overlain by ametasedimentary unit that comprises a largenumberofmaficintrusives(andvolcanics?)and

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locally contains ultramafic clasts. Similarsuccessions have been described from fossilocean-continenttransitionzoneselsewhere(e.g.ManatschalandMüntener2009).

Wesuggestthatthelithostratigraphicsuccessionnorth of Lesja represents a hyperextendeddomain in the magma-rich to magma-poortransitionzoneof thepre-CaledonianmarginofBaltica that received abundant mafic magmasduringandafterthemantlewasexhumedattheseafloor.

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TypesandstylesofvolcanismintheNorthAtlanticIgneousProvince:Implicationstowardsunderstandingtheirpotentialclimaticimpact.

DougalA.Jerram1,HenrikH.Svensen2,SverrePlanke3,JohnM.Millett4,MorganT.Jones2,LarsAugland2andMansourM.Abdelmalak51CEED,UniversityofOslo,Norway/DougalEARTHLTD,UK,2CEED,UniversityofOslo,Norway,3VBPR,Oslo,Norway/CEED,UniversityofOslo,Norway,4VBPR,Oslo,Norway/UniversityofAberdeen,Scotland,5VBPR,Oslo,Norway

The North Atlantic Igneous Province (NAIP) isarguably the best studied of the Large IgneousProvinces (LIPs), but it is somewhat unusual inthat its volcanism is somewhat protracted andpulsed.Twomainphasesarerecognisedwithoneoccurring some 5 million years before thePaleocene-Eocene thermal maximum (PETM)and another which occurs at the PETM. Thedifferent styles and types of volcanism that arefound during the onset, main phases and thewaningpartsoftheNAIP,aswellastheintrusiveplumbingsystemsthatgotofeedthem,allplayapotential role into how the LIP may havecontributedtothechangingclimateatthistime.Floodvolcanismisrarelyrestrictedtosimplelavaflows, and here we review the relative timingsand locations of the key types of eruption thatoccurred intheNAIP.Lavaflows,hyaloclastites,major volcanic centres, and thick ashaccumulationsbearstestamenttothevolcanism

as well as a full range from basic to siliciccompositions.ItcanbeshownthatoverthePETMtimes, the volcanism was particularlywidespread,withsignificantashbedsaswellasaplumbingsystemthatsignificantlyintrudedintothesurroundingsedimentarybasinsatthistimecausing a multitude of gas escaped ventingstructures. The changes in style from earlyeruptions to the secondphase volcanism in theNAIP need to be considered to help ourunderstandingofthePETMcrisis.

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FurIslandinDenmark:AwindowintoPaleocene-EocenehyperthermalsandNorthAtlanticvolcanism

MorganJones1,EllaStokke1,BoSchultz2,LarsAugland1,SverrePlanke1,ChristianTegner3,TamsinMather4,LawrencePercival5andHenrikSvensen11CentreforEarthEvolutionandDynamics,UniversityofOslo,Norway,2MuseumSalling–FurMuseum,Denmark,3DepartmentofGeoscience,AarhusUniversity,Denmark,4DepartmentofEarthSciences,UniversityofOxford,UK,5UniversitédeLausanne,Switzerland

ThePaleoceneandEoceneepochsweretypifiedbyice-freegreenhouseconditions,punctuatedbyeven warmer hyperthermal events driven byrapid release of carbon to the atmosphere. Thelargest of these, the Paleocene-Eocene ThermalMaximum(PETM),wasanextreme(5-6°C)andrapid(<20kyr)globalwarmingeventat~56Mathatpersistedfor~170kyr.ThePETMcoincidedwithamajorpulseofmagmatismfromtheNorthAtlanticIgneousProvince(NAIP),suggestingthatthe emplacement of the NAIP could beresponsible for the climate perturbations. Anexcellent locality to explore this relationship isthe island of Fur in Denmark, where over 180tephra layers originating from the NAIP arepreservedinadiatomiticclaysequence.Herewepresent the initial results of the project“Ashlantic”, which drilled a 73 m boreholethrough the Fur Formation inAugust 2017.We

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use a variety of detailed geochemical andstratigraphic analyses to assess the extent andduration of volcanism across the PETM. Inparticular, we use volcanic proxies such as Hgdeposition to assess the influence of volcanismandthermogenicdegassingonthesurfacecarboncycle.WewillcombinethiswithhighprecisionU-Pb dating of magmatic zircons found in tephralayers and high-resolution cyclostratigraphy toplace thePETMand laterhyperthermalswithinanimprovedabsolutetimeframe.Expandedshelfsections such as the Fur Formation arefundamentally important for understandinghyperthermal events and volcano-climateinteractions due to the possibility ofmeasuringvariationsonasub-millennialtimescale.

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Afossilmagma-richriftedmarginrevealedintheScandinavianCaledonides

HansJørgenKjøll1,TorgeirAndersen1,ChristianTegner2,LoicLabrousse3,FernandoCorfu1andSverrePlanke11CentreforEarthEvolutionandDynamics(CEED),UniversityofOslo,Norway,2CentreofEarthSystemPetrology,DepartmentofGeoscience,AarhusUniversity,Denmark,3UniversitePierreetMarieCurie,Paris,France

TheIapetusopened~610Maagopossiblyduetotheinteractionwithamantleplumeatthebaseofthe lithosphere. Stretching of the conjoinedcrystalline crust started prior to break-up andprovided accommodation for continental andshallowmarinesyn-riftsediments.Anearlynon-magmatic phase with discrete and localizeddeformation was followed by pervasive maficmagmatismwheredyke-emplacementaccountedfor the bulk of the stretching. During theCaledonian orogeny, the Iapetan marginwasthrustedonto Baltica as the Iapetus closed.Now, vestiges of themagma-richmargin residewithinnappes fromcentralSwedentonorthernNorway. Although overprinted by Caledonianfabrics,therearelocalitieswherepre-Caledonianstructures arewell-preserved, thereby allowing

for detailed studies of deep to intermediateprocesses at magma-rich rifted margins. Weproposethatthearchitectureofthemagma-richmarginofIapetusandmagma-richriftedmargins,ingeneral,canbestudiedintheCaledonides.Thewell-preservedpartsofthemargincomprise:1)Parts of a lower crustal magmatic complexw/gabbrosandmaficdykes intruding stretchedcrystalline basement; 2) Strongly stretched andattenuated crystalline basement intruded bymafic dikes; 3) Highly intruded pre- to syn-riftsedimentsand4)Extrusivemaficlavas,includingpillowbasalts,interlayeredwithmetasediments.Together these levels represent a nearlycontinuoussection throughamagma-richriftedmargin,withsomenever-beforedescribedlevels,suchasthelowercrustalmagmaticcomplex.

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Environmentalandecosystemresponsestomassivevolcanismduringtheend-Triassicmassextinction

SofieLindström1,BasvandeSchootbrugge2,GunverK.Pedersen1,AndreaMarzoli3,JoshuaH.F.L.Davies4,SaraCallegaro5,ChristianTegner6andHamedSanei61GEUS,2UtrechtUniversity,3UniversityofPadova,4UniversityofGeneva,5UniversityofOslo,6UniversityofAarhus

The end-Triassic mass extinction (201.56 Ma;Wotzlaw et al. 2014) is generally explained bymassive input of CO2 and/or methane to theatmosphere from theCentralAtlanticmagmaticprovince(CAMP).HighprecisionU/PbdatingofCAMPintrusivesandextrusiveshaveshownthatthe magmatic activity commenced c. 100.000yearsprior to theETE (Daviesetal.2017), andoccurred in at least four pulses overapproximately 600.000 years (Blackburn et al.2013).Indeed,bothcalcareousandorganicδ13C-records across the Triassic-Jurassic boundary(TJB) show that large scale emissions ofisotopicallylightcarbontotheatmospheretookplace at that time. Physiological responses in

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terrestrialplant fossils indicate that this lead tointenseglobalwarmingacrosstheTJB(McElwainet al. 1999), while in the marine realm, oceanacidificationfromtheincreasedpCO2isindicatedby the loss of calcifying organisms (van deSchootbrugge et al. 2007). Recently, a newcorrelation of TJB successions, based on acombination of biotic (palynology andammonites), geochemical (δ13Corg) and radio-isotopic(U/Pbagesofashbeds)constraints,wasproposed (Lindström et al. 2017). This newcorrelation has an impact on the causality andtemporal development during the end-Triassicevent,asitindicatesthatthebulkofthehithertodated CAMP rocks preceded or wascontemporaneous to the onset of the massextinction. Here, we investigate the temporalchainofeventsacrosstheETEasconstrainedbythe new correlation in combination with newhigh-resolution CAMP ages extrusives(Blackburnetal.2013;Daviesetal.2017).

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TheRelationshipBetweenPaleogeneHydrothermalVentComplexDiametersandConduitHeightsintheVøringandMøreBasinsOffshoreMid-Norway

BenManton1,SverrePlanke1,HugoThould2,SigurdKjoberg3,HenrikSvensen4andØyvindHammer51VBPR,OsloSciencePark,Oslo,Norway,2DepartmentofEarthSciences,OxfordUniversity,Oxford,UK,3CEED,OsloUniversity,Oslo,Norway,4DepartmentofGeosciences,OsloUniversity,Oslo,Norway,5NaturalHistoryMuseum,OsloUniversity,Oslo,Norway

LargeIgneousProvinces(LIPs)emplacedwithinbasins are frequently associated with manyhydrothermal vent complexes sourced fromthermal aureoles around sill intrusions. Thesepiercement structures consist of cylindricalconduitsthatconnectthesillaureoleswithventsatthepaleosurface.Moreenergyisconsideredtobe required to create both longer conduits, astheyrequirehigherfluidpressuretofracturelong

pathways,andlargervents,becausemorerockismobilized near the seabed.Four datasets fromthe Vøring and Møre basins (Mid-Norway),consisting of 718, 213, 106 and 13 Paleogenehydrothermal vent complexes, are used todetermine the relationship between ventdiameters and conduit heights. The ventcomplexes and associated sills were mappedusingregional2Dseismicdata(firstdataset)and3D seismicdata (threedatasets).Generally sillshave pipe-like vent complexes located abovetheirmargins or above sill steps or local highs,however,oneshallowsillhas>110hydrothermalvent complexesdistributedover its top surface.The upper part of the vent complexes displaymound, crater, or eye-shaped geometries.Observedventdiametersrangefrom~100mto~11 km,with a sizablemajority <2.5 kmwide.Theverticalconduitheightsrangefrom~100mto~4kmwithasizablemajority<2.5km.Thereareweakpositivecorrelationsbetweentheupperventcomplexdiametersandconduitheightsinallfourdatasets.Theweakcorrelationssuggestthequantity of energy transferred from the sillaureoles,viafluidtransport,tothehydrothermalventsispartiallydependentontheheightsoftheconduits.

ORAL

ReleaseofvolatilesduringNorthAtlanticfloodbasaltvolcanismandcorrelationtothePaleocene-EoceneThermalMaximum(PETM)

JonasMøllerPedersen1,ThomasUlrich1,AdamKent2,CharlesLesher1andChristianTegner11CentreofEarthSystemPetrology,DepartmentofGeoscience.AarhusUniversity.,2CollegeofEarth,Ocean,andAtmosphericSciences,OregonStateUniversity.

Significant environmental changes and globalwarmingduringthePETMhavebeenattributedtothereleaseofCO2ormethanegasdueeithertoextensivemeltingofhydratesat theocean floorortointeractionofmantle-derivedmagmaswithcarbon-rich sediments. Although it is wellestablished that flood basalt volcanism

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associatedwiththeopeningoftheNorthAtlanticOceanbroadlycoincideswiththePETM,furtherdetailed timing constraints from stratigraphiccorrelations, magnetostratigraphy, and thedurationoffloodbasaltvolcanismsuggestthatitis also possible that the main flood basaltsequenceinEastGreenlandpostdatesPETM.

Estimatessuggestthataminimumof1.8x106km3of basaltic lava erupted during North Atlanticfloodbasaltvolcanism.BasedonmeasurementsofmeltinclusionsfromtheEastGreenlandfloodbasaltsourcalculationsshowthatapproximately2300GtofSO2and600GtHClwerereleasedintotheatmosphere.Yearlyfluxesareestimatedtobe8-23Mt/ySO2and2-6Mt/yHCl ifall theNorthAtlantic flood basalts erupted in 100.000-300.000years.Thisisequivalentto≈18600Laki-likeevents,onehappeningevery5-16years.TheSO2releasedintototheatmosphereduringfloodbasalt volcanism can form acid aerosols thatabsorb and reflect solar radiation, causing aneffectivecoolingeffect.

The climatic changes due to the release ofvolatiles in these amounts, and for periodsextending for hundred thousand of years arelikely to be significant. One consequence of theNorth Atlantic flood basalt volcanism maytherefore have been the initiation of globalcoolingtoendthePETM.

ORAL

NEandNWAtlanticPaleogeneVoluminousMagmatismandGlobalCrises:SeismicObservationsandtheNeedforFutureScientificDrilling

SverrePlanke1,ChristianBerndt2,ChristianTegner3,RitskeHuismans4,HenrikH.Svensen5,JanIngeFaleide5,DougalA.Jerram5,JohnMillett6,MansourM.Abdelmalak6,CharlesE.Lesher3andReidunMyklebust71CentreforEarthEvolutionandDynamics(CEED),UniversityofOslo,Norway,andVBPR,Oslo,Norway,2GEOMAR,Kiel,Germany,3AarhusUniversity,Denmark,4UniversityofBergen,Norway,5CEED,UniversityofOslo,Norway,6VBPR,Oslo,Norway,7TGS,Asker,

Norway

TheNEandNWAtlanticcontinentalmarginsarecharacterized by massive Paleogene igneousconstructions, associated with continentalbreakup and early seafloor spreading.We haverecently completed a comprehensiveinterpretation of the nature and distribution ofthe extrusive and intrusive mafic rocks onregional2Dandselectedhigh-quality3Dseismicdata in both regions. Interpretations have beenaugmented by scientific and industry boreholedata and on-shore field work. On the VøringMarginal High, 3D mapping reveals a highlyvariable crustal structure, with large-scale pre-breakupstructuralhighsandsedimentarybasins.These structureswhere infilled and covered byfloodbasaltsandvolcanogenicsedimentsduringthe early stages of continental breakup in theearliest Eocene. Subsequently, rift basinsdeveloped along the continent-ocean boundaryand were infilled by up to 6 km thick basaltsequences, imaged as SDRs. Intrusive sillcomplexes and associated hydrothermal ventcomplexesintheVøringBasinhavedominantlyaPaleocene-Eoceneboundaryagebasedona fewhigh-quality U/Pb ages and seismic mapping.Similar igneouscomplexes, includingSDRs, lavadeltas, lava fields, sills, and hydrothermal ventcomplexes,werealsomappedintheNWAtlanticandontheNEGreenlandmargin.Thedominanthypothesis is that themassivemagmatismwascaused by amantle plume originating from thecore-mantle boundary, and that intense andshort-lived (<100,000 years) intrusive andextrusivemagmatism triggered global warmingduringthePaleocene-Eocenethermalmaximum(PETM). However, we argue that new scientificdrillingintheNEandNWAtlanticisrequiredtosubstantiatethesehypotheses.

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ORAL

Improving seismic interpretation ofigneous sill complexes via seismicmodelling

OleRabbel1,OlivierGalland1,KarenMair1,IsabelleLecomte2andJuanBautistaSpacapan31PhysicsofGeologicalProcesses,DepartmentofGeoscience,UniversityofOslo,Norway,2DepartmentofGeoscience,UniversityofBergen,Norway,3UniversidadNacionaldeLaPlata,Argentina

Seismicinterpretationhasbeenplayingakeyroleinestablishingtheroleofigneoussillcomplexesemplaced in organic-rich sediments on globalclimate change throughout geological history(e.g.,Svensenetal.2004,Aarnesetal.2015):theheatbroughtbythesillstotheirorganic-richhostleads to massive thermogenic generation ofgreenhouse gases (e.g., CO2, CH4), eventuallycatastrophically released to the atmosphere.Robust volume estimates of these greenhousegasesrelyonrobustestimatesofmagmavolumesof the sill complexes, which require confidentmappingofsubsurfacesillintrusions.

Large sills are easy to map in seismic data,because they create strong property contrasts,whichcausehighamplitudereflections.However,igneoussillsvarystronglyinthicknessandupto88 percent of the sills may be missing in theinterpretation,sincetheirthicknessisbelowtheseismicresolutionlimit(Schofieldetal.2015).

In this presentation, we present seismicmodellingstudydesignedtocharacterizetypicalseismic signatures (splitting, stepping, braidedreflections) of thin intrusions, and to indicatepotential ways to infer the shapes of thinintrusions in the seismic interpretation. Due totheir anomalously high vp/vs ratio, intrusionscauseacharacteristicamplitude-vs-offset(AVO)responsewithhighAVO interceptandgradient.Thus, we will highlight the great potential ofusing seismic pre-stack and offset data for theinterpretation of thin intrusions. Our resultsindicatehowseismicinterpretationandtherebyvolume estimates of sill complexes can besignificantly improved using data of relevantquality.

ORAL

U-PbbaddeleyitedatingofmultiplemaficdykeswarmsintheDharwarcraton,India–evidencefora30°internalblockrotationduringthePaleoproterozoic

UlfSöderlund1,WouterBleeker2,KursadDemirer1,RajeshK.Srivastava3,MichaelHamilton4,MimmiNilsson1,LauriJ.Pesonen5,RichardE.Ernst6andAmiyaK.Samal31DepartmentofGeology,LundUniversity,Sölvegatan12,SE-22362Lund,Sweden,2GeologicalSurveyofCanada,601BoothStreet,Ottawa,Ontario,K1A0E8,Canada,3CentreofAdvancedStudyinGeology,InstituteofScience,BanarasHinduUniversity,Varanasi22100,4JackSatterlyGeochronologyLaboratory,Dept.ofEarthSciences,UniversityofToronto,Toronto,ON,5LaboratoryforPaleomagnetism,GeologicalSurveyofFinland,P.O.Box96,02151Espoo,Finland,6DepartmentofEarthSciences,CarletonUniversity,Ottawa,ONK1S5B6,Canada

A significant portion of large igneous provinces(LIPs),especiallythosethoughttobeassociatedwith mantle plumes, have been linked withbreakup of continents and, therefore, provide acriticalsourceof information inreconstructionsof ancient crustal blocks. First-order crustalconnections to a plume include radiatingmaficdykepatterns, inferred to reflect lateralmagmatransport away from a plume centre located atthefocalpointoftheswarm1,2.The2.37GagiantBangalore-Karimnagar dyke swarm of theDharwar craton, southern India, displays adistinctradialpattern(ofatleast30º)fromwhicha western source of magma has beeninferred3,4. However, on the basis ofpaleomagnetic data and an arcuate trend tostructures in the Archaean basement, analternative interpretationof the fanningpatternof the Bangalore-Karimnagar swarm has beenraised5,6,7.Herewepresent17U-Pbbaddeleyiteages, which comprise seven generations ofPaleoproterozoicdykesswarmswithinthe2.37-1.79Gaageinterval.

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Byrestoringa30°counter-clockwiserotationofthe northern Dharwar block relative to thesouthernblock,weshowthatpre-2.08Gaarcuateand fanning dyke swarms consistently becomeapproximately linear, as do ancient curvilineartrending geological features, such as regionalDharwar greenstone belts and the lateArchean(ca. 2.5 Ga) Closepet batholith. This findingreinforces previous suggestions that the radialpatternisapparent,andnotaprimaryfeaturee.g.7.Ourfindingscall forreassessmentofpreviouspaleoreconstructions involving the Dharwarcraton based on tectonic/geologic piercingpoints, paleomagnetism and inferred plumecentrelocations.

ORAL

VolcaniccausesforthePETMandotherpasthothouseclimates

HenrikH.Svensen1,DougalA.Jerram2,AlexanderG.Polozov3,MorganT.Jones4,LarsE.Augland4andSverrePlanke51CEED,Univ.Oslo,2CEEDandDougalEarth,3CEEDandInstituteofGeologyofOreDep.,Petr.,Min.,andGeochem.,RAS,Moscow,4CEED,5CEEDandVBPR

Mass extinctions and transient climate eventscommonlycoincideintimewiththeformationofLargeigneousprovinces(LIPs).Classicexamplesinclude the end-Permian eventwhich coincideswiththeSiberianTraps,theend-TriassicwiththeCentral Atlantic Magmatic Event (CAMP), theToarcianwiththeKarooLIP,andthePalaeocene-Eocene Thermal Maximum (PETM) with theNorth Atlantic Igneous Province. Theemplacement of igneous sills into sedimentarybasins, and the associated contactmetamorphism of the host sedimentary rocks,has emerged as a major player in theunderstandingofthelinkbetweenLIPsandpastclimatic change. We stress that for theseprocesses to have an environment impact, thegasesneed tobe transferred to the surface andatmosphere on a very short timescale,which isborne out by dating of the sill complexes inquestion.Wehaveidentifiedarangeofdifferentpipe structures that acted as gas transport

channels during the end-Permian, theToarcian,and the PETM, and present a classification anddetailed overview of the key parametersgoverning their formation. We show that thepotential for degassing of greenhouse gases,aerosols, and ozone destructive gases insedimentary basins affected by volcanism issubstantial,andcanexplainthetriggeringofbothtransientclimaticeventsandmassextinctions.

ORAL

Thepre-CaledonianScandinavianDykeComplexand600MaplatereconstructionsofBaltica

ChristianTegner1,TorgeirB.Andersen2,HansJørgenKjøll2,EricL.Brown1,GrahamHagen-Peter1,FernandoCorfu2,SverrePlanke2andTrondH.Torsvik21CentreofEarthSystemPetrology(ESP),DepartmentofGeoscience,AarhusUniversity,Denmark,2CentreforEarthEvolutionandDynamics(CEED),UniversityofOslo,Norway

Aspectaculardyke complex is surprisinglywellpreserved along c. 1000 km in the CaledoniannappesofcentralandnorthernScandinavia.Thisdyke complex was originally emplaced intocontinental sedimentary basins along the riftedmarginofBaltica,itispartoftheCentralIapetusMagmaticProvince(CIMP),andithasU-Pbagesof615-590Ma.

To constrain its origin and to potentially guideplatereconstructionsofBalticawe:(1)re-visitedthe dyke complexes of the Ottfjället, Sarek,Kebnekaise, Tornetrask and Indre TromsmountainsofSwedenandNorway;(2)producednew and compiled published geochemical data;(3) modeled mantle sources and meltingdynamics; and (4) extended reconstructions ofthepaleo-positionofBalticabackto600Ma.Thecompiled dataset includes c. 600 analyses thatforms a coherent suite dominated by tholeiiticferrobasalt, but including alkali basalts in thecentralportion.

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The tholeiiticdykesdisplay lateralvariations ingeochemicalenrichment(e.g.delta-Nb,La/Sm(N)and Sr isotopes) in the southern and centralportions,gradingtomoredepletedcompositionsinthenorth.Ourpetrologicalmodelingsuggestsmelting of asthenospheric mantle involving atleast two source compositions at temperatureselevated about 100 °C above ambient mantle,consistentwithmeltingofazonedmantleplumeoriginatingfromaplumegenerationzoneatthecore-mantle boundary. If the position of thepresentplumegenerationzoneinthePacificcanbe viewed as stationary back to 600 Ma, weentertain the idea that the Scandinavian DykeComplex may be used to guide platereconstructions.

POSTER

PyroxenesusedasprobesforassessinggasloadsfromLIPmagmas:acrystal/meltpartitioningstudyforsulfurandhalogens

SaraCallegaro1,DonRBaker2,AndreaMarzoli3,MartinWhitehouse4,PaulRRenne5andHenrikSvensen11CEED-UniversityofOslo,2McGillUniversity,3UniversityofPadova,4Nordsim-NRMStockholm,5BerkeleyGeochronologyCenter

MagmatismfromLargeIgneousProvinces(LIPs)hasinseveralcasesbeencausallylinkedtomassextinctions, with at least five conspicuousexamples in the Phanerozoic. LIPs likelygeneratedchangesontheglobalenvironmentbydegassing of volatile species such as S, C andhalogen compounds, from both melts andthermalmetamorphismofvolatile-richintrudedsediments. However, quantitative estimates ofthe degassed volatiles are hard to obtain forancient magmatic systems, particularly in theabsenceofmeltinclusions.Weproposetofillthegapofknowledgeonsulfurpartitioningbetweenminerals and melts, at the aim of usingphenocrystsasprobesofvolatilecontentsinthemelts fromwhichtheycrystallized.Measuringavolatileconcentrationinnaturalminerals(chiefly

clinopyroxene) and combining it with anexperimentally determined partition coefficient(KD), the volatile load of basaltic equilibriummelts can be calculated. We measured aclinopyroxene/melt sulfur KD of 0.001±0.0003forbasalticexperimentsperformedatconditionstypical of LIP basalts (FMQ-2; 800-1000 MPa;1000°-1350°C), through ion microprobe(Nordsim). Experiments were alsosimultaneously analyzed forCl andF. For theseelementsthemeasuredKDswere0.0106±0.0089and 0.1837±0.0795, respectively. Compatibilityofsulfur,chlorineandfluorine inclinopyroxenefrom basaltic systems is markedly different(F>Cl>S), in agreement with what observed byprevious studies. Application of the newlymeasuredsulfurKDtosamplesfromthoroughly-datedlavapilesfromtheDeccanTrapsandfromthe Siberian Traps sills reveal that most of thebasalts were at or near sulfide saturation (ca.2000ppmforlowfO2melts).

POSTER

GlendoniteinanearlyEoceneKonservat-Lagerstätte(FurFormationofNorthernDenmark)andPalaeocene/EoceneformationsonSvalbardaregoodclimateandbiosphereinterpretiveindicators.

BoPaghSchultz1,JohanLindgren2,BarbaraTeichert3,MorganTJones4,ChristianTegner5,ReneSylvestersen6,JanAudunRasmussen7andHenrikMadsen81Museumcurator,MuseumSalling-FurMuseum,Nederby28,7884Fur,Dk,2Seniorlecturer,DepartmentofGeology,LundUniversity,Sölvegatan12,22362Lund,Sweden,3SeniorresearcherPh.d.,InstitutfürGeologieundPaläontologie,UniversitätMünster,D-48149Münst,4Ph.D.CentreforEarthEvolutionandDynamics(CEED)UniversityofOsloP.O.Box1028,Norway,5Professor,DepartmentofGeoscience,AarhusUniversity,DK-8000AarhusC,Denmark,6Museumcurator,MuseumSalling-FurMuseum,Nederby28,7884Fur,Dk,7SeniorresearcherPh.d.FossilogMolermuseet,MuseumMors,Skarrahagevej9,7900Mors.,8Headofdepartment,FossilogMolermuseet,MuseumMors,Skarrahagevej9,7900

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Mors

The early Eocene Fur Formation of Denmarkcomprises a 60 meters thick diatomite holdingover200volcanicashlayersrelatedtotheNorthAtlanticIgneousProvince(NAIP)(Larsen2003).TheFurFormationoverlays theØlst Formation(Stolleklint Clay) which includes both thePalaeocene-Eocene boundary and Palaeocene-EoceneThermalMaximum(Schoon2013,2015).IntriguingisthereforoutcropsinpartsoftheFurFormation of ikaite pseudomorph termedglendonite,CaCO3.Sedimentlegitshowsthatthecoldenvironmentmineralikaite,CaCO3•6H2O,formed shortly after deposition in relation tothick volcanic ash layers. (Hugget et al. 2005;Schultz 2009, 2014). The occurrence ofglendonitesindicatesaperiodofcoolingafterthePalaeocene-Eocene Thermal Maximum possiblydue to heavy volcanism (Brooks 2006). In theNAIP Palaeocene/Eocene Glendonites are alsoseen on Svalbard ( Spielhagen 2009). TheinterpretivepowersareimmenseasMoclayareaFossil Lagerstätte is unparalleled worldwide intermsofrepresentingtheinitialdiversificationofthe modern fish in the marine, offshore realm(Pedersenetal.2011).Itcontainsthefirstmajorpost-K/Tboundarydiversificationofmarinefishinassociationwithterrestrialorganismssuchasbirds, insects and plants, all of which areextremely well-preserved, as has beendemonstratedinpioneeringworksinthefieldofmolecularpalaeontology(Vinter2008;Lindgrenet al. 2012, 2014, 2017).The rich and diversefossil content comprising both marine andterrestrialorganismsmakestheMoclayareaanoutstanding window into the early Eocenebiosphere, where fossil indicate high latitudemigrationsofparticularfaunalelements.

POSTER

LithologicalandgeochemicalvariationsduringthePETMandlaterEocenehyperthermals:detailsfromanewdrillcorefromFur,Denmark.

EllaWulfsbergStokke1,MorganT.Jones1,ØyvindHammer2andHenrikSvensen11CentreforEarthEvolutionandDynamics(CEED),UniversityofOslo,2NaturalHistoryMuseum,UniversityofOslo,POBox1172,0318Oslo,Norway

One of the most extreme episodes of globalwarming in Earth’s history is the Paleocene-Eocenethermalmaximum(PETM),whichlasted~170000yearsfrom~55.8Ma,andwasfollowedby several smaller hyperthermal events duringthe Eocene. The period was initiated bysubstantial carbon release to the ocean-atmospheresystem,causingaglobaltemperatureincrease of ~5-8°C. This global warming eventcoincidedwiththesecondpulse fromtheNorthAtlantic Igneous Province (NAIP), suggesting apossibly causal relationship. One of the bestexposurescoveringthePETMintervalistheFurFormation and Stolleklint Clay, found on theisland of Fur in northwest Denmark. Over 180interbedded tephra layers of NAIP origin arefound within this diatomite and clay richsequence. The diatomite clays were depositedduring the latePaleoceneandearlyEocene inarestricted, shallow marine basin withinterchanging well laminated and structureless(strongly bioturbated) subsections reflectingalternating redox bottom conditions. During arecentfieldtripaspartoftheAshlanticproject,a~70m long core was drilled through thissedimentary succession in order to investigatethe role of volcanism in the prolonged globalwarming and observed climatic changes duringthePETM.Inthiscontribution,wewillpresentanewanddetailedoverviewofthelithologicalandchemical variations through the Fur Formation,including data from high-resolution XRF-corelogging.OurdatagiveanimprovedinsighttothePETMandpost-PETMclimaticperturbations,andhelpusunderstandtheclimaticresponsetoashdeposition.

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1.4. Tephra markers in thecircumNorthAtlanticarea

ORAL

ExplosivevolcanicactivityinIcelandduringtheWeichelian–DifferentfromtheHolocene?

EstherRuthGuðmundsdóttir1,GuðrúnLarsen2,JónEiríksson3andÓlafurIngólfsson41NordicVolcanologicalCenter,FacultyandInstituteofEarthSciences,UniversityofIceland,2NordicVolcanologicalCenter,InstituteofEarthSciences,UniversityofIceland,3InstituteofEarthSciences,UniversityofIceland,4FacultyandInstituteofEarthSciences,UniversityofIceland

Eruption frequency is high in Iceland and hasbeen estimated to exceed 20 eruptions percentury on average during the Holocene. Themajorityoftheeruptionsaremafic(~90%)andpredominantlyexplosive(~70%).

Forthepast10.000yearstheexplosiveactivityinIceland is relatively well known based onnumerous soil profiles and lake sedimentarchives across the country.What aboutduringtheWeichselian?HowwastheexplosivevolcanicactivityinIcelandduringthislastglaciation?WasitsimilartotheHolocene?Whichvolcanoeswereactive and what was the level of their tephraproducingactivity?

To answer these questions, tephra in high-resolutionlakesedimentsspanning10.000yearsand marine sediments extending 50.000 yearshave been investigated. Lake sediments in EastIceland (Lake Lögurinn), records 170 explosiveeruptions during the Holocene. The marinesediments (core MD99 2272) from the NorthIcelandic shelf records about 200 tephra layersbacktothemiddleWeichelian.

There are strong indications that volcanism inIcelandduringtheHolocenehasbeenperiodicatseveraltimescaleswithapparentperiodsof140,500,and4-5000years.Preliminaryresultsfromthisstudyrevealthatthe4-5000yearperiodicity

extendsasfarbackas50.000years,witheruptionfrequency peaks between 1-2000, 5-7000, 9-10.000, 12-14.000, ~16-18.000, ~22-23.000,~32-33.000, 36-~37.000,~45-46.000and~49-50.000years.

ORAL

ProximaltephrasfromSãoMiguel,AzoresIslands,andtheirlinkswithdistalsitesinEurope

HansJohansson1andStefanWastegård11StockholmUniversity

TheAzoresarchipelagoisoneofthemostactivevolcanicareasintheNorthAtlanticregion,withapproximately30eruptionsduring the last600years.Thegeochemicalcompositionofassociatedtephra-derived glass is, however, not wellcharacterized.Ithasrecentlybeensuggestedthattrachytic tephras found in distal areas such asNorthAfrica,theBritishIslesandGreenlandmayderive from eruptions on the Azores, butproximaldatafromtheAzoresarescarceandthecorrelations have been tentative at best. Thesetephras lie clearly outside the geochemicalIcelandic province and have a potential toimprove the European tephro-stratigraphy/tephrochronology framework,especially in sites in south and central Europewhere tephras from more than one Europeanvolcanicsystemhavebeenfound(e.g.Laneetal.,2015).Analysesoftephraglassfromfivemidandlate Holocene eruptions on the Azores Islandswere presented by Johansson et al. (2017) andthereisastrikinggeochemicalsimilaritybetweentrachytic tephras from volcanoes on the SãoMiguelislandandcryptotephrasfoundonIreland(e.g.Chambersetal.,2004).ThedominantwinddirectionovertheAzoresisfavourablefortephradispersaltowesternEuropeandwesuggestthatat least three tephras found in Ireland wereerupted from the Furnas volcano, and thattrachytictephraseruptedfromSãoMiguelhaveapotential to contribute to the construction of aEuropean-widetephrostratigraphicframework.

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ORAL

LinkinglateQuaternarypalaeoclimaterecordsintheNorthAtlanticarea:cryptotephrasatKörslättamossen,SSweden

SimonLarsson1andStefanWastegård11DepartmentofPhysicalGeography,StockholmUniversity

The spatial and temporal development of rapidclimateshiftsduring the lastdeglaciation in theNorthAtlanticareaisstilluncertain(e.g.Daviesetal.2012).Themethodoftephrochronologyhasthe potential to precisely link differentpalaeoclimate archives from sites separated byvast distances (e.g. Lane et al. 2017), which isparticularly useful to assess the issue of thetimingandspatialdevelopmentoftheseclimateevents(e.g.Lowe2001,Laneetal.2011,Daviesetal.2012).

The Körslättamossen fen in Scania, southernSweden—previously studied byHammarlund&Lemdahl (1994)—was analysed forcryptotephras. Preliminary results indicate thepresence of at least five separate cryptotephralayers(concentrations>500shards/cm3),twoofwhich have been geochemically analysed andidentifiedas theHässeldalenTephra(HDT)andthe Laacher See Tephra (LST). This is the firstgeochemically confirmed find of the LST onSwedish mainland, extending its dispersal areafurther northwest than in previousreconstructions and providing new insights tothedispersalsof itsseveraleruptivestages.TheKörslättamossen fen appears to be a promisingsite for the usage of tephrochronology to linkpalaeoclimate archives in the circum NorthAtlanticarea.

ORAL

TephrastratigraphyinIcelandduringtheHolocene

ThorThordarson1andÁslaugGeirsdóttir11FacultyofEarthSciences,UniversityofIceland

Tephrochronology plays a conspicuous role inpaleoclimate studies across the North Atlanticbecause tephra horizons are excellentstratigraphic markers and correlation tools inHolocene sedimentary archives. ComprehensiveknowledgeofthetephrastratigraphyinIcelandisessential for understanding of the far-fieldchronologies and for tephra detection anddiscrimination. Over the last two decades wehave seen momentous improvements in theHolocene tephra record in Iceland, especiallybecauseof theexpansionof the traditional soil-basedtephrastudiestoincludeglacial,lacustrineand marine sediment archives along withheightened awareness of the importance oftephrastudiesforvolcanologicalandpetrologicalresearch. This has been achieved via collective,inter-disciplinary effort involving severaldedicatedresearchgroupsandthekeyoutcomesinclude: (a) a near complete high-resolutionHolocenetephrastratigraphy,datingbackto8-12kaforWest,Central,SouthandSoutheastIceland,including the circumference of the Vatnajökullglacier, (b) a near-completeHolocene record ofmagma compositions produced by individualvolcanoes, including detailed geochemicalcharacterization of all major silicic tephradeposits, (c) a much improved, high precisionanalytical procedure for major and volatileelementconcentrationsinvolcanicglass,suitableforgrainsdowntothesizerangeof3-10mm,(d)a comprehensive geochemical procedure fortephraidentification,(e)thatsomeofthekeyfar-field tephra marker horizons previouslyconceivedtobetheproductofoneeruption,arein fact comprised of several tephra layersproduced over periods of few hundred year. Iintendtopresentacomprehensivereviewtheseresearchendeavorsandtheiroutcomes.

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ORAL

TephrochronologyofNorthEurope:Alookbackandprospectsforthefuture

StefanWastegård11Institutförnaturgeografi,Stockholm

Chronologicalcontrolandtheresultantabilitytoexaminethedegreeofsynchronyamongrecordsof different origin are critical for theunderstanding of climate and environmentalvariability. There is an increasing demand forexacttimemarkersinthepalaeoclimate

community as more investigations now aim athigh temporal resolutions. Tephrochronology,which is an age-equivalent dating method,exploits these time-synchronous markers andoffers a unique possibility to test hypothesesregarding synchronous or non-synchronousresponses to climate forcing. Few, if anygeochronological methods can match theprecisionitoffersbothtemporallyandspatially.A new generation of tephrochronologists hasbeen undertaking novel research intocryptotephras (layersofnonvisiblevolcanicashencompassedwithinsediments)inice-cores,theNorth Atlantic, the Mediterranean and severaladjacent areas. The range of tephrochronologyhas radically been extended into geographicareasnotpreviouslyconsideredsuitableforthisapproach and many more records can now beintegratedina'tephralattice'forpreciselinkingof sequence. In this talk, I will give acomprehensive overview of the state-of-art oftephrochronology of North Europe and alsopresentsomeprospectsforthefuture.

POSTER

HolocenetephrastratigraphyintheVestfirðirpeninsula,NWIceland

EstherRuthGuðmundsdóttir1,AndersSchomacker2,SkaftiBrynjólfsson3,ÓlafurIngólfsson4andNicolajKLarsen51NordicVolcanologicalCenter,FacultyandInstituteof

EarthSciences,UniversityofIceland,2DepartmentofGeosciences,UiTTheArcticUniversityofNorway,Tromsø;3CentreforGeoGenetics,Nat,3IcelandicInstituteofNaturalHistory,Akureyri,Iceland,4FacultyandInstituteofEarthSciences,UniversityofIceland,5DepartmentofGeoscience,AarhusUniversity,Denmark;3CentreforGeoGenetics,NaturalHistoryMuseum

Inrecentyearstheterrestrialtephrastratigraphyin Iceland has been vastly improved throughdetailedinvestigationsofsoilandlakesedimentarchives revealing hundreds of tephra layers.These studies have focused on areas in south,north, east and central parts of Iceland. FewerstudieshavebeencarriedoutinwestIceland.Theaimofthisstudywastosignificantlyimprovetheknowledge of tephra stratigraphy andtephrochronology in western Iceland byinvestigatingthesedimentaryrecordsfromeightlakes in thenorthernmost part of theVestfirðirpeninsula. In these eight lake sediment recordsspanning the Holocene, 39 tephra layers havebeenidentified,thoughttorepresent34eruptiveevents originating from five volcanic systems;Hekla, Katla, Snæfellsjökull, Grímsvötn andVeiðivötn-Bárðarbunga. Of these 39 tephralayers,34havenotbeen reportedbefore in theVestfirðir peninsula. Six have recently beenreported in the area; the Hekla 1693 tephra(Brynjólfsson et al., 2015) Snæfellsjökull Sn-1tephra,Hekla3tephra,Hekla4tephra,Brattihjallitephra (Schomacker et al., 2016) andSaksunarvatn tephra (Schomacker et al., 2016;Harninget al., 2016).Herewepropose that theBrattihjalli tephra is in fact the 6060 year oldHeklaÖtephramarkerlayer,demonstratingthattheHeklaÖtephraextendedmuchfurthertothewest than previously reported, covering about2/3 of the country. Thus, the Hekla Ö tephracoversanaslargeareainIcelandastheHekla5,Hekla 4, Hekla 3 and Hekla 1104 tephras,emphasizing the importance of Hekla Ö as achronologicalmarker.

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POSTER

TimingofearlyHoloceneexplosiveeruptionsinIceland–improvedtephrochronology

MaaritKalliokoski1,EstherRuthGuðmundsdóttir2,BergrúnArnaÓladóttir1,HreggviðurNorðdahl3andÍvarÖrnBenediktsson31NordicVolcanologicalCenter,InstituteofEarthSciences,UniversityofIceland,Iceland,2NordVulk,FacultyofEarthSciences,InstituteofEarthSciences,UniversityofIceland,Iceland,3InstituteofEarthSciences,UniversityofIceland,Iceland

The Icelandic tephrochronology isan importanttool for dating and correlating sedimentaryarchives,landformsandarchaeologicalsitesbothin Iceland and overseas. A robusttephrochronology is also essential for derivinginformation on eruption frequency patterns.However,theearlyHolocenepartoftheIcelandictephrochronology lacks securely dated tephramarker horizons. Ages of the tephra layersbetweentheHekla5andSaksunarvatntephrasinsoilprofilesandpeatlandshavepreviouslybeendated only indirectly by interpolating soil orsediment accumulation rates between tephralayers of known age. As this period representsabout one third of the Holocene, it is criticallyimportant to establish new tephra markerswithin this part of the tephrochronology. ThedetailedtephrastratigraphyfromLakeLögurinn,East Iceland (Gudmundsdóttir et al. 2016) wasused as an aid in selecting potential tephramarkers in soil sections, lake sediments andpeatlands in East, Northeast andNorth Iceland.Toqualifyasatephramarker,atephraneedstohaveatleastregionallysignificantdispersalarea,it must be securely dated and harbourcharacteristics which distinguish it from othertephras close in age (Larsen and Eiríksson2008).Thus, new marker tephras for the earlyHolocene are established by electron probemicroanalysis of tephra geochemistry, carefulcomparisonoftephrastratigraphybetweensitesandradiocarbondatingofselectedtephralayers.

1.5. New trends in the study ofthecrystallisationandevolutionoflayeredmaficcomplexes

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StrontiumisotopesinplagioclaserecordmagmachamberdynamicsoftheSkaergaardintrusion

GrahamHagen-Peter1,ChristianTegner1,PeterThy2andCharlesLesher11CentreofEarthSystemPetrology,AarhusUniversity,Denmark,2DepartmentofEarthandPlanetarySciences,UniversityofCalifornia,Davis,U.S.A.

We report Sr isotope data obtained by laser-ablation multi-collector ICPMS for individualplagioclase crystals from the Skaergaardintrusion.Guidedbymicro-XRFpetrography,wetargetedcoresandrimsofprimocrysts,aswellasinterstitialplagioclase fromallmajorzonesandsubzones of the Layered Series (LS), UpperBorder Series (UBS), and from the SandwichHorizon (SH) and transgressivegranophyre.Current analytical protocol enables87Sr/86Srdeterminationwithprecisionof1partin 104 using a Nu Plasma IImass spectrometerand RESOultion 193 nm excimer laser with a~150-um-diameterbeam. Initial 87Sr/86Srratios(weightedmeans for individual samples) rangefrom~0.7041 to0.7045 forplagioclase rangingfrom25–70An%.Therearecorrelationsbetween87Sr/86SrandAn%,with the largestvariation in87Sr/86Sr among An-rich plagioclase.Stratigraphic relations show a progressiveincreasein87Sr/86Srfrom~0.7041atthebaseofLower Zone A to ~0.7044 at the top of LowerZone B, a value that is essentially uniform upstratigraphythroughtheSH.TheUBSmirrorstheLS, but also contains radiogenic An-richplagioclase (87Sr/86Sr up to ~0.7045) near theroof of the intrusion in contact with Tertiaryvolcanic rocks. In the field these samples areassociated with rafts of partially assimilatedPrecambriangneiss. TheplagioclaseSr isotopicrecordsuggestsanimportantroleforinsituAFCprocesses during early stages of Skaergaardevolution that diminished with inwardsolidification and insulation of the magma

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reservoir from country rocks and, in particular,the roof zone of the UBS containing rafts ofbasementmaterial.

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Magmatic fractionation by cumulaterock formation with expulsion ofresidual melts: a case from theTertiary Kærven Syenite Complex,EastGreenland

PaulMartinHolm1andNiels-OlePrægel21UniversityofCopenhagen,2CopenhagenUniversityLibrary

The evolution of silicate melts by crystalfractionation processes in magma chambers isrelatively well understood from experimentalpetrology,thermodynamicmodelling,andsuitesof volcanic rock. However, from studies ofplutonic complexes it is evident that ourunderstandingofthephysicalprocessesactinginmagma chambers during the crystallisation ofmagmas,andwhicharebelievedresponsibleforthe evolution of silicate melts, needs furtherclarification, even with respect to quitefundamental issues.Wepresentnewmajor andtraceelementdata froman intrusiveunitof theTertiary Kærven Syenite Complex, EastGreenland. The geochemistry of the syeniticrocks of the WK-2 unit displays ambiguousindications for their formation. On one handaccumulationofagabbroicmineralassemblageisindicated from linear correlation of severalelements,andontheotherhandanalkalifeldspardominated assemblage significantly affects therockcompositionsasshownbyhighEu/Eu*,Baand K/Rb. A simple liquid line of descent byfractional crystallisation executed by crystalsettlingoropensystemwallrockcrystallisationcannot explain the geochemical variation.Instead, we present a crystallisation model forthe WK-2 unit consisting of a) partialcrystallisationofanisolatedmushduringwhichthe liquidus assemblage changes from gabbroicto alkali feldspar syenitic, b) expulsion of afraction of the residual liquid, and c) final

crystallisation of the remaining liquid fraction.The model is in line with the in the situcrystallisationofLangmuir(1989),andalso,withvariations, apply to some other KSC intrusiveunits.

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DifferentialmigrationofinterstitialimmiscibleliquidsintheSkaergaardLayeredSeries

MarianHolness1,GautierNicoli1andVictoriaHonour11Dept.EarthSciences,UniversityofCambridge

The liquid line of descent of the Skaergaardmagma intersects a binodal creating animmiscibleconjugatepaircomprisingadenseFe-richliquidandabuoyantSi-richliquid.Thesetwoliquidshavedifferentwettingproperties:theSi-richliquidwetsplagioclase,whereastheFe-richliquidwetsoxides,pyroxeneandolivine.Thetwoliquids may therefore undergo differentialmigrationwithinagabbroiccrystalmush:theFe-richliquidsinksandaccumulatesinmaficlayers,whiletheSi-richliquidrisesandaccumulatesinplagioclase-rich regions. Microstructuralevidence demonstrates that differentialmigrationoccurredinrapidlydepositedmodallygraded layers fromLZcupwards in theLayeredSeries.Themelanocraticbasesofmodallygradedlayers in UZa develop finely-spaced internallayering, consistent with patterning driven bydifferent wetting properties of the immiscibleinterstitialliquid.

Evidence for differential migration is alsorecordedbymafic and felsic rimsdevelopedonthetopandbottommarginsofanorthositicroofblocksinLZc.Highlytabularblockshaveanuppermm-thickmaficrimandalowerleucocraticrim.As the block aspect ratio decreases, the rimsdisappear,with themafic rimretainedat loweraspectratiosthantheleucocraticrim.TheserimsareformedastheFe-richinterstitialliquidsinksthrough themushuntil it reaches the relativelyimpermeable blocks, whereas the Si-rich liquid

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risesandpondsbeneaththem.Tabularblocksaremosteffectiveattrappingtheseliquids.

Theseobservationsdemonstrate thecomplexityof behaviour in a crystalmush containing two-phase interstitial liquid. Simple cumulateparadigmsdonotapplyinsuchasystem.

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Sedimentarylayeringinmaficintrusions:theSkaergaardtroughbands

MarianHolness1,ZojaVukmanovic1,JensAndersen2,GautierNicoli1,SamWeatherley3,BrendanDyck4andVictoriaHonour11UniversityofCambridge,2CamborneSchoolofMines,UniversityofExeter,3GeologicalSurveyofDenmarkandGreenland,4SimonFraserUniversity,Vancouver

The trough bands of UZa of the SkaergaardIntrusioncompriseindividualstacksofupwardlyconcave, crescentic, modally graded layers,formingelongatestructurespointingtowardstheintrusioncentrefromthenearbyverticalwallonthe western part of the chamber floor. Theirorigin is contentious, with some advocating asedimentaryoriginwhileothersargue forpost-accumulationformationviarecrystallizationandmetasomatism primarily triggered by localisedgravitationally-drivencompaction.

Crescentic modally graded layers are presentthroughout the Layered Series below UZa.Although theydonotcommonly formextensivestacks,theirbasesareclearlyerosionalsurfaces,attesting to their sedimentary origin. Similarerosional surfaces are commonly preserved intheUZatroughbands,associatedwithchangesinaxial positon or width of the trough. The UZatrough bands occur within a ~300m thickstratigraphicintervalcontainingabundanthighlyelongate prismatic plagioclase grains that weargue were derived from collapse of the wallmushylayer.Detailedmicrostructuralanalysisofthe modally graded layers in the trough bandsdemonstratesalocallydevelopedstrongminerallineationparalleltothetroughaxis,togetherwith

morphological evidence for deposition ofindividual euhedral grains. Evidence fromconsiderationofdihedralanglevariationandthemorphology of late-stage gabbroic pegmatitessuggeststhatthefloormushnearthewallatUZatimes was anomalously thick. We argue thattrough bands are a normal component ofsedimentation on the floor of the chamber, andthat the unusually extensive stacks of troughbands in UZa are a consequence of temporaryoverthickeningandsteepeningofthefloor.

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Late-stagemeltmigrationintheSkaergaardIntrusion

VictoriaHonour1,MarianHolness1,SamuelWeatherley2,GautierNicoli1,BrendanDyck3andJensAndersen41UniversityofCambridge,2GeologicalSurveyofDenmarkandGreenland,3SimonFraserUniversity,4UniversityofExeter

TheSkaergaardIntrusionpreservesavarietyoflate-stage melt structures such as gabbroicpegmatites, paired felsic and mafic lenses(interpreted to be solidified coarsenedimmiscible emulsions), dendritic anorthosites,andmelanogranophyres.Previousworkonsuchstructureshasfocusedonparticularlocalitiesintheintrusion,treatingeachstructureinisolation.

We have established relationships between thedifferent melt migration structures, linkingmorphologicalandcompositionalvariationtothephysical properties of the crystalmush and theprogressive evolution of the bulk magma.Gabbroic pegmatitemorphology varies throughthe floor cumulates due to changes in mushrheology (Larsen & Brooks, 1994), consistentwith newly developed constraints on mushthickness.Pegmatitesarepodiforminthickmushbut planar in thin mush. They are spatiallyassociated with paired felsic and mafic lenses,whichoccur5-10metresstratigraphicallyabovepegmatites in LZ, but at the same stratigraphichorizon inUZ.Thepaired lensesformirregular,approximately layer-parallel clusters in thick

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mush, but thin concordant dendritic structureswithin strongly foliated modally graded layers.The modal mineralogy of the paired lensesevolvesupwardconsistentwithevolutiondownthe binodal: below LZc the mafic componentcomprises olivine pyroxenite, but is dominatedby oxides above LZb. In UZb pegmatites aremelanogranophyric, and paired lenses areconfined to localised horizons recordingsignificant syn-magmatic disruption, consistentwith the inferred evolution of the bulk magmatowardstheSi-richsideofthebinodal.

Our observations demonstrate that mushphysical properties control the movement ofinterstitial liquids, with wide-rangingimplications for our understanding of sub-volcanicprocesses.

ORAL

Skaergaardgabbros:Fractionationanddissolutionincrystalmush

TroelsNielsen11GeologicalSurveyofDenmarkandGreenland

Recent work on the macro-rhythmic (MR)layeredgabbrosintheSkaergaardIntrusionthathostthePGE-Aumineralisationshowsthattheirevolution involved dissolution of early-formedliquidus phases and the convective loss ofinterstitial liquid (mush melt).An early formedliquidus paragenesis (P1) was replaced by agabbroicparagenesis(P2)thatcrystallisedfrommushmelt andwasoutof equilibriumwith thecontemporarybulkliquid.P2constitutesupto50vol.%ofthesampledgabbroandhostsdropletsofimmisciblesulphidemelt.

Meltsontheliquidlineofdescentreachthetwo-liquidfieldandunmixedinFe-andSi-richsilicatemeltswhentheintrusionwas90%solidified.Themineralization formed after 75% crystallisationandMRlayersofthemineralisationwouldretain~25 wt. % dense and Fe-rich melt after

crystallisation of 60% of its mass and aconvectivelossof~15wt%Si-richmelt.

In bulk MR rocks, FeO and P2O5 are negativelycorrelated.Gabbros rich inP2arepoor inP2O5,except for the main Au mineralisation andsamples with granophyric veins.Using a SOM(self-organizingmap)analysis,AuCe,Y,NbandPb are shown to follow P2O5, and Au is addedalonggrainboundariestolayersalreadyenrichedin precious metal bearing droplets of sulphidemelt.

The present-day gabbros represent the sum ofprocesses acting between the liquidus andsubsolidusinsemi-closed,proto-MRlayers.Mushmelts fractionated until their evolved residualswere re-mixed into and drove the evolutionofremainingbulkliquid.

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Untanglingtheformationofadcumulaterocksinlayeredintrusions:amicrostructuralstudyoftheSkaergaardandBushveldintrusions

ZojaVukmanovic1andMarianHolness11DepartmentofEarthSciences,UniversityofCambridge

Despite decades of study, the formation ofadcumulatesremainsatopicofdiscussioninthelayered intrusion community. Models for theformation of adcumulates broadly fall into twogroups:1)thosebasedonaprimaryoriginbythegrowth of primocrysts in chemicalcommunicationwith the overlying bulkmagma(Wageretal.,1960);and2)thosebasedontwo-phaseflow,wherebytheevolvedmeltisexpelledfrom the crystalmush by gravitationally-drivencompaction(McKenzie,2011,Meurer&Meurer,2006;Sparksetal.,1985;Tegneretal.,2009).

To resolve this issue, we performed a detailedmicrostructural examination of two differentexamples: the Layered Series of the SkaergaardIntrusion, and anorthosites fromUpperZoneofthe Bushveld intrusion. We analysed grain

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orientation by electron backscatter diffraction,and compared this with mineral chemistry.Plagioclase in the Skaergaard shows almost noevidence for crystal plasticity, and no evidencefor dissolution-reprecipitation. We argue thatSkaergaard gabbros underwent negligiblecompaction and therefore that the adcumulatesare primary. In contrast, Bushveld anorthositesshowampleevidence fordislocationcreepsuchas low angle boundaries, and neoblasts formedduring dynamic recrystallisation. However, theextent of deformation is the same foranorthositesbothimmediatelybelowandabovemetre-scale magnetitite layers, suggesting thatthe deformation is likely to be due to regionalslumping, rather than internally-generatedbuoyancyforces.

Our results suggest that compaction is not themain mechanism that drives the formation ofadcumulates but, when present, can result in aminormedicationoftheprimaryigneousfabric.

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Combined‘sedimentary’andin-situoriginformagmaticFe-Ti-Vdeposits:newinsightsfromtheSkaergaardintrusion,EastGreenland

SamuelWeatherley1,JensC.Ø.Andersen2,MarianB.Holness3,BrendanJ.Dyck4,GautierNicoli3andVictoriaC.Honour31GEUS,ØsterVoldgade10,1350CopenhagenK.Denmark,2CamborneSchoolofMines,UniversityofExeter,PenrynCampus,Penryn,Cornwall,TR109FE.UK,3DepartmentofEarthSciences,UniversityofCambridge,DowningStreet,CambridgeC23EQ.UK,4DepartmentofEarthSciences,SimonFraserUniversity,Burnaby,V5A1S6,Canada

New field observations from Skaergaard, EastGreenland reveal five 0.5–2m thick, oxide-richintervalswithina~30mthicksequencenearthetop of LZc. Individual intervals are continuousalongstrikefromthecentreoftheintrusiontothemargin.This sequence exhibits density-sortedmodallayeringdefinedbybasalconcentrationsofFe-Mg rich phases (including magnetite and

ilmenite) and top-of-interval concentrations ofplagioclase. The layering style develops frombeingwispyandlaterallydiscontinuousclosetothe margin, to strongly defined and laterallycontinuous at the centre. On-lapping, layer-truncation and channel-like features arecommonlyobserved.Theoxide-richhorizonsarecommonlyassociatedwithstopedwallandroofblocks,upto400mlong,whichareorientedwithlong-axesparallel to the floor. In the size range10-1–101m, the topsof high aspect ratioblocksexhibit cm-thick oxide rims; the undersidesexhibit cm-thick rims of leucocratic (felsic)material.Thesepairedrimsareabsentfromlow-aspectratioblocks.Oxide-richseeps,discordanttolayering,arealsocommonlyobserved.

On the basis of these observations wepropose a combined ‘sedimentary’ and in-situmagmaticoriginforFe-Ti-Vdepositswhereby(1)newly-crystallised, gravitationally unstablematerial, was removed from the wall anddeposited on the floor; the deposition processresulted indensity-sortedmodal layers,and(2)liquid immiscibility in the mush producedconjugate Fe-rich silicate and felsic liquids thatenhancedtheprimarymodallayering,andledtothe oxide-rich seeps and paired rims onblocks.This model is compatible with theabsenceofLZconSkaergaard'swesternmargin.

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1.6.Alkalinemagmatism,carbonatitesandassociatedmineralresources.

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Clinopyroxeneasapetrogeneticindicator:usingintegratedtraceelementandzoningprofilestorevealmagmachamberprocessesintheDitrăualkalinemagmaticsystem

AnikóBatki1,ElemérPál-Molnár2,M.ÉvaJankovics3,AndrewC.Kerr4,BalázsKiss1andGregorMarkl51MTA-ELTEVolcanologyResearchGroup,1/CPázmányPéterStreet,H-1117Budapest,Hungary,2DepartmentofMineralogy,GeochemistryandPetrology,UniversityofSzeged,Hungary,3MTA-ELTEVolcanologyResearchGroup,1/CPázmányPéterStreet,H-1117Budapest,Hungary,4SchoolofEarthandOceanSciences,CardiffUniversity,MainBuilding,CardiffCF103AT,UK,5FachbereichGeowissenschaften,UniversitätTübingen,Wilhelmstrasse56,D-72074Tübingen,Germany

Clinopyroxene is considered as a significantpetrogeneticindicatorthatcanbeusedtounravelthe evolution of magmatic systems. EMPA andLA-ICP-MShavebeenusedtoanalysemajorandtrace element compositions of diverseclinopyroxene crystals in seven related rocktypesof thealkaline igneoussuiteof theDitrăuAlkalineMassif,Romania.

Phenocrystandantecrystpopulationsfromhigh-Cr Fe-diopside to high-Zr aegirine-augite havebeen distinguished based on mineral zoningpatterns and geochemical characteristics.Clinopyroxenes record two major magmasources as well as distinct magma evolutiontrends.Thediopsidepopulation isderived fromanearlycamptoniticmagmarelatedtobasaniticparental melts, whilst a group of diopside-hedenbergite crystals represents a newlyidentifiedNa-,Nb-andZr-richmagmasourceforthe the Ditrău magmatic system. This magmafractionatedtowardsijoliticandlaterphonoliticcompositionswithpronouncedHREE,Nb,ZrandHfenrichmentalongwithincreasingNa/Caratio.

Field observations, petrography andclinopyroxene-melt equilibrium calculationsrevealopen-andclosed-systemmagmachamberprocesses that played a role in the magmaticevolution: magma recharge and mingling,pyroxenerecycling,fractionalcrystallisationandaccumulation. Repeated recharge events of thetwo principal magmas resulted in multipleinteractions between more primitive and morefractionatedco-existingmagmabatches.

Investigation of complex zoning characteristicsand equilibrium melt calculations show thatantecrystrecyclingisasignificantprocessduringmagma recharge and demonstrate thatincorporatedcrystalscansignificantlyaffect thehost magma composition and so whole-rockgeochemical data should be interpreted withgreatcare.

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ProbingthestructuralstateofYandNdineudialyteusingX-rayabsorptionspectroscopy

AnoukM.Borst1,PlatonN.Gamaletsos2,AdrianA.Finch1,NicolaJ.Horsburgh1,HenrikFriis3,TakeshiKasama2,JoergGoettlicher4,RalphSteiniger4andKalotinaGeraki51SchoolofEarthandEnvironmentalSciences,UniversityofStAndrews,UnitedKingdom,2CenterforElectronNanoscopy,TechnicalUniversityofDenmark,KongensLyngby,Denmark,3NaturalHistoryMuseum,UniversityofOslo,Oslo,Norway,4ANKASynchrotronRadiationFacility,KarlsruheInstituteofTechnology,Eggenstein-Leopoldshafen,Ge,5ScienceDivision,DiamondLightSource,HarwellScienceandInnovationCampus,Didcot,UnitedKingdo

Eudialyte group minerals (EGM) are importantrare earth-bearing alkali-zirconosilicates inagpaiticsyenites.Alongsidec.12wt.%ZrO2and1-2wt.%Nb2O5, EGMhost c.1-10wt.% total rareearthoxideswith relativelyhighproportionsofvaluableheavyREE(c.35%).TheEGMstructureaccommodates REE in various sites, mostlyinferred to occupy the 6-fold coordinated Ca-dominatedM1-site,orthelowsymmetry8-9-10-

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fold coordinated Na-site. However, XRDrefinement is relatively insensitive to REE siteallocation, and HREE and LREE may occupydifferent sites due to their varying ionic radii.How REE are distributed on the micro-/nanoscale, particularly following fluidinteraction,ispoorlyknown.WeusesynchrotronradiationX-rayabsorptionspectroscopytostudythestructuralstateanddistributionofLREEandHREE inEGMand theiralterationproducts.WecollectedYK-edgeandNdLIII-edgeµ-XANESandμ-EXAFS to quantify coordination numbers andbond distances, with Y and Nd as proxies forHREEandLREErespectively.Micro-XRFelementmapping combinedwith SEM and TEMprovideinsightsinthemicro-/nanoscaleREEdistributionin EGM and its alteration products. Crystalline(XRD-confirmed) EGM from Ilímaussaq,Narssârssuk, Norra Kärr, Kipawa and Lovozeroyield near-identical µ-XANES for Nd and Y,indicatingsimilarLREE/HREEsiteoccupationsinEGM of varying compositions. Preliminary YEXAFSprocessingof theNarssârssukEGMyieldoptimalfitsin6-foldcoordinationandY-Obonddistances of c. 2.26-2.32 Å, consistent with Ysubstitution for Ca on the octahedral M1-site.CeriumabsorptionintheNdLIIIpre-edgeregiondemonstrates minor variations in Ce-oxidationstateacrossthelocalities.

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TheSpatio-TemporalEvolutionofHfisotopesintheGardar:EvidenceforMid-ProterozoicCrustalRecycling?

AdrianAFinch1,AnoukMBorst1,WilliamHutchison1,NicolaJHorsburgh1,TomAndersen2andSiriLSimonsen21UniversityofStAndrews,2UniversityofOslo

The Gardar Province of Greenland refers toalkalinemagmatismfromintraplateriftingintheMesoproterozoic. To understand further thesourcesofheavyREEandHFSEintheGardar,weanalysed the Lu-Hf isotopes of several Gardarcentres, representing early (Motzfeldt, NorthMotzfeldt, Ivigtut) and late (Ilímaussaq,

Østfjordsdal, Narsarsuk, Nunarsuit, Paatusoq)Gardarmagmatism and the geographical extentof the Province from Ivigtut in the West toPaatusoq in the East. Gardar magmas intrudedArchaean crust (Ivigtut), Ketilidianmetasediments (Paatusoq) and Ketilidiangranitoids(theothers).

Age-corrected Hf isotopes show low Hf valuesinconsistentwithsourcingfromdepletedmantlein Gardar times. Early Gardar zircons havesignificantlylowerage-correctedHfthanthoseofthe Late Gardar. Hf signatures in Early GardarzirconsprojectbacktoKetilidianoroldermantleextraction ages (> 1.8Ma).Onemight interpretsuchdatatoindicatethatHfintheEarlyGardarzirconswasscavengedfromKetilidianbasement.However, primary Gardarmelts are unlikely tohave contained negligible Hf and an unrealisticproportion of assimilated Ketilidian Hf isrequired.HoweverthedataareconsistentwithamodelwherebysubductionofArchaeancrust(i.e.very low 176Hf/177Hf) during the Ketilidianenrichedthesubcontinental lithosphericmantlewith Archaean Hf. In Gardar times, mantlemelting preferentially accessed this subducted(Archaean) mantle component, providingmagmaswithanomalouslylowHfisotopicratios.As rifting continued, proportionately morecontemporaryHfwas present in themelts. Themodel suggests recycling of Archaean crust viathemantleinGardartimes.

ORAL

GeochemicalconstraintsontheformationoftheArcheanSiilinjärvicarbonatite-glimmeritecomplex,Fennoscandianshield

EsaHeilimo1,HughO'Brien1andPasiHeino21GeologicaSurveyofFinland,2YaraSuomiOy,Siilinjärvimine

With an age of 2610 ± 4 Ma the Siilinjärvicarbonatite-glimmeritecomplexinFinlandisoneof theoldestknowncarbonatitesandtheoldestbeing currently mined for phosphorous. It was

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emplaced in the Karelia Province followingcratonic stabilization. The Siilinjärvi complexconsists of carbonatite, calcio-carbonatite,carbonatite-glimmerite, and glimmeritesurroundedbyafenite,formingatabularbody16kmlongand1.5kmwide.Thecomplexisaffectedbynorth-southPalaeoproterozoicsteepshearing.Carbonatiteoccursas thin (several cm) roughlyvertical lenses in glimmerite that forms thicker(10 cms) vertical veins. Despite the largecarbonate-phlogopite modal variablity,compositions of the phases calcite, dolomite,tetraferriphlogopite,apatiteandrichteritedonotvary significantly across the complex. Thedistribution of apatite is rather uniform, withaverage glimmerite and carbonatite containing10.4 and 9.9 modal % apatite, respectively.Compositionallythecarbonatiteveinsarecalcio-carbonatites, whereas the glimmerites arepotassicultramaficrockswithMg#over0.8.Allare cumulates, but are geochemically linked,showingsimilartraceelementtrends.AverageC-O isotopic compositions are δ13C=3.7‰ andδ13O=7.4‰.The geochemical data indicate thatthe carbonatite and glimmerite are cogeneticwith fractionation processes possibly playing asignificant role in their genesis. Isotopiccompositions show relatively uniform patternsand,weproposethatthecarbonatiteandrelatedlithologies are evolved from primitivecarbonatite liquids produced by low degreemelting of a carbonated mantle source. Wepropose that the complex has represents arelativelydeepwellmixedmagmachamberwithconsequent accumulation and crystallization,feedingmagmaticactivityathigherlevels.

ORAL

Fluid-rockreactionsinthecarbonatitesofthe1.3GaGrønnedal-Íkaalkalinecomplex,SouthwestGreenland

EemuRanta1,GabrielleStockmann2,ThomasWagner3,TobiasFusswinkel3,ErikSturkell4,ElinTollefsen2andAlasdairSkelton21NordicVolcanologicalCenter,UniversityofIceland,Reykjavik,ICELAND.,2DepartmentofGeologicalSciences,StockholmUniversity,Stockholm,SWEDEN,3InstituteofAppliedMineralogyandEconomicGeology,RWTHAachenUniversity,GERMANY,4DepartmentofEarthSciences,UniversityofGothenburg,SWEDEN

Petrogeneticstudiesofcarbonatites–carbonate-dominated igneous rocks – are challengingbecause carbonatite mineral assemblages andmineral chemistry typically reflect variablepressure-temperature conditions duringcrystallization,andfluid-rockinteractioncausedbymagmatic-hydrothermalfluids.However,thiscomplexity results in recognizable alterationtextures and trace element signatures in themineral archive that canbeused to reconstructthe magmatic evolution and fluid-rockinteractionhistoryofcarbonatites.

Our study focuses on the 1.3 Ga Grønnedal-Íkacarbonatite-syenite complex in SouthwestGreenland.Thealkalinecomplexmarkstheonsetof the Gardar continental rifting event, duringwhich itwas subsequently intruded by basalticdikes and underwent extensive faulting. Wepresent LA-ICP-MS trace element data formagnetite,calcite,sideriteandankerite-dolomitefromtheiron-richcarbonatitesofGrønnedal-Íka,and use this data, in combinationwith detailedcathodoluminescence imaging, for identifyingmagmatic and secondary geochemicalfingerprintspreservedintheseminerals.

Thechemicalandtexturalgradientspointtowarda55mwidebasalticdikeasthefocalpointofafossilhydrothermalfluidflowsystem,providingheat for F and CO2 rich fluids that mobilizedLREEs, Nb, Ta, Ba, Sr, Mn and P. These fluidsreactedwithandalteredthecompositionof thesurroundingcarbonatitesuptoadistanceof40m

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from the dike contact, where a high-grademagnetite mineralization was formed throughoxidationofsiderite.Ourresultscanbeusedfordiscriminating between primary magmaticmineralsandlateralterationrelatedassemblagesin carbonatites in general, which can lead to abetterunderstandingofhowtheserarerocksareformed.

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AreviewoftheTransitionalLayeredKakortokite(TLK),IlÍmaussaqComplex,SouthGreenland

HansKristianSchønwandt1,GregoryB.Barnes1andThomasUlrich21G.B.Barnes&Associates,47LabouchereRoad,SouthPerth,W.A.6151,Australia,2DepartmentofGeoscience,AarhusUniversity,Denmark

Kakortokiterepresentsthelowestmemberoftheperalkaline magmatic stratigraphy of theMesoproterozoic IlÍmaussaq Complex, SouthGreenland. Kakortokite is an agpaitic nephelinesyenite of which the lowest part showsspectacular layering. Kakortokite is originallysubdividedintothreeparts:(1)Alowerlayeredkakortokite(LLK)about200mthick,(2)slightlylayeredkakortokite(SLK)about35thick,whichis overlain by (3) transitional layeredkakortokite(TLK)withathicknessofabout40m.The LLK consists of three-layered unitscomposedofblack,red,andwhitelayersformedbymodal enrichment of arfvedsonite, eudialyteand feldspar-nepheline respectively. SLK isalmost unlayered and appears as a greykakortokite, locallywith faint black layers. TLKrepresents a return to the black-red-white-layeredunits.

TLKisbestexposednorth-westoftheproposedfault along Lakseelv where it gradually gradesintotheoverlayinglujavrite.Inthissection,nineeudialyte-enriched layersoccurnamedA to I indescending order from the contact to thelujavrite.Theuppermostfourlayers(A-D)occur

as a complex intergrowthof several rock types,whichpinchandswellandincludeeudialyte-richand naujaite-like rock. These layers are not asimple modal enrichment of eudialyte, but areinterpretedbyusasareactionbetweennaujaiteslabs and kakortokite magma. The remaininglayers (E-I) occur as faint layers in greykakortokite and represent a local modalenrichment of eudialyte. Therefore, we suggestthe kakortokite stratigraphy to be described asLLK(≥200m)overlainbySLK(≈75m).

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AlkalinepegmatitesoftheLarvikPlutonicComplex–whatarethey?

ØyvindSunde1,HenrikFriis1andTomAndersen21NaturalHistoryMuseum,UniversityofOslo,P.O.Box1172,Blindern,0318Oslo,Norway,2DepartmentofGeosciences,UniversityofOslo,P.O.Box1047,Blindern,0316Oslo,Norway

The Larvik Plutonic Complex is a differentiatedalkaline complex situated in the Permian OsloRegionandconsistsofaseriesofsemiconcentricring intrusions of monzonitic rocks (Petersen1978;Neumann1980).Themonzoniticrocksarecollectively known as larvikite and extensivelyquarried as a dimension stone.Within the hostplutonsnumerousnephelinesyeniteandsyenitepegmatites, as well as minor nepheline syenitedykesoccurwithanambiguousrelationshipandcontrasting mode of emplacement. Althoughmanyofthesepegmatiteshavebeenextensivelystudied for their mineral content and providedfirst descriptions of 30 mineral species, thepetrological evolution of the pegmatites is stillpoorly understood. Different classificationschemes have been devised to relate andcomparecontrastingpegmatite featuressuchasmorphology, mineralogical zonation, and rocktextures(e.g.,Brogger1890;Piilonenetal.2012).However, such differences are not directlyrelated to petrogenetic similarities betweenthese pegmatites. Wöhlerite, ideallyNaCa2(Zr,Nb)(Si2O7)(O,OH,F)2,occursabundantlyamongtheearlyliquidusmineralassemblagesofthe nepheline syenite pegmatites. The flexible

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crystal structure of wöhlerite is able toincorporatecationsofdifferentsizeandvalence,and thus record contrasting pegmatite-formingmagmas.

Thiscontributionprovidesaregionalcomparisonof wöhlerite major- and trace-elementcompositioncoupledwithdetailedfieldmappingof selected pegmatites to reveal a closepetrogenetic relationship between pegmatitesandheterogeneitiesofthehostlarvikite.

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TraceelementandNd-isotopedataofeudialytefromtheKakortokitesequenceoftheIlímaussaqcomplexsuggestsubsolidusremobilizationofrareearthelementsbymagmaticfluids

MathijsvandeVen1,AnoukBorst2,GarethDavies1andAdrianFinch21VrijeUniversiteitAmsterdam,2St.AndrewsUniversity

Thekakortokites,agpaiticfloorcumulatesoftheperalkaline Ilímaussaq Complex, SouthGreenland (1160Ma1), constitute a world-classdeposit of rare earth elements (REE), largelyhosted in the alkali-zirconosilicate eudialyte.Autometasomatic and/or hydrothermalalteration of eudialyte has caused formation ofpseudomorphsexhibitingavarietyofsecondaryREE-/Zr-phases.Previouswork2identifiedthreealterationtypes,characterizedbythesecondaryzirconosilicatescatapleiite,gittinsiteandzircon.

HerewepresentICP-MStraceelementandTIMSSm/Nd isotope data of micro-drilled eudialyte-pseudomorphpairsfromfoursamplesspanningthe kakortokite stratigraphy (three catapleiite-type, one gittinsite-type) and one zircon-typepseudomorphsamplefromthe‘hybrid’unitsthatcross-cut them, to study the nature of alteringfluids and their high field strength element(HFSE-)mobilizingcapacity.

Trace element data show catapleiite-alterationcauseda15-25%decreaseinREE,Ta,Nb,Zr,SrandY(relativetoprecursoreudialyte)anduptofour-foldincreaseinRbandTh([Th]pmo=27-100ppm), while gittinsite- and zircon-alterationcaused stronger heavy REE (HREE) depletion(≤50%). REE fractionation is evidenced bylowered Sm/Nd ratios in all but onepseudomorph-sample, indicating that alteringfluids were capable of remobilizing andfractionatingHFSEandREE.

143Nd/144Ndt=1160ratiosoffresheudialyte(µeud=0.511090, s.d. = 5) are indistinguishable fromthoseofpseudomorphs(µpmo=0.511097,s.d.=7)atthe90%confidencelevel,suggestingthatfluidswere(late-)magmaticinorigin.However,zircon-type pseudomorphs yield higher143Nd/144Ndt=1160(0.511166±7),which,combinedwithstrongerHREEdepletionandenrichmentinSr (130%) and Ba (79%) hints at a differentoriginforthezircon-formingfluid.

POSTER

MineralogyandpetrologyofmaficdikesfromtheSiilinjärvicarbonatitecomplex,Finland

MatiasCarlsson1,HannesB.Mattsson2,KarinHögdahl3,AlirezaMalehmir2andPasiHeino41GeologyandMineralogy,ÅboAkademiUniversity,Akatemiankatu1,20500Turku,Finland,2Dept.ofEarthSciences,UppsalaUniversity,Villavägen16,75236Uppsala,Sweden,3Dept.ofEarthSciences,UppsalaUniversityandGeologyandMineralogy,ÅboAkademiUniversity,4YaraSuomiOy,Siilinjärvi,Finland

The 2.6 Ga Siilinjärvi carbonatite complex incentralFinlandistransectedbyalargenumberofmafic dykes. Here we combine field-relations,with mineralogical and petrological analysis toinferdikeemplacedinthreedistinctstages.Theoldertwogenerations(GenIandII)areinteselydeformed in constrast to the composite dike ofGenIII.

Mineralogically the dykes are comparable,containingplagioclase,amphibole,quartz,calcite

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asmajorphases,withaccessorychlorite,apatite,epidote, titanite and opaques. Gen I dykes havecharacteristically allanite and near-euhedralchamositecrystals(chlorite),surroundedbyfine-grained titanomagnetite/ilmenite. Thesechamosites are likely pseudomorphs replacingoriginalphlogopitecrystals.

The alkaline composition of Gen I dykes(predominantly K-rich foidites, with up to 13wt.%Na2O+K2O)suggeststhattheyarerelatedtodifferentdegreesofmantlemelting.Itissimplynot possible to produce the observedcompositions by fractionation of any potentialphenocryst phase. The two younger dykegenerations can be reproduced by a relatively“normal” basaltic fractionation series (spanningfrombasalts,viaK-richalkali-basaltstotrachyticcompositions).

The Gen I dykes seem to be directly associatedwith a mantle source similar to that whichproduced the apatite-bearing carbonatites. Thelater dyke generations have bulk-rockcompositions that are not normally found indirect relation to carbonatites, indicating asignificanttimegapbetweentheGenIdykesandsubsequentgenerationsinwhichtimethemantlesource had changed significantly to producethesechemicallycontrastingmagmasuites.

This is an ERA-MINStartGeoDelineationcontribution sponsoredbyVinnova, SGU,Tekes,NIOandYara.

POSTER

GeochronologyoftheSärnaalkalinecomplex,Dalarna,Sweden

JohnA.Eliasson1,ThomasZack1andAxelSLSjöqvist11DepartmentofEarthSciences,UniversityofGothenburg

TheSärnaalkalinecomplex isawell-knownyetpoorly studied locality of highly peralkalineigneous rocks in middle Sweden. It mainlyconsistsoftworocktypes:varietiesof intrusive

cancrinite nepheline syenite (särnaite) andcrosscutting tinguaite dikes. While differentwhole-rock särnaite samples did not form anisochron, mineral separates derived fromsärnaitehaveyieldedaRb–Srageof287±14Ma(2σ)(BylundandPatchett,1977),broadlycoevalwiththePermianOsloRiftmagmatism(ca.308–245 Ma: Larsen et al., 2008), but not preciseenoughtodrawconfidentparallels.

To further constrain the timing of magmaticactivity at Särna, we are studying the Rb–Srsystematicsof thesealkaline igneousrocksbyanewly developed technique for in situ Rb–Srdating by LA-ICP-MS/MS (Zack and Hogmalm,2016). Detailed characterization of mineraltextures and chemistry by SEM in combinationwithmicro-analyticaldatingcangivereliableRb–Sragesofalkalinerocks,whicharenotoriousforpervasivealterationandopen-systembehaviour.Preliminaryresults includethefirstradiometricage of a Särna tinguaite, which was dated at296±7 Ma (2σ) in biotite phenocrysts andconfirms that the särnaite and tinguaite arecoeval.Derivingmorepreciseagesfromavarietyof rock types will also allow us to make morerobustconnectionswiththephasesofformationoftheOsloRift.

POSTER

ThoriumineudialyteoredepositsfromGreenlandstudiedbysynchrotronradiation(μ-XRF/-XAFS)andelectronmicroscopictechniques(SEM,TEM)

PlatonN.Gamaletsos1,AnoukM.Borst2,TakeshiKasama1,AdrianA.Finch2,JoergGoettlicher3,RalphSteininger3,BeritWenzell1,ZoltanI.Balogh1andAthanasiosGodelitsas41CenterforElectronNanoscopy,TechnicalUniversityofDenmark,KongensLyngby,Denmark,2SchoolofEarthandEnvironmentalSciences,UniversityofSt.Andrews,StAndrews,UK,3ANKASynchrotronRadiationFacility,KarlsruheInstituteofTechnology,Eggenstein-Leopoldshafen,Ge,4DepartmentofGeologyandGeoenvironment,National&KapodistrianUniversityofAthens,Athens,Greece

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The Nordic region holds some of the world’slargest eudialyte deposits, which containpromisingrareearthsconcentrations.Duetolowcontentofactinides(including thorium/Th) insuch rocks, eudialyte would avoid many of theissues of potential radioactive contamination intailingsthatbedevile.g.,monaziteandxenotimeextraction. Here, we study the nature of Thassociated with rare earth elements (REE) ineudialyteoredepositsfromGreenlandinmicro-/nano-scale using the technical advance ofcombining synchrotron radiation (SR μ-XRF/-XAFS) and electron microscopic (SEM, TEM)techniques.Preliminarysynchrotronradiation&electron microscopic observations of alteredeudialyte reveal the presence of Th-bearingphases at the micro-/nano-scale. Similarheterogeneity is observed for the REE ineudialytereplacementproducts.WecollectedThLIII-edgeextendedx-rayabsorptionfinestructure(μ-EXAFS) spectral data of Th-enrichedmicroareas,identifiedbySRμ-XRFmappingthatconfirmedtheheterogeneousdistributionofTh,whichprovideinformationonthelocalstructuralenvironmentofThwithinalteredeudialyte.Th-bearing phases were detected along alteredmargins of eudialyte, in secondary phases, andinterstitial to primary phases such as feldspar,amphibole and eudialyte. Concerning fresheudialyte, Th is undetectable by SR μ-XRF.However, further research is needed to clarifythesephenomena.

POSTER

VarenasuiteinthecrystallinecrustoftheSouthernLithuania:implicationtothegenesisandmineralization.

VaidaKirkliauskaite1,GediminasMotuza2andRamintaSkipityte11PhDstudent,2Prof.dr.

CrystallinecrustinSouthernLithuaniaiscoveredby 200-500 m thick sedimentary cover and isinvestigated by potential field mapping anddrilling. It is composed by amphibolites

(metabasalts), biotite-quartz-plagioclasegneisses (metapsammites and porphyrymetadacite and metaandesite) of Orosirianperiod. Each lithology is predominant inalternating bands extended NNE-SSW.Supracrustalsaremetamorphosedonthelevelofamphibolite facies and migmatized. Intrusiverocks are represented by coeval rare bodies ofgabbro, peridotite and widespread Calymmiangraniticplutons(Motuza2005;Linnemannetal.2008).

Varena suite comprises olivine, enstatite,diopside, olivine-magnetite, magnetite, apatite-bearing, and presumably also dolomite rocks.They form integrated bodies few sq. km large,concentratedinthe~300km2areaextendedinN-Sdirection(Motuzaetal.2016).

Rocks of Varena suite and the country rocks(amphibolites, metaporphyres) are affected bystrong metasomatic alteration. Themineralization of REE (up to 2759-3100ppmof La and Ce respectively), Th, U, P hosted bymonazite, apatite(?), allanite is spatially relatedto the Varena suite and some metasomatizedsupracrustals.

The views on the genesis of Varena suite arecontradicting. By various authors they areregarded as skarns, presuming metasomaticorigin, as layered intrusions or products ofalkaline and carbonatiticmagmatism(Motuza etal,2016).

In this presentation the genetic model isreviewedbasedonreinterpretationofstructural,geochemical, petrographical data, and newisotopicstudiesofO,C,SrintherocksofVarenasuite.ItisalsoanattempttoraisemethodologicalquestionssuchasLu-Hfdatingofapatiteandfindopportunitiesforcooperationinfurtherstudies.

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POSTER

NewRb-SrandZirconU-PbdatingoftheGrønnedal-Íkaigenouscomplex,SWGreenland

GabrielleStockmann1,AndreasKarlsson2,AlexanderLewerentz1,TonnyB.Thomsen3,ThomasF.Kokfelt3,ElinTollefsen1,ErikSturkell4andLenaLundqvist51DepartmentofGeologicalSciences,StockholmUniversity,SWEDEN,2DepartmentofGeosciences,SwedishMuseumofNaturalHistory,Stockholm,SWEDEN,3GeologicalSurveyofDenmarkandGreenland(GEUS),Copenhagen,DENMARK,4DepartmentofEarthSciences,UniversityofGothenburg,SWEDEN,5SwedishGeologicalSurvey(SGU),Gothenburg,SWEDEN

Datingof theGrønnedal-Íka igneouscomplex inSouthwestGreenlandisimportanttounderstandthecontinentalriftingevent–theGardarepisode.Inthisstudy,threedifferentmethodshavebeenapplied to rock specimens and previouslypublisheddatatobetterconstraintheageofthecomplex:a)U-Pbdatingofzirconsextractedfromhand specimens of Upper Series nephelinesyenitesand fromdrillcoresamplesofacentralcarbonatite plug collected by KryolitselskabetØresund A/S, b) new in-situ Rb-Sr analysis onLower Series granular syenite, and c) re-calculationofwholerockRb/SrdatabyBlaxlandetal.(1978).

Prismatic zircons, 100-200 µm in size, lightbrown in colour, showing magmatically zonedcoresandirregularlyshapedalterationrimswithovergrowths of U andTh oxideswere analysedwith ThermoFinnigan Element 2 InductivelyCoupledPlasmaSectorFieldMassSpectrometerinstrument at GEUS. This gave an U-Pb age of1325±6 Ma after having selected suitable datapointsfromCL.

In-situ Rb-Sr dating using an Agilent 8800 ICPMS/MS on selected minerals from granularsyenitegavean isochronageof1314±14Maonthe basis of 20 spots in biotite and k-feldsparusing the technique outlined in Zack andHogmalm (2016). Re-evaluation and re-calculation of the whole-rock dataset from

Blaxlandetal.(1978)withthenewlyrevisionedRb-Srdecayconstant(Villaetal.,2015)yieldsanageof1311±26Ma.

ThisconfirmstheGrønnedal-ìkacomplexas theoldest of the Gardar intrusions andmost likelymarkstheonsetoftheGardarcontinentalriftingofSouthGreenland.

POSTER

Experimentalsimulationandpredictivemodellingofrareearthelementenrichmentincarbonatitesandalkalinemagmas

JohannTuduri1,ZinebNabyl1,FabriceGaillard1,MalcomMassuyeau2,GiadaIacono-Marziano1,JérémieMelleton1andLaurentBailly11BRGM,UMR7327,3avenueClaudeGuillemin,45100Orléans,FranceandalsoUniversityofOrléans,ISTO,2UniversityofJohannesburg,POBox524,AucklandPark2006,SouthAfrica

CarbonatitesandalkalinemagmasarekeypiecesofthedeepcarboncycleandconstituteoneoftheprincipalresourcesofraremetalsincludingREE.Several experimental studies have tackled therare metal partitioning between immisciblecarbonateandsilicateliquids(Martinetal.2013;Veskleretal.1998,2012).Theyshownegativetomassive enrichments in the carbonate liquid.However, no prevailing cause has been clearlyisolated as such enrichments can be ruled byexperimental conditions (P, T, ƒO2), meltcompositions (water and alkali contents), ortechnical issues such as unequilibratedexperiments.

The aim of this study is to simulate, by HP-HTexperiments in the nephelinite-carbonatitesystem, crystal fractionation and immiscibilitybetweencarbonateandsilicate liquids, inorderto assess the factors ruling REE enrichmentduringthedifferentiationofalkalinemagmas.

Thirty experimental charges were synthetizedusing piston-cylinder and internally heatedpressurevessel.ThepartitioningofREEbetween

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carbonate liquids, silicate liquids and crystals(pyroxene, calcite, nephelinite, perovskite,titanite) has been characterized. REE partitioncoefficientsbetweencarbonateandsilicateliquidincreasewhileCapartitioncoefficientincreases,suggesting that both have the same behavior.Also,themorethesilicateliquidispolymerized,the more REE are concentrated into carbonateliquids.TheCapartitioncoefficienthasbeenthuscalibrated by an empirical model based on thesilicatemeltcomposition.

This study reveals the optimum conditions forwhich carbonatite melts get enriched by >10timeswithrespecttotheresidualsilicatemelts.ThispredictiveapproachmayserveasguideforprospectionofREE-enrichedcarbonatites.

POSTER

Polymetallic,REEandpreciouselementsnewresultswithinSuwalkiAnorthositeMassif,NEPoland

JaninaWiszniewska1andMichalRuszkowski21PolishGeologicalInstitute-NationalResearchInstitute,2DepartmentofGeology,UniversityofWarsaw

TheSuwalkiAnorthositeMassif(SAM)islocatedin NE part of Poland, within Mezoproterozoic,beltiformmagmatic AMCG [anorthosite -mangerite - charnokite - granite rapakivi]suiteknown as a Mazury Complex. This complexassociatewithtectonicdeepriftcrustalstructure.TheSAMoccupiesanareaof250km2oftheovalshapediapiricstructure.Itscentralpartismadeupofanorthositessurroundedbyringsofnorites,gabronorites and diorites. Fe-Ti-V oremineralsconcentrations with subordinate Fe-Cu-Co-Nisulphides that represent 1 to 4% of the rockvolume(WiszniewskaJ.,2002,WiszniewskaJ.etal. 2002) locally even moreto a maximumcontentof8%.

Chalcopyrite, pyrrhotite, cubanite, pentlandite,cobaltite, bornite, chalcocite, millerite andsphalerite are most common magmatic sulfideminerals. These minerals coexist with Fe-Ti

oxides in variable proportion and forms ofmonomineralaggregatesof3-100µm,interstitialveins or schlieren of 30-250 µm dimensions.Pyrrhotite makes up nearly 75% of sulphidesbulk. Pyrrhotite, chalcopyrite and pentlanditehave magmatic origins confirmed by sulfurisotopesofδ34SCDTofabout0‰.(WiszniewskaJ.etal.)SulfidescontainoftennanoformsofREE(La, Ce and Nd) and precious elements (gold,platinum)mineral admixtures of 10-100 µm orevenup to300µm in sulfides.Untypical zircongrainsofblowncandleflamestructureandrimsaround ore minerals were observed andpreparedforagedeterminations.

New results of polymetallic and preciousmetalsulfides together with REE dispersedmineralizationmay increase an economic valueofFe-Ti-VdocumenteddepositsinSAM.

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1.7.MagmaticPlumbingSystems.

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Aseismicstudyofthe2014-15Bárðarbunga-Holuhraunriftingevent

ThorbjörgÁgústsdóttir1,RobertS.White1,JenniferWoods1,TimGreenfield2,TomHudson1andBryndísBrandsóttir31UniversityofCambridge,2UniversityofSouthampton,3InstituteofEarthSciences,ScienceInstitute,UniversityofIceland

On 16 August 2014 an unusual sequence ofearthquakesbegannearthesoutheasternrimofthe ice-covered Bárðarbunga caldera in centralIceland. Over the course of two weeks a dykepropagated 48 km beneath the glaciernortheastwards and into the Holuhraun lavafield,whereiteruptedforsixmonths,becomingthelargesteruptioninIcelandforover200years.During this time,agradual, incremental calderacollapse took place in the Bárðarbunga centralvolcano.Thisstudyanalysestheseismicresponseto the event, bothdue to thedykepropagation,and the associated caldera collapse.Approximately 35,0000 earthquakes wererecorded during the pre-intrusive, intrusive,eruptive and post-eruptive periods,whereof~4,000 earthquakes were associatedwith the caldera collapse, delineating faultsaccommodating the subsidence and showinggood correlation with geodetic data. Detailedanalysis of the earthquake source mechanismsshowsthat~90%canbeexplainedbyadouble-couplesolution.Thedominantfailuremechanismduringthecollapseissteepnormalfaulting,withsub-vertical P-axes, striking sub-parallel to thecalderarim.Thenorthernandsouthernsidesofthecaldera,howeverexperiencedverydifferentseismicity rates, highlighted by the order ofmagnitude difference in the cumulative seismicmoments. We present evidence of a complexasymmetriccalderacollapse,notcontrolledbyasingle caldera ring fault. The ~31,000earthquakes delineating the segmented, lateraldyke intrusion fracturedapathwaythroughthecrust, utilizingpre-existingweaknesses.Despite

the extensional rift setting, the dykeemplacement generated exclusively double-couple earthquakes with solely strike-slipfaultingmechanisms.

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Dyketipprocessesandlarge-scaledeformation:implicationsforgeodeticmodelling

HåvardSvanesBertelsen1,FrankGuldstrand1,OlivierGalland1andKarenMair11PhysicsofGeologicalProcesses,UniversityofOslo,Norway

Geodetic modelling of dykes using the Okadadislocation model has become a standardapproach when interpreting geodetic datamonitored over active volcanoes. The Okadamodel assumes that (1) dykes are tensilefractures and (2) the host is purely elastic.However, recent field observations andlaboratory results suggest an alternate dykepropagationmechanism;theviscousindenter,i.e.thedyketippropagatesbypushingitshostrockahead,failinginshear.Towhichextentdifferentdyke propagation mechanisms affect theassociated surface deformation is currentlyunknown.Toaddressthis,wecomparetwoseriesof laboratory models of dyke emplacement,duringwhichwemonitoredsurfacedeformationat high resolution and precision. In the firstseries, themodel crustwas elastic gelatine andthe dyke propagated as tensile fracture; theresulting surface deformation was comparablewiththepredictionsof theelasticOkadamodel,i.e. an elongated topographic trough above thedykeapex,surroundedbytwoupliftedzones.

Conversely,inthesecondseries,themodelcrustwasacohesiveCoulombsilicaflourandthedykepropagated as a viscous indenter; the resultingsurface deformation was only uplift. The first-order differences between the two series ofmodels show that local tip processes indeedcontrol large-scale deformation induced bypropagating dykes, and so the surfacedeformation patterns. Our results question the

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systematicuseof tensileelastic fracturemodelsto interpret geodetic measurements associatedwithdykeemplacement.Finally,ourresultsshowthat relevant interpretation of geodeticmeasurements requires a proper physicalunderstandingofdykepropagationmechanisms.

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SeismicInterpretationofSill-ComplexesinSedimentaryBasins:The‘Sub-SillImagingProblem’

ChristianHaugEide1,NickSchofield2,IsabelleLecomte1,SimonJ.Buckley3andJohnA.Howell21UniversityofBergen,2UniversityofAberdeen,3UniResearchCIPR

Application of 3D-seismic reflection-data toigneoussystemsinsedimentarybasinshasledtoa revolution in the understanding of mafic sill-complexes. However, there is considerableuncertaintyonhowgeometriesandarchitectureofsill-complexeswithinthesubsurfacerelatestothose imaged in seismic reflection-data. Toprovide constraints on how sill-complexes inseismic data should be interpreted, we presentsyntheticseismogramsgeneratedfromaseismic-scale (22x0.25 km) outcrop in East Greenlandconstrained by abundant field-data. This studyhighlightshowoverlyingigneousrocksadverselyaffectimagingofunderlyingintrusionsandrocksbydecreasingseismicamplitude, frequencyandmakingsteeplydippingfeaturesnear-impossibletoimage.Furthermore,seismicmodellinginthisstudyshowsthat,becauseofthehighimpedancecontrast between siliciclastic host-rock anddolerites,verythin(1-5m)intrusionsshouldinprinciplebeimagedinreflection-seismicdataat3 km depth. However, comparison with actualseismic data with well-data shows significantamountsofun-imagedsillintrusions,andthisislikely due to limited seismic resolution,overburden complexity, inadequate velocity-models, and interference between reflectionsfrom closely spaced sills and sill-splays.Significant improvements to sill imaging andinterpretationcouldbemadebybetterpredicting

occurrence and geometry of sill intrusions andincludingtheseinvelocitymodels.

ORAL

FracturenetworksinandaroundigneousintrusionsonSvalbard:implicationsforfluidflow

MarteFestøy1,KimSenger2andSten-AndreasGrundvåg31Mastergraduate,2Primarysupervisor,3Co-supervisor

Igneous intrusions exert a strong influence onpetroleum systems, groundwater aquifers andCO2storagereservoirs.Thisisespeciallytrueformigrationpathways,asanygivenintrusionmayact as a barrier to, or a carrier for fluid flow,potentially compartmentalizing a reservoir orcreating seal by-pass structures. The fracturenetwork in the intrusion and its surroundingswillcontrol thepermeabilityalongandacrossasingleintrusion.However,thevariousfracturingprocesses are relatively poorly constrained,beingcontrolledbymagmaemplacement,magmacooling and tectonic events, and field data arerequired to better understand this interplay. Inthis study we investigate 15 outcrops fromcentral Spitsbergen, Arctic Norway, in order toconstraintheimpactofEarlyCretaceousigneousintrusionsonsubsurfacefluidflow.Wecombinetraditional fieldmappingwith photogrammetryto construct high-resolution 3D virtual outcropmodels, providing 330 m of scanlines, 928fracture measurements using a geologicalcompass and an iPhone and 7993 fracturemeasurements from virtual outcrop models.Fracture sets, bothwithin the dolerites and thenearby host rocks, are predominantly orientedeitherparallelorperpendicular to the intrusioncontact. At one of the study sites, the fracturefrequency in the intrusion-proximal host rocksincreases toward the intrusion contact, from 6fractures/m (f/m) in thebackground to10 f/mapproximately 1 m from the intrusion contact.Calcite cemented fractures are frequentlyobserved in within intrusions, but also withinintrusion-proximal host rocks. A conceptual

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model for rock evolution and fracturedevelopmentinandaroundigneousintrusionsispresented.

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Therelevanceofsillsandrelatedflat-lyingintrusionsinvolcanicplumbingsystems

OlivierGalland1,HåvardS.Bertelsen1,ChristianH.Eide2,FrankGuldstrand1,ØysteinT.Haug1,HéctorA.Leanza3,KarenMair1,OctavioPalma4,SverrePlanke5,OleRabbel1,BenjaminRogers1,TobiasSchmiedel1,AlbanSouche1andJuanB.Spacapan61PhysicsofGeologicalProcesses,DepartmentofGeosciences,UniversityofOslo,Norway,2UniversityofBergen,Norway,3MuseoArgentinodeCienciasNaturales-CONICET,Argentina,4Y-TEC-CONICET,Argentina,5VBPR,CEED,UniversityofOslo,Norway,6YPF-CONICET,Argentina

Although dykes are considered to be the mainupward magma pathways through the Earth’scrust, the last two decades of research showedthat significant parts of volcano plumbingsystems consist of flat-lying igneous intrusions,namely sills. The aim of this contribution is toprovide a didactic overview of our currentunderstanding of the formation of sills and oftheirscientificandeconomicrelevance(Gallandetal.,accepted).

Sillsformmainlyinthelayeredpartsofthecrust,principallyinvolcanicdepositsandsedimentarybasins where lateral magma flow through sillcomplexes and networks can reach severalhundredskilometers.Sillexhibitsvariousshapes,from strata-concordant, transgressive sheets tosaucer shapes. Furthermore, sills representintermediate feeder structures for volcaniceruptionsand,therefore,abetterunderstandingofsillemplacementandevolutionisessentialforassessing volcanic hazards. Sills emplaced insedimentarybasinsalsodeeplyaffectpetroleumsystems and are essential components inexploringhydrocarbons.Finally,themassiveandfast emplacementof sills resulting fromLIPS insedimentary basins triggered catastrophic

climate changes and mass extinctions duringEarth'shistory.

In this presentation, I will develop the mainpointsofourunderstandingofsillformation,i.e.the feeders of sills, the factors controlling theirinitiation, their propagation mechanisms andsubsequent evolutions to saucer-shapedintrusionsorlaccoliths.

ORAL

DeepandshallowmagmastorageonBali

HarriGeiger1,ValentinR.Troll1,EsterM.Jolis1,FrancesM.Deegan1,ChrisHarris2,MartinJ.Whitehouse3,DavidR.Hilton4andCarmelaFreda51DepartmentofEarthSciences,UppsalaUniversity,Uppsala,Sweden,2DepartmentofGeologicalSciences,UniversityofCapeTown,SouthAfrica,3DepartmentofGeosciences,SwedishMuseumofNaturalHistory,Stockholm,Sweden,4GeosciencesResearchDivision,ScrippsInstitutionofOceanography,LaJolla,CA92093-0244,USA,5IstitutoNazionalediGeofisicaeVulcanologia,Rome,Italy

The architecture of sub-volcanicmagma supplysystemsexertsafundamentalcontroloneruptivebehaviour and thus on volcanic hazards. Theisland of Bali in the Sunda arc, Indonesia, isdensely populated and home to two activestratovolcanoes,AgungandBatur,butrelativelylittle is known of their underlying magmaplumbing systems.Herewe reconstructmagmastorage and evolution under Bali by employingclinopyroxene and plagioclase mineral-meltequilibrium thermobarometry, oxygen isotopecrystalstratigraphy,andHeisotopesinpyroxene.Clinopyroxene records magma storage at thecrust-mantle boundary, consistentwithmantle-like He isotope pyroxene values and mildlysubmantle δ18O values. Plagioclase, in turn,revealsuppercrustalmagmastorageandmantle-like δ18O values, indicating differentiation ofascending primary magma in upper crustalreservoirs. Indeed, recent arc-wide InSAR datafortheSundaarcrevealedfrequentshallow-levelmagma storage along the arc, which contrasts

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traditional petrogenetic models for arcs. Multi-level magma storage likely favours prolongeddifferentiationofSundaarcmagmas,whichcouldpromotefuturehazardouseruptionsonBali.

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Dykeinducedquasi-2DdeformationinaCoulombbrittehost—theinfluenceofhoststrengthonpropagationandemplacement

FrankGuldstrand1,OlivierGalland1,AlbanSouche1,HåvardSvanesBertelsen1andAlainZanella21PhysicsofGeologicalProcesses,UniversityofOslo,2L.P.G-LeMans,LeMansUniversité

TheemplacementofmagmaticdykeswithintheEarth'scrustrepresentsafundamentalprocessofmagma transport and feeding of volcaniceruptions.Understandingthedykeemplacementmechanismrequiresanunderstandingofhowthehost deforms to accommodate the dykepropagation andgrowth.Most establisheddykeemplacement models solely account for tensileopening of an elastic host, whereas the Earth'scrust alsoexhibitsprominent inelasticCoulombbrittle behavior. In this study, we aim toencompasshowbrittledeformationaffectsdykeemplacement in cohesive Mohr-Coulombmaterial.

We present quantitative experimental resultsobtained from a quasi-2D experimental setup(Hele-Shaw cell type), which consists of twovertical glassplates (3 cmgap) containing fine-grained dry Coulomb mixes of silica flour andglassbeadswithvaryingcohesions.Goldensyrupisslowlyinjectedintothesilicaflourviaabottominletataconstantflowratefor~1hour.Whilethequasi-2D setup restricts the injected syrup to a"sheet-like" intrusion, it allows directobservationofthehostdeformationsuchthatwecan measure displacement maps, shear strains,and surface deformations accommodating dykeemplacementfromstrongtoweakhostrocks.

Tofurtherinterpretourexperimentaldatasetweattempt a numerical comparison using a staticelastoplastic2Dcodetoinvestigatetheexpectedelasticandplasticdeformationusingtheimposedexperimental intrusion geometry and host rockproperties.

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GrounddeformationintheBárðarbungaVolcanicSystem,Iceland,Followingthe2014-2015LateralDyke,CalderaCollapseandMajorEffusiveEruption

SiqiLi1,FreysteinnSigmundsson1,VincentDrouin1,BenediktG.Ófeigsson2andMichelleParks21NordicVolcanologicalCenter,InstituteofEarthSciences,UniversityofIceland,101Reykjavik,2IcelandicMeteorologicalOffice,150Reykjavik,Iceland.

The largest instrumentally recorded grounddeformation event in Iceland occurred during2014-2015 within the Bárðarbunga volcanicsystem. A 48-km-long lateral dyke propagatedaway from the caldera, followed by six-month-longeffusiveeruptionatthefarendofthedyke,while the Bárðarbunga caldera graduallycollapsedby65meters(Sigmundssonetal.2015,Gudmundsson et al. 2016). We study grounddeformation in the volcanic system after theseevents, in order to provide an improvedunderstanding of the deformation that followsthe events, and distinguish signals induced byvisco-elastic responses from those related torenewedmeltsupply.

We observe ground deformation usingInterferometric analysis of Synthetic ApertureRadar (InSAR) and GPS geodesy. Two yearinterferograms (2015-2017) from Sentinel-1satellites are created to observe the overalldeformation field. Interferogram stacking isimplemented to reduce atmospheric noise.Observed deformation is a superpostion ofseveral sources, including glacial isostaticadjustment and steady platemovements. These

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effects are subtracted from the observations(Drouin et al., 2017) to reveal excessivedisplacement rates we attribute to post-riftingrelaxation inthedykearea.Themovementsareattributedtovisco-elasticresponseoftheEarth,whichresultsingradualrecoveryoftheareaandhigher displacement rate after eruption events.Thepost-riftingrelaxationismodelledbyatwo-layer model with elastic crust and visco-elasticuppermantle.

In the caldera area, a similar studywill help tounderstand if present inflation and earthquakeactivity at Bárðarbunga is induced by magmainflow or is a visoelastic response to the largedeflationin2014-2015.

ORAL

Syn-emplacementfracturingintheSandfelllaccolith,easternIceland

TobiasMattsson1,SteffiBurchardt1,BjarneS.G.Almqvist1andErikaRonchin11DepartmentofEarthSciences,UppsalaUniversity,Villavägen16,SE75236,Uppsala,Sweden

Felsic magma commonly pools withinmushroom-shaped magma chambers, so-calledlaccoliths or cryptodomes at shallow crustallevels,which can cause collapse of the volcanicedifice.Whiledeformationofmagmainvolcanicconduits is an important process for regulatingeruptivebehaviour(Pistoneetal.,2016),thebulkof the deformation associated with laccolithemplacementisconsideredtooccurinthehost-rock(Pollard&Johnson,1973),andtheeffectsofmagma deformation on the intrusionemplacement is largely unexplored. Here wedescribe the deformation associated with theemplacement of the 0.5 km3 rhyolitic Sandfelllaccolith in eastern Iceland, which formed in asingle intrusive event. By combining fieldmeasurements, 3D modelling, anisotropy ofmagnetic susceptibility, and microstructuralanalysis,wequantifydeformationthatoccurredin both the host-rock and the magma toinvestigate its effect on intrusion emplacement.Magmatic and magnetic fabric analyses reveal

contact-parallel magma flow during the initialstages of intrusion emplacement. The magmaflow fabric is overprinted by strain-localisationbands, which indicate that the magmasubsequently became viscously stalled andwasdeformed by consecutively intruding magma.Thischangeinmagmarheologycanbeattributedtotheinteractionbetweenthestrain-localisationbands and the flow bands, which causedextensivefracture-rich layers inthemagmaandled to decompression degassing, crystallization,and rapid solidification of half of themagmaticbody. Our observations indicate that syn-emplacement rheology change, and associatedfracturingof intrudingmagmanotonlyoccurinvolcanicconduits,butalsoplayamajorroleintheemplacement of shallow viscous magmaintrusions.

ORAL

Howdosillsbecomelaccoliths?Ananswerfromintegratedlaboratoryandnumericalmodelling

TobiasSchmiedel1,OlivierGalland1,ØysteinT.Haug1andChristophBreitkreuz21PhysicsofGeologicalProcesses(PGP),DepartmentofGeosciences,UniversityofOslo,Norway,2GeologicalInstitute,TechnicalUniversityBergakademieFreiberg,Germany

Igneous intrusions in the upper brittle crustexhibitdiverse shapes ranging from thin sheets(dykes, sills, cone sheets), to thick, massiveintrusions (laccoliths,plutons,plugs).Presently,none of the established models of magmaemplacementhavethecapabilitytosimulatethisdiversitybecause theyaccount forendmemberrheology of the host rocks (elastic, viscous orplastic), whereas natural rocks are complexelasto-plastic materials. We investigated theeffects of host rock rheology on magmaemplacement using scaled laboratory models.The model rocks were dry Coulomb granularmaterials of variable strength (cohesion). Weshow that strong (high-cohesion) host rock,results in the emplacement of thin, sheetintrusions (sills, cone sheets). Conversely,weak

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(low-cohesion) host rock results in theemplacement of massive intrusions (laccoliths,plugs).Weintegrateour laboratoryresultswithnumericalsimulationstoconstrainthehostrockdeformation mechanism that accommodatesmagma emplacement in the experiments. Ourresultsshowhowbothsillsandlaccolithsresultfrom initial thin sills that spread horizontallyuntiltriggeringshearfailureoftheoverburdenatacriticalradius.Twoscenarioscanthenhappen:(1)theoverburdeniscohesiveenoughandallowsspaceopeninginthesub-surfacetoaccommodateviscousmagmainflowalongthefailureplanes,sosills evolve as sheets (saucer shape or conesheets), or (2) the overburden is not cohesiveenough and does not allow sub-surface spaceopening toaccommodateviscousmagma inflowalong the failure planes, so the sill inflates andliftsuptheoverburdenalongshearzonestoformamassivelaccolith.

ORAL

StructureanddynamicsoftheKraflamagmadomainanditsassociatedgeothermalarea:GrounddeformationandmagmaplumbingattheKraflaMagmaTestbed,Iceland

FreysteinnSigmundsson1,VincentDrouin1,PallEinarsson1,KnuturArnason2,GylfiPallHersir2,LéaLevy3,ElíasRafnHeimisson4,ErikSturkell5,AnetteK.Mortensen6andJohnEichelberger71NordicVolcanologicalCenter(Nordvulk),InstituteofEarthSciences,UniversityofIceland,Iceland,2ÍSOR–IcelandGeoSurvey,Reykjavík,Iceland,3Nordvulk,ÍSORandEcoleNormaleSupérieure,Paris,4StanfordUniversity,California,USA,5UniversityofGothenburg,Gothenburg,Sweden,6Landsvirkjun,Reykjavík,Iceland,7UniversityofAlaskaFairbanks,USA

WeinterpretextensivevolcanogeodesyresultsatKrafla volcano, Iceland, together with resultsfrom various other observations, includinggeophysicalsurveyinganddrilling.Thecombineddataisinterpretedintermsofamagmadomainmodel, which we consider to represent thecrustalvolumehostingmagmaatashallowlevel.

Itmaybeofvariablesizeandshape,containingvariable amounts ofmagma,melts and crystalsand comprising magma bodies with variableconnectivity. At Krafla caldera, multipleconstraints can be applied, including directconstraintsfromaccidentaldrillingintorhyoliticmagmaat2.1kmdepth.Weinterpretthedatainterms of at least twomagma bodies at shallowdepth:(i)abasalticmagmabodywithapressurecenternearthecenteroftheKraflacalderainthe3-5 km depth range, contributing to S-waveshadowsandinfluencingseismicpropagation,aswell as being responsible for aninflation/deflationpatternduringthe1975-1984Kraflariftingepisode,and(ii)ashallowerbodyofrhyoliticmagmawithanuppersurfaceat2.1kmdepthunderlyingahigh-temperaturegeothermalarea. This rhyolitic body was inactive during1975-1984, but also contributes to S-waveshadows. It has been drilled close to or intomultipletimesandisresponsibleforsuperheatedsteam near the bottom of several geothermalwells. Future advance in our understandingvolcano interiors is expected from the KraflaMagma Testbed initiative (http://kmt.is); aninternationalefforttoestablishanin-situmagmalaboratory at Krafla, including drilling again tomagma and coring of the magma-geothermalinterface.

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Impactofhostrockheterogeneityonfailuremechanismaroundmagmaticintrusions

AlbanSouche1,OlivierGalland1andØysteinT.Haug11PhysicsofGeologicalProcesses,GeosciencesDepartment,UniversityofOslo,Norway

Rock failure mechanism accommodating theemplacement of magmatic intrusions isdominantlycontrolledbythelocalstressregimewithin the host rock. Most of the mechanicalmodels addressing rock failure conditions (e.g.,for a given tectonic regime or magmaoverpressure) simplify the stress calculationby

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assuming the homogeneity of the host rockproperties.

Inthisstudy,wehighlighttheimportanceoflocalheterogeneity in controlling the failuremechanism ahead of amagmatic intrusion. Theheterogeneity is introduced by mean of astochastic perturbation with given wave-lengthand amplitude on the host rock cohesion.Wenumericallymodelandquantifytheelasto-plasticdeformation of the system in response to theoverpressurizationofanintrusion.Dependingonthe characteristics of the heterogeneity, weobserve the development of plastic zonesrepresentative of either tensile or shear failure.We show that shear failure is the dominantmechanism as soon as heterogeneities areintroduced, even for relatively large dilatancyproperty of the host rock (up to the limit ofassociative plasticity). We conclude thatheterogeneitieswithinthehostrockmaylocally"seed" shear faults ahead of the magmaticintrusioninthepropagatingdirection.Wefurtherillustrate the implications of these results byconsidering the emplacement of a dyke in anextensionalsetting(Icelandiccase)andshowthatshear failuremay be a dominantmechanism inpre-eruptiveseismicactivityconsequenttodykeemplacement, in good agreement with seismicdatamonitoredduringrecentmagmaticevents.

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Theeffectofthehost-rockrheologyondykepropagationenergybalance:anumericalmodellingstudy.

RémiVachon1andChristophHieronymus11UppsalaUniversity

Propagation of magmatic intrusions such asdykesandsillsisanessentialfactorthatcontrolsvolcano dynamics. It has been shown that anintrusion,orafractureingeneral,willpropagatewhen G, the energy released due to crackextension, exceedsa critical energy release ratevalueGc,whichisconsideredamaterialpropertyof the host-rock. Estimates of Gc fromobservations of dyke length and aperture are

generallyaround100kJ/m^2forcompetentrock,whereaslabmeasurementsonsimilarrocksyieldestimatesGcwhicharesignificantlylower.

Inordertounderstandthediscrepancybetweenin-situandlabmeasurementsofGc,wetesthost-rock rheologies that aremore realistic than thecommonly used linear elastic theory.Theserheologiestakeadditionalprocessesintoaccountwhich affect the Griffith energy balance of agrowing crack, suchas: (1)pressuredependentelasticitywithreducedmoduliinregionsoflow-pressure,(2)plasticfailurewhereshearstressesexceedacriticalyieldstress,and(3)viscousflowaffectingthehostrockduringthecoolingphaseofthemagmaticintrusion.Totestthesehypotheses,we construct three numerical models, eachtestingoneofthehost-rockrheologiesdescribedabove.

Our results show that the most significantchanges to the Griffith energy balance areobtained from theelasto-plasticmodelwhereGvalues are almost 100 time lower than resultsfromthelinearelasticsolution.Wethusfindthatlarge-scale fracturing, which we model asplasticity,canresolvethelong-standingproblemof disparate critical energy release rate Gcobtainedbydifferentmeans.

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Anewmodelforsaucer-shapedintrusions:shearfailureversustensileopeningatsilltips

ØysteinHaug1,OlivierGalland1,PaulineSouloumiac2,AlbanSouche1,FrankGuldstrand1andTobiasSchmiedel11PGP,UniversityofOslo,2GéosciencesetEnvironnementCergy(GEC),UniversitédeCergy-Pontoise,France

Sills with a characteristic saucer shape arecommon features in many sedimentary basinsworldwide.Previousmodelsofsillemplacementusually assume that pure elastic bending of theoverburden of growing sills control theirevolution to saucer shape. However, fieldobservationsshowthatsignificantsheardamage

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also accommodate sill emplacement. To whichextent such damage plays an active role on sillemplacement or not is not understood. Toaddress this, we study the condition for shearfailure and the distribution of damage in theoverburden of sills using the limit analysissoftwareOptumG2.Throughaparameterstudy,we investigate the effect of the length-to-depthratio (L/D) of the sill, the cohesion of the hostrock and the emplacement depth on the over-pressure within the sill at failure. The resultsshow that the characteristic saucer shape isubiquitously reproduced using this approach(Haug et al, 2017). The over-pressure requiredfor shear failure scales linearly with the hostcohesionandasapower-lawofL/D.Fromtheseobservations,weproposeascalinglawforanewshearfailurecriterionintheoverburdenofasill.We compare our scaling law to an analyticalsolutionofhydrofractures,andshowthattensiletip propagation is favored for small sills, butoverburdenshearfailuremaybecomefavorableforlargesills.Fromtheseresults,wesuggestthatsillsinitiallygrowlaterallybytensilepropagationuntilreachingacriticalL*,whentheoverburdenfails in shear, leading to the emplacement ofsaucer-shapedsill’sinclinedsheets.

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THESEILANDIGNEOUSPROVINCE:IMAGINGAWELLPRESERVEDEDIACARANDEEPSEATEDMAGMATICSYSTEMBY3DGRAVITYANDMAGNETICMODELLING

ZeudiaPastore1,ChristineFichler1andSuzanneMcEnroe11DepartmentofGeoscienceandPetroleumattheNorwegianUniversityofScienceandTechnology(NTNU)

TheEdiacaranSeilandIgneousProvince(SIP) isthe largest complex of mafic and ultramaficintrusionsinnorthernFennoscandia,andoneofthefewexamplesintheworldofawellpreserveddeep-seated magmatic plumbing system. Theintrusive rocks of the SIP cause a prominent

gravity anomaly. A model for the subsurfacestructure of the SIP has been constructed byforward modelling of 3D gravity and magneticdatausingdensityandmagneticattributesfromtheoutcrops.

There aremultiple roots, two of which reach adepth of 9 km. The annular distribution of theroots suggests that this is close to the originalgeometry, which, despite the complexgeodynamic history, has been preserved.Therefore,theKalaknappeunithostingtheSIP,may not have experienced a strong tectonicreworking.

Forwardmagneticmodellingof theSIPallowedfor estimating the geometry and themagnetization of the magnetic sources. Thisindicatesthatmostofthesourcesofthemagneticanomaliesarerelatedtogabbroicbodies,andtoalesser extent to the contacts of the ultramaficintrusions with the country rock, possiblyindicating these contacts have some degree ofserpentinization,ormineralization.Basedonthecombined results of 3D gravity and magneticmodelling we suggest that the SIP is weaklymagneticatdepth.Furthermore,thedepthsofthenumerousmafic and ultramafic complexes varygeographically within the SIP. A low angledetachment fault dipping towards the northtruncating the deeper part of the SIP wouldexplaintheseobservations.

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Rockmagneticpropertiesandmagneticcarriersofadeepcrustalmagmaticsystem,theReinfjordUltramaficComplex,SeilandIgneousProvince,NorthernNorway

GeertjeW.terMaat1,SuzanneMcEnroe1,NathanChurch1,ZeudiaPastore1,AlexanderMichels1,HirokuniOda2andRuneLarsen11NorwegianUniversityofScienceandTechnology,2Geol.Surv.Japan,AIST,Tsukuba,Japan

TheReinfjordUltramaficComplex(RUC) ispartofthe5000km2SeilandIgneousProvince(SIP)in

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northernNorway.TheSIP is considered tobeadeep-seated conduit system of a large igneousprovince.TheSIPwasemplacedintocontinentalcrustat25-30kmdepthat570-560Ma.TheRUCintruded into gabbros and meta-sedimentarygneissesresultinginthreeformations.1)CentralSeries consisting of dunites; 2) Upper LayeredSeriesconsistingofdunitesandwehrlites,and3)Lower Layered Series containing the mostpyroxene-rich rocks, with an associated butmineralogically distinctmarginal zone resultingfrom contact metamorphism of the melts andhostrocks.Exposuresofdeepultramaficsystemsarerare,andRUCgivesauniqueopportunitytostudy themagnetic properties of the roots of adeepseatedmagmaticsystem.

The rock magnetic properties of the differentformationsgiveinsightinthemagneticcarriers,and can be associated to primary (spinel, andexsolutioninpyroxene),orsecondaryprocesses,such as serpentinization. Scanning SQUIDmicroscopy of thin sections combined withoptical and electronmicroscopy indicate whichminerals carry themagnetization, that then canbe linked to the rock magnetic properties.Characterizing the primary, and secondary,magnetic carriers, allows for assessing thecontribution of bodies such as the RUC tomagnetic signals from deep crustal rocks.Understanding the nature of the magneticpropertiesofdeepultramaficrocksnowexposedattheEarth’ssurfacewillaidintheinterpretationof ground-, aeromagnetic, and satellite surveysandpaleomagnetism.

1.8.BuildingBaltica

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Fennoscandia,SarmatiaandVolgo-Uralia:thebuildingstonesoftheEastEuropeanCraton/Baltica

SvetlanaBogdanova11DepartmentofGeology,LundUniversity,Sweden

The three lithosphere segments Fennoscandia,Sarmatia and Volgo-Uralia (Fig.), whichconstitute the East European Craton (Baltica),have each specific crustal architecture andevolution (Bogdanova, 1993; Gorbatschev &Bogdanova,1993;Bogdanovaetal.2008).WhileVolgo-Uralia is nearly all Archean, butcomplicated by thorough Paleoproterozoicreworking,FennoscandiaisArcheaninthenorth-east but Proterozoic in the south-west, whileSarmatia features several separate Archeanblocks cemented by Archean andPaleoproterozoiccollisionalbelts.Thesegmentsareseparatedbythemajorca.2.1GaVolga-Donandca.1.8GaCentralRussianPaleoproterozoiccollisional belts followed by Meso- toNeoproterozoicaulacogens.

Balticawasbuiltupduringnumerouscollisionalandaccretionaryorogenies,andalsobreakups(inGa):

• 2.8-2.7: most Archean blocks amalgamatedforming the protocratons of Fennoscandiaand Volgo-Uralia but still separated byoceansinSarmatia

• 2.5-2.4:firstrecordsofprotocratonbreakup(FennoscandiaandVolgo-Uralia)

• 2.4-2.0: continuing breakup of ArcheanFennoscandia when several small oceanswereopened

• 2.1-2.0: the Sarmatian and Volgo-UralianArchean blocks collided formingmegacontinentVolgo-Sarmatia

• 2.0-1.95:thecombinedNWmarginofVolgo-Sarmatia became the site of a widecontinental magmatic arc facing an ocean;

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strong deformation of Volgo-Uralia ‘s crustanduppermantle

• 1.94-1.90: the Lapland-Kola collisionencompassedArcheanFennoscandia

• 1.93-1.83: the Svecofennian accretionaryorogeny at SSW edge of the Karelianprotocraton

• 1.80-1.75: collision of Fennoscandia andVolgo-Sarmatia;Balticawascreated1.7-1.5:Gothian and Telemarkian accretion at thewesternBalticamargin

• 1.55-1.40: the Danopolonian (in partHallandian)intracontinentalorogeny

• 1.35-1.25: intracontinentalmaficmagmatism

• 1.0-0.9:Sveconorwegiancollisionalorogeny;BalticaparticipateinRodiniasupercontinent

ORAL

TraceelementgeochemistryandSm-Ndisotopesof2.1GamaficmagmatismintheKarelia-Kola,WyomingandSuperiorcratons

SarahDavey1,WouterBleeker2,SandraKamo3,RichardErnst4andBrianCousens11CarletonUniversity,Canada,2GeologicalSurveyofCanada,3JackSatterlyLaboratory,UniversityofToronto,Canada,4CarletonUniversity,Canada,TomskStateUniversity,Russia

TheKarelia-Kola,Wyoming,andSuperiorcratonsare proposed “nearest-neighbours” within theSuperiasupercratonreconstruction(BleekerandErnst, 2006). At 2.1 Ga, their kinship is bestconstrained by matching paleolatitudes in theMarathon (Superior) and Bear Mountain(Wyoming) mafic dyke swarms, and overallsimilarapparentpolarwanderpaths(Hallsetal.,2008; Kilian et al., 2015). Although Karelia’spositionwithinSuperiaisnotaswellconstrainedbypaleomagneticdata,itishypothesizedtohavebeen positioned at the southeast margin ofSuperiorbasedontheoverallcorrelationofmaficmagmaticevents(“magmaticbarcodes”)andthegeometry of associated giant dyke swarms,including the2.1GaTohmajärvidykesandMisi

gabbro sills (Pekkarinen and Lukarinen, 1991;Niiranen et al., 2003; Bleeker and Ernst, 2006;Salminenetal.,2014,Daveyetal.,2017).Hereweusewhole-rockandtraceelementgeochemistryand Sm-Nd isotopes to test whether Marathon(Superior), Bear Mountain (Wyoming) andTohmajärvi dykes and Misi sills (Karelia) weregenerated under similar conditions and from acommon source. Halls et al. (2008) report atransition from enriched to flat trace elementpatternsthroughtimebetween2125to2100Main the Marathon dykes. This geochemicalprogressionprovidesanancillarymeansinwhichto compare contemporaneous dyke swarmsfoundinothercratons.IftheBearMountainandTohmajärvidykesandMisisillswerefedbythesame magmatic pulses as the Marathon dykes,then the same secular changes in geochemistryshould be observed, in addition to sharingcomparable paleolatitudes, geometry, andgeochronology.

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Polyphase,transpressivedeformationoftheArcheanSiilinjärvicarbonatitecomplex,centralFinland

KarinHögdahl1,BjarneS.G.Almqvist2,FredrikKarell3,PietariSkyttä4,AleksiSalo5,AlirezaMalehmir2andPasiHeino51Dept.ofEarthSciences,UppsalaUniversityandGeologyandMineralogy,ÅboAkademiUniversity,2Dept.ofEarthSciences,UppsalaUniversity,3GeologicalSurveyofFinland,4Dept.ofGeographyandGeology,TurkuUniversity,5YaraSuomiLtd

The2.6GaSiilinjärvicarbonatitecomplexisoneof few known Archean carbonatites and theoldestcurrentlybeingmined.The16x1.5kmN-Strendingcurvedandtabularcomplexcomprisesdominatly glimmerite with subordinatecarbonatite,enclosedwithinafenitehalo,allcutbythreegenerationsofmaficdykes.Thecomplexhas been affected by polyphase deformation,including emplacement of the dykes and theirsubsequent structural overprint. Strain isheterogeneously distributed with the higheststrain localised into the glimmerite and the

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contactsofmorecompetentrocksrepresentedbyfenite blocks, mafic dykes, and glimmeritehosting richterite and carbonates. Therelationship between dyke emplacement anddeformation has been obtained using acombination of structural data and magneticfabricmeasurements.Theolderdykesaremainlysteep,N-StoNW-SEtrending,paralleltoboththeoverall structural grain and the magneticfoliation,andnarrowdykesarecharacterisedbyboudinage observed in both steep and sub-horizontal sections. Streching lineations withinand along the margins of these dykes are sub-vertical and coincides with the magneticlineation. Shear zones at dyke margins andelsewhere in the complex show dextralhorizontal shear with a W-block-up verticalcomponent. Later conjugate NNW-SSE dextralandNNE-SSWsinistralzonesarelikelyrelatedtofolding of the youngest dyke generation. Theconsistency between structural and magneticfabric measurements indicate two episodes ofdextral transpressive shear separated by anextensionaleventrelatedtoemplacementoftheyoungestdykegeneration.

This is an ERA-MINStartGeoDelineationcontribution sponsoredbyVinnova, SGU,Tekes,NIOandYara.

ORAL

BuildingorbreakingBaltica–theSvecofennian’intraorogenic’Herrängdykeswarm,east-centralSweden

ÅkeJohansson11DepartmentofGeosciences,SwedishMuseumofNaturalHistory,Box50007,10405Stockholm,SWEDEN

The mafic Herräng dykes are found in theRoslagen coastal area of east-central Sweden,where they intrude early Svecofennianmetavolcanicsandgranitoids(ca.1.87-1.91Ga),butarethemselvescutby late-topost-orogenicpegmatites andmetamorphosed to greenschist-or amphibolite-grade. This dominantly E-W-trendingdykeswarmhasthustraditionallybeen

referredtoas‘intraorogenic’withrespecttotheSvecofennianorogeny,e.g.byStålhös(1991).

Inthepresentstudy,twentyonesamplesofmaficdykeshavebeenobtainedfromtheHerrängtypearea (Magnusson 1940), from the area aroundlake Limnaren south of Norrtälje (Lundegårdh1946), and the islets Fogdö and RiddarskäretbetweenVäddöandSingö(Lundqvist1959).Thesampled rocks are dominantly composed ofplagioclase and amphibole (presumablyhornblende), with variable amounts of quartzandbiotite,andaccessorytitanite,apatite,zirconand opaque minerals. A couple of samples,however, have deviating mineralogy andgeochemistry.

Geochemically, the sampled dykes aresubalkalinebasaltstoandesites,with48-60wt%SiO2. They have variable character on differentdiscrimination diagrams: calc-alkaline ortholeiitic; MORB, volcanic arc or within-plate,possibly reflecting theiroriginduringextension(perhaps incipient back-arc spreading) ofjuvenilesubduction-relatedcontinentalcrust.

InitialEpsilon-Nd(at1.87Ga)fallsbetween-0.1and+1.6, and initialEpsilon-Srbetween+5and+24,suggestingasimilar‘mildlydepleted’mantlesource as for other Svecofennian mafic rocks.Spot analysis of eleven titanite grains fromonesampleyieldsaweightedaverage207Pb/206Pbageof1848±13Ma,interpretedtodateamphibolite-grade metamorphism, and yielding a minimumageofcrystallization.

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High-Nbandadakite-like1.86GamagmatisminsouthernFinland

JaakkoKara1,MarkkuVäisänen1,HughO'Brien2andYannLahaye21DepartmentofGeographyandGeology,UniversityofTurku,2GeologicalSurveyofFinland

Mafictointermediatec.1.86Gamagmatismhasbeen discovered within the boundary areabetween central and southern Svecofennia in

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southern Finland (Kara et al. 2016). ThemagmatismoccursasNW-SEtrendingdykesandsmallintrusionswhichcrosscutthesurroundingmigmatiticcountryrocks.Themagmatismcanbedivided into three different varieties based ontheirgeochemicalandisotopiccharacteristics:i)high niobium basaltic dykes (HNB), ii) highmagnesium basaltic dykes (HMB) and iii) highsilicaadakite-likerocks(HSA).

The HNB are alkalic and enriched in HFSE,particularlyNb(>20ppm)andshowhighLREE,P2O5, TiO2 and F contents. In-situ zircon Hf-analysesshowveryhighaverageinitialεHfvalueof c. +10. TheHMB exhibit highMgO (up to 12wt%) and Cr concentrations and show highaverage initial εHf values of c. +3 and +5 (twodykes).TheHSAgroupisenrichedinSrandLREEanddepletedinY(<20ppm)andYb(mostly<1.9ppm) among the other high silica adakitecharacteristic signatures (Martin et al. 2005).Two HSA-intrusions exhibit average initial εHfvalueofzeroandc.-3.

Theagesaswellasgeochemicalandisotopedataare clearly different from the adjacent, c. 1.90-1.88 Ga, arc-related igneous rocks suggesting adifferentkindofpetrogenesis for these twoagegroups. The similar ages and close spatialoccurrences support a genetic linkbetween the1.86 Ga groups. However, separate sources arelikely due to differences in geochemistry andisotopesignatures.

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PaleoproterozoicInarioroclineofnorthernFennoscandia:progressiveorsecondaryorocline

RaimoLahtinen1,MohammadSayab1andStephenJohnston21GeologicalSurveyofFinland,2UniversityofAlberta,Canada

Oroclinesarecurvaturesofpreviouslylineararcs(orbelts), andaredivided into twomain types:progressive and secondary (Johnston et al.,2013).Progressiveoroclinesareformedbystrain

heterogeneity experienced during progressivethin-skinned thrusting: a common feature ofmodernorogens.Secondaryoroclinesareformedinresponsetoanorogen-parallelshortening,aswitnessedbyPaleoproterozoiccoupledBothnianoroclinesofFennoscandia(Lahtinenetal.,2014).ThemaincomponentoftheInarioroclineistheLapland granulite belt (LGB) having an arcuateshape geometry in the northern Fennoscandia.Recent studies of Tuisku and co-workers (e.g.,Tuiskuetal.,2006;2012;cf.Cagnardetal.,2011)provide a solid base for the age and tectono-metamorphic history of the belt. Based on theexistingstudies,new fieldandagedata,andre-interpretationsof geophysical data,weproposefollowingstagesfortheevolutionoftheLGB:1)extensionandintrusionofenderbitesatca.1.92Ga in a linear rift basin; 2) thrusting andrecumbentfoldingduringbasininversionat1.92-1.91Galeadingtopeakmetamorphicconditions;3) intrusion of post-collisional appinites at ca.1905 Ma; 4) extension and decompressionmeltingat1.90-1.88Ga;5)renewedshorteningofthe linear orogen at 1.88-1.87 Ga that lead toupright folding and SW vergent thrusting; 5)orogen-parallel shortening at ≤1.87 Ga. Ourpreliminary interpretation is that the Inariorocline, including the LGB, is a secondaryoroclineformedduringbucklingaboutaverticalaxisofrotation.

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NewpaleomagneticandisotopicdatafortheLatePaleoproterozoicmaficintrusionsintheBlekingeProvince(southeasternSweden)

NataliaLubnina1,SvetlanaBogdanova2andUlfSöderlund21FacultyofGeology,M.V.LomonosovMoscowStateUniversity,Russia,2DepartmentofGeology,LundUniversity,Sweden

To the east of the Sveconorwegian orogen, thePrecambrian bedrock in Blekingecontainsgranitoids of the TransscandinavianIgneousBelttothenorthoftheSmåland-Blekinge

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Deformation Zone (SBDZ), and the c. 1.76 GaTving granitoids in the south (Johansson et al.2006). In this study, we have investigated themaficintrusionscuttingtheTvinggranitoids.

ThenewpaleomagneticandAMSexaminationsofthe Tving granitoids in eastern Blekinge showNW-striking foliation parallel to the SBDZ. Thestudied mafic intrusions carry a stablecomponent with shallow downward NNWdirection. The primary remanence is supportedby positive contact tests. New isotopic data forolivine gabbro andmetabasic rocks using U-PbbaddeleyiteandAr-Aramphibolegeochronologysuggestedaprotolithageofca1760Mafortheserocks. The mean paleopole for these maficintrusionsfromBlekingethuscorrespondstothec.1.76GapoleforFennoscandia.

IntheentireBlekinge,AMSlineationsmainlydipNW. The NNE upward overprint component isfoundintheTvinggranitoidsneartheKarlskronaDeformationzone,thatisclosetothatinthe1.45GaKarlshamngranites,probablyduetoregionalheating and deformation of the Blekinge block(Čečys & Benn 2007). AMS and structural dataindicate that the magnetic fabrics of the maficintrusionsarecontinuousand themetamorphicfabricsinthecountryrockswereformedduringENE–WSWcompression, andcanbe referred tothe Danopolonian orogeny. The newpaleomagnetic pole is close to 1.45 Ga pole forBaltica(Lubninaetal.2010).

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EarlyPaleoproterozoicpaleogeographyofKarelianandSuperiorCratons:newpaleomagneticandAMSdatafrom2.45-2.1GamaficintrusionsofCentralKarelianandKiantaterranes

NataliaLubnina1,AlexandraStepanova2,NikolayTarasov1andGrigoryNazarov11DepartmentofDynamicGeology,M.V.LomonosovMoscowStateUniversity,Russia,2InstituteofGeologyKarRCRAS,Petrozavodsk,Russia

WepresentanewpaleomagneticandAnisotropyof magnetic susceptibility (AMS) data from theEarlyPaleoproterozoicmaficdykesandArcheanhost rocks within two terranes of the KarelianCraton, eastern Fennoscandian Shield. Threegroups of dykes have been collected withinPyaozero area of Central Karelian terrane: NE-trending ca. 2450 Ma gabbronorite and dioritedykes,NW-trendingca.2310Madoleritedykes,and NNW-trending ca. 2130 Ma continentalMORB-type tholeiitic dykes (Stepanova et al.2014).AllthesedykesweretypifiedbasedontheAMSdata.Samplesfrom2130Madoleritedykeswithin Tulos area of Kianta terrane were alsocollected.

The paleomagnetic results show that a strongSvecofennian overprinting is pervasive in thearea.

All studied mafic dykes carried two stablecomponents. Most typical is component ofintermediatedown to theNNW,corresponds tothe Svecofennian remagnetisation (Mertanen1995). Component of SE intermediate downdirectionyieldingapaleomagneticpole2450Mabased on a positive baked contact test isinterpreted to represent the primarymagnetization.

The paleomagnetic results for dolerite dykewithin Tulos area show that a strongSvecofennian overprinting is pervasive in thearea,basedonanegativebakedcontacttest.

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The new paleomagnetic data from the KareliaCratoncomparedtosimilar-agedpaleomagneticdatafromtheSuperiorCratondoesnotsupportthe recently proposed Superia configuration(Bleeker&Ernst2006),basedupondykeswarmtrajectories.

We propose a new Early Paleoproterozoicpaleogeographyat2.45-2.1GafortheKareliaandSuperiorcraton.

This is a contribution to projects RFBR 17-05-01270.

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DevelopmentofthePaleoproterozoicSvecofennianorogeny,newconstraintsfromCentralFinland

PerttuMikkola1,EsaHeilimo1,JouniLuukas1andJukkaKousa11GeologicalSurveyofFinland

Significant amounts of new field and analyticaldata (whole-rock geochemistry, agedeterminations) were gathered by GeologicalSurveyofFinlandfromalittlestudiedareaalongthe southeast boundary of the Central FinlandGranitoid Complex (CFGC). As the area is theculmination point of several major geologicalunitsthisnewdataallowsrevaluationofpreviousinterpretations and correlations. The new datamostlyaffectsthefollowingaspects:

Units belonging to the older Svecofennianmagmatic phase (1.93–1.91 Ga) extend 100 kmfurthersoutheastastentativelysuggestedearlier.All of the paragneiss units in the area displaysimilardetritalzirconpatterns,defining~1.92Gaasthemaximumdepositionalageformostofthesamples.Theeruptiveultramaficunitsoccurringas interlayers in different paragneiss unitsdisplaydifferencesintraceelementpatterns.Butotherwise the earlier division of paragneissesmainly reflects differences in deformation andmetamorphichistory.The arc-type calc-alkalinemagmatism in thearea is similar in age (1895–1875Ma)andcompositiontothatoftheclassical

Tampere group 200 km further west. Thevoluminous granitoidmagmatism took place intwostages,atca.1895and1885–1875Ma.Thelatterphasecanbedividedintoseparateunitsoncompositionalbases,whichdisplaydistinctfieldrelationships,althoughtheobtainedagesoverlapwithinerrors.Thustheearlierdivisionintosyn-and post-kinematic units should be abandoned.Instead the units represent coeval magmasoriginating from different levels of the crust.Lowercrustmeltsroseonlylocallytothepresenterosionlevelviafavorablestructures.

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KinematicsanddeformationregimeoftheKynsikangasductileshearzone,SW-Finland.

SebastianReimers1,JonEngström2,JohannaBerckhan1andUlrichRiller11UniversityofHamburg,2GeologicalSurveyofFinland

TheNW-strikingKynsikangasShearZone (KSZ)is one of many prominent Paleoproterozoicductile shear zones in SW Finland that formedduringtheSvecofennianorogeny.TheKokemäkisegmentoftheKSZconsistsofanapproximately16kmlongand2kmwidecoreofhighlystrainedmetagranitoid and migmatite rocks displayingvariable mineral foliation (S) - lineation (L)geometry. Moreover, the core hosts abundantsmall-scale kinematic indicators, such as C-Sfabrics, rotated rigid objects and foldedmetamorphic layering. Besides unravelling thesignificance of major shear zones in theSvecofennian orogen, the KSZ allows us also toelucidate to what extent small-scale kinematicindicators are useful for identifying the overallsense-of-shear of ductile deformation zones ingeneral.Thecentralportionoftheshearzoneischaracterized by pronounced sub-horizontal Lfabrics, which merge along-strike of the shearzoneinbothdirectionsintoS>Lfabricgeometry.Eastofthefaultcore,thecurvatureinthestrikeof foliations, sub-horizontal mineral stretchinglineation and C-S fabric geometry point to astrongcomponentofleft-lateraldisplacement.By

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contrast, foliation pattern and moderately tosteeply plungingmineral lineationswest of thecore indicate dip-slip. Despite complex internalductileflow,evidentbythealong-strikevariationin S-L fabric geometry, the KSZ seems to haveaccommodatedastrongcomponentofleft-lateraltranspression.

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Long-livedLatePaleoproterozoictoMesoproterozoicconnectionofBalticaandLaurentia-apaleomagneticview

JohannaSalminen11PhysicsDepartment,P.O.Box64,00014UniversityofHelsinki,Finland

To understand processes occurring from theplanetary interior to thesurfaceenvironment,arobust paleogeography of tectonic plates isimportant. Paleomagnetism coupled withgeochronology is powerful quantitativemethodfor providing ancient latitudes and azimuthalorientations of continents. Mafic dykes areamenable for precise U-Pb dating and oftenpreserve a stable record of ancient magneticfields. Recently newhighquality paleomagneticandgeochronologicaldatafromMeoproterozoicmafic dykes in Southern Finland have beenproducedallowingreconstructionsofpositionofBaltica(Salminenetal.,2014;2016;2017).

There is a general agreement that Baltica andLaurentia form a tectonic "core" of theMesoproterozoic Nuna supercontinent in ageologically and paleomagnetically viableconnectionbetweenNorthernEuropeandNorthAmerica (NENA), where Baltica is in “upside-down” position relative to Laurentia (Gower etal., 1990; Salminen and Pesonen, 2004).However, contradicting reconstructions havebeenproposed(Hallsetal.,2011).WeshowthatnewhighqualityMesoproterozoicpaleomagneticdatawithnewgeochronologyresults forBalticasupport NENA connection. Those include datafrom1.64GaHäme,1.64GaSuomenniemi,1.58

GaÅland,and1.58GaSatakuntadykeswarmsinSouthernFinland.

Therotationaltransitiontoright-way-upBalticawithin Rodinia (e.g.Patchett et al., 1978; Piper,1980) isproposedtooccurredbetween1.12Gaand1.05Ga(Salminenetal.,2009;Evans,2009).Itagreeswithdistinctivepatternsoforogenesisand sedimentation around the common pivotpoint shared between Scoresby Sund, EastGreenland,andFinnmark,Norway(Cawoodetal.,2010;Evans,2013).

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PaleoproterozoicOsnitsk–Mikashevichi-MoscowIgneousBelt(OMMB):newgeochronologyandpetrologydatafortheRussiansegmentandtectonicimplication

AlexanderSamsonov1,SvetlanaBogdanova2,AlexanderPostnikov3,ViktorSpiridonov4,YuliaLarionova1andAlexanderLarionov51Instituteofgeologyoforedeposits,petrography,mineralogyandgeochemistryofRAS,MoscowRussia,2DepartmentofGeology,LundUniversity,Lund,Sweden,3DepartmentofLithology,GubkinStateUniversityofOilandGas,Moscow,Russia,4VNIIgeosystem,Moscow,Russia,5IsotopeResearchCentre,VSEGEI,StPetersburg,Russia

The OMMB is a large Paleoproterozoic north-east-trendingbelt inthecentralpartoftheEastEuropeanCraton(EEC).ItistracedfromUkrainethroughBelarustoCentralRussia(Bogdanovaetal., 2006, 2016). Themainpart of theOMMB iscoveredbyplatformsediments,thussamplingofthe belt is mostly provided by deep drill-holecores.Petrology,U-PbzircongeochronologyandSm-Nd isotope data for the Russian segment oftheOMMBwillbepresented.

Majorresultsarelistedasbelow:

1)IntheRussiansegment,theOMMBconsistsoftonalite, trondhjemite, granodiorites (TTG) andgraniteswith subordinate gabbros, diorites andmaficmetavolcanicrocks.

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2)Granites fromnorth-west flankof theOMMB(Vorob’evoandRoslavl’wells)yieldU-Pbzirconagesof1963–1970Mathatissomewhatyoungerthanthe2005–2028MaTTGandgranitesfromsouth-east flankof thebelt (Yasnogorsk,Kalugaand Vorotilovo holes) . The latter may havecausedhigh-Tlow-Pmetamorphiceventat2020–2036Ma,whichhasaffectedmetapelitesfromIngul-SevskandVolgo-DonorogensoftheVolgo-SarmatiablockneartheOMMBrocks(Bogdanovaetal.,2004;Savkoetal.,2017andourdata).

3) The OMMB TTG, granites and related maficigneous rocks have calc-alkaline affinities,subduction-related geochemical features andshowvariationofeNd(T)valuesfrom+2,5to-1,4where juvenile rocks with eNd(T)>0predominated.

4)AllthedatasuggestthattheOMMBwasformedin two stages, at 2.03 and 1.97 Ma along theAndean-typeactivemarginofVolgo-Sarmatia.

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1.86-1.79GamagmaticeventsinthewesternEastEuropeanCraton:fromsubductiontoback-arcsettings

GrazinaSkridlaite1,LaurynasSiliauskas1,AndriusRimsa2,MartinWhitehouse3,AkeJohansson3andSvetlanaBogdanova41InstituteofGeologyandGeography,NatureResearchCentre,Vilnius,Lithuania,2InstituteofGeosciences,VilniusUniversity,Vilnius,Lithuania,3SwedishMuseumofNaturalHistory,Stockholm,Sweden,4DepartmentofGeology,LundUniversity,Lund,Sweden

Remnants of a ca. 1.86-1.84 Ga continentalmarginwerefoundinsouthernpartof theMid-Lithuanian domain (MLD), the western EastEuropeanCraton(Bogdanovaetal.,2015),whilesomenewdata supports its continuation to theNW,towardscentralSweden.

The Randamonys gabbro-diorite-granodiorite-granite in southern Lithuania of calc-alkalineaffinity, metamorphosed in amphibolite facies,was emplaced between 1.86 and 1.84 Ga. Thesuite has volcanic-arc, and hence, subduction-

relatedcharacteristics.Ca.100kmtonorthwest,the ca. 1.85 Ga diorites metamorphosed ingranulitefaciesat1.80Ga(Skridlaiteetal.,2014)wereinterpretedasevidencingtheMLDmargincontinuationincentralLithuania.Anewca.1.85Ga SIMS age obtained from a felsic granulite(metatonalite) further west (in westernLithuania) confirms the extension of marginnorthwestwards.

Gabbro-norites which intruded into theRandamonys complex at 1.79 Ga are tholeiitic,havepositiveinitialεNd,hencejuvenile,mantled-derived characteristics. Some slightly older (ca.1.82-1.81Ga) fine-grained gabbro-noritewith avery primitive REE distribution and positiveinitialεNdresemblesoceaniccrust.

The1.86-1.84Gacontinentalmarginappears tocontinuethroughtheBalticSeaandmergewiththe 1.87–1.84 Ga Askersund-Loftahammarmagmatic belt along southern Bergslagen inSweden (cf. Stephens et al., 2009). Later, anAndean-typesubductioninthepresentwestwasresponsiblefortheformationofback-arcbasinsand1.79GamaficmagmatismintheMLD,coevalwith the intrusions of the 1.81–1.76 Ga TIB-1suite.Someremnantsofca.1.82-1.81Gaoceaniccrust completely reworked elsewhere may bepreservedintheseback-arcsettings.

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PaleoproterozoicmaficdykeswarmsinArcheanKola-MurmanskandKareliaprovinces,easternFennoscandia:barcodecomparisonandimplicationsforpaleocontinentalreconstructions

AlexandraStepanova1,AlexanderSamsonov2,EkaterinaSalnikova3,AndreyArzamastsev3,SvetlanaEgorova1,YuliaLarionova2,AlexanderLarionov4,KseniaErofeeva2andMariaStifeeva31InstitureofgeologyKarelianResearchCenterRAS,Petrozavodsk,Russia,2InstituteofGeologyofOreDeposits,Petrography,MineralogyandGeochemistryRAS,Moscow,Russia,3InstituteofPrecambrianGeologyandGeochronology,Saint-Petersburg,Russia,4CentreforIsotopicResearch,VSEGEI,Saint-Petersburg,Russia

EasternFennoscandiaconsistsofArcheanKola-MurmanskandKarelianprovinces,separatedbyca.1.98-1.85GaLapland-Kolaorogen(Dalyetal.,2006). New baddeleyite U-Pb (ID TIMS) andzircon(SIMS)ages,geochemicalandisotopicdatafor 2.65-1.86 Ga mafic dyke swarms in Kola-Murmansk province give insights into Lapland-KolaOceanlifespanandclarifyapositionofKola-MurmanskprovincewithinSuperiasupercraton(BleekerandErnst,2010).

Wide-spreadmaficmagmatismofage2650Maisrecognized in Murmansk domain. It is wellcorrelatedwith2640-2660MamagmaticeventinKeivy terrane, Kola domain (Bayanova, 2004).Mafic magmatism of this age in Karelia isunknown. It suggests strong differences in theNeoarchean history of Karelian and Kola-Murmanskprovinces.

NeverthelessbothKarelianandKola-Murmanskprovinces most likely belong to the Superiasupercraton as suggested by Bleeker and Ernst(2010). It supported by similarity in the eventssuccessionsince2500to2400Ma.

The noteworthy differences occur within theperiod2400-2060Ma.Maficdykesofsuchagedonot recognize in the Kola-Murmansk provinceyet.Incontrast,severalvoluminouseventsofageca.2310,2220and2140MaoccurintheKarelian

province (Stepanova et al., 2014, 2015, Vuollo,Huhma,2005).

Since 2060 Ma Karelian and Kola-Murmanskprovinces are similar in events succession andcompositionofmaficrocks.Sohugeca.1980Maevent widespread both in Kola-Murmansk andKarelianprovincesindicatesLapland-KolaOceanclosure.

The study is supported by RSF, grant 16-17-10260.

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MineralshapefabricanalysisoftheKynsikangasShearZone:Evidenceforatranspressiveorigin?

JohannaBerckhan1,JonEngström2,SebastianReimers1andUlrichRiller11UniversityofHamburg,Bundesstraße55,20146Hamburg,2GeologicalSurveyofFinland,Betonimiehenkuja4,FI-02151Espoo

The NW-SE trending PalaeoproterozoicKynsikangas Shear Zone (KSZ) is a prominentductileshearzoneintheSvecofennianOrogenofSW-Finland. The shear zone is located at theboundary between the Western Finland andSouthernFinlandSubprovinces.IntheKokemäkiarea, the KSZ formed under high-grademetamorphic conditions in migmatite andgneissicrocks.Theshearzoneisbelievedtohaveformedunderleft-lateralshear.Amorecomplexkinematic, possibly transpressive, origin of theshear zone, is evident from our analysis ofkilometer-scale pattern of metamorphicfoliations, maximum principal stretchingorientations and small-scale kinematicindicators. In order to elucidate the kinematicregimeofshearzoneformation,wequantifythegeometry and intensity of shape-preferredorientation (SPO) of metamorphic minerals.Therefore, oriented block samples from 50stationsarecutaccordingtotheprincipalplanesoffinitestrainandtheSPOofelongatemineralsandotherstrainmarkersarequantifiedbyimageanalysis. The results of this classical analysis of

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SPOwillbeusedtocalibratevisualestimatesoffabricintensityacrosstheKokemäkisegmentofthe KSZ and will be compared with moresophisticated3Dfabricanalysistechniques.

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ProvenanceofPaleoproterozoicclasticmetasedimentaryrocksinNorrbotten,northernSweden

AnnaLadenberger1,StefanBergman1,RistoKumpulainen2,GeorgeMorris1,FredrikHellström1,TonnyB.Thomsen3,EdwardP.Lynch1,StefanLuth1,SusanneGrigull1,MartiyaSadeghi1andHøgniVesturklett31GeologicalSurveyofSweden,Uppsala,Sweden,2StockholmUniversity,Stockholm,Sweden,3GeologicalSurveyofDenmarkandGreenland,Copenhagen,Denmark

Provenancezirconages(U-PbgeochronologybyLAICPMS)wereobtainedfromtwentysamplesofclastic metasedimentary rocks from severalsupracrustal units in Northern Norrbotten. Themajority belong to the Svecofennian sequences,withafewsamplesrepresentingstratigraphicallylowerKarelianunits.

TheKarelianrocksgenerallyhaveunimodalagedistributionswiththemainpeaksatc.2.7Maand2.55-2.60 Ga. The maximum depositional agevaryfromc.2.6-2.5GaforTjärroquartziteandasimilar quartzite collected in the Vakko Zone.Early Paleoproterozoic depositional ages(c.2.3Ga) occur in quartzite at Tärendo and inarkosic metasandstone from the Sockbergetgroup.

In the Svecofennian metasedimentary rocks,bimodal age distributions dominatewithmajorpeaks at Middle Paleoproterozoic andsubordinate ones at Archean. The oldest singleages are found in the Hauki quartzite(3742±19Ma), the Kiilavaara quartzite(3649±44Ma), the Stora Sjöfallet quartzite(3732±10 Ma) and in metasandstone from theRåneå group (3628±31 Ma). Maximum

depositional ages vary between 1.9 and 1.8 Ga.Ages as young as 1.75-1.8 Ga are reported,however, they may have been affected bymetamorphism, hydrothermal alteration orinaccuratecommonleadcorrections.

Thepresumedsourceoftheclasticsedimentsisgenerallythoughttobelocal.

TheobtainedgeochronologydatafromnorthernSweden, together with available detrital agesfromnorthernNorwayandFinlandconstituteamajor database for building models of tectonicand lithostratigraphic evolution of theFennoscandianShield.

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Petrogenesisofc.1.9Gameta-volcanosedimentaryrocksintheNautanen-Aitikarea,northernSweden:Geological,lithogeochemicalandSm-Ndisotopicconstraints.

EdwardP.Lynch1,TobiasE.Bauer2,HannuHuhma3andDavidDrejing-Carroll41DepartmentofMineralResources,GeologicalSurveyofSweden,Uppsala,Sweden,2DivisionofGeosciencesandEnvironmentalEngineering,LuleåTechnicalUniversity,Luleå,Sweden,3GeologicalSurveyofFinland,Espoo,Finland,4ExplorationDivision,NewBoliden,Boliden,Sweden

InnorthernSweden,Orosirianmetasupracrustalsuccessions provide critical insights intoSvecofennian-cycle tectonothermal processes.Additionally, they commonly host iron oxide-apatiteand/orCu±Aumineralization,andthusrepresentkeyexplorationtargets.Characterisingsuch rocks from a primary perspective is animportant prerequisite in understandingsubsequent deformation, metamorphic and/orhydrothermal events. We present newpetrogenetic constraints for a polydeformed, c.1.9 Ga metasupracrustal package in theNautanen-Aitik area (Norrbotten) hostingseveraleconomicallysignificantCu-Audeposits.

The investigated sequence mainly comprisestuffaceous metavolcaniclastic rocks and

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intercalated metasedimentary (epiclastic)horizons. Primary volcanic features includeremnant feldspar phenocrysts, accretionarylapilli-like features/clasts and inferredagglomeritic horizons. Epiclastic layers locallydisplay trough- and herring bone-type cross-stratification, suggesting relatively shallow,subaqueous depositional conditions.Compositionally, the rocksaremainlyandesitic,with lesser basaltic andesitic and daciticvarieties,andhavecalc-alkalineseriesaffinities.Chondrite-normalized REE patterns are LREE-enriched (LaN/YbN = 4.2 – 18.6), with flat toweaklynegativeEuanomalies([Eu/Eu*]N=0.59–1.16;avg=0.88).Whole-rockɛNd(1.88Ga)valuesrange from -4.5 to -0.3 (n = 10), whilecorrespondingTDMmodelagesrangefromc.2.2to2.5Ga.

The sequence attributes are broadly consistentwith formation in a continental arc-type settingundergoing extension, where precursor tephraaccumulated within a syn-volcanic depocenter(cf. Wanhainen et al. 2012). Geochemicalsignaturesalsosuggestparentalmagmasderivedfromamixedcontinental-juvenilesource.Giventhe spatial overlap of Orosirian and older(Rhyacian) successions across the region,however, a contribution from intracratonictholeiitic greenstones, remobilised bySvecofennian-related magmatism, may also bevalid.

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DeformationhistoryoftheArchipelagoofSouthernFinland

KaisaNikkilä1,AnnaSaukko1andOlavEklund11ÅboAkademiUniversity,GeologyandMineralogy,Finland

The Paleoproterozoic Svecofennian orogenicdomainofSouthernFinlandconsistsprincipallyof belts of strongly migmatized infra- andsupracrustal rocks and granitoids in upperamphibolitetogranulitefacies,withareasoflessmigmatized rocks in between. The granite-migmatite belts are presumably related to eachother, but their structural setting, deformation

stages and thus tectonic setting are vaguelyknown.

OurfocusistheonshoreareaandthearchipelagoaroundtheHankopeninsula.Asthesitewaslastresearchedbefore theplate tectonic theorywasestablished,thegoalofthisstudyistoupdatethegeologicalinterpretationsofthearea.Theprojectis ongoing and the results presented here arepreliminary.

Inthestudyarea,at leastthreedifferentductiledeformationstagesarerecognized(D1,D2,D3).During D1, the metasedimentary rocks werefolded into tight to isoclinal folds with E-Wstriking nearly vertical axial plane. The E-Wtrending horizontal to moderately plungingmineral lineation is in places stronger than thefoliation. The D2 developed open asymmetricfoldingwithSEplunging foldaxis.At thisstage,minerallineationiscommon,butthefoliationisdifficult to observe. TheD3 is representedby aminerallineationplungingtowardsNE.

The leucosomes in the migmatites are foldedtwice. This suggests that melts were generatedbeforeorduringD1.TheE-Wtrendingstructuresindicate N-S (at present) compression at stageD1.DuringD2,themainshorteningdirectionwaslikely in the NE-SW direction, whereas the D3structures seem to represent a NW-SEshortening.

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POSTER

Aca.1.89GamagmaticcomplexineasternLithuania:alinkconnectingwiththedomainsinEstoniaandtheBergslagenterraneinSweden

LaurynasŠiliauskas1,GražinaSkridlaitė1,MartinWhitehouse2andAlvarSoesoo31InstituteofGeologyandGeography,NatureResearchCentre,Akademijos2,LT-03223Vilnius,Lithuani,2SwedishMuseumofNaturalHistory,Box50007,SE-10405Stockholm,Sweden,3TallinnUniversityofTechnology,alvar.soesoo@ttu.ee

ConcealedcrystallinebasementoftheLatvia-EastLithuania(LEL)domainiscoveredby200-500mthicksediments.Itismostlycomposedofbasictoacidic intrusive rocks and their volcaniccounterparts that host ore deposits. Bogdanovaetal(2015)suggestedcorrelationsbetweenthe1.89-1.87 Ga Bergslagen microcontinent andLivonia megadomain (including Latvia-EastLithuania, South Estonia Granulite and WestEstonia domains). However, apart from a ca.1.887±7 Ma metadiorite in the south-westernLEL(Bogdanovaetal.,2015)andamuchyoungerca.1.5GaAMCGsuiteinthesouth(Sundbladetal,1994), almost none of the rocks from the LELhavebeenproperlydated.

Foursampleswithcalc-alkalineaffinityfromtheLELwere selected for zirconU-Pb SIMSdating:two samples of granodiorite from the southernpartoftheLELthatmightbeapartofaTTGsuite,a sheared diorite and a meta-rhyolite from thewesternborderoftheLEL.Thetwogranodioritesyieldedconcordiaagesof1892.3±5.7Ma(MSWD1.01) and1893.7±7.4Ma (MSWD1.9),whereasdioriteissomewhatyoungeryielding1876.1±4.8Ma (MSWD 1.6). The meta-rhyolite recorded aconcordantageof1898±8.3Ma(MSWD1.4).

OurnewlyobtainedU-Pbzirconagessupportthemodel proposed by Bogdanova et al. (2015) inwhich the Livonia and Bergslagen terranesformed simultaneously and can be correlatedacross central part of the Baltic Sea. It is alsoconsistentwith thegeneralsouthwestyoungingofterranesinthewesternEastEuropeanCraton(andBaltica).

POSTER

TheNisserShearZone–DiscoveryofaSveconorwegiancrustal-scaledetachmentzoneinsouthernNorway

EspenTorgersen1,IainHenderson2,BernardBingen2,KatiaSvendby2andAzizNasuti21GeologicalSurveyofNorway-NGUandDept.ofGeoscienceandPetroleum-IGP,NTNU,2GeologicalSurveyofNorway-NGU

In theTelemarkiaLithotectonicUnit, SNorway,thick successions of metasedimentary andmetavolcanicsrocks,knownastheTelemark-andNissedalsupracrustals,arestructurallyoverlyinggneiss complexes. The contact relationshipsbetween low- and high-grade rocks, whetherdepositional or tectonic, are contentious,althoughnotablypoorlydocumented.

Aspartofanongoingmulti-disciplinaryprojectinthe Nissedal-Drangedal area (BedrockInfrastructureinTelemark–BITE),fieldmappingreveals that the c.1200 Ma basalt-dominatedNissedal supracrustal rocks are separated fromtheunderlyingc.1200MagraniticgneissesoftheVråvatn Complex by a ductile to brittle shearzone, here called the Nisser Shear Zone (NSZ).The shear zone corresponds to a pronouncedasymmetricnegativemagneticanomaly,at least50kmlong,onthehigh-resolutionaeromagneticmap.TheNSZisupto200mthickandcomprisesa variety of high-strain rocks ranging fromultramylonite to cataclasite and fault gouge.Brittle structures appear to overprint ductilestructures.ItdipsshallowlytotheSE(c.150/25)and carries strongly developed SE-plungingmineral lineations and slickenlines. These areassociated with kinematic indicators (e.g.sigmoidal porphyroclasts and s-c shear bands)that consistently show a top-to-the ESE normalshearsense.Mylonitesdevelopedinthefootwallgraniticgneissesshowdynamicrecrystallizationof K-feldspar, testifying to deformation above500°C.

Provisionally,we interprettheNSZasacrustal-scaleextensionaldetachment linked to the late-

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Sveconorwegian orogenic decay. It exhumedlower-crustal gneisses and juxtaposed themagainstupper-crustalsequencesofasimilarage.Future studies will constrain the age, tectonicsettingandenvironmentalconditionsoftheNSZ.

POSTER

AMCGMazuryComplexinNEPoland–atimeframeofthesuiteformation

JaninaWiszniewska1andEwaKrzeminska11PolishGeologicalInstitute-NationalResearchInstitute

A Mesoproterozoic AMCG suite known fromcoveredpartoftheEeastEuropeanCratonontheborderofPolandwithLithuaniaandRussia,wasemplaced along E–W trending linear thrustingzone. An ~1.50 Ga crystallization age of therapakivi-like granitoids of Mazury Complex,obtained on zircon grains, was one of the firstgeochronological contribution, initiating moredetailed investigations in the frame ofEUROBRIDGE programme. Further age studieshave been focused mostly on the spatialchronology of the suite, controlled by A-typegranitoidsasadominantphaseacrosstheregion.

Aprincipalgoalofrecentstudieswastoconstrainthe time of emplacement of all AMCGcomponents,usingU-Pbzirconagesdeterminedby SHRIMPmethod. Themetaluminous,within-plate, A-type Mazury granites were intrudedbetween 1.53 and 1.50 Ga. The last pulse at1498±10Mawasdecipheredfromwesternmostpart(Filipówhole).Thegeochemicalandisotopicinvestigationspointedout thatAMCG suitewasformed by multiple magma batches, assembledby pulses, often in the same locality. AMCGmerged pluton was finally intruded by a netsystemofperaluminousgraniteveins,thatwerecrystallizedbetween1495±11Ma-1488.7±4Ma.This event recorded in Mazury AMCG suite,predatesaformationofAMCGmassifsinwesternLithuania (1447 -1445±8MaNemunas- Geluva),andregionalmagmatism(1.45Ga)inBornholm-Blekinge area. It alsopredates adynamichigh-grade metamorphism in SW Sweden related to

convergent active-margin processes during theDanopolonianorogeny.

The researchwas financed fromNCN grant no.2015/17/B/ST10/03540

POSTER

AlinkbetweenMesoproterozoicbasementofLithuaniaandNEPolandbyinheritedmetamorphiczircondata

JaninaWiszniewska1,EwaKrzeminska1,GrazinaSkridlaite2andSvetlana,V.Bogdanova31PolishGeologicalInstitute-NationalResearchInstitute,Warsaw,Poland,2NatureResearchCentre,Vilnius,Lithuania,3LundUniversity,Sveden

A number ofmetamorphic events between 1.7-1.6 Ga were recognized within the hiddenbasementofLithuaniaSkridlaiteetal.,2014).InBaltica,,thisperiodmarksatremendouschangeintectonic evolution (cf Bogdanova et al., 2008,2015), when an active accretionary marginshiftedto its western edge (cf Bingen et al.,2008).

Atpresent,1.7-1.6Gaoldzirconswerefoundinthe Mazury area (NE Poland) by U-Pb agedeterminations carriedout at SHRIMPLab,PGI,Warsaw; cf Krzeminska &Wiszniewska, 2017).They represent an inherited component from1.49-1.48 Ga peraluminous granite veins cross-cutting the Suwalki Anorthosite Massif (SAM).Themostofzircongrainshavecores,containingmaterial derived from various Paleoproterozoicsources. Important coherent group of inheritedgrains (about 20%) has cores in range of1710±12Ma-1617±9Ma,withsignaturetypicalfor metamorphic crystallization e.g. Th/U<0.1,butthehostrockswiththesecharacteristicshavenotbeenidentifiedsofarinproximityofSAM.

This inheritedpopulation correspondshoweverwith therecordsofmagmaticandmetamorphicactivity common in Lithuania and Belarus(Skridlaite et al., 2014; Vejelyte et al., 2015,Bogdanova et al., 2001), where zircons andmonazites from Randamonys (Lithuania) and

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Grodno(Belarus)havedocumentedreworkingat1668±9 Ma (and 1569±12 Ma) and granulitefacies metamorphism at 1727±30 Ma. Thismayindicategeneticlinkbetweenperaluminousthe Mesoproterozoic vein granites and theirbasement,thatcouldbesimilarinNEPolandandLithuaniaatthelevelofmagmageneration.

1.9.Micro-beamfrontiersinmagmatic,metamorphic,andhydrothermalsystems

ORAL

U-PbcalciteandzircondatingbyLA-ICP-MSimagemapping

DavidChew1,KerstinDrost1andJosephPetrus21DepartmentofGeology,TrinityCollegeDublin,Dublin2,Ireland,2SchoolofEarthSciences,TheUniversityofMelbourne,Parkville,Australia

Traditionally,LA-ICP-MSgeochronologyemploysspotablations,with the limitationthat the laserexcavatesmaterialseveraltens-of-µmbelowthesample surface.LA-ICP-MS mapping (ablating aseries of parallel, adjacent lines in a singleexperiment) yields much shallower ablationdepths (0.3-3 µm).The data contained in theparallellinescansarereducedwithsoftware(e.g.Iolite) to produce x-y-element concentrationand/or isotopic maps. We employ here a newflexible interrogation tool for LA-ICP-MS mapscalledMonocle (Petrus et al., 2017), and add-infor Iolite.Inadditionto inspectors toolssuchassize-and-shape adjustable loupes, user-definedregions-of-interest (ROIs) and live graphs (e.g.Wetherill or Tera-Wasserburg concordiae),Monocle allows the selection and pooling ofpixels that meet user-defined criteria.Potentialapplications of zircon U-Pb imaging includecharacterisation of complex polyphase zirconsand characterising the U-Pb systematics of keysamplesforTIMSdating.U-Pbcalcitedatinghasimportant applications including datingunfossiliferoussedimentaryrocksorore-bearingmineralization events.The functionality ofMonocle can circumvent limitationsof theU-Pbcalcite system, including low U concentrationsand/orhighamountsofinitialPb.Pixelsonamapcanbepooledinto“analyses”basedonECDFsofelements or isotopic ratios (e.g. 238U/204Pb) tocreate a spread of U-Pb data on concordia.Portions of the sample with elevated detritalcomponentsor chemically-different generationsofcarbonatecanberejectedbydefiningexclusion

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criteria (e.g. Rb<1ppm; Mg/Ca<0.004).Stratigraphically well-constrained Paleozoiclimestones and shell fragments yield accurateages with internal age uncertainties as low as±1%,confirmingthefeasibilityofthetechnique.

ORAL

PromisesandpitfallsofinsituSrisotoperatiomeasurementsbyLA-MC-ICPMS

GrahamHagen-Peter1,RasmusAndreasen1,OleSkursch1,MarkEdwards2,ChristianTegner1,GryBarfod1andCharlesLesher11CentreofEarthSystemPetrologyandAarhusGeochemistryandIsotopeResearchPlatform,Denmark,2DepartmentofEarthScience,UniversityofCalifornia,SantaBarbara,U.S.A.

The Rb-Sr isotopic system has been used fordecades for geochronology and radiogenicisotope geochemistry. The advent of laser-ablationplasma-sourcemass spectrometry (LA-MC-ICPMS)enhancedtheefficiencyofSrisotopeanalysis and—more importantly—enabledspatiallyresolvedmeasurements.However,overtwodecadessincethefirstmeasurementsofSrbyLA-MC-ICPMS, there is still no standard routinefor accurate and precise determination of Srisotope ratios in Ca-bearing silicates withvariableRb/Sr ratios. This is largely because oftheanalyticalchallengesinherenttothismethod,including numerous elemental (Kr, Rb, doublycharged REE) andmolecular (CaAr, Ca2, amongothers) interferences on the Sr isotopes ofinterest. Previous studies have successfullymeasured Sr isotopes in situ in plagioclase,carbonates, and phosphates, but interferenceshave thwarted accurate measurements ofmaterials with Rb/Sr > ~0.05. We test theeffectiveness of several commonly used data-reduction approaches on a large set of LA-MC-ICPMSmeasurementsoftwoin-houseplagioclasestandardsandwidelyusedrockglassstandardswith Rb/Sr up to ~0.7. Most approacheseffectively reproduce the plagioclase standardsbut yield highly inaccurate results for higherRb/Sr standards. We have developed custom

data-reduction approaches that now accuratelyreproducerockstandardswitharangeofRb/Srandcompositionalmatrices,expandingtheutilityofthismethod.Wehighlightseveralapplicationsof the method, including measurements ofplagioclase, volcanic groundmass, andarcheological glass samples, and alsosimultaneousmeasurements of Sr isotopes andtrace elements by laser-ablation split-streamanalysis.

ORAL

IntandemK–CaandRb–SrdatingofpotassicmineralsbyLA-ICP-MS/MS:Methodandprospectiveapplications

AxelS.L.Sjöqvist1,ThomasZack1,K.JohanHogmalm1andErikKangas11DepartmentofEarthSciences,UniversityofGothenburg,POBox460,SE-40530Göteborg,Sweden

Recent technical development in ICP-MSinstruments facilitates on-line chemicalseparationof isobaric ions (e.g. 87Rb+and 87Sr+)by gas reactions, which enables dating of beta-decaysystemssuchasRb–Srbylaserablationofminerals without wet chemistry (Zack andHogmalm2016;Hogmalmetal.2017).Wehaveanalysedmica-groupmineralsofvariousagesforK–CaandRb–SrisotopicratiosintandembyLA-ICP-MS/MS. Both Ca+ and Sr+ ions are highlyreactivewithSF6gas,whereasK+andRb+arenot.Ca and Sr isotopes were measured asinterference-freefluoridereactionproductsCaF+and SrF+, whereas 40K and 87Rb isotopes wereinferred from 85Rb+ and 39K+. Overlap fromisotopes of Ar, present in the plasma, wassuppressedbyaddingH2gas.

ByanalysingK–CaandRb–Srisotopesintandem,thesedualsystemswithdifferentdecayratesareanalogoustotheU–Pbdecayseries.Rb–Kisotoperatios can be assessed on various concordiadiagrams and reveal single-spot ages or open-systemdisturbances.Sincethenon-radiogenicCacompositionforthepurposeofmicadatingcanberegardedaspracticallyconstant(cf.Valdesetal.2014), the isochronmethod isnotrequiredand

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single-spot ages can in principle be derived,whichwould be useful inter alia in provenancestudiesofsedimentarymicas.

ORAL

Behaviourofboronisotopesduringmagmaticdegassing:acasestudyfromLesbosIsland,Greece.

KonstantinosThomaidis1,FrancesM.Deegan1,MartinJ.Whitehouse2,ValentinR.Troll1,FranzA.Weis1,AngelaH.Helbling3,HorstR.Marschall3andHarriGeiger11DepartmentofEarthSciences,UppsalaUniversity,Uppsala,Sweden,2SwedishMuseumofNaturalHistory,Stockholm,Sweden,3GoetheUniversityFrankfurt,Frankfurt,Germany

Boron is a fluidmobile trace element routinelyemployed as a tracer of slab-derived fluids insubduction zones. The fidelity of boron involcanic glass as an accurate tracer of slabdegassing is called into doubt, however, byexperiments that show that boron isotopes(expressed as δ11B) can fractionate by up toseveral permil (‰) duringmagmatic evolutionand degassing at high temperature. In order totest for isotopic fractionation during magmaticdegassinginanaturalcase,wecarriedoutSIMSanalysesofboron-richrhyoliticglassfromLesbosIsland, Greece. Analytical points were set astraverses from bubbles into the surroundingglassinordertotestforvariationsinδ11Bvaluesdue to volatile exsolution. The glass records apost-eruptive average water content similar tothe calculated water solubility in the final pre-eruptive melt, suggesting minor pre-eruptivedegassing took place. The average boronconcentrationandδ11Bvalueof theglass is102μg/g (n=61) and -4.9‰ (2SD=1.6‰, n=60),respectively,makingitoneofthemostboron-richsubductionzoneglassesyetrecorded.Moreover,the glass is statistically homogeneous at the 2σlevel,withmildheterogeneityatthe1σlevel.Thisobservation implies that during degassing atmagmatic temperatures in rhyolitic systems,boron isrelatively immobileand its isotopesdonotsignificantly fractionate.Ourfindingsallows

ustoreconstructtheLesbosmagma’sδ11Bvaluesat its final holding stage prior to eruption, andsuggestthatvolcanicglassmaybeareliabletoolforinvestigationofsubductionfluidsinarcs.

ORAL

MeltInclusionstudiesonbasalticmagmasinIceland

ThorThordarson11FacultyofEarthSciences,UniversityofIceland,101Reykjavík

Investigations ofmelt inclusions and their hostmacrocrystineruptedbasaltsfromIcelandhaveprovided important insights into subsurfacemagmatic processes. This presentation isintended as an overview of studies on meltinclusioninmaficmagmasinIceland.High-Mg#(˃65) melt inclusions are among the mostprimitiveliquidsknownfromIceland,yetrecordmodification of mantle-derived melts bydifferentiation and mixing. Furthermore, majorand trace element compositions of inclusionsspanning the basaltic spectrum demonstrate atraceelementdisequilibriumbetweenprimitiveandevolvedmaficmelts, indicatingthatarangeof mantle melt compositions must havecontributed to the formation of the relativelyevolved and compositionally constrained maficmagmas typifying the erupted products withinthe volcanic zones of Iceland. The eruptedmagmas appear to have evolved with time viapolybaricstorageat1.5-8kbars(=depthsof~5to30km),withfurthermodificationuponascenttoeruptionasevidentfromacommon0-1.5kbarsignal overprinted onto macrocrysts. Oxygenisotope measurements on host macrocrysts aswellasmeltinclusionsrevealhighlyvariabled18O(3.3–5.4permil)implyingsomeoxygenisotopicvariation within the mantle source. Volatilemeasurements in melt inclusions indicate atypicalpre-eruptionconcentrationintherangeof0.2-1.0wt%H2O,250-˃3000ppmCO2and1000-2500ppmsulphur.Thesulphurdatawereusedto propose a two-stage degassing model forbasaltic fissureeruptions in Iceland,whichnowhas been confirmed by recent study on the

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sulphur degassing during the 2014-15 eruptionatDyngjusandur,NorthIceland.

ORAL

Explosiveoceanislandvolcanismcausedbyhighwatercontentsinoceanislandbasalts

FranzA.Weis1,ValentinR.Troll1,FrancesM.Deegan1,HenrikSkogby2andJuanCarlosCarracedo31UppsalaUniversity,Dept.ofEarthSciences,SectionforMineralogy,PetrologyandTectonics,SE-752,2NaturhistoriskaRiksmuseet,Dept.ofGeosciencesSE-11418Stockholm,Sweden,3UniversityofLasPalmasdeGranCanaria,Dept.ofPhysics(GEOVOL),LasPalmasdeGranCanaria,Spain

Water fundamentally influences the physicalproperties of the mantle and mantle-derivedmagmas,includingrheology,viscosity,buoyancy,and explosive potential at the surface.Oceanislandbasalts(OIBs)usuallyerupteffusivelyandgenerally contain ≤1 wt. % H2O. However,explosive eruptions of OIBs occur on occasionand are thought to relate either to a volatile-enriched mantle source or to shallow gassegregation processes. Here we report onexplosively erupted, upper-mantle derivedcrystal-richankaramite lavasfromTanganasogavolcanoonElHierro(CanaryIslands)thatrecordmagmaticwatercontentsupto3.2±0.64wt.%.TheseH2OvaluesareamongthehighestknownforOIBstodateandweredeterminedthroughtheanalysis of hydrogen defects in clinopyroxenecrystals. Notably, the Tanganasoga volcanoformedwithintherecentElGolfogiantlandslideembayment(87–39ky),anditsformationlikelyreflects rapid magma ascent due to unloadingfollowing the El Golfo landslide. Our data alsoimply that the Tanganasoga magmas are notprimary melts but record a usually hiddensnapshotofmagmaevolution in thesub-Canarymantle.Atthispointstrongvolatileenrichmentinthemagma iscausedby fractionationprocesseswithintheunderplatingzonebeneaththeactiveocean island, yet the vertical load of the islandimpedes the magma’s ascent. However, in

exceptional cases, sudden external pressurechanges, such as from large crustal unloadingcaused by large landslides, may, similar to the“un-corking” of a champagnebottle, trigger fastascent and explosive eruptions of water-richmagma and associated explosive ocean islanderuptions.

ORAL

ImprovedcontroloninterferencesinlaserablationstudiesutilizingN2Oasauniversalreactiongas:Applicationstooremineralrelatedstudies

ThomasZack11DepartmentofEarthSciences,UniversityofGothenburg

Control on reaction chemistry of ions with arange of gases are instrumental in thedevelopmentofminimizinginterferencesinICP-MS applications. A recent breakthrough wasachievedinthisregardwiththeintroductionofanew generation of ICP-MS that utilizes aconfigurationcalledQQQ.Itturnsoutthatthisisofparticularimportanceforlaserablation-basedstudies as this technology precludes otherchemicaltreatmentstoremoveinterferences.

In the Microgeochemistry Laboratory at theUniversityofGothenburgweareintheprocessofevaluating different gases for their use ofinterference removal/minimization. It turnsoutthat nitrous oxide (N2O) is particular potentreaction gas. Rigorous testing has revealed thatthisgasisnotonlyabletoremove87Rbfrom87Sr(therefore allowing in-situ Rb-Sr dating;Hogmalm et al. 2017, JAAS 32, 305), but alsoserves as an almost universal reaction gas forroutinein-situtraceelementanalysis.Significantimprovementindetectionlimitsisachievedforawidesuiteofelements:Si,P,Ca,Ti,V,Cr,Mn,Fe,Ge and Se. A major reason for this is theminimization or removal of MAr+ and M2+interferences,respectively.

I will demonstrate that N2O as a universalreaction gas leads to a more reliable analytical

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protocolinlaserablationstudies,inparticularinore related studies where a wide variety ofmatrixes (sulphides, oxides, etc) leads tomultitudeofsevereinterferencesthatcaneasilyleadtofalseresults(e.g.,thewell-knownfalseRhandPdvaluesinthepresenceofCu).

POSTER

NewScanningElectronMicroscopeforautomatedmineralogical,crystallographicandchemicalanalyses

NynkeKeulen1andRikkeWeibel21Petrology&EconomicGeology,GEUS,Denmark,2ReservoirGeology,GEUS,Denmark

TheGeologicalSurveyofDenmarkandGreenland(GEUS) recently acquired a ZEISS Sigma 300VPField Emission Scanning Electron Microscope(SEM), and can now make automatedmineralogic, crystallographic and chemicalanalyses on entire thin sections or polishedmounts relevant for all areas of geoscienceresearch, including mining and exploration, aswellasinvestigationsofreservoirs(oil&gasandgeothermalenergy).Theinstrumentisequippedwith2BrukerXflash6|30129eVEDSdetectors,anBrukere-FlashFSEBSDdetector,a185-850nmLight-Guide Cathodoluminescence detector, aback-scattered electron detector and threesecondary electron detectors, including an in-lense detector. The SEM is able to work undervariable pressure conditions,with high vacuumcondition of 3.25 x 10-4Pa and low vacuumconditionsbetween2-133Pa.AlsoitisequippedwiththeZeissMineralogicsoftwareplatformformining and reservoir rocks.With this software,wewillbeabletoperformautomatedmineralogyonentirethinsections,polishedmounts(e.g.drillcores,heavymineralseparates,cuttingssamples,ores) or parts thereof. The strength of the newSEM instrument lies in the combinationpossibilities for the different detectors andimagingtechniques,whichwillshedacompletelynew light on geoscience microanalysis. In thepresentation,wewillgiveanoverviewover the

range of new possibilities, with a focus onmagmatic, metamorphic, and hydrothermalprocesses.Weareopentodiscusscollaborationopportunities.

POSTER

InsituRb-SrdatingofsnowballEarthtilliteclastsforprovenancestudyontheChuosformation,Namibia.

MartinThor1andThomasZack11DepartmentofEarthSciences,UniversityofGothenburg

Provenance studies can assist with valuableinsightsintotransportationdistanceandmodeoftransportation when producing reconstructionson ice sheet movement and mechanics. Recentadvancements in in situ Rb-Sr dating makesdating felsic clasts with Laser AblationInductively Coupled PlasmaMass Spectrometry(LA-ICP-MS) possible. This study applies thesetechniquestoproduceaccurateandpreciseRb-SrdatesonclastsfromtheChousformation.

TheOtavigroupinNamibia,whichcontainsboththe Ghaub and Chous formations, has been thesubjectofintensestudyfocusedonthesnowballEarth hypothesis. The Ghaub and Chousformationshavebeenhypothesizedtorepresentsnowball Earth deposits because of their capcarbonates (Hoffman et al., 1998). Some of theclastsinthetilliteareoffelsiccomposition,withabundant K-bearing mineral phases, makingthemsuitablefordatingusingRb-Sr.

UsinginsituRb-SrdatingwithLA-ICP-MSpairedwith an reaction chamber with N2O (Zack andHogmalm, 2016, Hogmalm et al., 2017), clastsfrom the Chuos tillite will be dated to examinewhether their provenance can be determined.The aim of this study is to investigate if acontinental-scaletransportationdistanceduringthe Sturtian glaciation can be inferred. Theresultscouldpotentiallyhaveanimpactonhowweviewand interpret snowball Earth ice-sheetdynamics. Initial tests have yielded ages frompegmatite clasts, 925 Ma and 975 Ma

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respectively,whichdoesnotappeartohavebeenreset or altered during the Damaran orogeny(550-495Ma).

1.10.GeochemistryandmodelingofIgneousSystems.

ORAL

MarkovChainMonteCarloInversionofMantleTemperatureandCompositionBeneathIceland

EricBrown1,KenniPetersen1andCharlesLesher11DepartmentofGeoscience,AarhusUniversity

Basalts are formed by adiabatic decompressionmelting of asthenosphere, and thus providerecordsof the thermal, chemical anddynamicalstate of the upper mantle.However, uniquelyconstraining mantle temperature, compositionand flow through the lens of melting ischallenging given the inevitability that primarybasalts are aggregates of partial melts derivedfromheterogeneousmantleovera rangeofP-Tconditions. We aim to place more rigorousconstraintsontheuniquenessanduncertaintiesofmantlesourcepropertiesbycouplingaMarkovChainMonte Carlo (MCMC) sampling techniquewith forward modeling of polybaric near-fractional fusionofheterogeneousmantleusingREEBOX PRO [1]. The MCMC methodsystematicallysamplesthedistributionofmantlepotential temperature (TP), and initialabundances and compositions of the sourcelithologies that produce models that “fit”geochemical and geophysical observationswithin their associated uncertainties. We haveappliedthemodeltomagmatismalongReykjanesPeninsula in Iceland, exploring melting ofdepleted peridotite ± G2 pyroxenite [2] ±enrichedKG1peridotite [3]±harzburgite.Best-fit models have depleted peridotite + enrichedperidotite/pyroxenitesourceshavingTP~122±15°Caboveambientmantlewith~95%depletedperidotite and ~5% pyroxenite spanning likelycompositions for G2 and KG1. The enrichedlithologies have EMORB-like [4] trace elementcompositionsandPaleozoicmeanages,whereasthe depleted peridotite exhibits very-incompatible element enrichments relative toDMM [5]. These results advance our

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understandingofthepetrogenesisoftheIcelandsource that differs significantly from depletedmantle sampled by the global spreading ridgesystem.

ORAL

EnrichedlithospherecontributiontothegenesisoftheFreetownLayeredComplex(SierraLeone):Isotopesystematicsofahigh-TiCAMPintrusion.

SaraCallegaro1,AndreaMarzoli2,HervéBertrand3,JanneBlichert-Toft3,LaurieReisberg4,GiancarloCavazzini5,FredJourdan6,JoshuaDavies7,UrsSchaltegger7andMassimoChiaradia71CEED-UniversityofOslo,2UniversityofPadova,3UniversitéLyon1,ENSLyon,4CRPG-CNRSNancy,5IGG-CNRPadova,6DepartmentofAppliedGeology,CurtinUniversity,7DépartementdesSciencesdelaTerre,UniversitédeGenève

Wepresentageochemicalandgeochronologicalstudy of amafic layered intrusion cropping outalong the Atlantic coast of Sierra Leone – theFreetown Layered Complex (FLC).Geochronology (40Ar/39Ar on plagioclase:201.7±0.7 and 202.3±2.3 Ma; U-Pb onbaddeleyite: 198.794 ± 0.048/0.071/0.22 Ma)and crystal chemistry (high-TiO2 pyroxene)demonstratetheconnectionbetweentheFLCandthe high-Ti magmatism of the Central AtlanticMagmatic Province (CAMP). Yet, Sr, Nd, Hf, Pb,andOs isotopesrevealanunusualsignature forthe FLC compared to most other CAMPoccurrences previously studied. Particularlydistinctive of the FLC rocks are their low206Pb/204Pb and high 207Pb/204Pb, suggestinginvolvement of an ancient component in thegenesis of thesemagmas. Although some lowercrustalassimilationisisotopicallyconfirmedandalso suggested by the presence of a granulitexenolithinoneoftheanalysedrocks,thisprocessalone cannot be responsible for the observedisotopicfingerprintoftheFLC.Weratherproposethatthemoststraightforwardwaytoconferthedistinctive isotopic signature to the FLC is by

hybridization of an upper asthenospheric meltwith small volumes (1-3%) of highly enrichedalkalinemelts derived from the sub-continentallithospheric mantle, possibly lamproites. Thisscenario is also supported by the geodynamicsettingoftheFLC,emplacedwithinaProterozoicmobilebelt(Rokelide)andborderinganArcheancraton(Man),aswellasbythereportedpresenceoflamproitesandkimberlitesinthearea.Originofhigh-TimagmatismofotherGondwanaLargeIgnoeusProvinces(Karoo,Paraná-Etendeka)canlikewisebeexplainedbysimilarprocesses.

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Evidenceofliquidimmiscibilityinthe1.8GaRaftsundmonzonite,Lofoten,NorthernNorway

NolwennCoint1,JakobK.Keiding1,PeterIhlen1andSuzanneMcEnroe21GeologicalSurveyofNorway,2DepartmentofGeoscienceandPetroleum,NorwegianUniversityofScienceandTechnology

The significance of silicate liquid immiscibilityand its petrogenetic role has been debated formanyyears.Althoughwelldocumentedinmaficlayered intrusions, it is not clear if liquidimmiscibilitycanoccurinmoreevolvedalkalinerocks.Here,wepresentevidenceforthisprocessinthe1.8GaRaftsundbatholith;amonzonitictolocally granitic ferroan intrusion. Fe-Ti-P-richmineralizationsoccursascm-scaleupto200mx50 m large scattered bodies, displaying bothsharp and gradational contacts with thesurrounding host pigeonite-clinopyroxenemonzonite to syenite. The mineralizations arecomposed of anhedral rare pigeonite, Fe-richolivine(Fo22-29),subhedralclinopyroxene(Wo34-45 En20-46 Fs23-44), anhedral magnetite andilmenite,scattered latehornblendeandvariableproportions of subhedral ternary feldspars.Inclusions of apatite, which can reach up to 12modal percent, are present in all minerals butternaryfeldspars.ThescarcityofpigeoniteintheFe-Ti-P-rich rocks and the presence of Fe-richolivineindicatethattheserockscannotrepresent

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direct cumulate from the host monzonite andsyenite. Bulk-rock compositional variations arewell explained by recent experimentalwork onliquidimmiscibility(Charlier&Grove,2012)withenrichmentinFe,Ti,P,Mg,Ca,Sc,Co,Zn,Cu,VandREE in themineralizations. Clinopyroxene fromthe mineralizations is enriched in Sc and to alesserextentinTi,ZnanddepletedinV,Co,Sr,Y,Nb, LREE and Al, which is consistent with co-precipitation of apatite and magnetite and theformationofsuchameltbyliquidimmiscibility.

ORAL

Evolutionofadeepcrustalmagmaconduitsystem

ThomasB.Grant1,RuneB.Larsen1,AxelMüller2andSuzanneMcEnroe11NTNU,2NHMOslo

SeilandIgneousProvince(SIP),NorthernNorwayrepresentsthelowercrustalplumbingsystemofa LIP where large volumes of ultramafic, maficandalkaline-carbonatitemeltsweretransportedfromthemantletoshallowerlevelsofthecrust.The Reinfjord mafic-ultramafic intrusion is amagma conduit system and offers an excellentlocation in which to study differentiationprocessesasmagmasenterthecrust(Larsenetal2016).

Field relationships clearly show the Reinfjordintrusionformedbyprogressiveinfluxesofnewmelts into earlier cumulates, resulting in asequenceofgabbro–olivineclinnopyroxeneite–wehrlite – dunite from themargins to the core(Grant et al 2016). Here, we determine therelative contributions of fractionalcrystallization,assimilationandrechargeonthecompositionsofultramaficcumulatelayers.

Trace elements in clinopyroxenes weredetermined using LA-ICP-MS. Melts inequilibrium with the clinopyroxenes fromReinfjordhaveOIB-likecharacteristics,similartopicrite dykes in the SIP. For dunites andwehrlites, fractional crystallization was thedominant processes. The magmas did not

fractionate by more than 30%, implying largevolumesofmagmaweretransportedverticallytoshallower levels of the crust. For olivineclinopyroxenites, LREE/HREE ratios record theimportance of assimilation aswell as fractionalcrystallization.

Withtime,theintrusionevolvedtomoreolivine-rich and ultramafic cumulates, fractionalcrystallization become more dominant overassimilation,andthemagmasleavingtheconduitsystem became increasingly MgO-rich. Theseresults may explain geochemical variationsobserved in flood basalt sequences (Yu et al2015).

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UnravelingthedifferentiationofafloodbasaltsequenceusingMagmaChamberSimulator

JussiS.Heinonen1,ArtoV.Luttinen2,WendyA.Bohrson3andFrankJ.Spera41DepartmentofGeosciencesandGeography,UniversityofHelsinki,2FinnishMuseumofNaturalHistory,UniversityofHelsinki,3DepartmentofGeologicalSciences,CentralWashingtonUniversity,4DepartmentofEarthScienceandEarthResearchInstitute,UniversityofCaliforniaSantaBarbara

TheMagmaChamberSimulator(MCS;Bohrsonetal., 2014) models the effects of recharge,assimilation, and crystallization on phaseequilibria, mineral chemistry, major elements,traceelements,andradiogenicisotopesthroughmassandenthalpybalanceinamulticomponent-multiphasemagma +wallrock system.Hereweprovide an example of utilizing MCS indeciphering the differentiation history of acompositionallyuniformcontinentalfloodbasaltsequence characterized by strong crustalgeochemicalsignaturefromtheAntarcticportionof the Karoo large igneous province. Ourmodeling shows that only a few percent ofassimilation of sialic crust may have profoundimpactonthecompositionoftheparentalmagma(major elements, 16 trace elements, and Ndisotopes).Isobaricandcontinuouslyassimilating

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models fail to produce the observed eruptivecompositions. Instead, we suggest thatcontaminationofthepicriticparentalmagmasbyassimilation of mid-crustal Archean TTGs (bystoping + hybridization or partial melting orboth) must have first taken place at depths of~10‒20 km, where orthopyroxene and olivineare stable phases in the magma. Most of thesubsequent differentiation happened in acomplexnetworkofdikesandsillsintheshallowupper crust without additional assimilation.There, the large temperature gradient betweenmagmainnarrowfeedingchannelsandcountryrock precluded anatectic melt formation andeffectively shielded the magma fromincorporation of wallrock partial melts. Thisexample illustrates the capabilities of MCS intesting possible petrogenetic scenarios andencourages application of the MCS tool todifferent igneous environments and tectonicsettingswhereassimilationtakesplace.

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DeepcrustalhomogenizationofdiversemaficandultramaficLIP-formingmantlemelts:LessonsfromtheEdiacaranSeilandIgneousProvince(SIP),Norway

RuneB.Larsen1,ThomasS.Grant1,BjørnE.Sørensen1,SuzanneMcEnroe1andChristianTegner21Dep.ofGeosciencesandPetroleum,NTNU,Trondheim,2EarthSystemPetrology,D.ofGeosciences,ÅrhusUniversity

SIP contains >5000 km2 of mafic/ultramaficintrusionswithminor alkaline, carbonatite andfelsic rocks emplaced at depth of 25 - 35 kmduring the formation of the Central IapetusMagmatic Province at 610-550 Ma (CIMP) andexposes 85-90 % layered gabbros, 8-10 %peridotitic complexes, 2-4 % alkaline intrusionemplaced within <10 Ma. Gravimetric datasuggests that SIP features six deep lithosphericrootsofultramaficrocksextendinginthedepthsof > 9 km that resembles the conduit systems.

FouroftheultramaficcomplexesareexposedatSIP in a right-way-up setting. They feature amarginal hybrid zone at the country rockcontacts,thenanolivine-mela-gabbrogradingtopyroxenite,thenanolivine-clinopyroxenitezonewhichisfollowedbyawehrlitezoneand,finally,pure dunite in the centre. From pyroxenite todunite,olivinecompositionchangesfromFo72toFo85 and clinopyroxene from Di80 to Di92 i.e.forming a reverse fractional crystallizationinwards. Parental melts were komatiitic topicriticwith16-21wt%MgO,1594ppmCrand611ppmNiandwereemplacedat1450-1500oC.Melts are OIB-like with LREE enriched overHREE. The high abundance of carbonated andhydratedmineral assemblages imply a volatile-rich nature of the mantle source region alsocorroborated by unusually high abundance ofmagmaticsulphides.

Essentially, the ultramafic complexes in SIPcomprise deep-seated transient magmachambers that facilitated mixing andhomogenization of a rich diversity of fertileasthenosphericmeltsenroutetotheupperpartsofthecontinentalcrust.

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GeochemistryoftheFeragenultramaficbody,CentralNorway.

AnnaPryadunenko1,LarsP.Nilsson2andRuneB.Larsen11DepartmentofGeoscienceandPetroleum,NTNU-NorwegianUniversityofScienceandTechnology,2GeologicalSurveyofNorway

Tectonically dismembered ophiolite fragmentsstretchforseveralhundredkilometresalongtheSwedish-Norwegian border [1]. One of thefragments, theFeragenultramaficbody, located30 km east of the town of Røros represents anexcellent natural laboratory for studying uppermantle melting and melt extraction processes.Uppermantle rocks inFeragenare representedby harzburgite, that occasionally changescomposition towards lherzolite and asubordinate amount of dunite. In the north-

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westernpartof themassif, close toapresumedmantle-crust boundary, the amount of duniteexceeds that of harzburgite. Dunitic rockswereobservedbothasreplaciveduniteswithgradualtransitions to harzburgite up to several meterswide,andasdunitechannelswithsharpborderstohostharzburgiteandamaximumwidthof50cm.Harzburgiterelictsofvariousshapeareoftenpresent within the dunite channels and thereplacivedunites.

Olivine present in the rocks is higlymagnesianwith Mg numbers ranging from 90 to 91 inharzburgite and from 92 to 94 in dunite. NiOcontentofolivine inall the rock typesdoesnotexceed0.4wt%.Someofthedunitesarerichinchromian spinel. Cr numbers for spinel arebetween 0.4 and 0.6. TiO2 content of spinelmineralsisaslowas0.15wt%[2].ChromititesshowextremedepletioninPtandtheoverallPGEcontentimpliesdepletedmantlecompositionforthe rocks analysed. Low TiO2 content of spineland high Fo content of olivine suggest a highdegreeofmelting,thatisgreaterthan25%

ORAL

Micachemistry-agenesisindicatoroftheSveconorwegianpegmatites,southernNorway

NannaRosing-Schow1,AxelMüller2andHenrikFriis11NaturalHistoryMuseum,UniversityofOslo,P.O.Box1172,Blindern,0318Oslo,Norway,2NaturalHistoryMuseum,UniversityofOslo;NaturalHistoryMuseum,CromwellRoad,London,UK

Mica minerals are the third most commoncomponentof graniticpegmatites.They containimportantmajorandtraceelementsincludingLi,F, and Rb, which can be used for pegmatiteclassificationandtobetterunderstandtheoriginand genesis of pegmatites (Marchal et al. 2003;Breiteretal.2017). SouthernNorway isknownfor its largepegmatiteprovincewithmore than5000 pegmatite bodies, occurring in theSveconorwegian orogeny (1.1-0.9) and formingoneoftheworld’slargestpegmatiteclusters.We

present the first comprehensive comparison ofmica from theTørdal, Evje-IvelandandFrolandpegmatitefields.MicafromTørdalissignificantlyenrichedinbothLi2Owt%andF%comparedtomica from the Evje-Iveland and Froland. TheTørdalmicacontainsupto5.4wt%Fand6.0wt%Li2O,whileonlyupto2.6wt%Fand0.6wt%Li2OaremeasuredfromtheEvje-Ivelandfieldand1.2wt% F, 0.3 wt% Li2O in the Froland mica. AsimilarpatternisseenintheK/Rbratioswiththelowest values found in theTørdalmica rangingfrom3.63to27.5contraryto16.5-365and29.9-62.5fromEvje-IvelandandFroland,respectively.The Tørdal pegmatite field contains the mostevolved mica and thereby the most evolvedpegmatites.ThestrongenrichmentofLi,FandRbsuggeststhatthesourceoftheTørdalpegmatitemeltsmightbedifferentthanfortheEvje-IvelandandFrolandfields.Thelatterarethoughttobeofanatecticorigin.

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ChronologyoftheNeboGranite,BushveldComplex

OleSkursch1,ChristianTegner1,FernandoCorfu2andCharlesE.Lesher11EarthSystemPetrologyGroup,Dept.ofGeoscience,AarhusUniversity,Aarhus,Denmark,2Dept.ofGeosciences,UniversityofOslo,Oslo,Norway

Theworld’slargestA-typegraniteunit(theNeboGranite)overliesthelayeredmaficandultramaficcumulaterocksoftheRustenburgLayeredSuite(RLS)Togetherwithminorgranophyreandothergranites these units make up the BushveldComplex, South Africa. The Nebo Granite oftencutstheRLSandexistingzirconU-Pbchronologysupports the view that the granite is slightlyyoungerandessentiallyunrelatedtotheRLS.Theage of the RLS is very well constrained at2055.91±0.26 to 2054.89±0.37 Ma (Zeh et al.,2015)We present new ID-TIMS zircon U-Pbchronologyfor9samplesoftheNeboGraniteandarelatedgranophyricvariety.Weshowthattheages obtained from the Nebo Granite areindistinguishable fromeach other and from theage of the RLS. Moreover, the granite also

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containsminoramountsofzirconthatareslightly(<9m.y.)older than the crystallization age. Theolderzirconsaremorphologicallysimilar to theyoung zircons and are found in all samples wehaveinvestigated.Theiragesalsooverlaptheageof the earliest phase of magmatism in theBushveldLIP.TheseobservationssuggestthattheolderzirconsareinheritedfrommagmaticrocksthatformedduringtheearliestphaseofBushveldmagmatism and are not xenocrysts from olderbasementrocks.EventhoughtheNeboGraniteisprobably an assembled body, it crystallized toofast for its temporal evolution to beresolved.ContemporaneitybetweentheRLSandthe Nebo Granite challenges the view that theyare essentially unrelated and introduces thepossibility of consanguinity between the twounits.

ORAL

FeandSiisotopesystematicsoftheThingmulivolcano,Iceland:therolesofcrystal–meltfractionation,oxygenfugacityandmeltstructure

NiklasStausberg1,ChristianTegner2,GryBarfod2andCharlesLesher21DepartmentofGeoscience,AarhusUniversity,Høegh-GuldbergsGade2,8000Aarhus-C,2EarthSystemPetrology,DepartmentofGeoscience,AarhusUniversity

TheTertiaryThingmulivolcano,EasternIceland,is a classic example of tholeiitic differentiationspanning the compositional range of basalt torhyolite. Whole rock and mineral compositionscoupled with forward modeling indicatefractionationofolivine,pyroxene,plagioclaseandFeTi-oxides buffered at an oxygen fugacityslightly below the FMQ buffer. The well-constrained liquid lineofdescent forThingmuliprovides an opportunity to investigate stableisotope crystal-liquid fractionation for the twomost abundantmajor elements, Fe and Si. Ironisotope fractionation isexpected tobesensitivetoredoxcondition,whileSiisnot.FeandSiwerechemically purified and analyzed for δ56Fe andδ30Si with a Nu Plasma II MC-ICPMS at Aarhus

Geochemistry and Isotope Research Platform(AGiR), Aarhus University, using pseudo-highresolution and sample-standard bracketing. Feisotope compositions of Thingmuli lavas rangefromδ56Fe=0.042‰to0.118‰formaficandintermediate compositions, and 0.124 ‰ to0.650 ‰ for rhyolites. The heaviest valuescorrespond to themost evolved, Fe-poor lavas.PreliminarySiisotopedatarangesfromδ30Si=-0.36‰to-0.06‰andshowsapositivelinearcorrelationwithwholerockSiO2(wt.%)content.Forward modeling of the stable isotopecompositions shows that Fe3+/Fe2+ partitioningbetween melt and crystallizing solids is theprincipal contributor to iron isotopefractionation, except during the final stages ofcrystallization where high melt polymerizationaffects the coordination environment andfractionation of iron. In contrast, Si isotopefractionation reflects the degree of Si-polymerization of melt and solid phasesthroughoutthecrystallizationsequence.

ORAL

Geochemicaldiscriminationcriteriaforindium-potentialgranitesintheFennoscandianShield

KristerSundblad1,IvanAlexeev2,MattiVuorisalo3,BenceBalogh3andSusannaMetso31UniversityofTurku,FinlandandStateUniversityofStPetersburg,Russia,2StateUniversityofStPetersburg,Russia,3UniversityofTurku,Finland

Spectacular discoveries of indium-richpolymetallic sulphide/oxide deposits haverecentlybeenreported fromtheFennoscandianShield; Pitkäranta, Russian Karelia (Valkama etal., 2016a) and Sarvlaxviken, southern Finland(Cooketal.,2011;Valkamaetal.,2016b;Bromanet al., 2017).These sulphide/oxidedeposits arecloselyassociatedwithA-typegranites,hostedbymarbles (Pitkäranta) at km-distance from the1.54GaSalmiBatholithorvariousgranitetypes(Sarvlaxviken) within the 1.64 Ga WiborgBatholith.

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The batholiths display complex magmaticevolution trends from gabbro-anorthosites, viawiborgites, pyterlites and transitional granitephases to evolved late-stage plutons. Thewiborgites and pyterlites have typical WPGgeochemicalpatternswithshallowREEpatternsandsignificantnegativeEuanomaliesbutdidnotcreate any hydrothermal systems or metalaccumulations.

Incontrast,some(butnotall)latephasegraniteplutons(<1kmdiameters),providedmetalsandheat for themetal-richhydrothermal fluids andthus indium-rich polymetallic accumulations.These plutons have also WPG characteristics(although fake “syn-collisional granite” signalsareseeninsomediscriminationdiagramsduetohydrothermalinfluence).

Zr/HfRb/Ba

Wiborgites,Sarvlaxviken43-50<0.2

Pyterlites,Pitkäranta28-40<0.3

Transitionalphases(RepomäkiandNietjärvi),Pitkäranta15-242-18

Lategranitephase(Marviken),Sarvlaxviken17-2211-23

Lategranitephases,Pitkäranta7-1410-150

The late igneous phases can be evaluated byseveral geochemical criteria but the low Zr/Hfratios, high Rb/Ba ratios and enrichments ofheavy REE are the most characteristic featuresfortheorefertilegranites(Torppusuo,Ristinoja-MosautodorandUuksuinthePitkärantaareaandMarvikenintheSarvlaxvikenarea).

POSTER

ChronologyandgeochemicalandstructuralevolutionofdykesintrudingtheReinfjordultramafictomaficintrusionintheSeilandIgneousProvince

AlfAndreOrvik1,BjørnEskeSørensen1,RuneLarsen1andThomasGrant11DepartmentofGeoscienceandPetroleum,NTNU,Norway

This study investigates the chronology,geochemical and structural evolution of dykesintruding the Reinfjord Ultramafic Complex(RUC) consting of large volumes of ultramafic,mafic, silicic and alkaline melts intruded thelower crust (~30 km) from 570-560 Ma in anextensional regime. The RUC was nested tobaltica the Caledonian orogeny. Earlier studieshave indicated horizons with anomalousconcentrations of Pt+Pd+Au+Os and enrichedhorizonsofCu-Ni.

The ultramafic rocks are cut by severalgenerations of dykes ranging from replacivedunitedykes intrudedintothesemi-consolidatehost-rockwithgradualcontacts,tolategabbroicdykesthathasachilledmargin.Thedykeshavecomplex crosscutting relations and in areas itconstitutes up to 50 % of the outcrop volume.Large variability in chemistry and volatilecontent ranging from wherlites, olivineclinopyroxenites, hornblende bearing olivineclinopyroxenites, hornblende gabbro, alkalineandlamphrophyricdykes.

A relative chronology of the dykes wasestablishedby the cross cutting relationsof thedykes during fieldwork and post processing of3D photogrammetry fromdrone imageswill beused to estimate the melt volumes within thedifferent dyke types and their orientationevolutionover timewithin selected locationsofthe central series. Petrographic descriptions ofattainedsamplestogetherwithchemicalanalysis,and hopefully radiometric dating, will incombinationwiththephotogrammetricdatagiveinsightintheevolutionofthemeltrelatedtothe

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dykes.Ourambitionisthatthedatawillprovidevaluable information and constrain thechronological progression of the geochemistryandtectonomagmaticassociationofthedykes.

POSTER

PlatinumGroupMineralsintheReinfjordUltramaficComplex

EvenSunnanåNikolaisen1,RuneBerg-EdlandLarsen1,ThomasGrant,BjørnEskeSørensen1andSuzanneMcEnroe11NorwegianUniversityofScienceandTechnology(NTNU),DepartmentofGeoscienceandPetroleum.SemS

Anupwellingmantleplume560-570MaformedtheSeilandIntrusiveProvince(SIP),a5400km2area of felsic to ultramafic rocks in NorthernNorway.TheReinfjordIntrusiveComplex(RUC)is the southernmost part, exposing 25km2 ofultramafic rocks that are generated from threeintrusive magmatic events and crystalfractionation. These events show evidence thatRUC is representing an open magma chamber,connectedtoaconduitsystemat25-30kmdepthand subjected to extensive magmareplenishment.

ExplorationdrillcoresinRUCin2011(RF-1andRF-2) show two spikes for economic elements,oneCu-NireeflowinPGEatdepthof86-93mandaPGEreeflowinCu-Niat107-113m

A detailed analysis of a 6 m drill core section,suggest PGE being segregated in differentlithologies,whichcombinetoatotalof0.79ppmPGE.When comparing the δ34S signature of thePGE reef with the Cu-Ni reef shows a distinctdifference -0.40 (PGE) and -4.56 (Cu-Ni),indicatingdifferentsources.

Thisstudy looks into thedetailsof thePGE’s,with the aim of identifying the ore formingprocesses. SEM imaging and mapping, EPMA,magneticanalysisandwholerockgeochemistryareusedtofindcrypticvariationsinthePGErichlithologies.BSEandEDSdetectsandidentifythePGE’s, with EPMA data to calculate empirical

formulas for PGM identification. Based on theresults, it is clear thatdespitea sub-economicalgrade,theRUCprovideavaluableinsightintotheore forming potential for deep-seated layeredintrusions.

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1.11.Opensessiononpetrologyandgeochemistry

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Additionalconstraintstotheevolutionoftheearlysolarsystem?AU-PbsystematicsstudyofungroupeddifferentiatedachondriteNWA4587.

YuriAmelin1andElinRydeblad21AustralianNationalUniversity,2UppsalaUniversity

The study of meteorites can help us answerquestionsstillunderdebate regarding theearlysolarsystemandtheprocesses therein. Itcouldhelpusunifyatimescaleforthedevelopmentofthe solar system, help us fully understand howourplanetsformed,andtellusaboutthenatureofelementaldispersalthroughouttheearlysolarsystem (Amelin and Ireland, 2011).It will alsoallow us to investigate how our solar systemcompares to other solar systems – giving us aninvaluabletool in thesearch forotherhabitableplanets and possible life, and future celestialexploration(White,2011).

Thisstudyaimstoaddadditionalconstraintstothe evolution of the early solar system by theisotopic analysis of ungrouped differentiatedachondriteNorthWestAfrica(NWA)4587.

All sample processing was performed at theSPIDE2R laboratory facilities, located at theResearchSchoolofEarthSciences(RSES)at theAustralianNationalUniversity(ANU).FortheU-Pb systematics, four separate hand-pickedpyroxenefractionswereanalysed.Thefractionswere chosen based on mineral grain texture,colour, and size. This study employed an acidleachinganddissolutionprotocol,combinedwithsingle-anddoublepassμ-columnprotocols.ThePbratiosandisotopiccompositionofthesampleswere analysed using a thermal ionisationmassspectrometer.

The age of NWA4587 is 4563.63±0.55 Ma,suggesting that its parent body was formedduring early planetary accretion. Further

analyses of Rb-Sr isotope systematics arecurrently being conducted, and the preliminaryresultsareconcordantwith theagedeterminedbytheU-Pbsystematics.

ORAL

TheEARTHTIMEInitiative:Acommunityworkingtoacceleratethedevelopmentandapplicationofintegratedmethodologiesforthequantificationofgeologicaltime.

DanielCondon11BritishGeologicalSurvey,Nottinghamshire,NG125GG,UK

The EARTHTIME Initiative is an internationalcommunity effort to 'To accelerate thedevelopment and application of integratedmethodologiesforthequantificationofgeologicaltimefortheunderpinningofEarthsciences'.Thefirstphase(from2004andongoing)wasfocusedonaddressingurgentshortcomingsinthe ‘high-precision’geochronometers(e.g.,U-Pband40Ar-39Ar),issuesthatlimitwidespreadapplicationatthequotedlevelsofprecision/accuracy.Manyofthese (e.g., inter-laboratory bias) have beenaddressed throughexperiments conductedoverthepast13yearsandtheaccuracyandprecisionofbothofthesewidelyuseddatingsystemshasbeen significantly improved. The EARTHTIMEInitiative has brought the40Ar-39Ar and U-Pbisotope dilution sides together (for bothexperimentsandapplication)butalsoexpandedto includearangeofdecayschemes(e.g.,Re-Osand U-Th) and analytical approaches (e.g.,microbeam U-Pb). Perhaps themost significantoutcome has been the development of a strongand lasting sense of a 'geochronologycommunity'.

Whilst these Phase 1 activities continue, theoriginalmotivation for accelerating progress inthe various dating methods has been that theyunderpinawiderangeofEarthscienceresearchareas. Starting in 2016 a second phase ofEARTHTIME has been initiated, following two

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communityworkshops,witharenewedemphasisonengagementofthegeochronologycommunitywith the 'end-users' of geochronology. Thispresentation will provide a summary ofEARTHTIME efforts since 2004 to present tocalibrate and inter-calibrate thegeochronometers, andwillprovideavisionandstrategyforthesecondphaseoftheEARTHTIMEInitiative.

ORAL

PangeaassemblyanditsimplicationstothemidPermian–TriassicmagmatismonthesouthwesternmarginofSouthAmerica

ÁlvarodelRey1,KatjaDeckart2,CésarArriagada2andFernandoMartínez21NaturalHistoryMuseumofDenmark,UniversityofCopenhagen,Copenhagen,Denmark,2DepartamentodeGeología,UniversidaddeChile,Santiago,Chile.

TheChileanFrontalAndesbatholiths(28°–31°S)represent part of the extensive late Paleozoic–Triassic magmatism along the southwesternmarginofSouthAmerica.Despiteitsimportance,a consensus regarding the tectonic modelcontrollingthemagmatismhasnotbeenreached.Several models1,2,3 have proposed cessation ofsubduction as the reason behind the apparentlack of typical arc magmas and abundance ofwithin plate signatures. Yet the causes for thiscessation differ and do not provide acomprehensivemodelforcoevalunitsalongthemargin.Here,newLA-ICPMSU–Pbinzirconages,and geochemical and isotope analyses (Rb-Sr,Sm-Nd,Lu-Hf,Re-Osandd18O)indicatethatmidPermian–Triassicgraniticmagmatismoriginatedin a slab rollback extensional setting withincreasing thinning towards Triassic times.Subductionandanataxisoflowercrustwerethemainmagma-generationmechanisms, the lattercaused by decompression and subsequentaccumulation of underplating basalts. Acomparison with other igneous units along theChilean–Argentinian border allows extension ofthis model from at least 21° to 40°S. The key

element triggering intense extension in asubduction setting (slab rollback) is lowsubductionvelocities-asnumericalmodelshavepredicted4, which can be attributed to thetransitory stage of Pangea (mid Permian–Triassic).Hence, subductionof thepaleo-Pacificoceanic plate beneath paleo-South America hasbeena continuousprocess fromearlyPaleozoictimesonwards;andPangeaassembly,thesettingbehindtheobservedchanges in themagmatismandnot thecessationofsubductionaspreviousmodelshaveinvoked.

ORAL

Tourmalinetexturesandstructuresasatracerforthemagmatic-hydrothermaltransitioninSWEngland

KristianDrivenes1,RuneLarsen1,BjørnEskeSørensen1andSamHughes21NorwegianUniversityofScienceandTechnology,2CamborneSchoolofMines,UniversityofExeter

Tourmalineisacommonmineralthroughoutthegranites of SW England. It occurs in multipletexturalandstructuralvarieties,includingveins,quartz-tourmaline orbicules, massive quartz-tourmalinerocks(MQT),pegmatiticpockets,anddisseminated in the granite. Field relationsindicate both magmatic tourmaline and post-magmatic,hydrothermaltourmaline,occuringasdisseminated grains and veins, respectively. Inaddition,more genetically complex textures areobserved as gradual exsolutions of quartz-tourmaline rocks within the granite, with orwithoutassociatedveining.Theseappearonthecm scale and up to several meter large bodies.Suchstructuresareobservedinlocalitiesseveralkmapart,andarearegionalfeature.Occasionally,the gradual transition from granite to MQT tomiarolitictourmalineorapuretourmalinezone,can be observed over tens of cm. Themicrotextures are strongly linked to themacroscopic structures, reflecting the diverseprocesses that formed the different tourmalineoccurrences. Strongly birefringent, green,

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acicular tourmaline dominates in vein-styletourmaline; disseminated tourmaline in thegranite isweakly zoned andbrown; tourmalinefrom MQT is brown with blue rims. Latertourmaline generations overgrow earliergenerations,addingtothecomplexity.Cassiteriteis only associatedwith the hydrothermal greenacicular tourmaline.Tinconcentrations inothertourmaline-richrocksarelessthan100ppm,andthese rocks are not a part of the mineralizingeventsoftheLand’sEndgranite.

ORAL

DendriticCoreCrystallizationinMinorPlanets–AnempiricallyconstrainedNumericalSimulationStudy

KimEsbensen1,HenningHaack2,KennyErleben3andMarekMisztal41GEUS,AAU,KHEConsulting,2MaineMineralandGemMuseum,Maine,USA,3DepartmentofComputerScience,CopenhagenUniversity,4NielsBohrInstitute

The Cape York meteorite shower typifies themagmatic iron meteorites. The Agpalilik massdisplays characteristic oriented, elongatedtroilite nodules, interpreted to testify to adendritic crystallisation mode of surrounding(Fe,Ni) metal phase (Esbensen (1981, 2017);Esbensen & Buchwald (1982); Esbensen et al.(1982; Haack & Scott (1992). The troiliteaccessorymineralogytestifiesthatthefractionalcrystallisation / late magmatic differentiationhistoryofasteroidcorescanbemodelled intheFe–Ni–S-Psystem.Accessoryschreibersiteandhigh-Nitaenitearefoundliningthemetal/troiliteinterface, representing very late crystallisationfrom an evolved Fe-Ni-S-P liquid. Atroilite/taenite eutectic represents the ultimateliquid-solid transformation product (theparagenesis shows that schreibersiteprecipitated prior to taenite crystallization,effectivelypurgingthesystemforP),allowingtheultimate crystallisation to be modeled in theresidual Fe-Ni-S system, which thus defines aniron meteorite analogue to the petrogenetic

residualsystemforsilicatemagmaticrocks.Theinter-dendriteresidualmeltpocketphysiography(3rd or 5th order arms) allows to attempt anambitiousfractalnumericalsimulationmodellingof the crystallization of the early solar systemasteroid/planetoidmetallic cores. Agpalilik willserve as an empirical constraint for numericaldendritic crystallization modelling, based on asimplifiedFe-Ssystem,believed toapproximate(Fe,Ni)-Swell.Itisfirstinthelatestyearsthatithas been possible to tackle the numericalsimulation challenges involved, Misztal MK,Bærentzen JA (2012); Misztal MK, Erleben K,Bargteil A, (2014). We present a first forayoverviewof the scopeof this challengingmulti-disciplinarystudy.

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AgeandgeochemistryofgranitoidsinthePrecambrianbasementofÖland,SESweden–implicationsfortheextensionoftheTransscandinavianIgneousBeltintheBalticSearegion

EvgeniaSalin1,KristerSundblad1,HughO'Brien2,YannLahaye2andJeremyWoodard31UniversityofTurku,20014Turku,FINLAND,2GeologicalSurveyofFinland,02151Espoo,FINLAND,3UniversityofKwaZuluNatal,Westville(Durban),X54001,SOUTHAFRICA

ThePrecambriancrustintheBalticSearegionismostly covered by Phanerozoic sedimentaryrocks but can be studied in drill cores. Twogranitoids from the crystalline basement belowÖland were collected from the archives of theGeological Survey of Sweden and analyzed forgeochemistryanddatedwiththeU-Pbmethodonzircons. The Böda Hamn granitoid (northernÖland)has amonzodioritic composition and anageof1799.8±3Mawhile theValsnäsgranitoid(central Öland) has a quartz monzoniticcompositionandanageof1784.9±5.7Ma.Thesegeochemical-isotopic characteristics arecompatible with those of generation 1 of theTransscandinavian Igneous Belt (TIB) in theFennoscandianShield,≥30kmwestofÖland.

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Amoredetailed reviewof theTIB-1generationshowsthattwosub-generations(1aand1b)canbe distinguished on each respective side of theOskarshamn-Jönköping Belt (OJB). Sub-generation1a(northofOJB)hasanagespanof1794-1808Mawhilesub-generation1b(southofOJB)hasanagespanof1769-1793Ma.Accordingtothissubdivision,theBödaHamnmonzodioritebelongstosub-generation1a,whichalsocanbefollowed to southernmostGotland (Sundblad etal. 2003) and the Valsnäs quartz monzonitebelongs to sub-generation 1b, which can befollowed to the Latvian/Lithuanian border,where a marginally younger granitoid wasreportedfromoffshoredrillcoreE-7(Salinetal.2016). Taken together, these data suggest thattheTransscandinavianIgneousBeltcanbetracedacross the Baltic Sea from the exposed partswithin the Fennoscandian Shield to theLatvian/Lithuanianborder.

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SrisotopezoninginplagioclasefromCenozoicandesitesfromCaboDeGata,Spain:evidenceforshallowanddeepcontamination

TodWaight1andJakobTørnqvist11DepartmentofGeosciencesandNaturalResourceManagement(GeologySection),CopenhagenUniversity

Subduction-related andesites from the Cabo DeGata region in Southern Spain are part of thelarger Alboran Magmatic Province whichstretches from Northern Africa, through theAlboranSeaintoSouthernSpain.Theprovinceisof interest due to the penecontemporaneousoccurrence of a wide variety of magmacompositions(incl.tholeiiticbasalts,calc-alkalineandesites, explosive rhyolites, peraluminouscrustal melts and lamproites) and temporaloverlapwiththeMessinianSalinityCrisis.ManyplagioclasephenocrystswithinandesitedomesatCaboDeGataarecharacterizedbyresorbedhigh-An% cores (An73-85) surrounded by oscillatoryzonedplagioclase(An40-60).Srisotopeanalysesofthe high An% cores of these plagioclases show

consistently radiogenic 87Sr/86Sr compositions(0.7127-0.7129). These compositions areinconsistent with an origin as xenocrysts fromearly formed mafic volcanics or frommetamorphosedcarbonatesinthebasement.Weinterpret these high-An% cores to be earlyformed phenocrysts crystallizing from moreprimitiveandrelativelywater-richmagmasinthedeep crust. Their radiogenic Sr isotopecompositions suggest that these early magmasalready had a significant crustal component,consistent with other evidence for importantinvolvementofasubductedsedimentcomponentduringmagmatism. The resorbed nature of thehigh-An% cores is interpreted to reflectresorption during rapid magma migration intotheuppercrust.LowerAn%rimsofthesesameplagioclases show increases in 87Sr/86Sr (up to0.7132)thatareconsistentwithinteractionswithcrust in upper crustal magma chambers. Theplagioclase Sr isotope data therefore provideevidence for both source and crustalcontamination during petrogenesis of the CaboDeGataandesites.

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RecyclingofcontinentalmaterialthroughthesuprasubductionzoneMawatophiolite,NEIraq

HeiderAlHumadi1,MarkkuVäisänen2,SabahIsmail3,YannLahaye4,HughO’Brien4,JaakkoKara2andMarjaLehtonen41Dpet.ofGeogr.andGeo.Uni.ofTurku,Finland/Dept.ofAppl.Geo.Uni.ofBabylon,Iraq,2DepartmentofGeographyandGeology,FI-20014UniversityofTurku,Finland,3DepartmentofAppliedGeology,CollegeofSciences,UniversityofKirkuk,Iraq,4GeologicalSurveyofFinland,FI-02151Espoo,Finland

Thefateofsubductedcontinentalmaterialisnotfullyunderstood.Itisestimatedthatupto20%ofitisrecycledbacktothecrust(Cliftetal.2009),mainly in volcanic arcs. Recently,suprasubduction zone ophiolites formed abovesubduction zones have also been shown tocontainrecycledcontinentalminerals(Robinsonetal.2015).

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We have analysed zircons and monazites fromthree felsic dykes and zircons from two maficrocks from the mantle section of thesuprasubduction zone Mawat ophiolite in NEIraq. Laser ablation single-grain U-Pb resultsshow a wide range of ages from the Late-Cretaceous to Paleo-Archean (c. 95-3500 Ma).Theyoungest95Maagerepresentstheformationof theMawat ophiolitewhereas the bulk of thezirconsareinheritedfromolderunknownmixedcontinental material. Lu-Hf isotopes on zirconsfroma felsic sample showaverage initial εHf=–2.4. The results indicate that the magmaoriginated from an older source possiblycontaminated in themantlewedge. In contrast,theinitialεHfvaluesofthemaficsampledisplayanaverage of + 9.4, indicating a juvenile magmasource.

The results show that the felsic rocks of theMawat ophiolite formed in a forearc positionpartly from recycled older continental materialwhich was most likely subducted as the upperlayeroftheNeo-Tethyanoceaniccrust.Theeffectoftheoldercrustalmaterialonthenewly-formedmafic crust is significantly less based on theHfdata,butneverthelessisinclearevidencebytheoccurrenceofoldxenocrysticzircon.

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OxidativeweatheringintheLateNeoproterozoic:PreliminaryCrIsotoperesultsfromtheUrucumDistrict,Brazil

TrygviBechÁrting1andRobertFrei21UniversityofCopenhagen,ØsterVoldgade10,1350CopenhagenK,Denmark,2UniversityofCopenhagen,ØsterVoldgade10,1350CopenhagenK,Denmark

The Fe andMn deposits in the Urucum district(BandaAlta Fm.) inMatoGrosso do Sul, Brazil,which are associated with glaciogenic deposits,areamong theyoungestand largestCryogeniansedimentaryFeandMnformations(IF,MnF).TheUrucum IF comprise plane-parallel, stratifiedhematite-chert iron with interspersedmanganesemicro- andmesobands.A lowerage

limitof695±17MaisdefinedbydetritalzirconU-PbfromshaleybedsintheBandaAltaFm.(Freiet al. 2017). Preliminary results from boreholesamples (Vetria borehole 28-32) supportprevious findingswith a positively fractionatedauthigenic Cr isotope signature throughout thestratigraphic section (d53CrSRM979 = 0.80 ± 0.25‰, 2s, n=26/28). This indicates a continentalsourceofoxidizedCr,implyinghighatmosphericO2levelsinthelateNeoproterozoic.

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Quadlab–A40Ar/39ArandnoblegasisotopelaboratoryattheNaturalHistoryMuseumofDenmark

MichaelStorey1andDanielWielandt11Quadlab,NaturalHistoryMuseumofDenmark

In this poster presentation we provide anoverviewofQuadlab,aVillumFoundationfunded40Ar/39Ar age-dating and noble gas isotopelaboratory thathasrecentlybeenestablishedatthe Natural History Museum of Denmark. Thelaboratory has two noble gas mass-spectrometers: (1) A Nu Instruments Noblessefrom2005-equippedwith3ioncounters(high,axial and lowmass positions) and a highmassFaradaydetector;(2)AThermo-FischerHelixMChigh-resolution noble gas mass-spectrometer(commissioned spring 2016), equipped with 5dual faraday/ion counting detectors with 1012and1013ohmamplifiersforimproved(signaltonoiseratio)ofargonisotopes.TheHelixhasa120degrees magnet with a standard resolution of900, allowing full resolution of hydrocarbonisobarsintheArmassrange36to40.Thehigh-resolutionmodeonchannelL2hasaresolutionof1700allowingpsudeoresolutionoftheHClisobarfrom 36Ar. Three independent laser-sample gaspreparation systems supply the 2 mass-spectrometers, with one preparation systemdesigned and dedicated specifically forcosmogenicnuclide exposuredating (3He, 21Ne)applications.ThissystemisequippedwithaJanisclosed cycle cold trap system (CCSTRAP-HT/204N) to 7K for sequential release and

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measurementofthedifferentnoblegases.Wearemainly applying these tools to Quaternaryproblems, such as hominin evolution and therelationshipbetweenvolcanismandclimate.We

arealsocurrentlyworkingonprojectsrelatedtometeoritesandimpactstructures.

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2.Metamorphicrocksandprocesses2.1.GeodynamicandgeologicalevolutionoftheArctic

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Whenaplatform-edgemeetsaplatform:3Dsedimentaryarchitectureofalarge-scaleprogradingparalicsystem,SWEdgeøya,Svalbard

IngridAnell1,DanielaRöhnert1,AlvarBraathen1,KeiOgata2,PerTerjeOsmundsen3,AleksandraSmyrak-Sikora4,HarmonMaher5,SnorreOlaussen4,GarethLord6,IvarMidtkandal1,MarkMulrooney1andSimonBuckley71DepartmentofGeosciences,UniversityinOslo,Norway,2VrijeUniversity,Amsterdam,Holland,3GeologicalSurveyofNorway,Trondheim,Norway,4DepartmentofArcticGeology,UniversityCentreinSvalbard,Norway,5UniversityofNebraskaatOmaha,USA,6TyrExplorationAS,Trondheim,Norway,7UniResearchAS,Bergen,Norway

The study combines facies analysis fromsedimentary logs with pseudo 3Dphotogrammetric observations to provide alarge-scaleregionalunderstandingoftheCarniandepositional development around SW Edgeøya,which was filled by strongly tidally influenceddeltaic systems. Prism-scale NW advancingTriassic clinoforms are documented in seismicdataonthenorthernBarentsShelf.Thesigmoidalclinoforms progressively form low-angle, lineartabular geometries, as the prograding systemapproaches Edgeøya. The studied successiondocumentsverylowangleinfillfromdeepbasinto coastal plain reflecting the advance of theclinoform system across the high. The studyprovides understanding of how the scale of thesystem, sandbody geometry and sedimentaryprocesses were affected by more limitedaccommodationandincreasedtidalreworking.

Thestudiedsuccessiondocumentsanearlybase-level fall during which large amounts of sand

were arrested in fault-bounded half-grabens atKvalpynten,whilebypassanderosionisapparenttowardstheEast.Accretionduringasubsequenttransgression documents continued highsedimentary inputduringrelativesea-levelrise.PaleocurrentandshalingoutattesttolocalinfluxfromanE/NEsourcearoundKvalpynten,whileatSvartpynten the regionalNW trend is apparent.Svartpyntenrevealsamoreshore-lineproximallocation, and following transgression, tidal barsindicate proximity to the fluvial source. AtKvalpynten laterally extensive subtidal sand-sheets grade into distinctly flat-based lens-shaped sand-bodies, likely shoaling barriersands.Avarietyofchannel-fillsisdocumentedinthe overlying succession, which consistspredominately of highly bioturbated shelteredintertidal mud-flats grading andinterfingeringwithvegetatedcoastalplain.

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LateTriassicsandstoneprovenanceoftheBarentsShelf;aregionalcomparisonofpreliminarydetritalzircongeochronologicalandpetrographicdata

TrondS.Harstad1,MaiBrittE.Mørk1andTrondSlagstad21NorwegianUniversityofScienceandTechnology(NTNU),2GeologicalSurveyofNorway(NGU)

Several scientific contributions have beenpublishedinthelastyearsonTriassicsandstoneprovenanceintheBarentsShelfandArcticareas.AsouthernoreasternUralidecomponentiswellestablishedinpartsoftheTriassic, inparticularinsouth-easternareasoftheshelf.Morerecently,possiblesedimentcontributionsfromapossiblenorthernUralidesourceareaintheLateTriassichas been discussed. In our study, we aim toidentify and compare sandstone provenancesignatures in selected locations of the UpperTriassicDeGeerdalenandSnaddformationsinanorth - south transect from Svalbard to the

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Nordkapp Basin. Petrographic observationsreveal lithic and feldspathic sandstonecompositions, notably with plagioclasedominatingoverK-feldspar,andcharacterisedbylithic fragments of volcanic, metasedimentaryand sedimentary origin. The polycrystallinequartzcontentrepresentsdeformedquartziteaswell as chert and spiculites. Chromium spinel,apatite, garnet, rutile, tourmaline and zirconheavy minerals are observed in varyingabundance. Preliminary detrital zircon agespectra from Svalbard, are similar to publishedzircon spectra of the larger Arctic region,including Triassic peaks of nearly syn-depositional ages. A dominance of Permian toCarboniferous zircons is compatible with anearlier inferred Uralide provenance to the east.However, a significant Caledonian agecomponent has also been identified, whichsuggests a possible contribution from westernareas.Currently,petrographicanalysisofcentraland southern areas of the transect will becomparedwithresultsinprogressfromongoingzircon analysis, and current regional geologicalknowledge, for better constraining alternativesourceareasignatures.

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FormationandOrigindeterminationbygeochemicalfingerprintingofrubyandpinksapphirefromtheFiskenæssetcomplex,Greenland

NynkeKeulen1,TonnyB.Thomsen1,JohnC.Schumacher2,MajkenD.Poulsen3,PerKalvig1,TorstenVennemann4andRitaSalimi11GeologicalSurveyofDenmarkandGreenland(GEUS),Denmark,2DepartmentofGeology,PortlandStateUniversity,Portland,3GeologicalSurveyofDenmarkandGreenland(GEUS),Denmark&Greenland,4InstituteofEarthSurfaceDynamics,UniversityofLausanne,Géopolis,Switzerland

Metamorphic petrology observations on rubiesfound in-situ in their host-rock are combinedwith geochemical measurements and opticalmicroscopy observations on the same rubies,with the aim to connect the ruby-forming

metamorphicreactiontoauniquefingerprintforthese minerals. The Fiskenæsset complex inGreenland is used as an area of case study.Isochemicalpressure-temperaturesectionswerecalculated based on electron microprobe andwhole-rock geochemistry analyses, andcompared to field observations. Rubies wereformed resulting from a reaction betweenolivine/serpentine and anorthite, triggered bythe intrusionof apegmatite.Al is sourced fromthe anorthite, the pegmatite reacts toanthophyllite, Cr3+ is mobile in the pegmatiticfluid, giving colour to the rubies. The ruby-formingreactionoccursat640°Cand7kbar.Inordertoestablishtheuniquefingerprintforthisruby-bearing ultramafic complex, laser-ablationinductively-coupled-plasma mass-spectrometrytrace element measurements, oxygen isotopecompositions, optical microscopy and scanningelectron microscopy were applied. Due to thesetting in an ultramafic rock-anorthosite-leucogabbro complex, the fingerprint of therubies from the Fiskenæsset complex is ratherunique.FiskenæssetcomplexrubiescontainhighCr, intermediate Fe, and low V, Ga, and Ticoncentrations,lowoxygenisotopevalues(1.6to4.2 ‰) and a rarely-observed combination ofoptical growth features and mineral inclusionslike anthophyllite+biotite. Results for otherGreenlandic localities are presented anddiscussedaswell.Eventhoughthesearederivedfrom ultramafic rock settings too, they recorddifferenttraceelementratiosandoxygenisotopevalues, resulting from variations in the ruby-formingreaction.

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NorskPolarNavigasjon’sarchiveofoldexploratorywellsonSvalbard

KirstiMidttømme11ChristianMichelsenResearchAS

Duringa30yearperiodfromthe1960'sto1990'sseveraldeepexploratorywells foroildrilledonSvalbard . The deepest well at Ishøgda was3304mdeep.NorskPolarNavigasjon(NPN),the

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first Norwegian oil company, was involved innine of the drillings. NPNs archive withinformation from the drillings has been madeavailableforthisstudy.

Though oil or gas was detected in the wells atIshøgda,TromsøbreenandSarstangen, allwellswaspluggedandabandoned.

Geologicalandgeophysicalinformationfromthewells are limited, but there are interestedinformation of borehole stratigraphy, gashydrates and geothermal gradients thatwill bepresentedanddiscussed

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DEVELOPMENTOFTHEAMERASIABASIN:WHEREAREWENOW?

VictoriaPease1,HeminKoyi2andFaramarzNilfouroushan31StockhkolmUniversity,2UppsalaUniversity,3UniversityofGävle

TheAmerasiaBasinisseparatedintotheCanadaBasinandtheMakarov-PovodnikovbasinsbytheAlpha-Mendeleev Ridges. Published datasupports a conjugate relationship between theAlaskan and Canadian Arcticmargins, in whichcounterclockwise rotationofArcticAlaska fromArctic Canada resulted in the opening of theCanadaBasin.Thusthetectonicdevelopmentofthe Canada Basin is ‘broadly’ understood,although the precise timing and the role of theChukchiPlateauremaindisputed.ThisleavestheAmerasia Basin andwe identify two significantbarriers to understanding its tectonicdevelopment: i) The northward extent of theCanada Basin fossil spreading ridge, and ii) theroleofLIPmagmatism. Inassessing the former,we simulated extension in a series of two-plateanaloguemodelswithpropertieshomologousofhomogeneous continental crust around acommonrotationaxis.Inallmodels,atriangular(ocean)basinformsbetweenthetwo‘diverging’plates, however, depending on the mode ofopening and initial plate configurationtranspressive,transtensive,and‘pure’strike-slip

structurescanbegeneratedandaccountforthefollowingfirstorderobservations:i)curvatureinthe fossil ridge, ii) transcurrent margins ofopposite motion, and ii)asymmetry of thebasin. Theseresultselucidatetheconsequencesofsea-floorspreadingintheAmerasiaBasinandhelptoconstrainopeningscenarios.

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Tectonostratigraphicatlases:furtherperspectiveinArcticresearch

OlegPetrov1,SergeyShokalsky1,NikolaySobolev1,SergeyKashubin1,EugenyPetrov1,DenisLeontiev1andTatianaTolmacheva11RussianGeologicalResearchInstitute(VSEGEI)

IntensivestudyintheArcticduringlast15yearshasresultedintheaccumulationofnewdataonthe geology of the region, including thoseobtained during geophysical sounding of theoceanfloor,examinationofbottomrockmaterial,studying geology of islands and the continentalpart of the Russian Arctic. One of theinternational projects is the Atlas of GeologicalMaps of the Circumpolar Arctic at a scale of1:5,000,000, which includes geological andtectonicmaps,potentialfieldmaps,andmineralresourcesmap.ModernlevelofknowledgeoftheArcticallowstheanalysisoftectonostratigraphyand litho-geodynamics of the region andinterpretationofgeologicalcomplexesintermsoftectonic settings of stratigraphic sequencesformationbased.TheAtlas“GeologicalHistoryofthe Barents Sea” (2009) by Russia andNorwaywasfirstexperienceintheimplementationofthiswork.

In 2014, geological surveys of the Arctic statescomplied the “Tectonostratigraphic Atlas of theNorth-East Atlantic region”. Currently, theRussian Geological Research Institute (VSEGEI)actively works on compilation of the“Tectonostratigraphic Atlas”, covering theeastern Russian Arctic continental part andeasternEurasianbasin.

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Compilation of the Atlas as a set of systematicmodern geological information is of greatimportance for understanding the geology andhistory of tectonic development of thisinsufficientlystudiedregion.

TogetherwiththeNPDandtheNGU,wearegoingtocompiletheTectonostratigraphicatlasfortheBarents-Kara region. The work atTectonostratigraphicatlasesisanewstageinthedevelopmentoftheinternationalcooperationintheArctic.

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CrustalstructureoftheEurekanOrogenonEllesmereIsland,ArcticCanada

ChristianSchiffer1andRandellStephenson21DepartmentofEarthScience,DurhamUniversity,2SchoolofGeosciences,UniversityofAberdeen

Receiver function analysis of new broadband-seismological data provides images of crustalstructurealonganapprox.500kmlongtransectacrossEllesmereIsland.Thegravityresponseofthis crustal transect is consistent with regionalgravity anomalies. The new data are,furthermore, integrated with existing crustalinformation to produce regional maps. Distinctcrustal features are identified, such as crustalthickness variations, the presence of highvelocity/density lower crust, thickmetasedimentary layers as well as shallowyoungersedimentarysuccessions.

Moho depths can be interpreted in terms ofEurekan(Cenozoic)andEllesmerian(Palaeozoic)deformation. A zone of thick metasedmentarylayersincentralEllesmereIslandcorrelateswithareas of dominantly Ellesmerian accretion. AWSW-ENE orientated zone of shallow Moho(Hazen Stable Block) underlies crust stronglydeformed in the Palaeozoic but essentiallyundeformed in the Cenozoic. A block of thickcrystallinecrustinthenorthofEllesmereIslandis clearly separated from the North American-Greenland Craton by the deep (meta-

)sedimentary successions, possibly a hint for anorthern microcontinent. High velocity lowercrustmay be related to igneous activity duringseveralriftepisodesand/orimpactbyHighArcticLarge Igneous Province magmatism. Acorrelationappearstoexistbetweentopography,MohodepthandthelocationofdykesinNansenSound suggesting the same tectono-magmaticorigin of these features. Lincoln Sea showsconsistentlythincrustlikelyrelatedtorifting.

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DetailsontheCretaceousoceanformationintheHighArcticbasedonsatellitegravitydata

ArneDøssing1,CarmenGaina2,OleBaltazarAndersen1andH.Ruth.Jackson31DTUSpace,Denmark,2CEED,UniversityofOslo,3(4)GeologicalSurveyofCanadaAtlantic,Dartmouth,NovaScotia

Understanding the evolution of ocean basins,critical for global studies in plate tectonics,mantle dynamics, and sea-level through time,relies on identifiable tectonic plate boundaries.Basedonthelatestgenerationofglobalsatellitegravitymodels, recentmarine geophysical dataand vintage aeromagnetic data, we documentconsistenttectonicdetailsontheremoteandill-defined Canada Basin spreading system: theoldestoceansystemintheHighArcticandpartofthe long-disputed greater Amerasia Basin. Weinterpret two distinct phases of possiblyCretaceous sea-floor spreading: the early stagebeing sub-orthogonal and intermediate-spreading (~50mm/yr) of possibleBarremian-Aptian age, while the late stage being highlyoblique, segmented,andslow-spreading (20–40mm/yr) of possible Aptian age. We furtherdemonstratethatthesouthernpartoftheCanadaBasinspreadingsystemmayserveasanancientanalogueofmodernmid-oceanridgepropagationintocontinentalcrust.

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SoapstonefromNuuk:fingerprintingtheoriginandgeologicalhistoryofsoapstone(steatite)suitableforcarvingintheGodthåbsfjord-Ameralikregion(southernWest-Greenland).

NynkeKeulen1,MajkenD.Poulsen2,RobertFrei3,KisserThorsøe4andRebekkaJ.Knudsen51GeologicalSurveyofDenmarkandGreenland(GEUS),NuukGLD&Copenhagen,DK,2GeologicalSurveyofDenmarkandGreenland(GEUS)Nuuk,GLD&DeptofGeosciencesNat.Res.,KU,DK,3DepartmentofGeosciencesandNaturalResourceManagement,CopenhagenUniversity,Denmark,4GeologicalSurveyofDenmarkandGreenland(GEUS)Nuuk,GLD,5GreenlandPerspective,NaturalHistoryMuseumofDenmark,CopenhagenUniversity,DK

SoapstonewasminedandtradedbytheSaqqaq,Dorset, Norse, and Morovian cultures living inGreenland through time, and still has a goodpotentialforsmall-scaleminingasarawmaterialfor carving of art products and for the touristindustry.Wecollectedsoapstone fromoutcropsaround Nuuk, which hold Greenland’s bestquality of soapstone, and analysed theirwhole-rockgeochemistry,Sm-NdandRb-Srisotopesforfingerprinting for geological and archaeologicalpurposes, such that historic artefacts thatweretradedfarawayfromNuukthroughtime,mightbetracedbacktotheNuukarea.FieldworkintheNuuk area showed that the quality of thesoapstoneintheGodthåbsfjord-Ameralikregionactually varies widely; however, a correlationexists with the age and/or the metamorphichistoryof the rocks.Thebestquality soapstoneoccursinabroadbandcuttingthroughthefjordsin the Nuuk area. This area roughly covers thearea with occurrence of Eo-Archaean gneisses.However, the same area was also subject tointense metasomatism of the soapstoneprecursor-rocks associated with fluid activityalongtheIvinnguitfaultzone.Furtherworkwillbe directed to investigate which of thoseprocessesplayedthemajorrole.Expectedly,oneorbothfactorswillprovideagoodfingerprintofthe Nuuk soapstone. Additionally, this

informationwillnarrowdowntheareawithgoodsoapstone occurrences considerably, such thatcitizenswantingto investigate forundiscoveredlocalitieswithgoodqualitysoapstonewillknowto which part of the Godthåbsfjord-Ameralikregion their investigations for new small-scaleminingareasshouldbedirected.

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AlargeDevonianultra-high-pressureprovinceinnortheasternGreenland

ThorstenNagel1,KathrinFassmer2,NikolausFroitzheim2,PeterSprung3andCarstenMünker31Departmentofgeoscience,Aarhus,Denmark,2Steinmann-Institut,BonnUniversity,Germany,3DepartmentforGeologyandMineralogy,CologneUniversity,Germany

The Caledonian orogen in northeasternGreenland consists of a 1200 km long, west-vergent nappe pile. It has traditionally beenviewed as the retro-wedge of the ScandinavianCaledonides. This concept, however, waschallenged by the finding of widely distributedeclogitesaswellasthelargeamountofhorizontalshortening accommodated in the nappe pile.ExistingU-Pb-zircon-andSm-Nd-garnetagesforhigh-pressure metamorphism in the centralsection of the Greenlandic Caledonides scatteraround 420 to 390 Ma. A single UHP-metamorphic location in a structurally internalposition yielded an exceptionally young zirconage of 360 ±5 Ma and a Sm-Nd-garnet age ofaround 330 Ma interpreted to record peak-pressure conditions and cooling, respectively(Gilotti et al. 2004).Wepresent newpetrologicandLu-Hfgarnetagedata from three locations.Samples fromDanmarkshavnrecordultra-high-pressure metamorphic conditions in eclogitesandgrt-pyroxenitesbymeansofSiO2-exsolutionsin cpx, opx-exsolutions in cpx andthermobarometric estimations. An eclogiteyielded a Lu-Hf garnet-whole-rock age of 357.5±2.9Ma thusconfirming theexistingzirconageforUHPmetamorphismobtained140kilometersto the north. Samples from two other locationspreserve the typical high-temperature-

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moderate-pressure eclogite-facies conditionsandyieldagesof383±17Maand398±14Ma,respectively.Resultssuggestthatbesidesthe400Ma event,Devonianultrahigh-pressure rocks innortheastern Greenland may be much widerdistributed than previously known creatingmajorpuzzlesfortectonicreconstructions.

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NewheatflowmeasurementsfromcentralArcticOcean

GraceShephard1,SteffenWiers2,EvgeniaBazhenova3,LaraPérez4,LuzMaríaMejía5,CarinaJohansson6,MartinJakobsson6andMattO'Regan61CentreforEarthEvolutionandDynamics(CEED),UniversityofOslo,2DepartmentofEarthSciences,UppsalaUniversity,3CenterforCoastalandOceanMapping,UniversityofNewHampshire//StPetersburgStateUniversity,4DepartmentofGeophysics,GeologicalSurveyofDenmarkandGreenland(GEUS),5GeologicalInstitute,DepartmentofEarthSciences,ETH,Zürich,6DepartmentofGeologicalSciences,StockholmUniversity

Constrainingthethermalevolutionof theArcticOcean is hampered by notably sparsemeasurements of heat flow. Furthermore,previous results from the central LomonosovRidgeandtheadjacentcentralAmundsenBasinreveal variable magnitudes, including thosehigherthanexpectedconsideringplatecoolingorsimple uniform stretching models. Here wepresentnewheatflowresultsgatheredfrom17sedimentcoresacquiredduringthe“ArcticOcean2016” and “SWERUS-C3” expeditions on theSwedish icebreakerOden.Threesites located intheAmundsenBasinrevealheatflowintheorderof71-95mW/m2, in line-withor slightlyhigher(1-21mW/m2)thanexpectedfromoceanicheatflowcurves.Thesevaluesaresubstantiallylowerthan values of another study, with 104-127mW/m2foundonsimilarlyagedoceaniccrustintheAmundsenBasinlocatedapproximately100-200 km away. Sites from the submergedcontinental fragments of the Lomonosov RidgeandMarvinSpurrecoveredheatflowintheorder

of53-76and51-69mW/m2 respectively.Whenconsideringthepotentialenhancedsurfaceheatfluxfromradiogenicheatproductioninthecrust,thesevariablemeasurementsarebroadlyinlinewithpredictionsfromuniformextensionmodelsfor continental crust. An upper mantle seismicanomaly in the vicinity of theNorthPolemightthereforehaveacompositionalaswellasthermalcomponent. This complexity highlights thedifficultindisentanglingtemporallyandspatiallyevolving crustal, lithospheric and mantleprocesses to present-day surface heat flowcontributions.

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2.2.Deformationandmetamorphismofrocks:Microstructures,processes,andphysicalproperties

ORAL

Anovelgel-mediatedreactionmechanisminmetamorphicrocks

MatthiasKonrad-Schmolke1,RalfHalama2,RichardWirth3,NicoKlitscher3,LuizMorales4andFranziskaWilke31EarthScienceDepartment,UniversityofGothenburg,Sweden,2SchoolofGeography,GeologyandtheEnvironment,KeeleUniversity,UK,3GeoForschungsZentrumPotsdam,GFZ,Potsdam,Germany,4ETHZürich,Switzerland

Fluid-mediated mineral dissolution and re-precipitation is a key mechanism for mineralreactionsindifferentfieldsofEarthandMaterialScience. Mineral reactions in the solid Earthconstrain many geodynamic and geochemicalprocesses,suchasdensitychangesinsubductedoceanic crust, the release of carbon dioxide insubduction zones and the precipitation of oreminerals from percolating fluids. Detailedknowledge about rate-limiting mechanismsduringsuchmineralreactionsisfundamentalforthe quantification of rock transformations andthe associated element transport. Unresolvedquestions regarding fluid-mediated mineraldissolution and re-precipitation are theformationofpermeabilityandthequantificationof the element transport during mineraltransformation.Herewepresentexampleswherethe entire cycle ofmineral dissolution, elementtransport and re-precipitation of newequilibriumphasesisvisualizedinhigh-pressuremetamorphic rocks that experienced re-hydrationinasubductionzone.Thereplacementof primary amphibole and pyroxene in oursamples occurs via coupled dissolution-re-precipitation that involves the formation of anamorphous alkali-Al-Si-rich material. Thisamorphous material forms directly from thereacting minerals by de-polymerization of the

original crystal lattice. De-polymerization startsalongdislocationcoresinthecrystal latticethatserveaselementexchangepathwaysandarealsosites of porosity formation. In our samples, theamorphous material resulting from this de-polymerizationoccupieslargevolumesinasyn-metamorphic interconnected porosity network.Thedirecttransformationofthemineralintotheamorphous state enables element transferdecoupled from the presence of ionic solutions.Precipitation of secondary amphibole occursdirectlyby re-polymerizationof the amorphousmaterialattheproductsurface.

ORAL

Connectionbetweengrainshape,chemicalzonationandtextureasindicatorforfabricdevelopmentineclogites

KaiNeufeld1,HolgerStünitz2,AneKongsroFinstad1andJiriKonopásek11DepartmentofGeosciences,UniversityofTromsø,Norway,2DepartmentofGeosciences,UniversityofTromsø,Norway;InstitutdeSciencesdelaTerre,Universit

Eclogites are the most important piece ofevidence of high pressure conditions insubductionzones.Theirfabricdevelopmentisaninterestingtopicandmayallowtodeterminethedeformation rates in subduction zones. Mostprevious studies suggested dislocation creep tobe the principal process causing the fabricdevelopment,becausemanyeclogite fabricsarequitestrong.Theviabilityofthismaybetestedbystudying the chemical zonation of garnet andomphaciteinordertotrackandquantifytextureand microstructure development in eclogites.Theaimofthisstudyistoassesstheinfluenceofcrystalgrowthonmineralpreferredorientationand therefore its role in fabric development ineclogite-faciesrocks.

VariscanandAlpineeclogitesfromtwodifferentlocations have been studied. In both cases,asymmetricbut still concentric chemical zoningdeveloped during prograde garnet growth

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togetherwithelongatedgarnetgrain shapeandcan be related to a corresponding prograde (interms of pressure change) chemical zoning inomphacitegrains.Crystalplasticdeformationofgarnet can be excluded based on chemicalzonationpatterns.Chemical,microstructuralandtexture data indicate a direct relationshipbetween the growth of garnet and omphacitegrains in the principal stretching direction,causing a strong fabric development duringprogradeandpeakmetamorphic conditions.Nodynamic recrystallization microstructures weredetected. Thus, the textures are interpreted asgrowth fabrics. Dislocation creep as a possiblefabric formation process is excluded. Instead,diffusion creep (grain scale precipitationproducingelongationinthestretchingdirection)is concluded to be the dominant deformationmechanism.

ORAL

Sheardeformationinthetransformationofgabbrotoeclogite:PotentialkeytorheologicalcontrastsinthechangefromHP/UHPconditionstolateramphibolite-faciesdeformation

PeterRobinson1,MichaelP.Terry2andFlorianHeidelbach31GeologicalSurveyofNorway(NGU)N-7491Trondheim,Norway,2POBox553,Naples,NY14512,USA,3BayerischesGeoinstut,UniversitätBayreuth,D95440Bayreuth,Germany

The Proterozoic ~1700-1550 Ma BalticanbasementofthenorthernWesternGneissRegion,Norway, consists of coarse granitoid gneisseslocally intrudedby1466and1250Magabbros.Progressiverelativerheologicalbehaviorof thisdiverse assemblage during Scandian (420-375Ma) subduction to HP/UHP metamorphicconditions (2.5-4 GPa) and exhumation back tonear-surfaceconditions,iskeytounderstandingtectonicdevelopmentthroughmultiplephasesofthrusting,recumbentfolding,andextension.

Recent studies of deformation-enhancedreactions en route to eclogite-facies conditionswithin sheared gabbro have demonstratedprogressivedestructionofplagioclaseinreactionwithpyroxeneandoxidesandgrowthofgarnet,to superplastic behavior in garnet by grain-boundary sliding. Plausibly, during this,rheological differences between deforminggabbroandgneisseswereminimal.Thus,gabbro-gneisscontactsaremostcommonlydecoratedby1-10m thick layers of strongly foliated, fine-grained garnet-rich eclogite, and nearby smalleclogitebodiesareusuallysimilarintextureandcomposition.

Theseobservationssuggestthatthegneissesmaynot have partially melted during HP-UHPconditions, but rather by fluid-absent partialmelting ofmicas during exhumation to <2 GPa.Theresultingchangedductilitycontrastbetweenmafic and felsic rocks producedmyriad gabbroandeclogiteboudinsthatcharacterizetheregion,allowing access to aqueous fluids facilitatinggrowth of secondary hornblende. Contacts ofsome gabbros show various processes:Somecontacts decorated by fine-grained foliatedeclogite, locally retrograded to foliated garnetamphibolite.Othercontactswithlittleeclogitizedgabbro,directly shearedagainstgneissat a latestage,butconvertedlocallybyinfiltratingfluidtoisotropichornblendegabbro.

ORAL

RecordofaLowerCrustalFossilEarthquakeInitiatedbyCO2FluxandReaction-drivenStrainSoftening

BjørnEskeSørensen1,ThomasGrant1andRuneLarsen11DepartmentofEarthScienceandPetroleum,NTNU,Norway

TheultramaficrocksoftheReinfjordintrusioninthe Seiland Igneous Province is cut locally bynarrow (mm-cm) thick extensional shearzones,containingextremely fine-grainedmaterialwitha distinct shape-preferred orientation. Theseshearzonesoffsetdykesacrossnumerousmicro-

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faultsaredocumentedinareasclosetothemajorfault zone cutting through the area.Within theshearzones olivine and clinopyroxene reacts toform orthopyroxene and dolomite atapproximately 7-11 kb and 750-850 degreesCelsiusaccordingtothereaction:

Olivine + Clinopyroxene + CO2 = Dolomite +Orthopyroxene

As evidenced by coronas of orthopyroxene anddolomitebetweenolivineandclinopyroxeneandbylargeolivinegrainsproximaltotheshearzonesdisplayingamicrostructurewithsubgrainwallsdecorated by rounded grains of dolomite andmore irregular and elongated grains oforthopyroxene. With clinopyroxene at leasthundredsofmicronsawaythissuggestedatleastsomematerialtransportwithintheshearzone.

The shearzones thus gives a unique view intoCO2-Metasomatismofthelowercrust.Moreovertheshearzonesprovideauniqueinsightintotheinterplay between CO2-metasomatism andreactionaccommodatedstrainsoftening.This isalsoconfirmedbyfracturesextendingintolargeolivine grains proximal to the shearzones. TheCO2crackingandmineralreactionalsoservestoreduce grain-size , making grain-boundaryslidinganefficientprocess,furtherenhancingtherheologicalcontrastbetweentheshearzoneandthe host rock. The sudden decrease in rockstrengthleadtosuddenfastdeformationandwesuggestarelationtopseudotachylitesandhencealsoearthquakesinnearproximityofthemicro-shearzones.

ORAL

Theeffectsofconfinementonreaction-inducedfracturingduringanhydrationreaction

XiaojiaoZheng11UniversityofOslo

Several geological processes involve mineraltransformations where nominally dry rockstransformintohydratedoneswhenleftincontact

withwater (i.e. eclogitization, serpentinization).Inthesesystems,thetransformationmayinducedensity variations which generate stressescontrolled by the rock confinement, also calledforce of crystallization. Here, we study aretrograde metamorphic reaction model, thehydration of periclase, MgO, into brucite,Mg(OH)2, to quantify the coupling betweenreaction, stress generation, porosity evolutionand fracturing. Samples of a microporous MgOceramic were reacted at 170-210°C, 5-80 MPaconfining pressure, 6-95MPa differential stressand 5 MPa pore fluid pressure. Three-dimensional X-ray microtomography imageswereacquired insituevery fiveminutesduringthe reaction. Results imply that below 30 MPamean pressure, the hydration reaction coupledwith the MgO ceramics fracturing. Thetransformationratefollowedasigmoidalkineticscurve with a slow initiation, a fast reactioncoupled to fracturing and the generation of atransient porosity pulse, and a slow-downuntilan almost complete transformation of periclaseinto brucite. Conversely, above 30 MPa, thereaction kinetics was slower and following thecommonly admitted reaction curve butwithoutfracturing. Considering the driving force of thehydration reaction, stress generation should beseveral hundreds MPa, whereas the presentexperiments show that fracturing occurs onlybelow 30 MPa. One interpretation is that thestresscreatedbythereactionmayovercomethedisjoining pressure at the grain-grain interface,expelling the water film trapped there andreducingdramaticallythekineticsofreaction.

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POSTER

Latemagmatic-hydrothermalalterationanddeformationofultramaficrocksanddikesfromtheReinfjordUltramaficComplex

FrederikValentinReinhard1,BjørnEskeSørensen2,ThomasWagner1andRuneBerg-EdlandLarsen21RWTHAachenUniversity,2NTNUTrondheim

This study concerns hydrothermal alteration ofultramafic rocks comprised by dunites andsubordinatewehrliteanddykesofultramafic tomafic and lamprophyric composition in the theReinfjord Ultramafic Complex the SeilandIgneous Province, northern Norway. The dikesandhostultramficrockswentthroughthreemainalterationstages:

Alt1. Microfaults with orthopyroxene, dolomiteandolivine.Alt2.Yellowishmagnesite-tremolite-talc alterations, comprised by central thinmagnesite veins (orientation 55/110)surrounded by thicker metasomatic sides oftremoliteandmagnesiteandthenathintalcrimtowards the host ultramafic host. Whenintersecting the more pyroxenitic dykes thealteration gives a blueish green color. Alt3 Lateserpentinisation intersecting all otherstructures.Thestudyfocusesonalterationtype2.Theusuallylessthancmwidemagnesite-bearingveins aresurrounded by up to dm widemetasomaticsides.Theweatheredsurfaceoftheveins form massive, creamy yellow to rust redcoloredmagnesitebearingmineralassemblages.The metasomatic sides stand out with a moreyellowcolorthantheweatheredhostrockandiscomprisedbyamagnesiteandtremolitebearingassemblage, rimmed by a mm-thin talc rimtowards the host rock. Furthermore the veinsalsocrosscut thedifferentgenerationsofdykes,resultingindifferentalterationassemblages.

Theaimofthestudyistousedifferentalterationassemblages to constrain PTX-fluid conditionsanddetermineore remobilization. FurthermorestableisotopedataofO,H,S,andCwillbeusedto

constrainthefluidsourcewhichisthoughttobeeithermagmaticormeteoric.

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3.Sedimentaryrocksandprocesses3.1.Sedimentologyposters

POSTER

Earlymid-DevonianvolcanismdatesinitiationoftheOrcadianbasinintheOrkneyIslands,Scotland

LarsEivindAugland1,AndersMattiasLundmark2,JohnF.BrownandAudunD.Bjerga1CEED,UniversityofOslo,2DepartmentofGeosciences,UniversityofOslo

Earlymid-Devonian sedimentary rocks formingtheOrcadian basin constitute large parts of theexposed geology on the Orkney Islands. Thelower sedimentary pile rest unconformably onfoliatedgranitesoftheca.430MaOrkneygranitecomplexandmarkstheonsetofLakeOrcadiaintheOrkneyIslandswithdepositionofthe lowerStromness flagstones (LSF), comprisingalternating lacustrine strata of fine grainedsandstones and shales. In the lower part of theStromnessflagstonesequencewehaveidentifiedanddated,usingzirconU-PbID-TIMS,arhyolitedomeorflowthatconstraintheageoftheLSFandessentially the onset of LakeOrcadia to ca. 390Ma. This new age combined with recentcyclostratigraphic results provide an improvedestimate for the Efelian-Givetian boundary andthe Kačák event marked by the top of theAchanarras level (Sandwick Fish Bed)constituting the top of the LSF. The rhyolitemagmatismonOrkneyisoverlappinginagewithintrusiverocksonShetlandandwesuggestthatthis magmatism is related to an episode ofimportantdisplacementsontheGreatGlenFault.

POSTER

TopographicDevelopmentasaresultofregionalincision,faulting,anddepositionattheonsetofrelativesea-levelrise;TheupperEntradaSandstoneandthelowerCurtisFormation,Utah,USA.

SigridØstmodaCosta1,NikolineBromander1,ValentinZuchuat1,AlvarBraathen1,AnjaSundal1andIvarMidtkandal11UniversityofOslo

A 43 km North-south section on the North-EasternmarginoftheSanRafaellSwellhasbeenstudied, focusing on the Upper Jurassic eolianEntrada Sandstone, the J-3 regionalUnconformity, and the overlying CurtisFormationofOxfordianage.Emphasis ison thedistribution of sedimentary facies in directcontactwiththeunconformity,andthoseaffectedbyerosionaltopographyduringdeposition.

The J-3 Unconformity displays at least 3generations of erosive incision, possibly 6. Thecomposite unconformity has been subaeriallyerodedbyeolianandfluvialaction,besidestidaldenudation postdating the onset of regionaldeposition. Present-day erosional relief,magnitude,andwavelengthcontribute tomulti-phase erosional processes resulting ininconsistenterosionalpatterns,anddistributionof sedimentary facies above and below theunconformity. Tectonic activity has influencedthe development concerning substratumfluidisationandbrittledeformation.

Generations of J-3s erosive incision variesregionallyandlocallyacrossthesection.Aseriesof 5-10m deep channel-like scours linked to astratigraphic level several meters above the J3Unconformity, erode to a deeper stratigraphiclevel than J3s original level. Intra-formationalfaultsinEntradaSandstonesuggestcontributionto focused erosion at the Entrada-Curtisboundary.

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Similarly, erosive lower boundaries of tidalsandstonebodiesindirectcontactwithJ3suggestthat repeated relative sea-level changes lead todeeper stratigraphic erosion of the J3Unconformity.

The on-going investigation will improveconstraints on how reservoir-quality sandstonevolumesareaffectedbyerosionaltopographyintidal environments, by determiningdistributional factors. Distinguishing betweenlocalandregionalvariabilityisatarget,tofiltratebasin-specificanomalies.

POSTER

Recognizingsandstonediagenesisfromoutcroptomicroscopicscale

RikkeWeibel1,NynkeKeulen2,MetteOlivarius2andMargretheThorupNielsen21GEUS(GeologicalSurveyofDenmarkandGreenland),2GEUS

Sandstone diagenesis is visible onmany scales,rangingfromthemicroscopicscaletotheoutcropscale. Traditionally, diagenetic features areinvestigated by opticalmicroscopy on core andoutcropsamples.Extendingtheinvestigationstomicronscalesmayhelptodefineasetoffeatures,whichmightberecognizedinthefieldandhenceusefulforfuturefieldcampaigns.Themineralogyandpetrographyofthesandstonesareevaluatedfrom thin sections by transmitted and reflectedlight microscopy, and from carbon-coated thinsectionsandgold-orplatinum-coatedrockchipsbyscanningelectronmicroscopy(SEM),applyingGEUS’ Zeiss Sigma 300VP field emission SEM,besides X-ray diffraction of bulk rock samples.Among the studied sandstone types, ‘rusty’sandstones proved to be siderite-cementedwhere the siderite had partly altered to iron-oxide/hydroxides during diagenesis. Sandstoneboulders or cliffs were intensively calcite-cemented, thoughwith calcite of smaller/largercrystal sizes and differentmorphologies.Spectacular reddish and purplecoloredsandstonescontainedopalcement,whichenclosed iron-oxides/hydroxides. Bluish or

yellowish concretions or cemented intervalsprovedtobepyrite,alteredtodifferentalterationproducts (e.g. jarosite, szomolnokite). Themineraldistributionatthemicroscopicscalecaneasily be shown by applying the MineralogicsoftwareoftheSEM.Altogether,investigationsata smaller scale can therefore explain theappearance of sandstones at the outcrop scale,andthisappearanceis largelydependingonthetypeandabundanceofthecementingphases.

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3.2.Depositionalbasins

ORAL

TriassicoftheWandelSeaBasin,NorthGreenland

MortenBjerager1,PeterAlsen1,JussiHovikoski1andSofieLindström11GEUS

In Triassic times theWandel Sea Basin formedthe western continuation of the basins in thesouthernpartoftheBarentsSeaandthenortherncontinuationoftheDanmarkshavnBasinoffshoreNortheastGreenland.TheresultsofrecentGEUSfieldwork campaign in the area show that theexposedTriassicofNorthGreenlandspansanearcomplete Induan (Dienerian) – Noriansuccession, up to 700 m thick. The successionrests unconformably on Upper Permiansediments and it is unconformably overlain byUpperJurassic–LowerCretaceousdeposits.

TheLowerTriassic(Dienerian, Induan)consistsofmarinesandstones,fluvialconglomeratesandsandstones,andmuddyflood-plaindeposits.Itisconformably overlain by the Lower Triassic(Smithian–lowerSpathian)offshoremudstoneswithminorsand-dominatedintervals.TheupperSpathian to Ladinian is represented mainly byshallow marine sandstones in the westernproximal part and laminated mudstones withminor thinsandstoneunits thatweredepositedinslopeanddeepbasinalsettingsintheeasterndeeperpartoftheWandelSeaBasin. AmarkederosionalunconformitycharacterisesthebaseoftheoverlyingUpperTriassic (Carnian–Norian)ofmarinemassivesandstones,conglomeratesaswell as cross-bedded and biomottled marinesandstones and minor mudstone units. TheTriassic succession of the Wandel Sea Basinrepresents a well-constrained basin margin todeepbasintransectandthusformsanexcellentoutcropanaloguetothetimeequivalentintervalsin the western Barents Sea basins and theDanmarkshavn Basin offshore North-EastGreenland.

ORAL

FlintintheDanianKøbenhavnLimestoneFormation

JensGalsgaard11Rambøll

TheDanianageKøbenhavnLimestoneFormationwasexamined in219coredboreholesdrilled inconnectionwiththe“Cityringen”metroprojectincentral Copenhagen. Shape and colour of flintbodiesweredescribedduringmacroscopicvisualinspectionofcoresamples,aswellasfromdigitalcorephotos,andfourdiagnosticflinttypeswereidentifiedinthelimestone.Theyare1)greyflintbands, 2) light grey flint bars, 3) irregular flintbodies, and 4) dark grey flint blots. The well-known informal tripartition of the KøbenhavnLimestone Formation into the upper regularlybedded, the middle nodule-rich and the lowerlaminated unit (Stenestad 1976,Knudsen et al.1995,Klittenetal.1995,Olsen&Nielsen2002)islargelysupportedbythedistributionofthefourflinttypes:Type1dominatestheupperunit,Type2dominatesthemiddleunit,whileType4istheonlytypefoundinthelowerunit.Types1,2and3alloccurtosomeextentinboththeupperandmiddle unit. Type 4 is also characteristic of theunderlying Bryozoan Limestone, making itdifficult in core samples to determine theboundary between København Limestone andBryozoanLimestone.

TheconspicuouschangesinshapeandcolourofflintbodiesupthroughtheKøbenhavnLimestoneFormationseemto indicatethat the flintbodiesdisplaydifferentstagesofflintformationandthatthis limestonemay conceal narratives yet to betold about flint formation and depositionalenvironment.

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ORAL

Evidenceofhyperpycnallyfedturbiditesinabasinfloorsetting,EoceneofSpitsbergen,ArcticNorway

Sten-AndreasGrundvåg1andWilliamHelland-Hansen21DepartmentofGeosciences,UiT–theArcticUniversityofNorway,2DepartmentofEarthSciences,UniversityofBergen

The Eocene of Spitsbergen, Svalbard, hasreceivedconsiderableattention inthe literaturebecause of its spectacular seismic-scaleclinoforms exposed along many fiords andvalleys. Previous investigations particularlyfocusedon the slope segment of the clinoformsand demonstrated how sustained-type,hyperpycnal flows deriving from shelf-edgedeltasplayedamajorroleinbringingsandontothe slope, contributing to slope accretion.Periodic sand delivery beyond the slope isevidentbythepresenceofsandstone-dominatedturbiditelobesinthebasinfloorsegmentofsomeclinoforms.Bycombiningoutcropandcoredatafrom central Spitsbergen, our study focus onsedimentary processes that formed theseturbiditelobes.Atbed-to-bedscale,manyoftheturbiditebedsdeviatefromtheclassicalBouma-type facies patterns typical of deposition fromsurge-type,low-densityturbiditycurrents.Thick(0.5–3 m) turbidite beds characterized bypervasive amalgamation, internal scouringsurfaces,andvarioussoft-sedimentdeformationstructures dominate. Further, beds exhibiting alower sandstone-dominated turbidite divisionsucceeded by a mud-rich upper divisioncontainingabundantcoal/plantfragmentsoccurfrequently.The latterbedarchitecture is typicalofdepositionfromhybridsedimentgravityflowsand indicate that some turbidity flowstransformedintoslurryflowsordebrisflowsontheirway to their finaldestinationon thebasinfloor. The dominance of thick, amalgamatedturbidite beds and the abundance of coal/plantfragments documented in this study, aswell asthe presence of hyperpycnal flow turbidites onthe slopes documented in previous studies,

suggests that hyperpycnal flows are capable ofdeliveringsandontothebasinfloor.

ORAL

Stratigraphictreasuresofan“uglyduckling”:towardsanintegratedbasinmodeloftheLowerCretaceousRurikfjelletFormation,ArcticSvalbard

MadsE.Jelby1,Sten-AndreasGrundvåg2,PeterAlsen3,KasiaK.Śliwińska3,LarsStemmerik1,WilliamHelland-Hansen4andSnorreOlaussen51NaturalHistoryMuseumofDenmark,UniversityofCopenhagen,2DepartmentofGeosciences,UiTTheArcticUniversityofNorway,3GeologicalSurveyofDenmarkandGreenland,4DepartmentofEarthScience,UniversityofBergen,5DepartmentofArcticGeology,TheUniversityCentreinSvalbard

The Lower Cretaceous (Valanginian–Hauterivian) Rurikfjellet Formation inSpitsbergen, Svalbard, forms an up to c. 300mthick successionof fine-grained shelf and lowershoreface shales, siltstones and sandstones(Dypvik et al. 1991). The formation constitutesthe regressive part of an >1000 m thick first-ordersequencewhichformedduringalong-termshoreline progradation (the RurikfjelletFormation)andback-stepping(theHelvetiafjelletandCarolinefjellet formations) in response to afullcycleofrelativesea-levelchange(Gjelberg&Steel 1995). In contrast to the overlying LowerCretaceoussuccession,theRurikfjelletFormationhas received relatively little attention and isrelatively poorly exposed. Its age is also ratheruncertain. We present a revised basin-scalesedimentological and sequence stratigraphicmodel of the formation, tied to a newbiostratigraphic framework.Themodel isbasedon data recently collected across the LowerCretaceous outcrop belt, including >3500 m ofmeasured outcrop sections; seven subsurfacecores; >130 palaeocurrent measurements;>50,000 photos; three bulk-rock δ13Corg curveswithameanresolutionof2m;andhundredsofdinocyst, ammonite, belemnite and bivalve

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biostratigraphic samples. Our data reveal aregionally persistent regressive–transgressivesequencedevelopmentof the formation,aswellasseveralhithertounrecognisedprogradationalpulsesofapparentlydiachronousclasticwedges.Wearguethattheirdepositionalarchitectureandinterfingering were controlled by prodeltaiccoupled storm-dominated and hyperpycnalsedimentationacrossawide,low-gradientramp,with important implications forpalaeogeographic reconstructions for theValanginian–HauterivianofSvalbardandnearbyareas.

ORAL

Elasticmoduli,stiffnessandeffectivestressofchalkfromZealand(Denmark)andfromDanfield(NorthSea).

LauraPaci1,IreneRocchi1andIdaLykkeFabricius11TechnicalUniversityofDenmark,DepartmentofCivilEngineering,NordvejBuilding1192800Kgs.Lyngby

Thesuccessfulemploymentof theUndergroundThermal Energy Storage in the subsurface ofCopenhagenisinvestigated.Thestudyconsidersthe geotechnical and physical properties (i.e.stiffnessandporosity)ofthemediumdepth(400-800 mbgl) Chalk Group. The majority ofgeotechnicaldataavailablecoversshallowdepth,while deep well logs data are fewer and ofvariablequality.Inordertoovercomethelackofinformation,thisworkevaluatesDanfieldasananalogforthechalkfromZealandcomparingtheeffectivestressandstiffnessatthetwolocations.The chalk formation is found at much greaterdepthintheDanfield(1800mbslcomparedtoanaverage of 200mbsl in Zealand), resulting in agreateroverburdenstress.However,theeffectivestress is comparable to the maximum valueencountered in Zealand (i.e. before uplift anderosion),duetooverpressure.TheresultsshownwereobtainedcalculatingthemaximumeffectivestressbasedontheburialanomalyasstudiedbyJapsen (1998). In addition, the stiffness was

calculated by means of P-wave velocity anddensitydata(Fabricius,2003).Themodelallowstoestimatethedegreeofcementationandhencethe Biot´s coefficient by comparing the elasticmodulusobtainedbyP-wavemeasurementswiththe theoretical one obtained under theassumptionsofeitherparticlesinsuspensionorclose-packed particles. The results showsimilaritybetweenthetwolocationsconcerningthe elasticmoduli and porosity, but not for thesame sample.Thisdiscrepancy couldbe causedeither by a different heating history or bydifferenttexture.

ORAL

TheMiocene-PlioceneSkade-Utsiraaquifer,NorthSea:Updatedmapsandnewinsightsindepositionalpatternsandsyn-sedimentarydeformation

FridtjofRiis1,TorEidvin1andYngveRundberg21NorwegianPetroleumDirectorate,2YRGeoAS

DuringMiocene-PliocenethedeltaicsystemeastofShetlandprogradedintotheNorwegiansectoroftheNorthSea.Sandsweredepositedinaslopeandbasinsetting.Thickdepositsofhighporosityand high permeability Utsira and Skadeformationscoveranareamorethan300kmlongand60kmwide.Themaximumtotalthicknessofsands in the aquifer reachesmore than 500m.MapsoftheaquiferwerepublishedbytheNPDaspartoftheCO2StorageAtlas(www.npd.no).

Inthisupdatedstudy,NPDhasincludednewwelland seismic data, as well as new results frommicropaleontology and Sr isotope stratigraphy.In addition to the lower Miocene SkadeFormation and the upper Miocene to lowerPlioceneUtsiraFormation,thetopofthemiddleMiocene sandy unit (Eir formation, informal) isalso available. The depocenter of the SkadeFormationisfoundinthecentralpartofthearea.During themiddleMiocene therewas a shift tothenorth,whileinthelateMiocene,amajorlobedeveloped in the south. During the latest late

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MioceneandthePliocenethebasinaldepressionwasfilledin,andashelfalsettingisinterpreted.

The whole basin region is strongly affected bylarge scale soft sediment deformation.Mobilization of sands took place where sandyformationswere sealedbydeep-water clay andooze. Evacuation structures, pillow-likestructures and injectites are found at severalstratigraphic levels and were apparentlytriggered by deposition of turbidites or massflows.

ORAL

AeoliansilttransportprocessesasfingerprintedbydynamicimageanalysisofthegrainsizeandshapecharacteristicsofChineseloessandRedClaydeposits

YuanShang1,AnuKaakinen1,ChristiaanJ.Beets2andMaartenA.Prins21DepartmentofGeosciencesandGeography,P.O.Box64,00014,UniversityofHelsinki,Finland,2DepartmentofEarthSciences,FacultyofEarthandLifeSciences,VrijeUniversiteitAmsterdam,DeB

Thisstudyapplieddynamicimageanalysis(DIA)to characterize the grain size and shape ofChineseaeoliansedimentsinordertofingerprinttheirtransportationprocesses.Weselectedfourwell-studied Quaternary loess-palaeosolsequences along a north-south transect acrossthe Chinese Loess Plateau and compared theirgrainsizedistributionobtainedbyDIAwiththatyielded by laser diffraction(LD) particle sizeanalysis. The results demonstrated that DIA isable to characterize clearly spatiotemporalvariations in the grain size records of loess-palaeosolsequences formedduring the last twoglacialandinterglacialperiods.ThisisconsistentwithgrainsizeresultsobtainedusingLD.DIAisalsoabletocharacterizespatialvariationsinthemorefine-grainedaeolianRedClaydepositsandto allow the quantification of the fluvialcontribution to Red Clay sequences. DIA of thegrain shapes characteristics in loess-palaeosol

and Red Clay deposits revealed a systematicpattern,wherebytheaspectratiodecreasedwithincreasinggrainsize,indicatingsystematicshapesorting occurred during the aeoliantransportation of these dust particles. Alsoevident from our DIA data was a subtle butsystematic downwind decrease in the aspectratio of the particles in the loess units. Thisobservation suggests that elongated and/or flatparticles (with a low aspect ratio) weretransported further downwind than moresymmetrically shaped particles (with a highaspect ratio). This study indicates that DIA ofgrain size and shape characteristics can be anadditionalpowerfultoolforfingerprintinggrainsizeandshapesortingtrendsandreconstructingthetransportationpathwaysofsilt-sizedaeoliansediments.

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AnewobservationofabiosiliceousopalbearingsequenceintheMioceneLarkFormationintheDanishNorthSea.

HenrikSulsbrück1andJørgenToft11MærskOlieogGasA/S

ThePaleogene–LowerNeogeneLarkFormationoftheDanishNorthSeaconsistsofabiosiliceous,opal-bearing sequence of sediments whichextend into the German, Norwegian and UKsectorsoftheNorthSea.Theuppermost50-100mpartoftheLarkFormationischaracterizedbyabundantbiogenicsilica in the formofdiatoms,radiolarians, Bolboforma and sponge spicules.Thisbiosiliceous-richsection isofEarly toMid-Miocene age and formed during a period ofclimaticoptimum.Theintervalcancontainupto40%biosiliceousmaterial,togetherwithdetritalclay and quartz. Carbonate stringers and pyriteoccur inminoramounts.ThecontentoforganicmattercanbesignificantwithTOC’sofupto8%.In the lower parts of Lark (Early Miocene),diagenesis has transformed the biogenic silicafrom Opal A into Opal CT. No Opal has beenobserved in the Oligocene part of the Lark

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Formation. This talk discusses the keycharacteristic of this biosiliceous section of theLarkFormation,andtheregionalcontrolsonit’sdevelopment.

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AcrosstheEocene-OligoceneTransitionininlandAsia:Bio-,Litho-,andMagnetostratigrapyofUlantatal,InnerMongolia,China

JoonasWasiljeff1,AnuKaakinen2,JohannaSalminen3andZhaoqunZhang41DepartmentofGeosciencesandGeography,P.O.Box64,FI-00014UniversityofHelsinki,Finland,2DepartmentofGeosciencesandGeography,UniversityofHelsinki,Finland,3DepartmentofPhysics,UniversityofHelsinki,Finland,4InstituteofVertebratePaleontologyandPaleoanthropology,ChineseAcademyofSciences,China

Coherent terrestrial sequences are critical inscrutinizing past environmental and climaticchanges through successive fossil andsedimentary records. Central Asia has been anexquisite locality for past and ongoingpaleontological investigations for Eocene toOligocene aged mammalian faunas. Transitionfrom Eocene to Oligocene (EOT) at ~34 Masignified considerable changes in climate, flora,andfauna,externalizedbythedecreaseofmeanannualtemperatureandthechangeinvegetationfrom Eocene forests to more bare lands of theOligocene. The faunal transition in inland Asiawas characterized by replacement of Eoceneperissodactyl-dominant faunas to theOligocenerodent-lagomorph-dominantfaunas.

Ulantatal is a renowned Oligocene mammalianfossillocalityinInnerMongolia,China.Althoughtheareahasproducedasignificantcollectionofvertebratefaunas,knowledgeofthestratigraphy,ages and depositional environments haveremainedpoorornearlynon-existent.Litho-andmagnetostratigraphiccontext,andcorrelationofthe Ulantatal area sediments with theGeologicTimeScale(GTS) is

presented,thusprovidingageestimationsforthefossil-bearinghorizons.

Landscape of the Ulantatal formation ischaracterizedby flat lined topographywith lowuplands and small gullies. Outcrops of the areashow a uniform pattern predominated by fine-grained massive sediments occasionallyinterbeddedwithcoarsergrainedhorizons.Thesequence produces fossils along most of thesection,withtherichestfossiloccurrencesinthelowerhalfofthesequence.Ourmagneticsectionsuggestsacorrelation inmagnetozonesC15ntoC9n,with an age range of about 35-27Ma, andplacesthelowermostfossilsiteinUlantatalinthelatestEocene.

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3.3.Compositionofsiliciclasticrocks

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Howcanprovenanceandsortingeffectsbedifferentiatedfromdetritalzircondata?ExamplefromtheGermanTriassicBuntsandsteinGroup

CaritaAugustsson1,ThomasVoigt2,KristinBernhard2,MarianKreißler2,ReinhardGaupp2,AndreasGärnter3,MandyHofmann4andUlfLinnemann41InstituttforPetroleumsteknologi,UniversitetetiStavanger,4036Stavanger,Norway,2InstitutfürGeowissenschaften,Friedrich-Schiller-UniversitätJena,Burgweg11,07749Jena,Germany,3SenckenbergnaturhistorischeSammlungenDresden,KöningsbrückerLandstr.159,01109Dresden,Germany,4SenckenbergnaturhistorischeSammlungenDresden,KöningsbrückerLandstr159,01109Dresden,Germany

Thisstudystresseshowsortingandprovenanceeffectscanbedifferentiatedbycombiningzircon-grainlengthandU-Pb-agesforindividualdetritalgrains.Weexemplifythisbyaprovenancestudyfor continental deposits of the Lower Triassic,continental Buntsandstein Group in centralGermany. The study is based on > 1000 zircongrains from 12 sandstone beds. The unbrokengrainsinsevenofthezirconseparateshavemeanlengths of 190-220 µm and five are composed100-140 µm long grains in average. All have amain population of 340-320 Ma ages,representative of granitoid from the VariscanOrogenof theMassifCentral and theBohemianMassif. This detritus was mixed with abradedgrains from Ediacaran to Palaeozoic(meta)sedimentaryunits feeding thebasinwith610-460Ma(EdiacarantoOrdovician)and2Gaage grains. The 610-460 Ma age population iscommon only in five samples with mean grainlengthsof100-140µm.Thosegrainsmainlyare<130 µm in the east, but equally common in allgrain sizes in the west. This indicates that theeast-west age difference is a provenance effect

but that internal differences in the east is asorting effect. Thewestern groupwas fed fromtheMassifCentralandtheeasterngroupfromtheBohemian Massif. We conclude thatinterpretation of detrital zircon ages preferablyareseparatelyfordifferentsizeclasses,becausezircon studies performed on broad grain-sizeintervals without considering possible size-agecorrelations may disguise sorting effects thatpotentiallycan leadtoamisleadingsource-areainterpretation.

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MiddleTriassicsiliciclasticdepositsofSvalbardasapartofsourcetosinkframeworkoftheArctic

UrszulaCzarniecka1,BeyeneGirmaHaile2andKrzysztofKrajewski11InstituteofGeologicalSciences,PolishAcademyofSciences,Twarda51/55,00-818Warszawa,Poland,2DepartmentofGeosciences,UniversityofOslo,P.O.BOX1047,Blindern,0316Oslo,Norway

Sandy facies of the Bravaisberget Formation(Middle Triassic) exposed at the southernmostpart of Spitsbergen (Svalbard archipelago)represent an uplifted part of the northwesterncorneroftheBarentsSeashelf.Thedepositsareinterpreted as an effect of shallow marine anddeltaicsedimentationandtheirfacialequivalentsin the Barents Sea are considered as goodreservoirrocksforhydrocarbonaccumulation.

The aim of this study was to characterise andrecognise potential source areas for theMiddleTriassic siliciclastics based on petrological andgeochemical methods. Standard quantitativepetrographicalanalysisofthinsectionsandbulkrock geochemistry technics have beensupplementedbyU-PbandLu-Hfzirconanalysis.

The studied deposits have quartz-dominatedframework composition, with minor content offeldsparsandlithoclaststhereforetheyhavebeenclassified as quartz arenites, subfeldsarenites,sublitharenites. Concentrations of major, traceelements and REE point to silicic source rocks

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composition. Distribution of zircon ages showsdominationofPaleo- andMesoproterozoic ageswith significant content of Archean ages,minorCaledonian zircons and lack of Uralian grains.This provenance signature has been comparedwithdatafromotherareasoftheArcticregion.

Theareaanalysed in this study representsonlysmallpartof thewholeArctic sediment routingsystem existed in the Mesozoic time and theinvestigateddepositshaveprovenancesignaturewhichisconsistentwiththeTriassicprovenancesignatures from Canadian Arctic and Greenlandandlinkingtheirproto-sourcestoLaurentia,butthe deposits components were recycled fromolder sedimentary rocks, likely from Devonianstrata.

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Quartzcementationanddiageneticeffectsinsandstone–ananalogstudyofCambrianquartzarenitefromScandinavia

SanneLorentzen1,CaritaAugustsson1,JohanP.Nystuen2,JensJahren2andNielsH.Schovsbo31DepartmentofPetroleumEngineering,UniversityofStavanger,2DepartmentofGeoscience,UniversityofOslo,3GeologicalSurveyofDenmarkandGreenland

LowerCambrianquartzareniticdepositshaveaworld-wideoccurrence.Nevertheless,diageneticeffects are rarely taken into consideration toexplain the existence of these mature, shallowmarine deposits. In this study, petrographic,geochemical and mineralogical analyses werecarriedoutoncoreandoutcropsamplesfromthequartz-rich Ringsaker Member from SouthernNorway and the corresponding HardebergaFormation from Bornholm in Denmark andScaniainSweden.Thesandstoneunitshavebeenexamined in a state of complete quartzcementation in order to study the diagenetichistoryand theeffects leading todestructionofporosity and permeability. Quartz cementationwas estimated by comparing the amount ofcementpresenttothemodelledamountofquartzcement based on its time-temperature history.

ThequartzarenitefromSouthernNorwayhasanintergranular volume of ca. 20%, and close to100%oftheinitialporosityhasbeenreplacedbyquartz cement. For most samples, otherauthigenic cement minerals, together withdetrital phyllosilicates, represent < 5% of thepresent-day composition. Preliminarypetrological investigation on the HardebergaFormation points to similar quartz-dominatedchemical diagenesis. This indicates that thesedimentcompositionwasextremelyquartz-richalready during deposition throughoutScandinavia, as is supported by the high SiO2contentaveragingat95.6%.Sedimentreworkingby waves, and subsequent removal of earlyauthigenic components produced fromsubsurfaceleachingofunstablegrainsarelikelytohaveinfluencedthecompositionseverely.Thefindings contribute to an increasedunderstanding of the formation of both quartz-rich sediment and the end products ofcementationprocesses.

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IMPACTOFMETEORIC-WATERDIAGENESISONRESERVOIRQUALITYINPALEOCENETURBDITICSANDSTONES,UKCENTRALGRABEN,NORTHSEA

HowriMansurbeg11PetroleumGeosciencesatSoranUniversity/KurdistanRegion-Iraq,andKPSMetal,CzechRepublic

This petrographic and stable isotopes study onthe distribution of diagenetic alterations and oftheir impact on reservoir-quality evolution ofPaleocene marine turbidite successions(AndrewsFormation,UKCentral Graben,NorthSea)revealed the important roles of tectonicsetting, depositional facies, and changes in therelative sea level. Diagenetic modificationsinclude dissolution and kaolinitization offramework silicates, cementationby carbonatesand quartz, mechanical compaction ofsedimentary rock fragments, and chemical

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compactionofdetritalquartz.Despitetensofkmdistancefromthepaleoshoreline,kaolinitizationisattributedtometeoric-waterfluxduringmajorfall in the relative sea level. The wide range ofδ13CV-PDBvaluesofcalcitecement(about-18‰to+22‰) is attributed to the input of dissolvedcarbon from microbial methanogenesis andmethaneoxidation.Thewiderangeofδ18Ovalues(about -17‰ to -1‰) of this cement mightreflecttheinvolvementofvariousfluidsincludingmarine,meteoric,andevolvedformationwaters)and wide range of precipitation temperatures.Preservation of porosity and permeability insandstonesfromthepassivemarginbasins(upto30% and 1Darcy, respectively) is attributed tothe presence of abundant rigid quartz andfeldspar grains and to dissolution of carbonatecementaswellasmicaandfeldspars.

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FactorsinfluencingstylolitedevelopmentandquartzcementationintheJurassicStøFormationsandstone,TromsøBasin,SWBarentsSea

MaiBrittE.Mørk11NTNU,DepartmentofGeoscienceandpetroleum,N-7491Trondheim,Norway.

Stylolites are common diagenetic structures inquartzcementedsandstonesandproviderecordsof extensive chemical compaction. Asdocumented and modelled in the diagenesisliterature, thedevelopmentofstyloliteseamsinsandstoneinvolvesdissolutionofquartzgrainsaswellas“re”-precipitationofthedissolvedsilicaasquartz cement. This study comparesmicrostructuresofstyloliteandquartzcementinstrongly cemented Jurassic sandstones from awellinthesouthwestern-mostpartoftheBarentsSea to interpret diagenesis and deformationstructures.Theimpactofsedimentaryfabricandbioturbation in development of stylolites isemphasized based on comparison of sandstonecoresof

different degrees of bioturbation. The styloliteforming processes involved differentialcompaction in several stages of diagenesis: 1)Initialmechanicalcompactioninducingfoldingofsofter clay-rich lamina. 2) In deeper burialchemical diagenesis with enhanced graindissolution at clay contacts accompanied withquartz cementation and 3) continued stylolitegrowth involving also dissolution of earlierprecipitated quartz cement. Micro shear-zonesalongstylolitefoldlimbsareinterpretedintermsofdissolution-enhanceddifferentialcompaction.Deformation accompanying quartz cementationis evidenced by a frequent distribution ofdauphine twins at adjacent cement – cementcontacts, revealed by use of SEM-backscatteredelectron diffraction techniques. The latest stageof diagenesis involved abundant pyritecrystallization, in particular along stylolites,questioning if stylolites could have acted asconduits for fluidmigration.Furtherresearch issuggested to examine regional tectonic andthermal influences on the distributions ofextensive quartz cementation in some of thewesternmostareasoftheBarentsShelf.

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StiffeningeffectfromtemperatureandstressonsandstonesfromthedeepNorthSeaBasin

TobiasOrlander1,KatrineAllingAndreassen1andIdaLykkeFabricius11TechnicalUniversityofDenmark

Weinvestigateeffectsoftemperature,stressandstresssymmetryonthedynamicstiffnessoftwosandstonesfromdepthsofapproximately5kminthe North Sea Basin. The studied temperaturerangewas25-170°C,whereasthestudiedstressrange was 2.5-15 MPa. Two stress symmetrieswere compared: 1) hydrostatic stress and 2)uniaxialstresswithconstantconfiningstress.Wederived dynamic compressional and shearmodulifromdensityandultrasonicP-andS-wavevelocitiesandshowthatthestiffnesscanincreasewith up to 20% and 100% for respectively

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increase in temperatureandstress.We link theincreased stiffness to two physically differentmechanisms, both resulting in closure ofrupturedgraincontactscreatedbyequilibratingsample material to atmospheric conditions.Eventually, the increase is hence recoverystiffnessbymechanismsof:1)framedeformationdue to increase in stress and 2) thermalexpansiondue to increase in temperature. Thatcontact ruptures (micro-cracks) can full orpartiallycloseby1)isanacceptedmechanismforpartialrecoveryofin-situstiffness.Weshowthatstiffness recovery by 1) or 2) have differentmagnitude, but that both aremost pronouncedforsandstoneswithalowdegreeofcementation.This is probably because cementation hindersprogression of micro-cracks during deloadingand cooling. The results demonstrate thesignificance at testing samples at their naturalstressandtemperature.

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ThediageneticimpactonreservoirsandstonesoftheHenoFormationintheRavn-3well,DanishCentralGraben,Denmark

SimoneSuhrPedersen1,NielsHemmingsenSchovsbo2andRikkeWeibel21UniversityofCopenhagen,DepartmentofGeosciencesandNaturalResourceManagement,2GEUS,GeologicalSurveyofDenmarkandGreenland,ØsterVoldgade10,DK-1350CopenhagenK,Denmark

TheUpperJurassicHenoFormationintheRavn-3 well is the deepest producing sandstonereservoir in the Danish North Sea. A combinedapproach including petrography, geochemistry,porosity and permeability analysis and coredescription have been achieved to investigatevariationsindiagenesisupthroughtheformationand howpost-depositional changes impacts thesandstone reservoirs. Three depositionalenvironments characterize the reservoirsandstones: lower shoreface, middle shorefaceand foreshore. Results show that the reservoirpotential of the sandstones predominantly

depend on occurring digenetic phases and notdepositional environment. The dominatingdiageneticphasesareeogeneticmicrocrystallinequartz, mesogenetic precipitation of illite,extensive mesogenetic quartz overgrowth andextensiveFe-dolomiteandankeritecementation.Thedifferentdiageneticphasesarepresentinallthreedepositionalenvironments.Diagenesishada major impact on either preserving ordestroying porosity, but did in all cases highlyreducethepermeability.ThedifferentdiageneticphasescanberecognizedintheRavn-1wellandinlessdegreeintheRavn-2well.

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Terrestrialpaleoweatheringandthepresenceofdeepbiosphereinfracturedgranites,UtsiraHigh,NorwegianNorthSea

LarsRiber1,StevenG.Driese2,HenningDypvik1,GaryE.Stinchcomb3,RonaldSørlie4andLizThompson41DepartmentofGeosciences,UniversityofOslo,2DepartmentofGeosciences,BaylorUniversity,3WatershedStudiesInstituteandDepartmentofGeosciences,MurrayStateUniversity,4LundinNorwayAS

Whereas the global stratigraphic record isdominantlymarine,deeplyburiedpaleoregolithprofilesarerareand importantremnantsof theterrestrialpaleoenvironment.OntheUtsiraHigh,Norwegian North Sea, the crystalline basementwas probably close to the surface from thePermo-Triassic until the early Cretaceous(Ksienzyketal.,2016).RecentK-Aragesofilliteclays from weathered granites in the areasuggested commencement of regolith/paleosolformation in mid-Triassic (Fredin et al., 2017).Drill cores fromwell 16/1-25S in the Rolvsnesdiscovery include ~21 m of fractured andweatheredgranitebelowCretaceouscover.Inthestudied regolith, two intenselyweathered, clay-richintervalswereidentifiedintheupperpartoftheprofile.Theycontainrandomlyinterstratifiedmixed-layerillite-smectiteandpoorlycrystalline

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kaolinite clays, pseudomorphically kaolinitizedbiotite, anddendritic aggregates of fine-grainedhematite.Althoughquartzispreserved,feldsparsare affected by chemical weathering withplagioclase nearly completely removed. Thefracture network facilitated deeppercolation ofmeteoricwaterand insamplesmorethan20mbelow the basement-sediment contactweathering is evidenced by minor amounts ofwell-crystallized kaolinite and moderatelyaltered feldspars. Estimates of MAP and MATusingthePaleosol-PaleoclimateModel(PPM1.1)(Stinchcomb et al., 2016) from the clay-richintervalsindicateformationundersubhumidandtemperateconditions.Useofgeochemicalproxiesis complicated because of heterogeneousprotolithcomposition, truncationof theoriginalpaleosol,andthelikelihoodofmultiplealterationepisodes.Mycorrhizal fungal hyphae have beenobserved down to about 20 m below thebasement-sediment contact, indicating thepresenceofdeepbiosphere.

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Impactofelectrostaticforcesonsedimentporosity

LeonardoTeixeiraPintoMeireles1,EinarMadsenStorebø1andIdaLykkeFabricius11TechnicalUniversityofDenmark,KogensLyngby,Denmark

In thispaper,weassess the impactof electricaldoublelayerrelatedforcesonsedimentporosityusing low field Nuclear Magnetic ResonanceSpectrometry. Samples of Calcite, Quartz orKaolinite powder were saturated with brinescontaining ions found in seawater (Na+, Ca2+,Mg2+,Cl-andSO42−)atvaryingionicstrengthsandas a non-polar reference, with ethylene glycol.The difference in porosity between a samplesaturated with ethylene glycol and a samplesaturatedwithagivenbrinereflectstherepulsivepressureresultingfromtheelectrostaticforces.

Wefoundthatforcalcitesamples,saturationwithsolutions containing divalent cations (Ca2+ andMg2+)leadtohigherrepulsiveforcesbetweenthe

grains,whileadsorptionofSO42-counteractstheinitially positive surface charge, leading to adecrease of the repulsive forces. For kaolinite,differences in potential between the silica andaluminafacesaswellastheedgescaneitherleadtorepulsionbetweenparticlesortoflocculationdependingonionicstrengthandionicspeciesofthefluid.Forquartz,relativelyhighporosityforpowders saturated with sodium chloride brineindicatesthatNa+isapotentialdeterminingionfor the quartz surface. The repulsive pressureinferred from the experiments could becorrelated to zeta potential measurementsavailableintheliterature.

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4.Tectonicsandstructuralgeology4.1.Trans-AtlanticcorrelationofProterozoiccollisionalbeltsandPaleoproterozoicMetallogenyoftheArctic

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TheAmitsoqPlutonicSuite–anewlydiscoveredsuiteintheKetilidianOrogen,SouthGreenland

KatrineBaden1,LeonBagas2,JochenKolb3,TonnyB.Thomsen1andTodE.Waight41GeologicalSurveyofDenmarkandGreenland,2ChinaUniversityofGeosciences,3KarlsruheInstituteofTechnology,4UniversityofCopenhagen

The studyarea is situated in the ca. 1855-1735Ma Ketilidian Orogen of South Greenland. Sixfine- to medium-grained felsic rocks from thenortheastcoastofAmitsoqIslandweredatedbyLA-ICPMS (U/Pb zircon). Observations fromfieldwork show show complex mixing andminglingstructuresoffeldspar-phyricmonzoniteand leucogranite. Both rocks have an intrusivecontactwithgranodiorite,whichitselfintrudesametasedimentary rock. North of themetasedimentary rocks, a banded,porphyroclasticfelsicgneissoccurs.

The gneiss yields an age of 1784±7 Ma,that isinterpreted as the intrusion age of a felsicprecursor.Thisageoverlapswithregionalpeakmetamorphism (1790-1770 Ma) and the latestageof the JulianehåbIgneousComplex(1781-1807 Ma). The fine-grained metasedimentaryrockgivesaspreadofconcordantages fromca.1800-2800 Ma, supporting its sedimentaryorigin. The feldspar-phyric monzonite has anintrusion age of 1680±8 Ma, which isindistinguishablefromthe1704±11Maintrusionageofthegranodiorite.Homogeneousmonzonitefrom the same site yields an intrusion age of

1735±6Ma.Thisca.45MaolderagefallsintherangeoftheIlluaPlutonicSuite(1755-1728Ma).

TheAmitsoqIslandisunderlainbyacomplexsetofigneousandmetamorphicrockswithintrusiveages (ca. 1700 Ma) never reported for theKetilidianOrogenbefore.Thenewdata indicatethatitsgeologyismorecomplexthanpreviouslythought,whichhighlightstheneedforremappingand reinterpretation, to improve ourunderstanding of the geological history andeconomicpotentialforgolddeposits.

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Anewconfigurationofcrustal-scaleshearzonescontrollingcopper-goldmineralizationinnorthernSweden

TobiasEBauer1andEdwardPLynch21DivisionofGeosciencesandEnvironmentalEngineering,LuleåUniversityofTechnology,Sweden,2DepartmentofMineralResources,GeologicalSurveyofSweden

Northern Sweden is a well-mineralized area inEurope and contains three major metallogenicbelts; namely, the Gold Line, Skellefte andNorthern Norrbotten ore districts. Gold and/orcopper deposits occur in all three belts asorogenic Au, Au-rich VMS and IOCG-stylemineralization. Regardless of mineralizationstyle, however, most deposits appear to bespatially controlled by a set of crustal-scalePaleoproterozoic shear zones, which sharesimilar structural characteristics anddeformationhistories.

Reappraisal of regional geological andgeophysical data, coupled with structuralmapping,suggestscrustal-scaleshearzonesformcontinuous,c.N-S-trendingzonesextendingfromthe Gold Line in the south to NorthernNorrbotten. An example from Norrbotten is azone that extends SSW fromKaresuando in the

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northtowardsSvappavaara.Whilethiszonehastraditionally been inferred to continue SWtowards Arjeplog (i.e. the KADZ, Karesuando-Arjeplogdeformationzone,Bergmanetal.2001),we favour its deflection SSE into theNautanen-Aitik trend, which mimics the configuration ofanalogous zones to the east and west.Furthermore, we tentatively suggest splays ofthismajorzonecontinuesouththroughtheLaverareaandterminateintheSkelleftedistrictclosetoBjörkdalandBoliden.

Crustal-scale shear zones show a long-liveddeformation history with several reactivation-hydrothermal events. The most important oreformingeventsalongthesezonescanbeassignedtoanearlyphaseofcrustalextensionatc.1.90Ga(Skyttä et al. 2012), and two phases of crustalshorteningataround1.87and1.80Ga,coincidingwith major Svecofennian-cycle tectonothermalevents(c.f.Baueretal.2016,2017).

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Paleoproterozoicvolcanogenicmassivesulfidemineralization,KarratGroup,CentralKangiusapKuua,WestGreenland

YvonneMichelleDeWolfe1,JochenKolb2andDiogoRosa31MountRoyalUniversity,DepartmentofEarthandEnvironmentalSciences,Calgary,Canada,2KarlsruheInstituteofTechnology,InstituteofAppliedGeosciences,GeochemistryandEconomicGeol,3GeologicalSurveyofDenmarkandGreenland,Copenhagen,Denmark

The Karrat Group of CentralWest Greenland iscomposed of the Qeqertarssuaq (Lower KarratGroup),Qaarsukassak,Mârmorilik,Kangilleq,andNûkavsak formations (UpperKarrat Group). AllvolcanicrocksoftheKarratGroupareplacedinthe Kangilleq formation (informal), which isdefined as a package of meta-volcanic(greenschist) rocks that unconformably overliemeta-sedimentary rocks of the QeqertarssuaqFormation and are conformably overlain bymeta-sedimentary rocks of the Nûkavsak

Formation. The Kangilleq formation showsdominantly within-plate, alkali basaltgeochemicalsignatures.

Auniquesequenceofmeta-volcanicrocks(~100m)occursintheCentralKangiusapKuua.TheserocksdifferfromallotherrocksoftheKangilleqformationinthatthey:1)showtholeiiticarc-likeaffinities;2)containfelsicvolcanicrocks;and3)contain VMS-type sulfide mineralization. Thebasal ~60 m consist of pillow basalt lavacontaining flow top breccias and hyaloclastiteindicating subaqueous eruption. Overlying thepillows is an ~30 m sequence of maficvolcaniclastic rocks where normal to reversegrading, massive to crudely bedded, andchannel/scour structures suggest emplacementby mass debris flows. The mafic volcaniclasticbeds are overlain by a rhyolite breccia ~5 m),whichiscappedbyastronglysilicifiedrock(~2m). The felsic breccia hosts stringer tomassivesulfide (pyrite, pyrrhotite ± sphalerite,chalcopyrite).

Our work documents the first occurrence of atholeiitic, bi-modal volcanic sequence with arc-like signature, and VMS-type mineralizationwithin theKarratGroup.Thus, it has importantimplications for mineral exploration, and theinterpretation of the geodynamic setting of theKangilleqformation.

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Anewreef-typePGE-enrichedzoneintheearlyPaleoproterozoicNäränkävaaraLayeredIntrusion,northeasternFinland

VilleJärvinen1,TapioHalkoaho2,JukkaKonnunaho2andO.TapaniRämö11UniversityofHelsinki,Finland,2GeologicalSurveyofFinland

The 2.44 Ga Näränkävaara layered intrusion islocated 100 km south of the Arctic Circle. Itbelongs to a belt of 2.45-2.43 Gamafic layeredintrusions formed during continental extension(Lauri et al. 2012). These intrusions contain

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contact-, reef- and offset-type PGE deposits(Rasilainenetal.2010).

The intrusion is 25 km long and 5 km wide.Geophysical modelling infers a triangular keelextendinguptoadepthof10km.WallrocksareArchean TTG, migmatites, gneisses andmetavolcanicrocks(Alapieti1982).Theintrusionconsists of four principal units (stratigraphicthicknessinparentheses):abasaldunite(2km),aperidotitic-pyroxeniticunit(700m),agabbroicunit(400m),andaquartz-dioriticunit(200m).Parental magma has boninitic or siliceous highmagnesiumbasalt affinitiesexcept for thebasaldunite,whichiskomatiitic.

Five drill holes intersect a 10–25 meter thickPGE-enriched zone located at the border zonebetween the pyroxenitic and gabbroic units(Lahtinen 2005). Average intersection is 15meterswith0.25ppmPt+Pd+Au.Highestassayis0.39ppmPt+Pd+Auina1meterlongsample.ThePd/Pt is 2.5–8.7. Sulfides are rare (highestanalyzedSat2440ppmandCuat262ppm).ThePGE-enrichedzoneiscontinuousalongstrikeforatleast5km.

Thistypeof PGE-enriched zone has not beenfound in similar stratigraphic position fromotherFinnish 2.43-2.45 Ga layered intrusions(e.g.Iljinaetal.2015).Lithologicallyitresemblesthe PGE mineralization in the Munni MunniComplex(Barnes&Hoatson1994).

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LinkingtheUmivikandScouriedykeswarmstighterintoapre-Iapetusplateconfiguration

MartinKlausen1,RiaanBothma1andThomasKokfelt21DepartmentofEarthSciences,StellenboschUniversity,PrivateBagX1,Matieland7602,SouthAfrica,2GeologicalSurveyofDenmarkandGreenland,GEUS,OesterVoldgade10,1350KøbenhavnK,Denmark

Themafic Umivik dyke swarm in SE Greenland(64˚10-30’N)wassampledduringtheGEUS2012

‘SEGMENT’ expedition and mapped in GoogleEarth for structural and petrologicalinvestigations. This approximately 40-km-wideexposedpartofamuchmoreextensive igneousprovinceismadeupofmorethan160roughlyE-Wtrendingdykes,whichconstitute5-15%oftheoutcrop.WithinUmivikwerecognizeatleasttwoslightly oblique cross cutting sub-swarms withsimilar geochemical signatures. Theircompositions are comparable to those of theScouriedykeswarm,acrosstheconjugateriftedmargininScotland(Myers,1987),whichmayallhavebeenderivedfromthesamemetasomatisedsub-continental lithospheric mantle source(Hughesetal.,2014).According toNilssonetal(2013)andDavies&Heaman(2014),thesedykeswereemplacedbetween2.42-2.36Ga,duringthebreak-up of the Superia supercontinent.Subsequently, dykes were variably deformedthrough a combination of conjugate shear andthrust zones during theNagssugtoqidian/Laxfordian orogeny, with thesouthernmost extent of this orogen’sdeformation front coinciding with the Umivikarea.Withtheexceptionofa few lessdeformed‘crustal enclaves’, mafic intrusions becomeprogressively more deformed andmetamorphosedacrossthisnearly150kmwidedeformationfront,exemplifiedbyfourcasestudyareas up along the coast. The Atlantic Oceaneventually separated the Greenlandic andScottishpart fromeachotherandourprimarilyaim is to use both structural and petrologicalevidence provided bymafic intrusions to bringthese two craton fragments tighter togetherwithin their post-Nagssugtoqidian and pre-Atlanticconfiguration.

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ArchitectureoftheRinkianOrogenbetweenSvartenhukandHolmØ,westernGreenland

JochenKolb1,CrystalLaFlamme2,AnnikaDziggel3andKristineThrane41InstituteofAppliedGeosciences,KarlsruheInstituteofTechnology,Germany,2ARCCentreofExcellenceinCoretoCrustFluidSystems(CCFS),UniversityofWesternAustralia,Aus,3InstitutfürAngewandteMineralogieundLagerstättenlehre,RWTHAachenUniversity,Germany,4GeologicalSurveyofDenmarkandGreenland

The Paleoproterozoic Rinkian Orogen extendsfrom Nuussuaq to north of Holm Ø along theGreenlandicwestern coast. It has recently beeninterpreted as northern extension of theNagssugtoqidian Orogen that continueswest inthe Trans-Hudson Orogen of Canada. Weconcentrate on the high-grade metamorphicnorthernpartoftheRinkianOrogen.

The rocks are characterized by Archeanorthogneiss, ultramafic rocks, amphibolite,Paleoproterozoic paragneiss, charnockite of the1.90-1.87GaPrøvenIgneousComplex(PIC),andca. 1.82 Ga granite. The PIC has a diameter of~100 km, with increasing foliation intensitytowardstheoutercontact.Inthesouth,rocksofthe PIC are thrust E on top of Paleoproterozoicparagneiss, which records peak metamorphicconditions at 750-800°C and < 4 kbar. In thenorth,contactrelationshipsbetweentheigneousrocksofthePICandparagneissarecomplex.Thenear-vertical, several km wide Tussaaq shearzonemarks the boundary between the PIC andPaleoproterozoic paragneiss. From this shearzone to the N, the fabrics flatten progressively,turning into a NW-vergent fold-and-thruststructure. Leucosomes are ubiquitous, mostabundant around the Tussaaq shear zone andform syn-deformational structures, indicatinghigh temperature metamorphism. Theseleucosomescoalesceintopegmatitesandplutons,whicharedatedat1.82Ga.Similaragesforpeakmetamorphism indicate a tectonothermal eventsome 50 m.y. after emplacement of the PIC,exhumingrocksofthemiddlecrust.Thefactthat

theyoungestoftheca.1.82Gagranitescrosscutthehigh-Tfabrics,indicatesthatexhumationwasafasttectonicprocessandnotdrivenbyerosion.

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Sniffsof‘IOCG-style(?)’chalcopyritemineralisationinnorthwesternGreenland

CrystalLaFlamme1,KathleenBathgate1,JochenKolb2,DiogoRosa3,MarcoFiorentini1andKristineThrane31CentreforExplorationTargeting,UniversityofWesternAustralia,2KarlsruheInstituteofTechnology,3GEUS

TheNutaarmiutComplexwasidentifiedduringa2016 field campaign in the PaleoproterozoicRinkian Orogen. It is notable for: 1) blebbychalcopyrite and extensive malachite staining,and 2) being low grade and undeformedcomparedtotheadjacentstronglydeformedandgranulite-facies lithologies. Field mappingdefined locallychalcopyritemineralized,gabbroand syenite layers. Further petrologic,geochronological, geochemical, and isotopicinvestigationhas sincedemonstrated that theselithologies rather form locally mineralizedmetasomaticrocks.

The‘felsic’layerscomprisesericitisedorthoclaseand albite. At least two generations ofassemblagesareobservableinthe‘mafic’layers:1)quartz+albite+epidote+biotite+chlorite+sericite,and 2) an overprinting assemblage ofhematite+ilmenite+chalcopyrite+apatite+monazite+zircon. The second assemblage containsabundant iron oxides that are intimatelyassociated with blebs and stringers ofchalcopyrite. Sulfur isotope measurements ofchalcopyrite yield δ34S of +10‰, indicatingsourcingofsulfurfromanoxidisedfluid.A‘felsic’layeryieldedmetamicturaniferous (up to8000ppm)zircon.Thezirconwiththelowesturaniumcontent (<2000 ppm) are used to constrain a207Pb/206Pbageofca.1783Ma.Regionally,thishydrothermal event follows peak high-T

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metamorphismbyabout40m.y.,coincidingwiththetimingofmetamorphictitantiteandresettingof hornblende Ar-Ar ages. In the ChurchillProvince,thisagecorrespondstomagmatismofthepost-orogenicNueltinSuite,whichissourcedfromlowercrustalandmantlemelts.Petrologicalobservations,geochronology,sulfurisotopesandmineralisation style define a package ofmetasomaticrocks that isconsistentwith fluidsthat, in other areas, form IOCG-stylemineralisation.ThisremoteareaofnorthwesternGreenland could be prospective for IOCGmineralisation.

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Structuralinheritanceandbasement-coverlinkageswithinthePalaeoproterozoicPeräpohjaBelt,NorthernFinland

PietariSkyttä1andSimoPiippo21Dept.ofGeographyandGeology,UniversityofTurku,Finland,2Dept.ofGeosciencesandGeography,UniversityofHelsinki,Finland

Correlation of regional-scale bedrock structureandstratigraphywithinthePeräpohjaBelt(PB),NorthernFinland,showsthattheevolutionofthePalaeoproterozoic cover sequences have anintimate relationship with the underlyingArchaeanbasement.Byrecognizingthebasementcontrol the heterogeneous nature of thecontractionalstructuraloverprintwithinPBmaybe explained by one progressive south-vergingthrustingeventinsteadofseveralcompressionalevents with highly contrasting palaeostressorientations. Compressional deformation wasadditionallycontrolledbystrainlocalizationintoa basin-wide basal detachment zoneaccommodated by a mechanically weak unit.Hard linkages between the basement and thecoverisshownbyexposureofthedeepestpartsof the PB stratigraphy in the hanging walls ofreversefaults,whichconsequentlymustcontinuedowntothebasementandrepresentreactivatedbasement structures. By contrast, soft linkagesareshownbydeviationsfromthetypicalthrust-

and-fold belt fold patterns, such as abrupt foldterminations. The recognized major basementstructures comprise fault-bound, approximatelyE-W trendinghorstsandanorthogonally cross-cuttingcentralgraben.ThebasementstructuresweregeneratedundersynchronousextensioninbothNE-SWandNW-SEorientations,whichweattribute to development of a pull-apart basinwith pre-existing basement weakness zones, atan overstepping zone between two major N-Sdeformation zones. This indicates that the N-Sstructures experienced lateral slip during thebreak-up of the Archaean continent at around2.45Ga,andtheinferredsettingexplainswhyPBdidneverprogressintoaproperrift.Recognitionof the major basement structures significantlyimprovestargetingofmineralexplorationinPB.

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LinkingorogenesisacrosstheNorth-Atlantic;theGrenvillianandSveconorwegianorogens,differentinstyle,butgeodynamicallycoupled

TrondSlagstad1,NickM.W.Roberts2andEvgeniyKulakov31GeologicalSurveyofNorway,Trondheim,Norway,2NERCIsotopeGeosciencesLaboratory,Keyworth,UK,3CentreforEarthEvolutionandDynamics,UniversityofOslo,Oslo,Norway

The Sveconorwegian orogeny in SWFennoscandia comprised a series ofgeographically and tectonically discrete eventsbetween1140and920Ma(Slagstadetal.,2017).Thrusting and high-grade metamorphism at1140–1080 Ma in central parts of the orogenwerefollowedbylong-livedarcmagmatismandultra-high-temperaturemetamorphismat1070–920Mainthewesternmostpartoftheorogen.Intheeasternpartoftheorogen,crustalthickeningand high-pressuremetamorphism took place at1050 in one domain and at 980Ma in another.These discrete tectonothermal events are bestexplained as series of accretionary events offragmentedandattenuatedcrustalblocksoftheSW Fennoscandian margin behind an evolving

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continental-margin arc. In contrast, the coevalGrenvillian orogeny is ascribed to long-livedcollisionwithAmazonia.Weargue that roughlycoeval, but tectonically different events in theSveconorwegian and Grenville orogens may belinked through the behaviour of the Amazoniaplate. Subduction of Amazonian oceanic crust,and consequent slab pull, beneath theSveconorwegian may have driven long-livedcollision in the Grenville. Conversely, thedevelopmentofamajororogenicplateau in theGrenvillemayhaveslowedconvergence,therebyaffectingtherateofoceanicsubductionandthusorogenic evolution in the Sveconorwegian. Ourmodel shows how contrasting but coevalorogenic behaviour can be linked throughgeodynamic coupling along and across tectonicplates, and cautions against comparing andcorrelating orogenic belts mainly based ongeochronologicaldata.

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PaleoproterozicvolcanismoftheKarratGroup

ErikVestSørensen1,MichelleYDeWolf2andSimonMoseThaarup11GeologicalSurveyofDenmarkandGreenland,2MountRoyalUniversity

Exceptionallywellexposedandpreservedmeta-volcanicrocksofthePaleoproterozoicKangilleqformation (informal), Upper Karrat Group. arefoundthroughouttheKarratregion.Thisallowsus to characterize the Kangilleq formation andthevolcanicenvironmentpriorto-andduringtheearly formational stages of the NukavsakFormation that comprises the bulk of thePaleoproterozoicstratigraphy.

Through field-observationsand3D-mappingwedocument that the stratigraphyof theKangilleqformation varies from one dominated by mafictuffbrecciaswithsubordinatepillowandmassivebasaltlavastoonedominatedbyalternating,thin(1–10m)pillowandmassivebasalt lavaflowswith lesser mafic volcaniclastic rocks. Thissuggestadynamicsubaqueousenvironment for

the emplacement of the Kangilleq formationvolcanic rocks, one inwhich active, synvolcanicfaulting caused the formation of one or morebasins restricting both the deposition ofvolcaniclasticdebris,andthedistributionoflavaflows.

Themeta-volcanic rocks of Kangilleq formationare greenschist facies consisting of amphiboleand chlorite with variable proportions ofcarbonate, quartz, feldspar, titanite, apatite, Fe-oxides +- biotite. Immobile elementlithogeochemistry characterize these rocks asalkali basalt, with minor tholeiitic basalt, thatdisplaysignificantlightREEenrichmentandhighfield-strengthelementconcentrationssuggestiveof within-plate basalts. Volcanic lithofacies andstructures, combined with lithogeochemistrysuggest the Kangilleq formation erupted in alocalized intracratonic rift, possibly associatedwithmantleplumeactivity.

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IndicatormineralsobtainedbygoldsluicinginLapland,acluetopossibledeposittypesinthearea

PekkaTuisku11UniversityofOulu

Lapland gold rush started 150 years ago,whenvisiblegoldwaspannedatIvalojokiinSeptember1868.Awidespectrumoforemineralshasbeenobtainedsincethenasbyproductofgoldsluicing.Astonishingly,only fewstudieshavebeenmadetousethismaterialasexplorationtoolinthearea.Thereasonforthismightbe,thattheclaimsareusuallysmallandmanytimesrunbymanpower.Therearealso societal andnature conservationreasons thatpossibly repulse explorers interestin the region. Also, the Lapland Granulite Belt(LGB) bedrock is quite monotonous. TheindicatormineralsmaybegroupedtoPGMsandassociatedminerals as chromianmagnetite; Fe-Ti-oxides togetherwithsomesilicates;differenttypesofcorundum;tantalite,columbite,ferberiteand related minerals; different gold nuggetssometimes togetherwith pieces of parent rock;

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REEminerals,especiallyabundantmonazite;andobjectswithpossiblyextraterrestrialorigin.

AvarietyofPGMshasbeenfoundbutthestudyhasmostly targeted to new species rather thanusingthemineralcompositionsandassemblagesto identify the parent deposit type(s).Isoferroplatinum is the most common of thePGMs.TheinclusionsindicateenrichmentofRu,IrandOswhichisusualtochromititeassociateddeposits.Thisisreinforcedbytheoccurrenceofchromian magnetite and chromite in theconcentrate. Some mineral associations askashinite-laurite-cooperite could indicateAlaskan-typeintrusionparent.

Tantalite-columbite etc. and possibly monazite,couldbederived from themarginal zoneof theLGB, which is characterized by anomalous REEconcentration.

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Drone-bornemineralexplorationinCentral-WestGreenland:NewinsightsfromthePaleoproterozoicKarratgroup

RobertZimmermann1,RosaDiogo2andRichardGloaguen11Helmholtz-ZentrumDresden-Rossendorf,HelmholtzInstituteforResourceTechnology,2GeologicalSurveyofDenmarkandGreenland,DepartmentofPetrologyandEconomicGeology

During the last two field seasons, two differenttypes of Unmanned Aerial Systemswere testedand evaluated for mineral mapping in centralWestGreenland.Afixed-wingsystemturnedouttobemoresuitableaslargeareascanbecoveredfasterandmoreefficiently.

In 2017, a sensefly ebeePlus fixed-wing systemwitha4channelmultispectralSequoiacamera(4channels in VIS-NIR with 1.2 MP and anadditional 16 MP RGB camera) was deployed.Flight altitudewas set to achieve 11cm groundsamplingdistance(GSD).Processingfollowedin-house routines using Structure-from-Motion

photogrammetry to get Digital Surface Models(DSM) and geometrically correctedorthomosaics. In total 6.4 km2 of the VMSshowingsinKangiusapKuuaatSvartenhukwerecovered. The VMS showings are hosted in theNûkavsak Formation of the PaleoproterozoicKarrat Group. In certain stratigraphic horizonswithin the meta-turbidites, meta-basalt withassociated sulfide-rich sea-floor alterationoccurs. Flight plans were set to cover bothalteration and host rock. A validation datasetincludes sampling and spectral characterisationofselectedhandspecimens.

Gossanandassociatedalterationofhost rock iseasilymappablebyintegratedmorphologicalandspectral analysis as they form ridges with adistinct iron feature. Moreover, traces offracturesandfaults,theirspatialdistributionandrelationtothealteredhorizonareretrieved.

This further highlights the capability of drone-borne application for high-resolutionreconnaissance mapping within short turn-around times. Intermediate insights from theproject Multi-sensor drones for geologicalmapping (MULSEDRO) will facilitate theapplication of drones under unfavourableconditions.

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NewU-PbgeochronologyfortheArcheanbasement,KarratGroupcoversequenceandlaterintrusionsoftheRayProvince,WestGreenland.

KristineThrane11GeologicalSurveyofDenmarkandGreenland

TheRayProvinceofWestGreenland comprisesArchean orthogneisses and overlyingPaleoproterozoic supracrustal rocks, the KarratGroup.TheKarratGroupistraditionallydividedinto a lower Qeqertarssuaq Formation that isoverlain by the Nukavsak Formation [1]. TheArchean basement and the Karrat Group areintrudedbythePrøvenIgneousComplexat1.90-1.87Gaandallwerereworkedtovaryingextents

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and metamorphic grades during thePaleoproterozoic[1,2,3].

NewU-Pbdata from theArcheanorthogneissesyield ages of ca 3.1-3.0 Ga in the central RaeProvince ofWest Greenland,which giveway toyounger ages of ca. 2.7 Ga to the north. Thisapparent progressive younging either reflects adifferent terrain to the north or northwardgrowthofthecraton.

The Qeqertarssuaq and Nukavsak formationsyield distinctly different detritus patterns. TheQeqertarssuaq Formation is dominated by agescorresponding to the underlying Archeanbasement, whereas the Nukavsak Formationyields detritus pattern dominated byPalaeoproterozoic ages, typically with asignificantmodeatca.2.00-1.95Ga[3].

Metamorphicmonaziteages from theNukavsakFormation revealmultiplemetamorphic events,theearliestbeingcoevalwiththeintrusionofthePrøvenIgneousComplexat1.90-1.87Ga.Alatermetamorphiceventranges inage fromca.1.83-1.80Ga.GraniticintrusionsofsimilaragearealsopresentinthenorthernpartoftheProvince.Theyoung agesmay be related to convergence andeventual collision of the Superior and Raeprovinces.

4.2.Caledonianorogeniccycle:theGreenland-Svalbard-Scandinaviaconnection

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Chemistry,ageandtectonicevolutionofthewesternTrondheimNappeComplexintheOppdalarea,CentralNorway

BjørgunnH.Dalslåen1,DetaGasser2,TorGrenne3,LarsEivindAugland1,FernandoCorfu1andArildAndresen11UniversityofOslo,2WesternNorwayUniversityofAppliedSciences,3GeologicalSurveyofNorway

The evolution of, and along-strike correlationswithin the Iapetus-derived western TrondheimNappe Complex (TNC) have been debated foralmostacentury.TheareaclosetoTrondheimisbeststudied.ItconsistsoftheLøkken,Vassfjelletand Bymarka (LVB) ophiolitic fragments in theNW, and the Støren s.s. greenstones in the SE,whichbothareunconformablyoverlainbyMid-OrdoviciantoSilurianvolcanicandsedimentaryrocks of the Hovin and Horg successions. Untilrecently,theTNCintheOppdalareatothesouthhas been less studied, but metabasaltic andmetasedimentary rocks have been correlatedwiththeLVB/Støren,HovinandHorgunits,andalarge-scale tectonic inversionhasbeen inferred.Herewepresentnewlithologicalandstructuralfieldobservations,geochemicaldata,anddetritalandmagmaticzirconagesfromtheOppdalarea,and suggest a new tectonic model for thissouthern part of the TNC. Our results indicatethattheareaconsistsoffourdifferentunits:(1)a~480-472 Ma volcanic and sedimentarysuccession comprising submarine basaltic andminorrhyoliticflows,(2)a~472-469Mavolcanicunit dominated by intermediate to rhyoliticpyroclasticdeposits,(3)a<450Masedimentaryand volcanic succession, and (4) anunconformablyoverlying<430Masandstoneandvolcanicsuccession.Therocksinthearearecordthe change frommarginal basin or ocean floorspreadingtosubduction-relatedandcontinental

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volcanism.Thestudyhasconsequencesforalong-strike correlations within the TNC and offersfurther insight to the complexity of the IapetusOcean closure preserved in this part of theScandinavianCaledonides.

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TheSevesubductionsystemintheScandes

DavidG.Gee1,Per-GunnarAndreasson2,HåkanAustrheim3,ChristophHieronymus1,IwonaKlonowska1,JaroslawMajka1andRemiVachon1UppsalaUniversity,Sweden,2LundUniversity,Sweden,3OsloUniversity,Norway

The Seve Nappe Complex (SNC) in theScandinavian Caledonides provides some of thebestexposedevidenceonlandforthecharacterof a highly attenuated, magma-intruded, outermargin of a continent (including the continent-ocean transition zone). The last forty years ofresearch has shown that this Baltoscandianmargin of continent Baltica was initially riftedand locally intrudedduring the lateTonianandCryogenian and subsequently extensivelyinjected by mafic magma during break-up andseparationofBalticafromLaurentiaintheearlyEdiacaranatc600Ma.PartialeclogitizationoftheSNCwasrecognizedinthe late1960sandmorerecent studies of themetamorphic historyhaveshownthatOrdovicanUHPmetamorphism,withmicrodiamonds ingarnets, iswidespread in thehostmetasedimentsoftheSNCoveravastarea,apparently related to subduction beneathoutboard volcanic arcs during closure of theIapetus Ocean (now preserved in the overlyingKöliNappeComplex).Itissuggestedherethattheincreaseindensityrelatedtoeclogitizationofthemafic magma-rich margin, promoted thesubduction process. The SNC is dominated byupper crustal components – psammitic andpeliticmetasediments,hostingthedoleritesandgabbros; most of the underlying attenuated,magma-intruded, lower crustal “basement”wasapparently eclogitized and lost into themantle.Our preferred hypothesis is that most of thissubductedbasementwasofSveconorwegianage

and included a substantial, granulite faciescomponent.

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TheNorthAtlanticCaledonides-fromScandinaviaandGreenlandtoSvalbardandthehighArctic

DavidG.Gee1andJaroslawMajka11UppsalaUniversity,Sweden

The typeareaof theCaledonides in theUKandIreland is disrupted by major late- to post-orogenic, orogen-parallel faults. WesternScandinavia provides a more coherent sectionthrough the orogen and, together withcomplementarypartsofnortheasternGreenland,comprise an excellent laboratory forunderstanding this collisional orogen. Thesouthernmost Scandes also suffer from similarproblemstothoseinScotland,withtheOsloriftdisrupting the Caledonian foreland basin.Nevertheless, thewhole1700kmlongScandianmountain belt provides an amazingly coherenteasternflankoftheOrogen,withwell-preservedOrdovician and Silurian foreland basinsuccessions, abundant evidence of OrdovicianHP/UHP subduction of the outermostBaltoscandian margin during accretion ofIapetus-relatedterranes,andculminatingSiluro-Devonian,ScandianunderthrustingofLaurentiabyBaltica,involvingvastlateraldisplacementofallochthons. Northeastern Greenland, providingthecomplementarywesternflankoftheOrogen,is also dominated by major thrust systems, allcomprising parts of the Laurentian margin,emplaced at least 200 km westwards onto theplatform.

InthedeephinterlandofboththeScandinavianandGreenlandianCaledonidesthereisabundantevidence of late-orogenic, early Devonian axialextension,superimposedonthenappepile;also,hinterland-vergent extension. Both thesephenomena are prominent in the SvalbardCaledonides, where the rock units and tectonichistoryofdepositionandthrustingissosimilartonortheast Greenland; only in southwestern

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Spitsbergen, inthedomainoftheCenozoicfold-and-thrust belt, is there a Caledonian terranewith affinities to northernmost Greenland,Pearya and the Timanides, providing keyevidence forunderstandingCaledonianorogenyintheArctic.

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Remnantsofthepre-CaledonianBalticariftedmarginpreservedinalithologicallymixedunitbetweenBergenandTynset,ScandinavianCaledonides,SouthandCentralNorway

JohannesJakob1,JoostM.vandenBroek1andTorgeirB.Andersen11TheCentreforEarthEvolutionsandDynamics,DepartmentofGeosciences,UniversityofOslo,Norway

Remnants of the magma-poor and magma-richpre-Caledonian rifted margin of Baltica arepreservedintheallochthonsoftheScandinavianCaledonides.Thetransitionfrommagma-poortothe magma-rich domain corresponds to thenorthern termination of the Jotun NappeComplex.Solitarymetaperidotitebodiesaboundin the magma-poor segment and the transitionzone.

The metaperidotite bodies display acharacteristic early flattening fabric. Theflattening fabric is well-developed in theultramafic bodies enclosed in themetasedimentary units structurally below thelarge crystalline basement nappes of SouthernNorway including the Jotun, Lindås, and upperBergsdalen nappe complexes, but can also befound in the metaperidotite lenses betweenVågåmo and Tynset. Pre-Scandian contactrelationships between those deformedmetaperidotites and the metasediments havebeen obliterated during the Scandian Orogeny.However, well-recrystallised, pre-Scandian,extensional and sedimentary “ghost structures”within the metaperidotite bodies are locally

preserved and can be found on favourablyweatheredsurfaces.

Theinterpretationofthelithologicallymixedunitbetween Bergen and Tynset is challenging,because, no geochronological evidence of theearly rift stages from within the unit have yetbeenreported.Moreover,theunitmayhavebeenreworkedbetweenthelatestCambrianandearlyMid-Ordovician(Jakobetal.2017).However,anoriginal lithostratigraphic succession of theancientBalticariftedmarginmaybepreservedina thrust nappe north of Lesja (Jakob et al. thisvolume)andmayhelptoshedlightontheoriginand pre-Scandian history of the mixed unitbetweenBergenandTynset.

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SubductionandthrustemplacementoftheLowerSeveNappeintheScandinavianCaledonides:Pressure-Temperature-DeformationconstraintsalongtheCOSC-1boreholeinÅre

PaulineJeanneret1,JohannaHolmberg1,IwonaKlonowska1,JaroslawMajka1,HenningLorenz1,BjarneS.G.Almqvist1,AnnaLadenberger2,KarolinaKośmińska3andDavidG.Gee11DepartmentofEarthSciences,UppsalaUniversity,Villavägen16,75236Uppsala,Sweden,2GeologicalSurveyofSweden,Villavägen18,75128Uppsala,Sweden,3FacultyofGeology,GeophysicsandEnvironmentalProtection,AGH–UniversityofScienceandTechnol

The Scandinavian Caledonides comprise thrustsheets transported onto the Paleozoic platformsuccessions of the Baltoscandianmargin. Thesethrust sheets are subdivided into the Lower,Middle, Upper and Uppermost allochthons. Thetectonostratigraphically highest part of theMiddle Allochthon is the Seve Nappe Complex,the target for the Collisional Orogeny in theScandinavian Caledonides (COSC-1) scientificdrillingproject.Acontinuous~2.4kmlongdrillcore through the metamorphic Lower Seve

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Nappe(LSN)hasbeenretrieved.TheSevenappesare considered to have been still hot whenemplacedand, consequently, theCOSC-1profileprovides a unique opportunity to relate thepressure-temperature-deformation (P-T-D)historyof this criticalallochthon to the tectonicstructures that formed during emplacementunder mid-crustal condition. Moreover, thisresearch will endeavor to establish a coherentmodel of mid-Palaeozoic (Scandian) mountainbuilding.OurresearchfocusesondecipheringthecompleteP-T-DevolutionoftheLSNbasedonacombination of established and innovativemethodologiesofP-Testimates(QuiGbarometryand TitaniQ thermometry). The finite ductilestrain pattern of the LSN results from thesuperposition of two major tectono-metamorphic eventsM1-D1 andM2-D2.M1-D1features are interpreted as the consequence ofthe LSN subduction, and M2-D2 eventcorresponds to the final exhumation andthrusting of the LSN above the underlyingallochthons.

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AnewtectonicmodelfortheSeveNappeComplexinNorrland,Sweden

HansJørgenKjøll1,TorgeirAndersen1andLoicLabrousse21CentreforEarthEvolutionandDynamics(CEED),UniversityofOslo,Norway,2UniversitePierreetMarieCurie,Paris,France

The Seve Nappe Complex (SNC) in Norrbotten,Swedenhasclassicallybeenmappedasaseriesofnappes formed by the telescoping of the riftedmargin of Baltica. Typically, the SNC is sub-dividedintothelower,middleanduppernappe-series. The lower Seve generally constitutesslivers of basement and are overlain by meta-sedimentary and meta-igneous rocksrepresenting both the middle and upper Sevenappes. The peak metamorphism variesconsiderablywithintheSevefromlocaleclogitefaciestoamoreregionalamphibolitefaciesanddomainswhere original pre-Caledonian contactmetamorphismrelatedtodoleriteintrusionsare

preserved. This has led to the norm ofsubdividing the SNC in different thrust nappes.Wepropose,however,amodelwheretheSeveinNorrbottenrepresentsamorecontinuoussectionthrough the magma-rich, attenuated margin ofBaltica and that the metamorphic overprint,rather than representing decoupling and re-stacking, represent differential reactivity ofindividual lithologies with different reactionpotential. High strain zones are presentthroughout Sevebut theneed for large internalthrustsjuxtaposingolderrocksontopofyoungeris not present internally in the Seve. This hasdramatic consequences for, not only theunderstanding of the mountain building in theCaledonides,butmayalsoopenanewinterestfortheSeveasaplacetostudythedeepprocessesofmagma-richpassivemargins,whichareoftenlostinsubductionandingeneraldifficulttostudyinseismic lines due to masking of high velocitymaficintrusiveandextrusiverocks.

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UHPmetamorphismintheSeveNappeComplexintheScandinavianCaledonides

IwonaKlonowska1,JaroslawMajka1andMarianJanák21UppsalaUniversity,Sweden,2SlovakAcademyofSciences

Evidence for ultrahigh-pressuremetamorphism(UHPM) and deep subduction of the Balticanouter margin in provided by diamond-bearinggneisses in three localities, on TväråklumparnaandÅreskutaninwest-centralJämtlandandnearSaxnäs in southern Västerbotten. These UHPgneissesarefoundwithintheMiddleSeveNappe.

Microdiamonds are identified by microRamanspectroscopy and are found as inclusions ingarnetaswellasinzircon.TheUHPMwithinthisrocksisalsoconfirmedbythephaseequilibriummodelling. The peak pressure conditions of theÅreskutan gneiss are estimated to 4.1-4.2 GPaand830-840ºC,whereasoftheMarsfjälletgneiss(Saxnäs)to~3.6GPaand750ºC.Monazitesfrom

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all three localities were chemically dated andthey yielded Ordovician ages of migmatization(post-UHPstage).Thedating forÅreskutanandTväråklumparna gneisses shows that thediamond-bearing gneisses underwent partialmelting between 445 and 435Ma,whereas thepost-UHPM in Marsfället gneiss is older (ca.470Ma). The timing of the UHPM and diamondformation still remains tobe resolved,howevertherecentstudiesprovideimportantinformationabout the tectonometamorphic evolution of theSeve Nappe Complex in the SwedishCaledonides.

ORAL

AreviewofmagmaticandmetamorphiceventsrecordedbycrystallinebasementofSouthwesternSvalbard

KarolinaKośmińska1andJarosławMajka21AGHUniveristyofScienceandTechnology,Kraków,Poland,2UppsalaUniversity,Uppsala,Sweden

Svalbard’s Southwestern Basement Province(SBP) consists of numerous tectonic unitsjuxtaposedbymajorstrike-slipfaultsandthrustzones of early Paleozoic (perhaps alsoNeoproterozoic)toCenozoicage.FelsicandmaficigneousrocksofvariousaffinitiesareofEctasian-Stenian, Tonian and Cryogenian-Ediacaran age.SedimentarysuccessionsweredepositedduringMesoproterozoic, Neoproterozoic and earlyPaleozoic. Majority of both igneous andmetamorphicrockshavebeenaffectedbyatleastone metamorphic event. Metamorphic eventswere associatedwith the Torellian (c. 640Ma),Caledonian and Ellesmerian (c. 360 Ma)orogenies. The grade of metmorphism variedfrom greenschist and amphibolite to blueschistand eclogite facies. The SBP is definitely acomposite terrane assembled piece by pieceduring the aforementioned orogenic events aswell as the Eurekan orogeny that shaped finaltectonic framework observed nowadays.Comprehensive recognition of the geological

complexityoftheSBPisakeyforunderstandingofwholeSvalbardtogetherwithadjacentarea.

ThisworkwassupportedbytheNationalScienceCentre (Poland) through the “NAC” project no.2015/17/B/ST10/03114.

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Syn-collisionalScandianextensionandmagmatismontheOrkneyIslands,Scotland

AndersMattiasLundmark1,LarsEivindAugland1andAudunDaleneBjerga11UniversityofOslo,DepartmentofGeosciences,POBox1047Blindern,0316Oslo,Norway

TheOrkneyIslands,NWScotland,aredominatedby sedimentary rocksof theDevonianOrcadianbasin. The sparsely outcropping basement hasreceived less attention than its cover, but istypically interpreted as Grampian or Scandiangranites intrudingNeoproterozoicMoine schist.Newstructural, TIMSage andgeochemical datademonstrate that a grey and a pink graniteintrudedmetasedimentarygneissat432±0.5Maand430±1Ma,respectively,toformtheOrkneygranitecomplexduringtheScandianphaseoftheCaledonian orogeny. Inherited zircons in thegranites give ages typical of Moine schist. Bothgranites display geochemical characteristics ofthe Scandian high Ba-Sr granite suite in thenorthernBritishIsles.Boththegranitesandthegneiss are cut be previously undocumentedextensional mylonite zones, which areoverprinted by similarly oriented extensionalphyllonites,andinonecasebysimilarlyorientedextensionalbrittlefaults.Threesuchdeformationzones are observed: in the north, the Yesnabyshear zone display top-to-north extensionalshearsenseandinthesouththeStromnessandthe Graemsay shear zones display top-to-southextensionalshearsense.Successiveemplacementof granite, pegmatite and aplite into the shearzones,cross-cuttingsomestructureswhilebeingdeformed by others, allow dating of thedeformation. We propose that the ductile to

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brittle evolution of the shear zones reflectdeformationduringemplacementandcoolingofthegranitecomplexatarelativelyshallowcrustaldepth. The N-S extension on Orkney duringScandianoverallNW-SEdirectedcollision likelyreflectstranscurrentfaultingassociatedwiththenearbyGreatGlenFault.

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AreSouthwesternSvalbardandthePearyaTerranecounterparts?

JarosławMajka1andKarolinaKośmińska21UppsalaUniversity,Uppsala,Sweden,2AGHUniversityofScienceandTechnology,Kraków,Poland

Svalbard’s Southwestern Basement Province(SBP) and the Pearya Terrane of northernEllesmere Island are thought to be possiblecounterparts dismembered by long-distancestrike-slip faults. Both terranes indeed sharesome similarities including Mesoproterozoic toNeoproterozoic igneous rocks and associatedsedimentary successions locally intruded byyounger mafic dykes as well as thickNeoproterozoic sedimentary successions thatincludehorizonsofdiamictitesofpossibleglacialorigin. However, there are also dissimilaritiesbetweenthetwoterranes.TheSBPbearsarecordof the Torellian orogeny (c. 640 Ma), which ishitherto lacking in Pearya. Also, clearlysubduction related Caledonian blueschist faciesrocksareknownonlyfromtheSBP.OntheotherhandthePearyaTerranecomprisesavestigeoftheOrdovicianislandarc,whichcouldhavebeenapartofthesamesubductionsystem.ThePearyaTerranealsohostsDevonianintrusiveswhichdonotoccurintheSBP.Despitethesedissimilarities,itcanbestatedthatboththeSBPandthePearyaTerrane form a coherent system of tectonicallyjuxtaposed sub-terranes, but much morecomprehensive tectonic, petrological andgeochronological research in both terranes isneeded to decide whether they are truecounterpartsornot.

ThisworkwassupportedbytheNationalScienceCentre (Poland) through the “NAC” project no.2015/17/B/ST10/03114.

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Integrationofpalaeomagnetic,isotopicandstructuraldatatounderstandSvalbardCaledonianTerranesassemblage

KrzysztofMichalski1,GeoffreyManby2,KrzysztofNejbert3,JustynaDomańskaSiuda3andMariuszBurzyński11InstituteofGeophysics,PolishAcademyofSciences–CentreforPolarStudiesKNOW,2NaturalHistoryMuseum,London,GreatBritain,3DepartmentofGeology,UniversityofWarsaw,Poland

DuringthePALMAGproject(2012-2016)atotalnumber of 828 palaeomagnetic specimens ofmetacarbonates and metabasites from 46 sitesrepresenting all three of Svalbard’s CaledonideTerranesweredemagnetizedintheLaboratoryofPalaeomagnetism(InstituteofGeophysicsPolishAcademy of Sciences) to recognize their NRMpatterns. Simultaneously, 13 samples of micaschists and amphibolites from theWestern andEastern Terranes and mylonites from theKongsfiord,BillefiordandEolusslettaFaultZoneswere subjected to in situ laser ablation40Ar/39Ar age determinations at the CEPSAR(The Open University, UK). Integration ofpalaeomagnetic and isotopic experimentsaccompaniedbydetailedstructuralobservationslead to the following palaeogeographic andtectonicconclusions: (a) theresultsconfirmthecomplete remagnetization of the investigatedmetamorphiccomplexesofSpitsbergen(WestofHinlopenstretet) during Caledonian tectono-genesis(Burzyńskietal.2017);theyalsoconfirmtheamalgamationofSvalbardwithBalticainLateSiluriantime(Michalskietal.2012,2014);(b)theresultsindicateasignificantreorganizationofthegeometry of the sampled sectors of the WestSpitsbergen basement by listric faulting relatedtotheopeningoftheNorthAtlantic-ArcticOceanBasins (Michalski et al. 2017); (c) In

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Nordaustlandet(EastofHinlopenstretet),relictsof a pre-Caledonian (primary?) magnetizationappears to have survived; (d) analyses of thepalaeolatitudesderivedfromtheMurchisonfiord(Nordaustlandet) samples do not confirm thepositioning of Eastern Svalbardnear toEasternGreenland in Neoproterozoic time, the resultssuggest,rather,thatEasternSvalbardconstitutedaseparatemicroplateorcouldhavebeenlocatednear the N. Greenland/Pearya blocks.(manuscriptinrevision).

ORAL

TheSiljanRing;ALowerPaleozoicpetroleumsystemwithkitchensinaTelychianriftbasin,disruptedbymeteorimpactandrejuvenatedbybiologicalandQuaternaryglacialprocesses

JohnMichelsen1,GanjavarKhavari-KhorasaniandJollinusSalehy1GigawizLtd.Co

Theoils inSiljanarethoughttohaveformedbyFrasnian impact heating of the Katian Fjäckashale (Vlierboomet al., 1986).However, oilremains are not unique to the Siljan crater andoccur throughout the subsurface of centralSweden(Sandströmetal.,2006).Byreexaminingpublishedseismics(Juhlinetal.,2012;Muhamad2017), well descriptions (Lehnertet al., 2012;Muhamadet al., 2015) together with our ownsource rock observations, we demonstrate thattheoilformedinkitchensinaTelychianriftbasinpriortotheimpact.WeseenoevidenceofNW-SEoriented Ordovician facies belts (Lehnertet al.,2013), and imagedmajornormal faults and theMora structural high are Telychian rather thanimpactrelated.Themajorunconformityseen intheMora1well(Lehnertetal.,2012)isthebaseofa200m+deepNNW-SSEoriented600m+wideincised valley, triggered by associated normalfaulting.Wesuggesttheriftbasinformedduetoextension over the flexural bend in front of theCaledonian orogeny.We also observe youngerincised valleys, possibly related to theSheinwoodianglacially triggered regression.We

explain the post-Ordovician deformation as acombinationoftheTelychianextension,andthemeteor impact. The gas produced in the SiljanRingisbiogenicandlikelyfrombiodegradationofresidual oils (Rouchonet al., 2015).The gasseeping activity however, is likely due to thedecompression (around 200 bar) from thewithdrawal of the Weichselian ice cap and theassociated subglacial basement water flowpatterns.

ORAL

TimingofcollisioninitiationandlocationoftheorogenicsutureintheScandinavianCaledonides

TrondSlagstad1andChristopherL.Kirkland21GeologicalSurveyofNorway,Trondheim,Norway,2CentreforExplorationTargeting–CurtinNode,CurtinUniversity,Perth,Australia

The Scandinavian Caledonides formed duringBaltica–Laurentia continent-continent collisionin the late Silurian. We propose that initialcontact along continental-margin promontoriesled to a drop in convergence rate, resulting inincreasedslabroll-backalongpartsofthemarginstill undergoing oceanic subduction. Slab roll-back caused extension of the overlyinglithosphere with orogen-wide emplacement ofmaficlayeredintrusions,ophioliteformationandbimodal magmatism at 438–434 Ma, in whatimmediately thereafter became the upper plate(Laurentia) in the Scandian collision. Initialcollisionatpromontoriesmaybechallenging toidentify due the metamorphic effects of full-fledged collision shortly thereafter. However,rapid deposition of sediments from erodingorogenic highs just prior to or during the 438–434Maperiodmay represent a tell-tale signofearlycollision.AnexampleofsuchearlySiluriandeposits may be present on Magerøya, in thenorthernmostScandianavianCaledonides(Corfuet al., 2006), where the sediments appearpenecontemporaneouswithmaficintrusiveunitslikely formed in a back-arc setting. This model

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provides a tight constraint on the timing ofcollisioninitiation,andprovidesaframeworkbywhich some tectonic units comprising theScandinavian Caledonides can be assigned aBaltican or more exotic heritage, where othermethods,suchasdetritalzircon(DZ)chronologycannot,asprovedbyDZstatisticalsimilarityrightacross the entire North Atlantic region (e.g.,Slagstad & Kirkland, in press). Tracking thesuture through the intrusive model highlightsthat many units conventionally ascribed aBaltican heritage are in fact much more fartravelled.

POSTER

TheageofmetagabbrofromtheBangenhukunit,AtomfjellaComplex,Ny-Friesland,Svalbard

JakubBAZARNIK1,JarosławMAJKA2,JarosławMAJKA3,KarolinaKOŚMIŃSKA3,WilliamC.MCCLELLAND4,KarstenPIEPJOHN5,ZbigniewCZUPYT6andTomášMIKUŠ71PolishGeologicalInstitute–NRI,CarpathianBranch,Skrzatow1,31-560Krakow,Poland,2DepartmentofEarthSciences,UppsalaUniversity,Villavägen16,752-36Uppsala,Sweden,3FacultyofGeology,GeophysicsandEnvironmentalProtection,AGH–UST,Krakow,Poland,4DepartmentofEarthandEnvironmentalSciences,UniversityofIowa,IowaCity,Iowa52242,USA,5BundesanstaltfurGeowissenschaftenundRohstoffe,GeologiederEnergierohstoffe,Hanover,Germany,6PolishGeologicalInstitute–NRI,Address4,RakowieckaStreet,00-975Warszawa,Poland,7EarthScienceInstitute,SlovakAcademyofSciences,Ďumbierska1,97401BanskáBystrica,Slovakia

The Bangenhuk unit is a part of the AtomfjellaComplex and belongs to the Svalbard’s EasternBasement Province. Whole Complex has beenmetamorphosedinamphibolitefaciesduringtheCaledonian Orogeny (Witt-Nilsson et al. 1998).TherocksoftheAtomfjellaComplexcropoutinwestern Ny-Friesland and form north-southtrending antiform, which includes metagraniticbasement covered by younger metasediment(Gee&Tebenkov,2004).

TheBangenhukunitof theNordbreenNappe iscomposedmainlyofgraniticgneisseswhoseagewas estimated to c. 1750 Ma (Johansson et al.1995, Bazarnik et al. 2017). However, older (c.2709Ma)quartz-monzonitehasalsobeenfound(Hellman et al. 2001). Both gneisses andmetasedimentary covers are intruded by maficdykesofunknownage.

A sample of metamorphosed gabbro wascollectedfromthesoutherncoastofMosselbukta,near a small cottage on the Bangenhukenpeninsula, during the CASE 18 Expedition in2015. It formsadykecuttingthoroughgneissesand striking approximately north-south. Thegabbro is composed mainly of plagioclase,pyroxene, amphibole and garnet with minoramountofapatite,ilmenite,quartzandzircon.

U-PbzircondatingwasperformedintheMicro-Analyses Laboratory in Polish GeologicalInstitute in Warszawa using SHRIMP IIe/MC.About 40 fragments of euhedral zircon grainswithoscillatoryzoninghavebeenanalyzed.Theobtained result ca. 1382 Ma has not beenrecordedintheNyFrieslandareabefore.Similarages were noticed in Zig-Zag Dal Formation ineasternNorthGreenland(Uptonetal.2005).

POSTER

DetritalzirconsignaturesofthemetasedimentaryrocksoftheLowerSeveNappeintheCOSC-1drillhole,Åre,Sweden.

Yuan Li1, David G. Gee2 and Anna Ladenberger31State Key Laboratory for Continental Tectonics andDynamics, Chinese Academy of Geological Sciences,,2Department of Earth Sciences, Uppsala University,Sweden., 3Geological Survey of Sweden

The ICDP- “Collisional Orogeny in theScandinavian Caledonides” (COSC) drillingproject, targetedtheLowerSeveNappe, locatedin the footwall of the microdiamond-bearingÅreskutan Nappe of the Seve Nappe Complex(SNC)inwesternJämtland;itpenetrated2500mof mainly psammitic metasediments,

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amphibolitesandafewfelsic,usuallypegmatiticintrusions.U-PbdatingbyLA-ICPMSofzirconsinthese lithologies provides evidence of a mainlyMesoproterozoic provenance of themetasedimentary rocks and it also confirmsevidenceofmidOrdovicianfelsicmagmatism(Lietal.2014).Theageofthemaficrocksisdifficulttoconstrainbecausetheyhaveallbeensubjecttoacomplexmetamorphichistory(Jeaneretteetal,this volume). Over twenty samples of thepsammitic schists and gneisses have beenanalysed.AsinpreviousinvestigationsoftheSNC(Gee et al 2014) and underlying Särv Nappes(Be´eri-Schlevinetal2011) in central Jämtland,andfarthernorthnearthebordertoVästerbotten(Kirkland et al 2011) and also southernNorrbotten (Gee et al 2015), the zirconpopulations are nearly all dominated bySveconorwegian signatures; many also by astronglatePalaeoproterozoiccomponent.Atthebaseofthehole,thereisasignificantlateArcheanzirconpopulation.Alongwith thedata fromtheKalakNappeComplexcorrelativesoftheSNCandSärvNappesinnorthernmostNorway(Kirklandetal2007),thenewdataemphasizethecommoncharacteroftheprovenanceofthesediments inall thesenappes,derivedfromtheoutermarginofBaltica.

4.3.EvolutionoftheNorthAtlanticmargin:fromMesozoicriftingtoCenozoicinversion

ORAL

Deltaicgrowth-faultsoftheTriassicBarentsShelf;structuralstyleanddeformationmechanismscontrollingbasinconfiguration

AlvarBraathen1,MarkMulrooney1,AleksandraSmyrak-Sikora2,BeyeneHaile1,IngridAnell1,KeiOgata3,HarmonMaher4,PerTerjeOsmundsen5andIvarMidtkandal11DepartmentofGeosciences,UniversityofOslo,Norway,2DepartmentofArcticGeology,UNIS,Norway,3VrijeUniversity,Amsterdam,Holland,4UniversityofNebraskaatOmaha,USA,5GeologicalSurveyofNorway

Deltas represent major sedimentaryaccumulation zones with distinct subaqueous,sigmoidal geometry and principal depositionconcentratednearthetop,whichare inherentlyprone to instability that leads to mass wastingand/orstructuralcollapse.Wecomparetectonicandcollapse-relatedfaultsassociatedwithdeltaprogradationoftheupperTriassicsuccessionofEdgeøya(SESvalbard),tocollapsestructuresinamore“typical”LastChanceDelta(Utah).Commonforbothinvestigateddeltasystemsisthatfaultshave listric geometries instigated by linkage ofvariouslyorientedsegmentsabovewelldefineddetachment zones. Hangingwalls form rolloverfolds, locating accommodation in the half-grabenstowardsfaults.Infill ischaracterizedbywedge-shaped, sandpronebodies that attest torapidslipincrementsonfaultscontemporaneoustomilderosionalongthecrestsoffaultblocks.Inthe footwall (underneath) of listric faults, mudpillowsortriangle-zonesaredeveloped.Relatedsmaller structures attest to a transition fromhydroplastic shear to brittle, frictional flowdeformation along with diagenesis andcementation.

Edgeøya half-grabens arrested high amounts ofsand in the prodelta realm, whereas the Last

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Change delta records deposition mainly in thedeltatop.Thetriggeranddrivingmechanismfordelta collapse by faulting is the localized,differential loading of the sand bodies ofchannels/mouthbarsandfault-controlledbasins.Faultsmovematerialtowardsthefreesurfaceofthe delta-front. Complementary, compaction ofprodelta muds offers localized and gradualmechanical decoupling from overlying densersand.Further,thecompactionfrontbelowdeltascan trigger faulting in the prodelta realm, withland-ward dipping faults facing the progradingdelta-front.

ORAL

TheMesozoicbasinofRamsåinNorthernNorway:Characteristics,Developmentandregionalimpact

MarcoBrönner1,TorArneJohansen2,BørreDavidsen3,HåkonRueslåtten3,BentOleRuud2andTormodHenningsen41GeologicalsurveyofNorway,Trondheim;DepartmentforGeoscienceandPetroleum,NTNU,Trondheim,2UniversityofBergen,Bergen,Norway,3GeologicalsurveyofNorway,Trondheim,Norway,4UniversityofTromsø,Tromsø,Norway

TheRamsåBasin onAndøya,NorthernNorwaygives a unique insight into the Mesozoicsedimentary strata onshore the mainland ofNorway. Itexperiencedagreatdealofattentionsince the 19th century and was studiedgeologically several times. However, extensivegeophysical mapping was missing and thetectonic development of the basin itselfis stilldisputed.

Moreover,thebasinispartofthewelldevelopedstrandflat of eastern Andøya where remains ofdeeply weathered basement around andunderneath the sedimentary strata indicate ahistory of repeated uplift and erosion whichmakes it to a key location to understand thedevelopment of this remarkable landscapewidelyobservedalongtheNorwegiancoast.InacooperationprojectofNGUandtheUniversityofBergenwecarriedoutextensivegeophysicaland

geological profiling including seismic andpotential fieldmeasurements to investigate thecharacteristics and settingsof theRamsåBasin.Specimens were analyzed sedimentologically,petrologically/mineralogically andgeochemically. Four new boreholes were core-drilled and are currently subject to furtheranalyses.

This integrated study provides an enhancedunderstanding of the geometry and tectonicsettingsof theRamsåBasinasasetofaNE-SWoriented normal faulted half-graben, whichdevelopedinthelateststageoftheopeningoftheAndfjorden Basin. Our results indicateweathering ina tropical to sub-tropical climate,and K/Ar dating reveals Late Triassic age. Twonewly found Mesozoic sub-basins south of theRamså Basin confirm repeated erosion andtransgressionphaseswith a burial depth of thesedimentsnotexceedingmorethan2km.

ORAL

CorrelationoftheOligocene–PliocenesuccessioninNorway,Denmark&UK

TorEidvin1,ErikS.Rasmussen2,FridtjofRiis1andKarenDybkjær21NorwegianPetroleumDirectorate(NPD),P.O.Box600,N-4003Stavanger,Norway,2GeologicalSurveyofDenmarkandGreenland(GEUS),ØsterVoldgade10,1350,CopenhagenK,Denmark.

The almost complete, mainly deltaic, upperPaleogene-Neogene succession from Jylland,DenmarkwasinvestigatedforSr-isotopes,micro-fossils,andpalynologyinordertomakearobuststratigraphic framework for the North Seaarea.The investigation shows that the Danishsuccession correlate readily with lithologicalunits,intheNorwegianNorthSea,theNorwegianSea shelf and the East Shetland Platform. Inparticular,Bolboformaanddinocystcorrelationsshow that the upper part of the Danish GramFormation correlateswith the base of theMoloFormationinit’ssouthernpart,andthatthispartof the Molo Formation corresponds to the

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middle/upper part of the Kai Formation(Norwegian Sea shelf). The new robustcorrelation between the North Sea and NorthAtlantic realm is fundamental in theunderstanding the palaeogeography during thelate Paleogene and Neogene. For instance, TheBolboformaassemblageshavetheiroriginintheNorwegianSeaandtherefore,duetothepresencein theDanish area, confirm that itwas anopenstraitinthenorthernNorthSea(theonlyseawaypassage into the North Sea Basin during theMiocene). The glauconitic Utsira Formation(approximately5.7-5Ma), in the thresholdareaclosetotheopeningtotheNorwegianSea,overlieerosional unconformities comprising 21and 13my.Webelievethatthisunconformitywaspartlyrelated to the activity of strong currents in thenarrowstraitbetweenNorwayandtheShetlandplatform and partly related to the Messinianglacio-eustaticleveldrop.

ORAL

LateCretaceousbasininversionintheKattegat–Skagerraksegment,Sorgenfrei–TornquistZone,Denmark,andMesozoic–CenozoiccrustaltectonicsoftheeasternNorthSeaBasin

OleGraversen11DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,Denmark.

The Sorgenfrei – Tornquist Zone is a NW-SEtrending,50-100kmwidefaultzonethatcutofftheEastNorthSeaBlock(ENSB),i.e.theMesozoicbasement of the Eastern North Sea Basin, fromthe Baltica Palaeozoic platform. The break wasestablishedintheTriassic,wheretheENSBwasestablished as the hangingwall block in theKattegat area; by contrast, the Baltica platformdevelloped as the hangingwall block in theFjerritslevhalfgrabentothenorthwest(1).

In the Kattegat area, the Triassic faultingestablishedastaircasefaultblocktrajectorywithdownfaulting towards the southwest into the

DanishBasin.IntheJurassic–EarlyCretaceous,the Kattegat segment changed into anasymmetric, northeast dipping graben, theKattegat Graben. In the Late Cretaceous,maximumsubsidencereturnedtothesouthwestintotheDanishBasin,whiletheKattegatGrabenwasinvertedduringbackwardtiltofthegrabenblock.

The ENSB formed the northeast flank of theCentral North Sea Dome (2). The Jurassic –Cenozoic structural evolution of the ENSB wasgoverned by the rise and fall of the CentralGrabenriftdome:1)synriftriseintheJurassic–Early Cretaceous, 2) Late Cretaceous transitionphasewithcollapseoftheCentralGrabenrift,3)Cenozoicpostriftsubsidence(3).AmodeloftheMesozoic crustal tectonics associated with theENSB illustrates the interrelationship betweentheevolutionoftheKattegat–SkagerraksegmentandtheCentralGrabenDomeacrosstheeasternNorthSeaBasin(4).

ORAL

MesozoicbasininversiongovernedbycrustalextensionintheBornholmarea,Sorgenfrei-TornquistZone,Denmark

OleGraversen11DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,Denmark

Basin inversion describes the deformation ofasymmetricgrabenscharacterizedbyfoldingandthrusting, i.e. horizontal shortening, associatedwithuplift of the sedimentary graben fill aboveregional (1). The compressive stress field hasbeeninterpretedinaplatetectonicconceptasaresult of continent-continent collision thatestablished a compressive stress field in theorogenicforeland(2,3).

However,structuralanalysisofbasininversionintheSorgenfrei –TornquistZone illustrates, thatbasininversionwastheresultofsuperpositionofasymmetric extensional fault basins dipping inoppositedirections.Theevolutionofthegraben

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basins, tookplaceduringsuccessiveextensionaltectonicregimesseparatedbystillstandintervals.Duringsubsidenceofthesuperposed,extensionalbasin,theprimarybasinwastiltedbackward,andthebasinwasinvertedduringlocalcompressionbetweentheprimaryfootwallblocks.

TheMesozoicfaultblockpatternoftheBornholmarea illustrates, that the NW-SE trendingSorgenfrei–TornquistZonewasextendedintwodirections:Themainextensionwas in aNE-SWdirectionacrossthestrikeofthefaultzone,andasecondaryNW-SEextensionalongthefaultzonetrend.

Based on the changing graben activity, theMesozoichasbeendividedintoTriassic,Jurassic– Early Cretaceous and Late Cretaceousextensionaltectonicregimes.Grabensubsidencestarted in theTriassic, and basin inversionwasactiveintheJurassic–EarlyCretaceousandagainintheLateCretaceous(4,5).Thetectonicregimeswere separated by turnover intervalscharacterized by onlyminor tectonic activity inthe late Late Triassic and the early LateCretaceous.

ORAL

Evidenceofpost-breakuptectonismontheNortheastGreenlandshelf:Implicationsfor“passive”marginconditions

ThomasGuldborgPetersen11TechnicalUniversityofDenmark,DTU

The break-up between the Eurasian and NorthAmerican plates during the Paleogene is wellconstrained by geophysical data. The structuralhistory of Northeast Greenland following thebreakupisontheotherhandstillverymuchanareaofdiscussion.Here,analysisofseismicdataoffshore Northeast Greenland constrains thetiming of the post-breakup tectonic events bycorrelation with the well-dated magmaticintrusions in the region and their associatedthermal uplift and venting of gasses. Previousstudies have mapped large-scale faulting along

the western margin of the Thetys Basin whereextensional faultingwith anoffset exceeding1sTWTontheseismicprofiles isobserved.This isoften associated with dramatic failure of theuplifted footwall where vast quantities ofsediment slid into the Thetys Basin, apparentlyinstantly, which suggests relatively fastpropagation of the fault system. The time ofbreakup is constrained in the seismic data bymagmaticintrusionsdatedtopeakintheearliestEocene.Bothasouthwardsdeepeningerosionalincision,aswellasseveralventsassociatedwiththede-gassingofintrudedmagmacoincideswiththe continentalbreakup.This seismicmarker isclearlytruncatedbythefailureofthefootwallaswellasoffsetbythefault,whichshowsthatthefaultingoccurredinpost-breakuptimes,duringatectonicphasewherenofaultingonthe“passive”margin is expected. Significant progradationassociated with tilting and erosion supersededthe observed faulting. This indicates that activetectonism may explain the exhumation andprogradation observed on the NortheastGreenlandmarginduringtheNeogene.

ORAL

ThelateCenozoicevolutionofthemidNorwegianMargin

HelgeLøseth1andEilertHilde11StatoilASA,R&DTrodnehim

Even though North Atlantic post break-upsediments are well recorded on the structuralrathersimplemidNorwegianpassivemargin,theunconstrained ages and uncertain paleo-geographicreconstructionshasledtodebate.TheaimofthispaperistoconstrainthelateCenozoicgeological evolution with focus on verticalmovementsoftheinnermarginandpositionsofcoast-lines.Thedatabaseconsistsofregional2Dand3Dseismicandwelldata.

PriortotheMiocenecompressionphase,Eoceneto lower Miocene coastlines were locatedlandward of the subcrop with an unresolvedeastward extent. The mid to late Miocenecompression phase, which formed inversion

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structures more than 1000m high and 300kmlong, also caused dramatic shifts in base levelsalongtheinnerpassivemargin.Thebaselevelfell100’s ofmeter at onset of compression and thecoastline shifted ocean-ward. The Mid MioceneUnconformitydevelopedandthesyn-tectonicKaiFormation was deposited. Upon termination ofthecompressionphasethebaselevelroseintheorder of 500m. Sediments from the followingtransgression (lower Molo Formation) isdocumentedforthefirsttime.Theyoungercoast-parallel600kmlongupperMoloFormationshelfdeltaisoverlainbytheQuaternaryglacio-marineNaustFormation.Theinnershelfwastilted0.5°westwardduringtheglacialperiodduetoisotaticadjustments fromonshoreerosionandoffshoredeposition.

The observed vertical base level fall andsubsequent rise of the inner passive marginoccurredwith the onset and termination of thecompression phase. Similar shifts may occuralonganypassivemargin.

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PalaeostressanalysisandhydrocarbonleakagepotentialofdisparatefaultsetswithintheSwaenGraben

NathaliaMattos1,KamaldeenOmosanya2,StåleJohansen3andTiagoAlves113DSeismicLab,SchoolofEarthandOceanSciences,CardiffUniversity,2DepartmentofGeoscienceandPetroleum,NorwegianUniversityofScienceandTechnology,3GeoscienceandPetroleum,NorwegianUniversityofScienceandTechnology

The Swaen Graben represents one of theCretaceousstructuralelementsoftheSWBarentsSea whose growth and development remainspoorlydescribedintheliterature.Majorityoftheprevious works undertaken in the study areaproposedacloseconnectionbetweentheSwaenGraben and the Eastern Loppa High with thelikelihood of a strike-slip tectonics being thedominantprocessforfaultgrowthonthewesternsectionof thegraben. In thiswork,weassessed

thepalaeostressandsliptendenciesoffivefaulttypes in the Swaen Graben. These faults wereselected based on the assumption that they arestrike-slipfaults,flowerstructures,riedelshears,isolated-erosionallydecoupledfaults,andsmall-scale transfer faults. The principal palaeostresstensor associated to the faults,was determinedbased on the relationship between the sliptendencyvaluesandthemeasureddisplacement.Our model shows a sub-vertically oriented σ1plunging76.9ºalongaN246.4ºazimuthforallthefivefaulttypes.Theorientationsofσ2andσ3aresub-horizontal.Sliptendencyvaluesforthefaultsvariesfrom0to1.MostoftheType1faultsshowsliptendencyvalues0to0.67.Type3and5faultshave the highest slip tendency values.Hydrocarbonleakagefactorrangesfrom0.16to1andishighestwithintheType3and5faults.Weshow that these faults are extensionalwith theType5faultsactingastransferfaultsconnectingtwo disparate fault systems. The studied faultsare analogous to modern day examples in theEastAfricanRiftSystems.

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InfluenceoflateCenozoicerosionanddepositionontemperaturedistributionbeneaththenorth-easternpartoftheMid-Norwegiancontinentalmargin(theLofoten-Vesterålenarea)

YuriyMaystrenko1,LaurentGernigon1,OdleivOlesen1,DagOttesen1andLeifRise11GeologicalSurveyofNorway,Trondheim,Norway

A3Dthermalpatternbeneaththenorth-easternpart of the Mid-Norwegian continental margin(theLofoten-Vesterålenarea)andadjacentareasof the continent has been investigated tounderstand the thermal effect of relatively higherosionalanddepositionalratesobservedduringthePleistocene.

A lithosphere-scale 3D structural model of theLofoten-Vesterålen area fromMaystrenko et al.(2017)hasbeenusedasarealisticapproximation

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of the geometries of the sedimentary infill,crystallinecrustandlithosphericmantleduringa3Dthermalmodelling.The3Dthermalmodellinghas been performed by use of the commercialsoftware package COMSOL Multiphysics. TheEarth'ssurfaceandseafloorhavebeentakenasanupperthermalboundaryconditionwithtakinginto account palaeoclimatic changes during theCenozoic. The lithosphere-asthenosphereboundary has been used as a lower thermalboundary.Theerosionanddepositionhavebeenalsoincludedinthe3Dthermalcalculations.

The modelled thermal influence of the lateCenozoic erosionwithin the Lofoten-Vesterålenmarginsegmentisreflectedbyapositivethermalanomaly within the areas where sedimentaryand/orcrystallinerockswereeroded.Anegativethermal effect has been modelled in the areasaffectedbydepositionofsedimentaryrocks.Theerosion-induced, positive, temperature anomalyisupto+27oCatdepthsof17-22kmbeneaththeeastern part of the Vestfjorden Basin. Twodeposition-induced, negative, temperatureanomalieshaveminimalvaluesofaround-70oCat17-20kmdepthand-48oCat12-14kmdepthbeneaththeoceanicLofotenBasinandthenorth-easternpartoftheVøringBasin,respectively.

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Extensionaldetachments,breakawaycomplexesandsupradetachmentbasinsinriftedmarginformation:examplesfromoffshoreMidNorway

PerTerjeOsmundsen1andGwennPéron-Pinvidic21GeologicalSurveyofNorway,7491Trondheim,Norway&Dept.ofGeosciences,P.O.box1047,Universit,2Dept.ofGeosciences,P.O.box1047,UniversityofOslo,0316Oslo,Norway

The large-magnitude faults that control crustalthinningandexcisionatriftedmarginscombineinto laterally persistent structural boundariesthat separate margin domains of contrastingmorphology and structure. We term thembreakaway complexes. At the Norwegian riftedmargin, the constituent faults operated on the

crustal scale, cut large thicknesses ofheterogeneously layered lithosphere andfacilitatedfundamentalmarginprocessessuchaspost-orogenic equilibration, deformationcouplingandeventualexcisionornearexcisionofcontinentalcrust.Manyofthemcanbeclassifiedas extensional detachment faults, and theyperformed different types of work on thelithosphereandoccupydifferentlocationsinthemargin architecture. The array of associatedsynrift basins thus record the changing state ofthe continental lithosphere as the crystallinecrustwasnearlyorwhollyexcisedinaseriesofmajor deformation stages. The association ofsynrift supradetachment basins withfundamentalmodesof crustal thinning explainstheparticularlocationsofdistinctbasinstylesinthemargin architecture and provides the basisfor a broad classification. Supradetachmentbasins appear to dominate the population ofsynrift basins on the margin scale. They weredraped by a basin that post-dated local blockrotationbutpre-datedbreakup,andthatwasstillstrongly affected by a subsidence pattern thatmuch reflected the earlier large-magnitudefaulting.

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ThesourceareaoftheMioceneRibeGroup,EasternNorthSeabasin:thecontrolofclimateandtectonism.

ErikS.Rasmussen1,MetteOlivarius1,KarenDybkjær1,TorstenUtescher2andPeterJapsen11GeologicalSurveyofDenmarkandGreenland(GEUS),esr@geus.dk,2SteinmannInstitute,UniversityofBonn,Nußallee8,53115BonnandSenckenbergResearchInstitute.

The sediment provenance was investigated bycomparingradiometricagedatingofthesinkareato the comprehensive data available from thesource area. Thebasement in southernNorwayand southwestern Sweden, and possibly itsderived sediments, is theprimary sourceof theMiocenesand.However,smalleragepopulationsshowthattherivershadalargercatchmentarea.Overall,itisthesametypeofsedimentthatwas

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fedfromsourcetosinkduringtheearlyMiocene,but heavy mineral analyses show that thematurity of the sediment varies, presumably inresponse to changes in the erosion rate. Thestudy of the source area encompassesinvestigationsofclayminerals,flora,andfissiontrack data, in order to unravel the climate anduplifthistory.Theinitialtopographyofthesourcearea (FennoscandianShield)was relatively low,less than 500 m in the earliest early Miocenewhenapronouncedphaseofupliftanderosioninthis regionbeganaccording to interpretationofapatite fission-track data. The elevation of thesource area during the early Miocene iscoincidence with a major reorganisation ofsediment routing systems in the eastern NorthSea region. This occurred during a period ofclimatic stability and thus most likely anindicationoftectonicactivityinthesourcearea.An increasedreliefof thehinterland isrevealedfrom steadily higher contents of mountainelementsinthepollenfloraandbytheendoftheearlyMiocene,atapp.15Ma,thehighestpeaksinthesourcearealikelyexceeded1500m.

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DeepcrustalstructuresinthenorthernNorthSearift:observationsfromnew3-Dseismicreflectiondata

ThiloWrona1,HaakonFossen1,RobertL.Gawthorpe1,JanIngeFaleide2andMaritStokkeBauck31DepartmentofEarthScience,UniversityofBergen,Allégaten41,5007Bergen,Norway,2DepartmentofGeosciences,UniversityofOslo,P.O.Box1047Blindern,N-0316Oslo,Norway,3CGG,P.O.Box43Lilleaker,0216Oslo,Norway

Pre-existing basement structures can affect thenucleation,growthandlinkageofnormalfaultsinriftsandriftsystems.ThenorthernNorthSeariftdevelopedontopofanextremelyheterogeneouscrustcontainingstructures fromtheCaledonianorogeny to Devonian extension. Ourunderstandingofthesestructureshaslongbeenlimited by poor imaging of the basement withconventional 2-D seismic reflection data. New

broadband3-Dseismicreflectiondataallowustostudy the extent, geometry and orientation ofthese deep crustal structures in unprecedenteddetail. The data contain a wide range offrequencies (2.5-155 Hz) and provides high-resolution, three-dimensional images of deepcrustal reflectors.The improved imagingallowsus to map a high-amplitude lower crustalreflection package over an area of more than4000km2.Thepackagevariesindepthfrom20to30kmwithelevationscoincidingwithfootwallsofmajorN-Strendingnormalfaults.

DeepcrustalreflectivityobservedinthenorthernNorth Sea has been explained by eclogizedcontinental crust using a combination of 2-Dseismic, gravity and magnetic data. This studyexplores alternatives to this explanation. Moreprecisely, we examine the role that igneousintrusions, Caledonian thrusts and Devonianextensionalshearzonescouldhaveplayedinthegeneration of the observed reflection package.Moreover,weexaminethetimingandinteractionbetween these structures and subsequenttectonicfaults.

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PliocenePockmarksintheeasternDanishCentralGraben,NorthSea-FormationandSignificance

KaziwaMohammadi1andKatrineJ.Andresen21Student,2Supervisor

In this study, we describe abundant Pliocenecircular depressions from the Danish CentralGraben,mappedusing3D-seismicdatawhicharecourtesy of Maersk Oil, Operator of DUC. Weinterpret the depressions as buried pockmarksformed due to focused fluid-venting to theseafloor during the Pliocene. The origin of thefluidsandthesignificanceofthefluid-ventingarenot fully understood. Our preliminary analysesshowthatthemajorityofthepockmarksoccuronone distinct surface suggesting a very confinedtiming of formation. The distinct pockmarkedsurface is comprised within a westwardprogradingsetofclinoformssuggestingthatthe

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pockmarksmayhaveformedinresponsetosea-level changes and/or climatic fluctuations. Thepockmarksfurthermoreoccurspatiallyclusteredin a large pockmark field, which could becontrolled by lithology variations along theclinoforms. Alternatively, deeper structuralelements vertically below the pockmark fieldsuch as the Coffee Soil Fault, which marks theeasternedgeoftheDanishCentralGraben,couldhave focused migration of deep thermogenicfluids and controlled the spatial distribution ofthepockmarks.Hence,ourseismicobservationspoint towards a combined control of pockmarkformation from both deep structures anddepositionalenvironment.Ourfurtheranalysisofthepockmarkswillincludeboreholedataandwillfocus on constraining the timing and thecontrolling factors in more detail. We willinvestigate the origin of the escaped fluids andthepossiblerelationswithregionaleventsintheLate Neogene-Quaternary such as climaticfluctuations and maturation of thermogenicsourcerocksintheCentralGraben.

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OriginandsedimentbudgetofanearlyNeogene-earlyQuaternarycontouritedriftsystemontheSWBarentsSeamargin

TomArneRydningen1,GertHøgseth1,AmandoLasabuda2,JanSverreLaberg2andPolinaA.Safronova31Dep.ofGeosciences,UniversityofTromsø,2Dep.ofGeosciences,UniversityofTromsø;ResearchCentreforArcticPetroleumExploration(ARCEx),3ENGIEE&PNorgeAS

Alongslope ocean currents distribute sedimentsacross continental slopes surrounding oceanbasins,making contouritedrifts deposited fromsuch currents important paleoceanographicarchives.Furthermore,onhigh-latitudemarginssubmarinefailuresoftenrelatetocontourites,asthey may act as weak layers due to theirlithologicalcharacterand/orphysicalproperties.Although identified several places along the

Norwegian-Barents Sea-Svalbard margin,contourites are not described from the SWBarents Sea. Using 2D-seismic data, we heredescribeacontouritedriftcoveringasubstantialpart(~20,000km2)oftheSWBarentsSeaslope,locatedmainly beneath the Bear Island TroughMouthFan.Fromcorrelationtocommercialwelldata,thismoundeddriftcoversatimespanfromearly Neogene to early Quaternary. This drifttherefore likely started to form at the onset ofalongslopeflowsimilartothepresentcirculationfollowingtheopeningoftheFramStraitgatewayand the subsidence of the Scotland – Faroe –Iceland – Greenland ridge. It continued toaccumulatesedimentsfollowingtheonsetofthenorthernhemisphereglaciationsinlateNeogeneuntil glacigenic deposits completely dominatedthispartoftheslope.Partsofthedrifthasbeenremobilized,thusithasinfluencedonthestabilityof the continental slope,most likely because ofstress exerted by up-flank accumulation ofglacigenicsedimentscausingthedriftdepositstofail.Wewilldiscusstheonsetofdriftgrowthandits implications for the evolutionof themargin,and – for the first time, present sedimentationrates and sediment volume for a high-latitudecontouritedrift.

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4.4.Verticalmovements,changesinplatemotionandmantledynamics:observationsandmodelsinthenorth-eastAtlanticdomain

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Anundereexploredmethodfordeterminationofpaleotemperatureandburialdepth.

ClausBeyer11CB-MagnetoAS

A number of methods are used to estimatepalaeotemperatures.Fluidinclusionsstudiesgivea direct measure of the palaeo temperature.Other methods are based on changes inmineralogy,e.g.Quartzcementationat70°C.Claytransformation fromsmectite topotassium richillite happens in several stages with increasingtemperatures.Fissiontrackanalysis isbasedonformationofdamagetrailsformedbyradioactivedecayinapatiteandsubsequentannealingasa

function of temperature. Methods based onblockingtemperaturesarebasedondiffusionofagas out of the crystal lattice at certaintemperatures.

Othermethodsarebasedonthecombinedeffectof temperatureandthetimeofexposureto thistemperature. One such method is a hithertounderdeveloped method based on themagnetisation of a sediment or rock. If themagnetic grain size is favourable, the rockmayacquireandpreserveamagnetisationwhichwillbeaddedtothealreadypresentmagnetisation.Ifa rock changes position by folding at a certainpointintime,thisnewmagnetisationwillhaveadifferent direction and may be easily defined.Knowing the temperature, the duration of therock being in its present position may becalculated. Knowing the time period, thetemperaturemaybe calculated. In addition, theageofthecomponentmaybecalculatedfromthepalaeopole to which the magnetic component

points. Examples were determination of burialdepth (approx. 5km) during Carboniferous of asuevite fromtheRitland impactcrater,Norway,and determination of palaeotemperatures ofsedimentsintheBarentsSea.

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EarlypostglacialreboundtectonicswithintheTjörnesFractureZone,North-Iceland.

BryndísBrandsdóttir1,SigríðurMagnúsdóttir1,NealDriscoll2,RobertDetrick3andJeffreyKarson41InstituteofEarthScience,UniversityofIceland,Reykjavik,Iceland,2ScrippsInstitutionofOceanography,UCSanDiego,USA,3IncorporatedResearchInstitutionsforSeismology,WashingtonDC,USA,4SyracuseUniversity,SyracuseNY,USA

The multi-branched plate boundary acrossIcelandismadeupofdivergentandobliquerifts,and transform zones, characterized by complextectonics.TheTjörnesFractureZone(TFZ)linksthe northern rift zone (NVZ) on land with theKolbeinsey Ridge off shore. The TFZ lacks theclear topographic expression typical of oceanicfracture zones and consists of broad zone ofdeformationroughly150kmwide(E-W)by50-75 km long (N-S), involving a complex array ofoblique-slipfaultsbounding(NS)riftsandright-lateral (WNW) strike-slip faults, activethroughout Holocence.The magma-starvedsouthernextensionoftheKR,the~80kmNSand15-20EWEyjafjarðaráll rift (ER), ismadeupofdominantly extensional faults mergingsouthwards a system of right-lateral strike-slipfaults with vertical displacement up to 15m.within the Húsavík FlateyFault Zone(HFFZ).A500-700mdeepasymmetricrift,with20-25mverticaldisplacementonnormal faultscharacterizesthenorthernERwhereastransformalongtheHFFZhascreatedaNW-strikingpull-apart basin with frequent earthquake swarms.WepresentthetectonicframeworkoftheERandSkjálfandadjúp (SK) basins multibeambathymetry, high-resolution seismic reflectiondata(Chirp)andseismicity.Bothbasinscontainpost-glacial sediments of variable thickness.

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Correlation of Chirp reflection data andtephrachronology from a sediment core withinthe SK basin reveal major rifting episodesbetween10-12.1kyrsBPactivatingbothbasins,followed by smaller-scale fault movementsthroughout Holocene. These vertical faultmovements reflect increased tectonic activityduring early postglacial time coinciding withisostatic rebound enhancing volcanism withinIceland.

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Thesurfacebelowca900maltitudeinsouthernNorwaywasprobablyburiedbylateMesozoicsedimentsandre-exposedbyNeogeneupliftanderosion

JamesChalmers11GeologicalSurveyofDenmarkandGreenland

Analysis of the ASTER DEM over southernNorwayconfirmsthatthelandscapeofsouthernNorwayaboveanaltitudeofabout900mconsistsof3sub-horizontalsurfacesseparatedbysteeperslopes and incised by deep glacial valleys(Lidmar-Bergstömetal.,2000).ThesurfaceofthePre-Cambrian basement rocks below 900 m insouthwest and south Norway consists of auniformroughslopedippingtosea-levelortothestrandflat, also incised by deep glacial valleys.Fieldworkshowsthatthelandformsbelow900m asl and between the deep glacial erosionconsist of "hilly relief" and "joint valleys" asinterpretedonshore in southern Swedenwherethey were buried below Late Cretaceouslimestone (Lidmar-Bergstöm, 1994). Similarstructuresobservedonseismicsectionsoffshorewestern Norway and south-west Sweden havebeen buried by Late Jurassic and Cretaceousrocks respectively. Hilly relief and joint valleysformedduringwarmwetclimatesduringtheLateMesozoicbyweatheringoffeldsparsinfracturesto produce kaolin. Subsequent erosion of thekaolinproducesjointvalleyswherethefracturesare aligned and hilly relief where there areintersecting sets of fractures. Burial and later

erosion are required to preserve theselandscapes. Norway south of HardangerviddamustthereforehavebeenburiedbelowMesozoicsedimentsthathavesubsequentlybeenremoved.No kaolinitic weathering of the Pre-CambrianrocksofHardangerviddatookplacebecausetheywerecoveredduringtheMesozoicbyCaledonianmetamorphicrocks.

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BurialandexhumationhistoryoftheUpperJurassicsedimentsonAndøya,northernNorwaybasedonAFTAandVRdata

PeterJapsen1,PaulF.Green2,JamesA.Chalmers1andJohanM.Bonow31GEUS,2GeotrackInternational,3Geovisiona

Outliers of Middle–Upper Jurassic sedimentsoccuronshoreandinthecoastalzoneofNorwaynear Bergen, Trondheim and in the Lofotenarchipelago (Bøe et al. 2010). But only on theislandofAndøya(Lofoten)dotheycropout;hereacoal-bearingJurassic–Cretaceoussuccessionof900 m occurs in a small, partly fault-boundedarea on the easternpart of the island.Wehavemeasured vitrinite reflectance (VR) on samplesfrom Norminoil well B (courtesy of theNorwegian Petroleum Directorate) thatpenetrated the entire Jurassic sequence onAndøya(Petersenetal.2013);themeanVRvalueis0.48%for6samplesfromdepthsbetween218and 520 m. This value corresponds to apalaeotemperature of 78°C, and for anyreasonable palaeogeothermal gradient thisimplies that a km-thick cover of Jurassic andyounger sediments must have covered theJurassic–Cretaceous sediments exposed onAndøya; e.g. around 2 km for 25°C/km and apalaeo-surfacetemperatureof20°C.Newapatitefission-trackanalysis(AFTA)datafromsamplesof Jurassic sediments and basement from theLofotenregionprovideresultsthatareconsistentwith the interpretation of the VR and provideinformation about when cooling (exhumation)from maximum palaeotemperatures (burial)

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began. Our results thus suggest that thermalsubsidencefollowingriftclimaxinthelateMiddleJurassic (Hansen et al. 2012) led to burial ofLofotenandtheadjacentregionbyathicknessofsedimentary cover equivalent to the altitude ofthehighestpeaksinthepresent-daylandscape.

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NeotectonicsinNorway

OdleivOlesen1,JohnDehls1,SofieGradmann1,YuriyMaystrenko1,LarsOlsen1,ConradLindholm2,IlmaJanutyte2,HalfdanKierulf3,JanMichalek4,LarsOttemöller4,DagOttesen1,LeiRise1,MariaAsk5,TomRuneLauknes6andFridtjofRiis71GeologicalSurveyofNorway,2NORSAR,3NorwegianMappingAuthority,4UniversityofBergen,5LuleåUniversityofTechnology,6Norut,7NorwegianPetroleumDirectorate

We summarize results of the 2013-2017NEONOR2 project (Neotectonics in Nordland –implications for petroleum exploration) andcompare it to previous research projects (e.g.NEONOR project 1997-2000) and other recentrelevantdiscoveries.TheNEONOR2project is acollaboration project between NGU, Kartverket,NORSAR, Norut, NPD and the universities inBergenandLuleå.TheprojectissponsoredbytheNorwegianResearchCounciland tenpetroleumcompanies.Theproject investigatesneotectonicphenomena onshore and offshore through amultidisciplinary approach including geological,seismological and geodetic studies combinedwith rock mechanics, applied geophysics andnumericalmodeling.

Within this project, a 26 seismograph networkmonitoredtheseismicitywithina2.5yearperiod.Morethan1000earthquakeswereregisteredand123 focal mechanisms have been derived. Anupdated compilation of all geodetic stations inNorway and Fennoscandia were analyzed forregional and local present-day strain patterns.Numerical modelling of the present-day stressfieldevaluatedtheeffectofridgepush,sedimentloading/unloading, glacial isostasy and

topography. The effect of the Pleistocenesediment redistribution on the subsurfacetemperature has also been modelled. Theoccurrence of earthquake swarms is to somedegree correlatingwith highmountains locatedalongthewideNordlandstrandflat.

Twopresumablypostglacial faults (StuoragurraF. andNordmannvikdalenF.)havebeensubjectto more detailed studies such as trenching,ground penetrating radar and resistivityprofiling.TheStuoragurraF.inFinnmarkandtheGrønna F. in Nordland are seismically activefaults in Norway. These results are entering anupdatedneotectonicmapofNorway.

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4.5.OpenSession:StructuralGeologyandTectonic

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CouplingoftheductileandbrittlestructuresofthebedrockinHyvinkää,SouthernFinland

BenceBalogh1,EemiRuuska1andPietariSkyttä11UniversityofTurku,DepartmentofGeographyandGeology,FI-20014Turunyliopisto

Thereisageneraldifficultyinunderstandingtheattitudes of the inherently discontinuousfractures of the bedrock in contrast to thecontinuousductilestructures.Thisstudyaimsatlinking the ductile and brittle features and,consequently, getting a better control over thefracture occurrence and orientation within thepoorly-exposed bedrock. This study relates tostudying the relationship between the bedrockandtheoverlyingglacifluvialaquifersoftheFirstSalpausselkä formation in Hyvinkää, SouthernFinland. The results provide input data for theongoing implicit modelling, and bedrock DEMinterpolation development in the future. Basedonexistinggeologicalandgeophysicaldata,andnew mapping observations, three principal,structurally homogeneous domains weredefined.Brittleandductiledatafromtwoofthedomains correlatewith the E-Wmain branchesand NE-SW splays of the regional-scale shearzone,whereasfracturingwithinthethirddomainis more irregular, controlled dominantly by aregionalscale,uprightfoldandsecondarilybyN-S structural trends. On individual outcrops,mutually parallel fractures were assigned intofracturesets.Thesetswerethencorrelatedwiththe regionally dominant fracture and foliationorientations,andreassigned intorepresentativesets within the respective structural domains.Fracturing is dominantly of cubic typewith themain fracture set (R1) orientation stronglycontrolled by the foliation. The second mostabundantset(R2)tendstobeapproximatelyataright angle to R1 and the third group (R3)consistsofhorizontaltosub-horizontalfractures.

Deviations from this pattern are attributed tofracturing caused by non-coaxial deformationalongshearzones.

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Sandtectonics-sandmobilitylinkedtofaultingandtheinfluenceondepositionalsystems

KristineHalvorsen1,SusanneTveterås1,AlvarBraathen1,IvarMidtkandal1andValentinZuchuat11UniversityofOslo

Mobility of sand by fluidisation, so-called sandtectonics, can drive surface movements andimplicity have a significant impact on sedimentdistributionandsandbodygeometries.Althoughsimilarities between sand- and salt tectonic-relatedstructuresexist,substantialdifferencesindeformation style and geometries occur. Weadress the understanding of sand tectonicprocesses.Threeoutcrops in theUpper JurassicEntradaSandstoneandCurtisFormationinUtah(USA) have been used to characterise thestructural and sedimentary response to theunderlying mobilisation of sand. Keyobservationsareassembledfrommappingofsag-upwarp and fault geometries, as well as fromlogging and description of growth succession.The latterdepositsattest tochannelisedsub- tointer-tidaldepositionalenvironments.Datashowthatmildsandmobilisationresultsinmeter-scalegentlesagandupwarps(sandpillows).Increasedsandmobility leads toprogressivelyhigherandsteeperreliefbetweenupwarpsandsags,whichlinks to nucleation of faults and therebydevelopment of small fault-bound grabens.Duringfaultactivity,growthsequencesattesttorepeated faultmovementevents,demonstratingthe strong structural control on the basin fill.After graben formation, many of the faults inhigherpositionsofthegrabensaretruncatedandremoved by erosion. Subsequent lenticular-shaped basin fill reflects a wider channelizeddepositional body than that of the grabens.However,thegrabensseemimportantinlocating

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thesechannels.Theresultfromouranalysismayprovide important input applicable to both CO2storageoperationsandthepetroleumindustry.

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BrittlefaultsystemsofdeepgeologicalnuclearwasterepositoryatOlkiluoto,SWFinland

NicklasNordbäck1andJussiMattila21GeologicalSurveyofFinland,2PosivaOy

OlkiluotoIslandhasbeenselectedasthesitefordeepgeologicalrepositoryforhigh-levelnuclearwaste. This study aims to improve thecharacterisation of the brittle structuresintersecting the repository. The objective is togain a better understanding of the structuralevolution of the site, with the ultimate goal ofenhancingtheunderstandingofthereactivationpotentialofdifferentfaultsystemsandassociatedseismichazard.

ThestructuralcomplexofOlkiluotoiscomposedof ductile and brittle structural systems, whichbothhavealongandcomplexhistory.Theductilesystems comprise ductile structures, formedduring several different phases ofPaleoproterozoic ductile deformation. Theductile deformation has affected the bedrockproperties, resulting in prominent anisotropyand manifested by ductile structures such asfoliation, foldingandductile shearzones,whichallformplanesofweaknessinthebedrock.Thesetypeofstructureshavealsoplayedanimportantrole in the localisation anddevelopment, of thebrittle structures in Olkiluoto. The brittlestructural system is composed of brittlestructuressuchasjoints,veins,singleplanefaultsand fault zones. The faults were in this studyclassified into fault systems, with each systembeing composed of fault zones with similartectonic history and structural properties. Theclassificationcanbeemployedintheassessmentof the reactivation potential of the faults at thesite, as the faults in each fault system areconsideredtohavesimilarpropertiesandthus,a

similarchance for reactivation ineithercurrentorfuturestressstates.

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Target-rockweakeningmechanismsduringpeak-ringformationoftheChicxulubimpactcraterinferredfromIODP-ICDPExpedition364

UlrichRiller1,FelixSchulte1,MichaelPoelchau2,AuriolRae3,RichardGrieve4,JoannaMorgan3,NaomaMcCall5andSeanGulick51InstitutfürGeologie,UniversitätHamburg,Bundesstrasse55,20146Hamburg,Germany,2UniversitätFreiburg,Geologie,Albertstr.23b,79104Freiburg,Germany,3DepartmentofEarthScienceandEngineering,ImperialCollegeLondon,UK,4EarthSciencesSector,NaturalResourcesCanada,Ottawa,Ontario,Canada,K140E4,5InstituteforGeophysics,UniversityofTexas,Austin,TX,USA

Thefloorsoflargeimpactcratersarelargelyflatand contain one or more morphological rings.Theformationoftheinnermostring,theso-calledpeak ring, and the causes of target rockweakening leading to the observed flat craterfloors are not well understood. Constrainingthese mechanisms is the prime structuralgeological objective of Expedition 364 “Drillingthe K-Pg Impact Crater”, using the Chicxulubcrater,Mexico, as a terrestrial analogue for theformationofplanetaryimpactbasins.Thetargetrocks of the crater are replete with cratering-induced,microscopictomesoscopicdeformationstructures including: (1) pervasive grain-scalefractures,(2)centimeter-thickcataclasitezones,(3) striated shear faults, (4) crenulatedmineralfoliations, and (5) ductile band structures.Structuraloverprintingcriteriapointtoarelativeage for these structures. Specifically, cataclasitezonescutgrain-scalefracturesdisplayingjigsawgeometryandareconsistentlydisplacedbyshearfaults. Impact melt was emplaced in zones ofdilation, often localized by shear faults. Theseobservations indicate that pervasivefragmentation was respectively followed bylocalizedcataclasticdeformation, shear faulting,andemplacementofmeltintodilationzones.This

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succession of deformation mechanisms iscorroboratedbytheobservationthatmeltbodiesare devoid of shear faults. Asmelt bodieswereviscous during formation of ductile bandstructures, these structures formed after theshear faults. Based on the overprintingrelationships, we relate the deformationstructurestocrateringstagesknownfromimpactmechanics.

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3DmodelofthelithotectonicunitsandregionaldeformationzonesinthebedrockofSweden

PhilCurtis1,Carl-HenricWahlgren1,StefanBergman1,ldikóAntalLundin1,ClaesMellqvist1,StefanLuth1andSverkerOlsson11SGU

A three-dimensional model has been createdrepresenting the lithotectonic units and theirbounding regional deformation zones in thebedrockofSweden.Themodel,includingabriefdescription and basis for modelling of eachmodelled deformation zone and lithotectonicunit,isadevelopmentoftheexistinglithotectonicsubdivision included in the bedrock map ofSweden at the scale 1:1million (Bergman et al.2012).Theaimistovisualizetheinterpretationoftheoverallgeometricalrelationshipsbetweenthevariouslithotectonicunitsonanationalscaleandprovideabasicframeworkandbackgroundformoredetailedregionalandlocalscalemodels.Theaimistolinkthemodeltogeneralgeologicaldescriptive texts aimed at schools and otherinterested parties as well as scientificpresentations.

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EastGreenland72-74°NInlandtoCoastThermo-tectonicEvolution

Jensen,PeterK.1;Hansen,Kirsten21Strandparksvej12,1MF,DK-2900Hellerup,Denmark;klint@geologi.com

2NaturalHistoryMuseumofDenmark,UniversityofCopenhagen,ØsterVoldgade5-7,DK-1350CopenhagenK,Denmark;kirstenh@snm.ku.dk

FissiontrackanalysisofeightsamplesfromEastGreenlandyields informationoftheexhumationhistory. Modelling the thermal evolution of thesamples indicates thatessentialelementsof therecent landscape were established before 250Ma. Thus, altitude variations of 2-3 km at thattimearelikepresentvalues.Frombefore350Matobefore200Ma,startingformSW,deepvalleyswereincisedintoaplateaubeingmorethan3kmabovethepresentlandscape.Afterabout200Mathe exhumation rate of the overall area wasmoderated,howeverwithanincreaseespeciallyinthevalleysafter50Ma.

Our interpretation is based on a simulation oftemperature history through time intervalsderived from the track length distribution. Weuse signal analysis theory to enhance theresolution of the time-temperature informationof the fission tracks. Statisticalnoiseandbiasessuchastrackannealinganisotropyaretakencareof.Wecalculatethethermalhistorybackwardsintime and analyse the results as erosion/burialdepths,which leads toour interpretationof thegradualinlanderosion.

Allmeasurementsareperformedintransmittedlight on prismatic faces, however, horizontaltracklengthsaremeasuredwithoutangletothec-axis.

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POSTER

Modellingthefracturecharacteristicsofcrystallinebedrockforthepurposesofbedrocksurfaceinterpolations

EemiRuuska1,AnttiKallanranta2,PietariSkyttä1andMichaelHillier31DepartmentofGeographyandGeology,UniversityofTurku,FI-20014Turunyliopisto,2Dept.GeosciencesandGeography,UniversityofHelsinki,PL-6400014Helsinginyliopisto,3GeologicalSurveyofCanada,Ottawa

The purpose of the study is to characterize thebedrock fracturing and its spatial variabilitywhichmaybesubsequentlyusedininterpolatingthe digital elevation models (DEMs) of theglacially eroded bedrock surface. The workfocusses at testing and developing the implicitmodelling approach and tools, validating theresultsbyusingexplicitmodelsandcomparedtofracture networks defined with the DiscreteFractureNetworkmodellingtool(DFN).Theusedimplicit modelling approach, by contrast to theconventional explicit approach, allowsgeneration ofmore objective, time-efficient andrepeatable3D-models.

This study is conducted in the Hyvinkää area,southernFinland,underanumbrellaofabroaderSalpausselkä project investigating therelationshipbetweenthebedrockstructuresandtheoverlyingglacifluvial aquifers.Theprincipalinputdataofthisstudyarefractures,correlatedwith foliation data and regrouped into sets asdeterminedwithinaparallelongoingstudy.

As a central tool, a new functionality “LocalAnisotropy Interpolator” of SURFE plug-in forGOCADhasbeendeveloped.Withthistool,weareable to generate a grid with an interpolatedfracture plane at each grid cell displaying thelocal variations within the anisotropy of thebedrock across the study area. The resultinganisotropy will provide improved control overthe fracture orientations, and the results of theDFN models will provide constraints on the

fracturedensities.ThesetogethermaybeusedtoevaluatetheexistingDEMsofunexposedbedrocksurfacesbasedonsparsedata,andasinputdatain futuredevelopmentof theDEMinterpolationtools.

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Mechanicalseparationofcrustfromslabssubductedbelowthetransitionzone

AndersVesterholt1,ThorstenNagel1andKenniDinesenPetersen11DepartmentofGeoscience,AarhusUniversity

As oceanic crust subducts into the mantle, iteclogitizes and becomes negatively buoyantrelativetotheperidotiticuppermantle.However,experimental studies indicate that, at depthsbetween 660 km to 800 km, below the mantletransition zone, MORB compositions arepositivelybuoyantatcertainconditions.Thishasraised the possibility that oceanic crust canbecome mechanically separated duringsubduction below the 660 km discontinuity.Several conceptual and simple physical modelshavebeenproposedforsuchcrustalsegregation.Herewepresenta2Dthermomechanicalmodelthat employs recent experimental constraintsthat indicate that majoritic garnet is relativelyweakattransitionzoneconditions.Weshowthatchannel-like upward flow within oceanic crustcan occur in the density-inversion windowbetween 650 and 750 kmdepth. Depending ongeometricandthermalboundaryconditions,thisflow is sufficient to cause runaway instabilities,episodicmechanicalseparationofcrustfromthedowngoingslabandthustheformationofstablecrustal patches at the lower-upper mantleboundary. Our results have far-reachingimplications for our understanding of thecompositional stratification of the mantle, itsconvective circulation and the seismic velocitystructurenearthemantletransitionzone.

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5.Mineralogy5.1.Mineralogyanditsapplications

ORAL

Occurrenceofindiumwithlate-stageintrusionsintheKymigranitestock,SouthernFinland

ThairAl-Ani1,TimoAhtola1andJanneKuusela11GeologicalSurveyofFinland

The Kymi granite stock contains hydrothermalgreisenandquartzveintypeF––SnandZn––Pb––Cusulphidemineralization.Theseintrusionsareenriched in indium and rare earth elements,roquesite(CuInS2)beingamajorindium-carrier.The accessory minerals are fluorite, zircon,apatite, cassiterite anddifferent sulphides, suchas sphalerite, chalcopyrite and galena. Theindium and REE-bearing mineral assemblageswerestudiedbyacombinationofopticalandfieldemissionscanningelectronmicroscopy(FE-SEM)and electron probe micro-analyzer (EPMA)techniques. Roquesite occurs as microscopicgrains(10–40micron)ingalena.EPMAanalysesof these grains yield an average composition of26.16%S,0.02%Fe,25.06%Cu,0.03%Zn,1.06%As, 0.31% Sb and 47.14% In. Indiumincorporationintothegalenastructureprobablyoccurred according to the relation Pb2+S2-↔Cu+In3+S2-,whereaszincpresent in thegalenawas probably replaced by indium. Thereforecoupled substitution 2(Pb2+ Zn+) = Cu+In3+mayalsohaveoccurred.

ORAL

ThefumarolicmineralsoftheFimmvörduhals2010eruption

TonciBalic-Zunic1,KristjanJonasson2andAnnaKaterinopoulou31DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,2IcelandicInstituteofNaturalHistory,3HaldorTopsøeA/S

The eruption at Fimmvörduhals, Iceland, lastedfromMarch toApril2010 followedby thewell-known Eyjafjallajökul explosion. It formed twocraters, Magni and Móði and expelled asubstantialamountofvolcanicgasses.

Thesamplesoffumarolicmineralswerecollectedin three campaigns in2010, followedby two insubsequent years. The locality temperaturesrangedfromaround50toalmost800oC.

Themineral parageneses can be divided in fivemaintypes:

1)AluminofluoridesandsilicofluoridesofNa,Mgand Ca, including two recently described newminerals characteristic for Icelandic fumaroles,plustwonewmineralsunderinvestigation.Theyarecharacteristicforsiteswithlowerformationtemperature(<200oC)foundsouthfromcraters,outerrimofMagniandnorthfromMóðicrater.

2) Halite-dominated associations. They includeboth low-temperature associations (<100oC)withhydroussulfatesfoundsouthofcraters,andoccurrences at high-temperature fumaroles(>500oC)inthenorthernpartofMagnicrater.

3)Anhydrousandhydroussulfatescharacteristicfor low to medium-temperature fumaroles(<300oC)occurringsouthofcratersandonMóði.TheyarerepresentedbyvariousNa-K-Mg-Ca-Alphases,twoofthemnewspecies.

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4) High-temperature Na-K sulfates found attemperatures >600oC on the rim of the Magnicraterandinonecrevicesouthfromcrater.

5) Other high-temperature Na, K, Mg and Casulfates forming at similar temperatureconditions as 4) and also found on the rim ofMagnicrater.

ExceptionalforFimmvörduhalsfumarolesisthatthehigh-temperature sites contain acidicK andNa hydrogen sulfates mercalite (KHSO4) and anewmineralwithcompositionNa3H(SO4)2.

ORAL

ElementmobilityandnewparagensesoftheIvigtutcryolitedeposit,SouthGreenland

HenrikFriis11NaturalHistoryMuseum,UniversityofOslo,P.O.1172,Blindern,0318Oslo,Norway

TheIvittuut,formerlyIvigtut,cryolitedeposithasbeen known since the late 18th century as asourceofuniquemineralsinparticularfluoridesofwhichcryolitewasminedforalmost100years.The majority of scientific publications aboutIvittuut have focused on the formation of thedeposits,thefluoridesorthesulphides.However,little is known about the alteration mineralogyandconsequentlyelementmobilityinthisuniquefluorine-richenvironment.

A fieldtrip to Ivittuut in the summer 2016specifically targeted various paragenesisshowing signs of alteration. Consequently, wehave discovered 11 minerals new for IvittuutincludingaseriesofalterationstagesofprimarysulphidesandthefirstRareEarthElement(REE)paragenesis.

Galenaisoneofthemainsulphidemineralsandto date only cerussite (PbCO3) and wulfenite(PbMoO4) are known secondary Pb-minerals ativigtut.However,newtypesofgalenaalterationhave been observed consisting of Pb-chloridesandcarbonates(cotunnite,PbCl2,andphosgenite,Pb2CO3Cl2) and sulphates (anglesite, PbSO4, and

linarite, PbCu(SO4)(OH)2) and at places nativesulphur.ThesourceofchlorineislikelytobetheArsukfjord,borderingthedeposit.Thepresenceof S in three oxidations states reveals aprogressive oxidation event at places, but alsosubtlevariationsinsecondarymineralogywithinthe same sample. A similar oxidation situationhasbeenobserved forS andAs inarsenopyrite(FeAsS), which is being replaced by kaňkite(FeAsO4·3.5H2O)andnativesulphur.

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Nanoscaleobservationsof‘invisiblegold’fromtheOlympiasmine,Greece

TakeshiKasama1,PlatonN.Gamaletsos1,StephaneEscrig2,BeritWenzell1,LouiseH.S.Jensen2,AndersMeibom2,DimosthenisSokaras3,Tsu-ChienWeng3,DimitriosDimitriadis4andAthanasiosGodelitsas51TechnicalUniversityofDenmark,KongensLyngby,Denmark,2ÉcolePolytechniqueFédéraledeLausanne,Lausanne,Switzerland,3SLACNationalAcceleratorLaboratory,CA,USA,4HellasGOLDS.A.,Athens&Chalkidiki,Greece,5National&KapodistrianUniversityofAthens,Athens,Greece

In some gold deposits, gold exists as invisibleform inpyrite or arsenopyrite. Such gold is notrecovered readily from ore materials. Theidentification of the gold form and distributionmay provide some insight into the recovery ofgold. Here, we use electron microscopy,NanoSIMS and high energy resolutionfluorescence detection X-ray absorptionspectroscopy (HERFD-XAS) to investigate‘invisible gold’ from the Olympias Au-Ag-Pb-Znpolymetallic carbonate replacement deposit,northernGreece.

Bulk analyses show that given ore samplescontain gold up to ~30 ppmw and gold haspositive relationships with arsenopyrite andprobablyAs-containingpyrite.Thearsenopyriteandpyritemakeup15%and19%ofthesamples,respectively. Assuming that all the gold isaccumulated in arsenopyrite, each arsenopyritegrain would contain ~200 ppmw. NanoSIMS

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suggests that gold is present primarily inarsenopyrite and is distributed with largevariationsalongthegrowthdirection.Pyritealsocontainssomegoldbuttheconcentrationisevenlowerthanthatinarsenopyrite.TEMwasusedtoexaminethenear-surfaceofarsenopyrite,wheregold is usually concentrated. However, no goldprecipitateswereobserved,whichmightsuggestthatgoldispresent intheformof ionsineitherthe crystal lattice or interstitial position.Thisresult is also supported from the HERFD-XASstudy,inwhichgoldislikelypresentasahigheroxidation state (e.g., Au3+) occurring as achemically bound form in the structure. Thus,gold may have been incorporated intoarsenopyrite and pyrite during relatively rapidgrowthofthem.

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Plasticite,(Plas-TI-Kite)anoremineralizationfromthelateAnthropocine

ErikNilsson11LuleåTechnicalUniversity/OuluUniversity

The Late Anthropocine has caused a noticeableshift in theability fornewminerals to formviahumanmechanisms.Onesuchmineral,plasticite,isarelativelyabundantmineralatEarth'ssurfacederiving from plastic. The general chemicalformula for plasticite and all plasticite likeminerals(withaplasticprovinance)are

(Contactauthorforbetterformatting)

\centerline{$(C_{2}H_{4})_{n}\pm(F^{-},Cl^{-},Br^{-},I^{-})\pm(Pb,Sn)$}

The discussions in the last chapter details aproposal formineralis, a newmineral categorytaking into account the prospect ofanthropogenic minerals having a class of theirown to accommodate for the potentials of therapidlyincreasingcarbonmineralcategory.

(note: this can also be considered under the"Othercategory"butIwon'tdoublesubmituntilthecommitteeallowsme, I canalsoexplain the

concept in more detail, I am working with Dr.EeroHanski ofOuluUniversity andDr.RichardWunderman, formerSmithsonian institution,onthe concept. This serves as a discussion for theanthropocine'simpactongeologyofthefuture.)

POSTER

PredictionofswellingpotentialusingtheAtterberglimits

AikateriniBiotaki1,IreneRocchi1,JeppeBendixRegel2andHelleFogedChristensen21TechnicalUniversityofDenmark(DTU),2GEO

Expansive soils are known to cause numerousproblems on surface and undergroundconstructions. In the oil and gas industry, theymay causeoperationalproblemsduringdrillingand completion, workover, production, andstimulationprocedures.Theuseofwater-basedmud during drilling operations can cause clayswellingandconsequentlywellbore instabilitiesthat,inextremecases,couldleadtocompletewellabandonment.Moreover,swellingclayscanaffectthequalityofthereservoirandleadtoproblemsduring the conventional hydrocarbonproduction, or Enhanced Oil Recovery (EOR).Therefore, to avoid serious complications andexcessive operational costs in the case ofhydrocarbonoperations,itisofhighimportancetofullyunderstandthebehaviourofswellingclayandquantifythevolumechange,linkingittothemineralogy.

Throughout the years, several researchersstudied the correlation between the Atterberglimits and the swelling potential or swellingpressure of soils providing numerous empiricalcorrelations. During this study, data acquiredfrom12differentpublicationswereexaminedtodetermine whether there is a correlationbetweenthePlasticityIndex(PI)andtheSwellingpotential (SP) for varying samples andmethodologies.AlinearcorrelationbetweentheSI and PI was found, with a coefficient ofdetermination (R2) = 0.731, which is rathersatisfactory given the different methodologiesand soil conditions used. The influence of the

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mineralogy was assessed using the Casagrandechartanditwasfoundthatthemontmorilloniticsamples resulted in a significantly highercoefficientofdetermination.

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Anewsingle-crystalXRDformineralsciencesinScandinavia

HenrikFriis11NaturalHistoryMuseum,UniversityofOslo,P.O.1172,Blindern,0318Oslo,Norway

The natural history museum in Oslo haspurchased a state of the art single-crystal XRD,which is dedicated to mineral sciences. Theinstrument is a Rigaku Synergy-S dual-beaminstrumentequippedwithMoandCuμ-sourcesand a HyPix-6000HE hybrid photon countingarea detector. The instrument comes withvariousoptionsforGandolfimovementmakingitideal formineral identificationofminutegrainsandaggregatesaswellaspowders.TheGandolfidata can be exported in various file-formatsmaking it importable into a range of othersoftwareusedfortraditionalpowderXRDsearchandmatchfunctions.

Thehigh-intensityμ-sourcescombinedwith thefastdetector read-out timemakes itpossible tocollect data rapidly. The Cu-source is moreintensethantheMo-source,whichisparticularlybeneficial for data collection of low absorbentmaterials and the Gandolfi methodology. Thesoftware controlling the instrument (CrysAlisPro) is combined with on-site license ofAutoChem, which makes it possible to solvestructureswhiledata iscollecting.This functioncombined with the high-intensity sources andfastdetectorenablesrapidscreeningofcrystalsto identify the best suitable for full datacollection.Thesoftwarehandlesuptoeighttwinsor intergrowth domains for full structuredetermination. The software for data reductionandfaceindexingcanbedownloadedforfreeandconsequently all data processing canbe carriedoutoff-site.

The instrument should be installed in spring2018 and we invite users from the mineralogycommunity in Scandinavia to come to Oslo fortheirsingle-crystaldiffractionwork.

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6.Paleaontology6.1.PaleozoicandMesozoicstratigraphy,paleoceanographyandpaleoclimate

ORAL

AttheboundarybetweenthemiddleAlbianhoplitinidandgastroplitinidammoniteprovinces:linkingtheArcticwithnorthwestEuropewithammonitesinNorthGreenland.

PeterAlsen11ThegeologicalsurveyofDenmarkandGreenland(GEUS)

The Albian is characterized by pronouncedprovincialism, and within the Boreal Realmendemic faunas form defines separate faunalprovinces with only limited faunalcommunication. Palaeobiogeographicsubdivision of the Albian in the Boreal Realmincludes a Boreal-Atlantic Subrealm, an ArcticSubrealm and a Boreal Pacific Subrealm(Lehmannetal2015).DuringthemiddleAlbiantheBoreal-Atlanticischaracterizedbyhoplitinidsand corresponds to the European or hoplitinidprovinceofOwen(1979,1996,2007).HoplitinidsweredispersedwidelyintheEuropeanshelfseasbutalsotowardsthenorth,whereimpoverishedfaunasare recorded inGreenlandandSvalbard.TheammonitezonationbasedonthehoplitinidsformastandardfortheEuropeanProvince.IntheneighbouringArcticorgastroplitinidprovincetothe north hoplitinids are totally absent and theissue of accurately dating the gastroplitinids ofthe Arctic from correlation to the hoplitinidzonation has been a long-lasting problem andcommonlydiscussedintheliterature.North-EastGreenland (Donovan 1957) and Svalbard(Yershova 1983; Nagy 1970),where faunas arereportedtooverlap,have,however,nolocalities

were hoplitinids and gastroplitinids are foundtogether inassemblages,oratpreciselydefinedlevels within a faunal succession. Recently, anammonite-rich horizon was discovered in anotherwise rather unfossiliferous AlbiansuccessioninKilen,NorthGreenland.Itcontainsan assemblage with both gastroplitinidrepresentatives of the Arctic Province andhoplitinid representatives of the EuropeanProvince. The ammonites thus represent a rareand unique occurrence record of a mixedhoplitinid-gastroplitinidassemblage.

ORAL

ThesecretwondersofthemiddleDanian

BodilWesenbergLauridsen1,KasperBlinkenberg1,TrineEdvardsen1andLarsStemmerik11NaturalHistoryMuseum,Denmark

The Danian is named after and known for theimposing bryozoanmounds of StevnsKlint andthe cold-water coral mounds of Faxe. Lessattention has been on themiddle Danian chalklocalitiesinthenorthwesternpartoftheDanishBasin.Herethechalkissoft,withalowdiversitybenthic fauna and a relatively high degree ofunevenly distributed flint.The fauna composedmostly of irregular echinoids, bryozoans andcrinoids.However,adetailedlookintotheDanianchalk in Dalbyover, northern Jutland, reveals amuch more vivid ecosystem. Echinoids (bothregular and irregular), bryozoans, brachiopods,bivalves, serpulids, sponges, asterozoans andcrinoidswerethrivinginthisrelativelydeepandnutrientpoorsetting.Thespeciesallshowspecialadaptations to survival in the environment andmany are Mesozoic survivors from the LateCretaceous chalk sea. One of the dominatingspecies, the irregular echinoid EchinocoryssulcatusappearstobecrucialfortheecosystemandisatruewonderofthemiddleDanian.

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ORAL

Triassicbiostratigraphy(ammonoidsandpalynology)andorganicδ13C-isotoperecordoftheWandelSeaBasin,NorthGreenland

SofieLindström1,PeterAlsen1,MortenBjerager1andJussiHovikoski11GEUS

The presence of Triassic sedimentary rocks inNorth Greenland was first reported from theDanish Peary Land Expedition 1948-49 byTroelsen(1950).ThefirstdescriptionsofTriassicfossils, mainly ammonoids, were made byKummel (1953), and laterbyPeel et al. (1974).DuringtheTriassictheWandelSeaBasin(WSB)constituted a continuation of basins in thesouthernpartoftheBarentsSeatotheeast,andof the Danmarkshavn Basin offshore NortheastGreenlandtothesouth.TheTriassicsuccessionoftheWSBwasdepositedunconformablyonUpperPermian sediments and succeeded by UpperJurassic–LowerCretaceousdeposits(Håkanssonet al. 1991). During recent field campaigns(2012–2013) several outcrop sections and acored drilling were sampled for palynology,macrofossils, and organic δ13C-isotope analysis.The integrated ammonoid faunas and spore-pollen biostratigraphy shows that the exposedTriassic succession of the WSB encompasses anear complete Induan (Dienerian) – Noriansuccession.Theammonoidfaunasarecorrelatedwith the established zonation forArcticCanada(Tozer, 1994), and spore-pollen assemblagescorrelate well with those of Svalbard and theBarents Sea (Vigran et al. 2014).Anespeciallydetailed organic δ13C-isotoperecordis registered for the Smithian–Spathian interval,which can be correlatedwithpreviously reportedrecords globally (e.g.Galfettietal.,2007,Grasbyetal.,2013).

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BiostratigraphiccorrelationoftheCretaceoustoNeogenesuccessionofthewesternandeasternmarginsoftheLabrador–BaffinSeaway.

HenrikNøhr-Hansen1,GrahamL.Williams2andRobertA.Fensome21GeologicalSurveyofDenmarkandGreenland,GEUS,ØsterVoldgade10,Dk-1350CopenhagenK,Denmark.,2NaturalResourcesCanada,GeologicalSurveyofCanada(Atlantic)BedfordInstituteofOceanography

Newanalysesofthepalynologicalassemblagesin13offshorewellsontheCanadianmarginandsixon the West Greenland Margin, in conjunctionwith onshore data, have led to a newbiostratigraphic framework for the Cretaceous–CenozoicstrataoftheLabradorSea–DavisStrait– Baffin Bay (Labrador–Baffin Seaway) regionandthefirstbroadbiostratigraphiccorrelationofthe Canadian and Greenland margins. Thisframeworkisbasedon167lastoccurrencesand18 local or regional, peak- or common-occurrence events for dinocysts (which includethreenewgeneraand16newspecies),acritarchs(including one new species), miospores(including one new species), fungal spores andmassulae of the fresh-water fern Azolla. Ourfindings delineate several local and regionalhiatuses on both sides of the seaway. Thepalynomorph assemblages show that mostAptian to Albian sediments were deposited ingenerally non-marine to marginal marinesettings, interrupted by a short-lived shallow-marine episode in the Aptian. A marinetransgression commenced in the Cenomanian–Turonian and led to the most open-marine,oceanic conditions in the Campanian–Lutetian.SubsequentshallowingprobablybeganinthelateLutetianandcontinued into theRupelian,wheninner neritic and marginal marinepalaeoenvironments predominated. Throughoutthe rest of the Cenozoic, inner neriticpalaeoenvironments alternated with marginalmarine conditions on the margins of theLabrador–Baffin Seaway. Our findings broadly

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reflectthetectonicevolutionoftheseaway,withriftconditionsprevailing fromAptian toDaniantimes, followed by drift through much of thePaleocene and Eocene, and post-drift fromOligocenetothepresent.

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Biodiversity,climateandtime–resolvingthescale,tempoanddriversbehindtheGreatOrdovicianBiodiversificationEvent

ChristianM.Ø.Rasmussen11NaturalHistoryMuseumofDenmark

The early Palaeozoic witnessed two significantpulsesinbiodiversityincreaseandacatastrophicmassextinction.AllarefundamentaleventsandnotablythetworadiationshadalastingimpactonPhanerozoic ecosystems. The early Palaeozoichas traditionally been considered a super-greenhouse period. This interpretation wasprimarily based on two lines of evidence:modellingscenariossuggestingCO2levels15–20timesPAL, and a general perceptionofwarmerclimateduetowhatwaslikelyaPhanerozoicsealevelmaximumduringtheearlyLateOrdovician.The interpretation of early Palaeozoic climate,however, is currently undergoing a paradigmshift. Increasing evidence is suggesting a coolerclimate throughout most of the OrdovicianPeriod, and the short-lived icehouse conditionstraditionally linked to the endOrdovicianmassextinctionsnowappeartocontinuewellintotheSilurian. In themidst of this paradigm shift liesthe Great Ordovician Biodiversification Event(GOBE)–thegreatestmarinespeciationeventofthe entire Phanerozoic. Thus, this event nowseems to have been unfolding against abackgroundofcoolerclimateinsteadofasuper-greenhouse, but the exact onset of the GOBE isobscuredbycontradictingbiodiversityestimates.The current talk presents ongoing efforts tounravel the speed and causes of the GOBE bycombiningthreeapproaches:1)theconstructionof a new, high-resolution biodiversity estimatefor the early Palaeozoic, 2) an astronomicallycalibrated timescale through the GOBE, and 3)

newabioticclimateproxiesbasedonbrachiopod18Odata.Together,thesethreelinesofevidenceprovides a highly interesting novel perspectiveontheevent.

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StratigraphiccontextandenvironmentalchangesintheTuxenandSolaFormations(Barremian-EarlyAptian,NorthSea):newresultsfromhigh-resolutioncarbonandoxygenstableisotopes,majorandtraceelements,sedimentologyandcalcareousnannofossils

NicolasThibault1,KrestenAnderskouv1,EmmaSheldon2,JonIneson2,AnastasiosPerdiou1andMohammadJ.Razmjooei11IGN,UniversityofCopenhagen,2GEUS

TheBarremian to lowerAptianTuxen and SolaFormationshavebeen investigated in theNorthJens-1well (Danish Central Graben, North Sea)for environmental changes based on a revisedcalcareous nannofossil biostratigraphy,geochemical analysis of 316 samples (stableisotopes, hand-held XRF element analysis) andquantitativenannofossilabundancecountsof75samples. Our results delineate the well-establishedBarremianriseincarbonisotopesaswell as the typical excursions across the earlyAptian Oceanic Anoxic Event (OAE) 1acharacterized by two short and prominentnegativeexcursionsrightbelowandatthebaseoftheFischschiefer laminatedblackshalehorizon,followed by the long-lasting positive carbonisotope excursionof the lower toupperAptian.Our new results also show significant cyclicchanges in the Barremian carbon cycle with anumber of new possible negative and positiveexcursions that could be defined and used forrefinement of the stratigraphy of this stage.Oxygen isotopes and calcareous nannofossilassemblages highlight the coupling ofsignificantly warm episodes associated toeutrophic conditions during deposition of thelower Barremian Munk marl and early Aptian

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Fischschiefer laminated horizons whereas asignificant cooling associated to oligotrophytriggered thedepositionofnannoconid chalk intheupperBarremian.Majorand traceelementssuggestrathersimilarenvironmentalcontextsinbottom-waters for the deposition of the Munkmarl and Fischschiefer and advocate for theselevels but we denote a conflicting sequencestratigraphic context for the Munk Marl in theNorthSeaandtheequivalentHauptblättertonintheLowerSaxonyBasinofNorthGermany.

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TheOrdovicianconodontsofthewestSørkappLand(SouthernSpitsbergen)

TatianaTolmacheva1,AleksandrLarionov1andNataliaKosteva21A.P.KarpinskyRussianGeologicalResearchInstitute,2PolarMarineGeosurveyExpedition

The Ordovician in the Sørkapp Land is knownsince the 50-ies, yet it is relatively poorlyexamined and its faunas are studiedinsufficiently. The western Sørkapp Land partbetween the Olsokbreen and Bungebreen wassurveyedin2013.HeretheOrdovician(SørkappLandGr-HornsundtindandNigerbreenFms)andpresumably Ordovician-Silurian (Arkfjellet Fm)have been found to form an NE-strikingtectonostratigraphic antiform. The section isdominated by various limestones that range incolorfromalmostblacktolight; layersofchert-bearinglimestonealsopresent.Theantiform’sSElimb contains two psammitic layers as well aslayers of schists and conglomerate. The EarlyPaleozoic rocks are unconformably overlain bytheDevonianredsandstonesand/orTriassic.

Conodonts imply that the Hornsundtind andNigerbreenFmsembracetheFloiantotheMiddleDarriwilian stratigraphic interval. The lowerFloianpart of the section yeldedWandelia guyiSmith, Paroistodus proteus Lindstrom,Colaptoconusquadraplicatus(BransonetMehl),Oepikodussp.,Parapanderodusstriatus(Graveset Ellison). The conodont assemblages aredominatedbyWandeliaguyitypicalfortheEastand North Greenland. The Early Darriwilian is

confirmedbyMultioistodus sp.,Drepanoistodussp., Periodon sp. The youngest Middle-UpperDarriwilian ages of the section are based onfindingsofBelodinasp.,Periodonsp.,Panderodussp., Drepanodus sp., Protopanderodus sp. Theconodonts have Laurentian biogeographicaffinity, supporting conclusions based onconodontsfromHornsundandNyFriesland.

POSTER

TheSilurianLauevent–testingplantweatheringasdriverforoceananoxiaandanimalextinction

JuliusHavsteen1,ÁlvarodelRey1andTaisWittchenDahl11NaturalHistoryMuseumofDenmark,UniversityofCopenhagen

The Silurian period witnessed several climaticevents expressed as large positive carbonisotopicexcursionsinthecarbonaterockrecord.Oneofthese–theLudfordianLauevent–isthegreatest isotopic excursion in the Phanerozoic(δ13C increases by ~9‰). Marine carbonatesexposed on Gotland (Sweden) preserve thisrecord. Here, we present new isotope dataobtainedfrombulkcarbonaterocksusingCavityRing-Down Spectroscopy. Several extinctionevents are observed in conjunction with theisotopeexcursions.DuringtheLauevent,marineanimals from the pelagic zone to the benthoswere affected in less than 200 kyr. WehypothesizethattheLaueventreflectsanorganiccarbonburialepisodedrivenbythecolonizationofvascularplantson land.At this time, the firstrootedplantsappearedinthefossilrecord.Theycould have intensified weathering rates andsourced more of the biolimiting nutrient,phosphorus, into the oceans. This increasedmarine primary productivity and ultimatelyorganic carbonburial–nowrecorded inhigherδ13Cvaluesincarbonatesediments.WetestthisrelationshipusinguraniumisotopesinthesamesamplestoconstraintheoxygenationstateoftheSilurian oceans. Uranium’s long oceanicresidence time (~400 kyr) and the preferential

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incorporationof238Urelativeto235Uintoanoxicsediments makes δ238U a powerful proxy forglobalmarineanoxicsedimentburial.

POSTER

ChemostratigraphyacrosstheToarcianOceanicAnoxicEventintheAubachsectionofSWGermany

IbenW.Hougaard1,JørgenBojesen-Koefoed2,OluwaseunO.Edward1,MałgorzataRizzi1,ClemensV.Ullmann3andChristophKorte11DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,Denmark,2GeologicalSurveyofDenmarkandGreenland(GEUS),Denmark,3CamborneSchoolofMinesandEnvironmentandSustainabilityInstitute,UniversityofExeter,Penryn,

Early Jurassic strata, covering the ToarcianOceanicAnoxicEvent(T-OAE),areexposedintheAubachsection,Wutacharea,SWGermany.TheT-OAE is characterized by significant organicmatterburial,numerousgeochemicalanomaliesandoneof themost significantnegative carbonisotopeexcursions(CIE)intheMesozoic(Jenkynsand Clayton, 1997; Küspert, 1982; Röhl et al.,2001). In the present study,we generated neworganic and inorganic carbon isotope values aswell as element concentrations (Mn, V, Mo),common organic geochemical data andbiomarkersofbulkrocksamples.Theresultsarecurrentlyutilizedtodeterminefluctuationinthecarbon cycle, to evaluate bottom water redoxconditions during sediment deposition, and todetermine variation in the source of organicmatter.

The first results show thewell-known negativeorganic carbon isotope excursion from thesemicelatum to exaratum Subzones and theorganic geochemical characterization allow thepreliminary interpretation that the organicmattersourcechangedtoamoremarinesourceduring the T-OAE. Fluctuation in the anoxiaproxiesMo and V are asynchronous suggestingthattherestrictedconditionsoccurredinalargerbasin and the reduced conditions prevailedthroughoutmostofthefalciferumZone.Sea-level

proxies (Rb/Zr,Zr/Al, Si/Al) suggesta sea levelrise synchronous with the change to a moremarinesourceoforganicmatterandtheonsetoftheT-OAE.

POSTER

SeawatertemperaturechangeacrossthePliensbachian–Toarciantransition–newisotopedatafromtheAubachsectioninSWGermany

ChristophKorte1,ClemensV.Ullmann2,JesperA.Frederiksen1,RobertFrei1,IbenW.Hougaard1andMałgorzataRizzi11DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,2CamborneSchoolofMinesandEnvironmentandSustainabilityInstitute,UniversityofExeter

In the Wutach area of SW Germany,biostratigraphically well-defined LateSinemurian to earliest Aalenian siliciclastic andcarbonate sediments are exposed along theAubach stream (Riegraf, 1980; Riegraf et al.,1984;Schlatter,1997;Urlichs,1997).Thelocalitywas sampled in high resolution during severalfield campaigns in the last years, and carbon,oxygenandstrontiumisotopedatasetshavebeengenerated from Low-Mg-Calcite fossils (mainlybelemnites)whichwerescreenedfordiagenesis(see Ullmann and Korte, 2015). Known carbonisotopefluctuationsforthisperiod(e.g.KorteandHesselbo,2011;Peti et al., 2017) are expressedclearly intheAubachdata, includinganabout2‰ negative excursion across the Sinemurian–Pliensbachianboundary, apositive excursion inthe Late Pliensbachian margaritatus Zone, anegative excursion in the spinatum Zone(hawskerenseSz),anegativeexcursionofacrossthe Pliensbachian–Toarcian boundary andrelatively heavy values up to +4 ‰ in thefalciferumZone.TheoxygenisotopevaluesshowanincreaseacrosstheSinemurian–Pliensbachianboundary, reaching heaviest values of ~ +1‰(with periodic fluctuations) in themargaritatusand early spinatum zones (Late PliensbachianCoolMode;Korteetal.,2015).Thevaluesstarttogradually decrease in the higher hawskerense

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Subzone (with some heavy values in thesemicelatum Subzone), lasting till the earliestToarcian tenuicostatum Zone. The new dataindicate that relatively cool temperatures haveexisted in the Swabo-Franconian Basin atpalaeolatitudes below 40° for most of thePliensbachian, and that the Toarcian warmingmayhaveprecededthenegativecarbon isotopeexcursionoftheT-OAE.

POSTER

Orbitalforcingoforganicmatterqualityandquantityinasource-rockformation:thecaseoftheVacaMuertaFormation,Tithonian-Valanginian,NeuquénBasin,Argentina

JohannesMonkenbusch1,AlainLejay2,MathieuMartinez3,HeikoPälike4andFrançoisGelin21DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,ØsterVoldgade,2TOTAL,CSTJF,AvenueLarribau,64000Pau,France.,3UniversitédeRennes,UMR6118GéosciencesRennes,CampusdeBeaulieu,35042Rennescedex,France.,4MARUM,CentreforMarineEnvironmentalSciences,LeobenerStrasse8,UniversitätBremen,28359Bremen

The Vaca Muerta Formation from the NeuquénBasin is an important petroleum source-rockformation in Argentina. A cyclostratigraphicstudy was conducted, based on a set ofcontinuous data from four wells. The TotalOrganicContent (TOC)wasmeasuredusing theLIPSmethodtoinvestigatethecontroloforbitalforcing on the variation of organic matterdistribution. Moreover, the integration of theRock Eval 6 Hydrogen Index (HI) and OxygenIndex(OI)weretestedtounderstandtheclimaticconditions which favoured the deposition andpreservationoforganicmatter.

Cyclic changes are attributed to astronomicalforcing.Themaindriveroftheoxygenationofthebasinwastheobliquity.HI,OIandTOCcorrelatewiththeprecessionandtheeccentricity.

WeattributethislinktochangesinthesealevelduetofluctuationsinicecoverageduringthelateJurassic–earlyCretaceousandsuggestthat,withfalling sea level, the connection between theNeuquén basin and the proto-Pacific gotshallower,resultinginstratificationofthebasinwith warm fresh water sealing off the deeperbasin.Withrisingsealevel,theconnectiontotheocean deepened and the stratificationsweakened. Nutrients were mainly supplied bycontinental run-off from the south of the basindue tomonsoonal activityduringwinter,whichvaried with the precessional cycle. Warm,hypersalinewaterswere synchronously formedin the south-east of the basin during summer.Thisledtotheformationofahypersalinelensinthedeepestpartof thebasinandthuscutting itofffromoxygensupply.

POSTER

ThegiantLowerTriassicsponge-microbialbuild-upsfromNeotethys

SylvainRichoz1,EvelynFriesenbichler2,AymonBaud3,LeopoldKrystyn4,KatrinHeindel5,LilitSahakyan6,JörnPeckmann7andJoachimReitner81DepartmentofGeology,LundUniversity,Sölvegatan12,Se-22362,Sweden,2PaleontologicalInstituteandMuseum,UniversityofZurich,Karl-Schmid-Strasse4,8006Zurich,Swit,3BCG,ParcdelaRouvraie28,CH-1080Lausanne,Switzerland,4DepartmentforPaleontology,UniversityofVienna,Althanstraße14,1090Vienna,Austria,5GeoZentrumNordbayern,FachgruppePaläoumwelt,UniversityofErlangen-Nürnberg,Loewenichstraße28,,6InstituteofGeologicalSciences,NationalAcademyofSciencesofArmenia,24aBaghramianAvenue,37,7InstituteforGeology,UniversitätHamburg,Bundesstraße55,20146Hamburg,Germany,8DepartmentofGeobiology,CentreofGeosciences,UniversityofGöttingen,Goldschmidtstraße3,37077

Aftertheend-PermianmassextinctiontheupperPaleozoicskeletalcarbonatefactorywasabruptlyreplacedbyanon-skeletalcarbonatefactoryandPermian-Triassic boundary microbialites(PTBMs) were flourishing. These PTBMs wereabundant in low-latitude shallow-marinecarbonateshelves incentralTethyancontinents

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and present during at least four events in theLowerTriassic.

The investigated PTBMs from three differentsitesinsouthernArmeniawereformedinadistalopenmarinesettingonapelagiccarbonateramp.Theygrewduring twomicrobialgrowthphasesinGriesbachiantimes,whereasthemicrobialitesfrom the first microbial growth phase co-occurwith calciumcarbonate crystal fans (CCFs).Themicrobes formed predominantly thrombolitesthat vary in size between 5 cm to 1.5 m. Thebiggest thrombolitehas a cone-shapedbuild-upgeometry and an asymmetrical growth, whichindicates the influence of a steady bottomcurrent. It consists of numerous thrombolitedomes with a top head diameter of up to 8 mwidth and a total height of up to 12 m. Themicrobialites are surrounded by a bioclasticwackestone that mainly contains ostracods,foraminifers, microgastropods, thin-shelledbivalves.

Carbonisotopestudieswereperformedonboththemicrobialitesandthesurroundingsediment.A comparison between the δ13Csediment andδ13Cmicrobialiterevealedthatthereislittledifference(<0.4‰) between these values in themicrobialites that formed during the secondmicrobial growth phase. In contrast, themicrobialites and CCFs from the first microbialgrowthphaseshowdifferencesintheδ13Cvaluesofupto2.3‰,whichcouldbeduetomicrobialactivity.

6.2.OpensessioninPalaeontology,palaeoecologyandpaleoenvironments

ORAL

Pushingresearchboundaries:BenefitsoftemperaturerampedgaschromatographyinEA-IRMS

ChristopherBrodie1,OliverKracht,AndreasHilkertandSørenDalby1Dr.

The Thermo ScientificTM EA IsoLinkTM IRMSSystemhasfundamentallyimprovedanalysisbyEA-IRMS using temperature ramped gaschromatographywith a singleGC columnandapatented helium management system thatreduces cost per analysis. These innovativefeaturesopendoorstopushresearchboundariesatnew levels,especially for theanalysisofverysmall concentrations andon veryhighC/NandC/Sratiosamples.

This presentation will principally focus on theadvantages of using temperature ramped gaschromatography. Traditionally, gaschromatography in EA-IRMS employed a GCcolumnheldatanisothermaltemperatureasthegases eluted. However, using temperatureramped gas chromatography in the EA IsoLinkIRMS System, a feature common in GC-MS andGC-IRMS,thetemperatureoftheGCcolumncanbequicklychangedasanalytegasesareeluting,improvingpeakseparation,peakfidelity,analysisof very small sample amounts and precision ofreplicatemeasurements.

We will discuss these improvements in peakseparation, background determination,troubleshootingofthecombustion,pyrolysisandchromatographicprocesses,blankdeterminationandanalysisofverysmallsampleconcentrations.Our improved GC technique is illustrated inFigure1,whichshowsachromatogramofaNCSanalysis on wood (C/S ratio of 7900:1) from asinglesampledrop.Completebaselineseparation

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of each analyte is achieved with soundbackground correction and peak fidelity,including for very large (7000 μg C) and verysmall(11μgNand1μgS)analyteamounts.For5replicate measurements on wood, δ13C = -24.10±0.06‰; δ15N = 3.20±0.23‰ and δ34S =5.92±0.26‰.

ORAL

BryozoanbiotaasaproxyfortheclimaticchangesinCenozoicofWestAntarctica

UrszulaHara11PolishGeologicalInstitute-NationalResearchInstitute

Bryozoans in the marine and glacio-marineCenozoic sedimentary sequences form amorphologically and taxonomically diversifiedbiota inWest Antarctica. During the late Early-late Eocene of the La Meseta Fm. they aredominated by hemispherical, multilamellarcyclostome cerioporines, cheilostomeascophoran lepraliellids and anascanmicroporoideans with a high number of a newtaxaforthescience,agreatvaluefortheaustralbiogeographical connections, as well as withconsiderableevolutionaryinterest,includingtheoldeststratigraphicalrecords(Hara,2001).

Bryozoansoccur at least intermittently throughthe late Miocene-Pliocene glaciomarine HobbsGlacierFormationoftheJamesRossIslandgroup(Pirrie et al. 1997; Jonkers, 1998). The latePliocene assemblage from the shallow-marinepectinid-rich biofacies preserved in the near-shore Pecten Conglomerate (= Cockburn IslandFormation)ofCockburnIslandintheJamesRossIslandarea(NEAntarcticPeninsula)containstheabundanceoftheencrustingcolonies.

ThemajorityofthelatePliocenecheilostomesareknownfromtheMid-LateCretaceous,theothersare considered to have originated in thePaleogene (Eocene-Oligocene), evolving in theAntarctic region and becoming widespreadthrough the Neogene to the Recent, along withone well-represented wholly NeogeneMicroporellidaefamily.

ThedistributionoftheRecentbryozoanswithadominant ascophoran lepraliomorphs ofSchizoporelloidea– themostrichlyrepresentedsuperfamily as well as umbonulomorphsillustrate a dynamicevolution of the highlyendemicAntarcticfauna.Thebryozoan’scolonialgrowth-formcouldbeusedasapotentialtoolininterpretation of the different Cenozoicecosystems and climatic regimes ranging fromgreenhousetoicehouse.

ORAL

ElementsofEoarcheanlifetrappedinmineralinclusions

TueHassenkam1,MartinP.Andersson1,KimN.Dalby1,DavidM.A.Mackenzie2andMinikT.Rosing31Nano-ScienceCenter,Universityofcopenhagen,Denmark,2CenterforNanostructuredGraphene(CNG),DepartmentofMicro-andNanotechnology,TechnicalUnivers,3NaturalHistoryMuseumofDenmark,UniversityofCopenhagen,1350,Denmark

Metasedimentary rocks from Isua, WestGreenland (> 3.7 billion year old) contain 13Cdepletedcarbonaceouscompounds,withisotopicratios consistent with a biogenic origin.Metamorphic garnet crystals in these rockscontain bands of carbonaceous materialcontiguouswithcarbon-richsedimentarybedsinthehostrock,wherecarbonis fullygraphitized.Here we studied carbonaceous inclusionsarmoured within garnet porphyroblasts by in-situ Infrared absorption on ~10-21 m3 domainswithin these inclusions. The absorption spectraare consistentwith carbon bonding toN andOandlikelytophosphate.C-HorO-Hbondscouldnotbedetected.Theseresultsareconsistentwithbiogenicorganicmaterial isolatedforbillionsofyears and thermally matured at temperaturesaround 500 oC. They therefore provide spatialcharacterization for potentially the oldestbiogeniccarbonrelicsinEarth’sgeologicrecord.

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ORAL

Sedimentology,stratigraphyandpalaeoenvironmentsoftheMioceneprimate-bearingsequenceinInnerMongolia,China

AnuKaakinen1,LeenaSukselainen1,ZhaoqunZhang2,JohannaSalminen3andMikaelFortelius11DepartmentofGeosciencesandGeography,UniversityofHelsinki,2InstituteofVertebratePaleontologyandPaleoanthropology,ChineseAcademyofSciences,3DepartmentofPhysics,UniversityofHelsinki

CentralInnerMongoliahasbeenanareaofgreatpalaeontological interest since the beginning ofthe20thcentury.AlthoughtheareahasproducednumerousdiversecollectionsofMiocenefaunas,fossil records from the early Miocene of InnerMongoliaarerelativelyrare.

Our field investigations in Damiao, InnerMongolia have yielded more than 30 newfossiliferous localities, which have produced arich mammalian fauna, including pliopithecidremains.Wepresentamultidisciplinarystudyofthe Damiao sequence, integratingsedimentological, stratigraphical, geochemicalanddiversepalaeontologicaldata.

WehaveinterpretedtheDamiaosequenceastheremainsofafluvio-lacustrinesystemcomprisingchannels, subaerially exposed floodplains andephemeral/marginal lacustrine environments.The bulk of the vertebrate fossils have beenrecovered from threemain fossil horizons: Thepaleomagnetic results and faunal evidencesuggestacorrelationoflowermostfossilhorizonproducing relatively rich small mammalassemblagetotheearlyMiocene,roughlyin20–21Ma age range. The pliopithecid locality levelrepresentslatestmiddleMioceneandhasanageestimate of about 12.1 Ma while the youngestlocalitieswithcervoidsandabundantanddiversesmallmammalfaunarepresentstheearliestlateMiocenewithanageestimateofabout11.6Ma.

Hypsodonty, estimated mean annualprecipitation, local sedimentology, and large

mammal fossils suggest relatively humid andpossibly more forested and woodedenvironments for the primate-bearing locality.ThischallengesthescenariossuggestingaridandhighlyseasonalconditionsforCentralAsiasinceEarlyMiocene.

ORAL

Sinemurian-PliensbachianabundanceandsizechangesinthecalcareousnannofossilSchizosphaerella–relationtoclimaticandpalaeoenvironmentalchangeintheParisBasin

NicolasThibault1andPeti1Leonie

Abundance and size changes in the calcareousnannofossil Schizosphaerella have beeninvestigated through the Early Jurassic (lateSinemurian to early Toarcian) of the Sancerre-Couy core (Paris Basin). Measurements arecompared to variations in CaCO3 content, totalorganic carbon (TOC) content, and isotopictrendsincarbonandoxygen.Ourresultsconfirmthat Schizosphaerella was better adapted toproximal areas than coccoliths as expressed bythe stepwise rise in abundance ofSchizosphaerella,followedbyariseinabundanceof coccoliths during the major transgression oftheSinemurian.Theresultsshowthatchangesinthe size of Schizosphaerella were mostly aresponsetoEarlyJurassictemperaturevariations(icehouse and coolhouse versus-greenhouseconditions)butcomparisontobelemniteoxygenisotopedatashowthattemperaturealonecannotexplainallthepatternsobservedinsizechanges.Biometry statistics suggest the presence of 3main morphotypes. The large morphotype ispresent mostly during proximal, coolenvironmental conditions of the upperSinemurian. The medium morphotype wasadapted to more distal conditions and coolsurfacewaterswhereasthesmallmorphotypeisassociated with warm episodes an highernutriency.

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POSTER

ThemicrostructureofEuselachian(Chondrichthyes)toothandscalesfromLatePermianofLithuania-LatviaRegion

DarjaDankina-Beyer1,AndrejSpiridonov1andSigitasRadzevičius11DepartmentofGeologyandMineralogy,VilniusUniversity,M.K.Čiurlionio21/27,LT03101,Vilnius,

The Late Permian palaeoichthyofauna of theLithuanian-Latvian border Region is poorlyknown due to lack of the information andcomparative isolated material from SouthernPermian Basin. The studied region is locatedgenerally on the flat coastal zone of thenortheasternshoreoftheZechsteinSea(Dankinaet al. 2017). The assemblages of the fishmicroremains such as teeth and scales ofchondrichthyansandosteichthyansfromNaujojiAkmenė Formation (northern Lithuania) andAlši, Kūmas, and Auce Formations (southernLatvia),Lopingian,UpperPermianwerefound.

Previous studies on tooth and scale enameloidmicrostructure provided a single crystalliteenameoid (SCE) as a monolayer in the mostprimitive chondrichthyan taxa (Botella et al.2009).However, thedentalanddermaldenticlemicrostructureofthePaleozoicichthyofaunahasyet to be investigated. We have studied thecrushingtoothandsomescalesmicrostructureofthe Late Permian chondrichthyans. As a result,the investigation with scanning electronmicroscope(SEM)hasshownthepresenceofthecrown and superficial cap of single crystalliteenameloid of euselachian-type scales aswell astubulardentineontheHelodussp.tooth.

POSTER

PalynologicalinvestigationofthelatePliocenetoearlyPleistoceneproto-GulfofCorinth,Greece

GautiTrygvasonEliassen1,MartinMuravchik1,RobGawthorpe1,GunnMangerud1andGijsHenstra11UniversityofBergen,DepartmentofEarthScience

Riftbasinshaveproveneconomicallysignificantas hydrocarbon provinces and, furthermore,record the structural, sedimentary and climaticevolutionofthebasinsandassociatedcatchmentareas. The aim of this study is to utilizepalynological methods to constrain rift basinevolution and provide insight into easternMediterranean late Pliocene climatedevelopment.

Inthisstudy,wetakeacloser lookattheactiveCorinthrift,Greece,whoseearlysyn-riftdepositsare spectacularly exposed on the northernPeloponnese peninsula. So far, research andexisting literature has focused on the westernpart of the onshore stratigraphy, whereas thecentral and eastern areas have received lessattention.ThestudyareaisthenorthernSythasValley, where late Pliocene to early Pleistocenedeep-water deposits of the Rethi-DendroFormation (RDF) are exposed in extensive cliffsections.

TheRDFhasbeenmappedusingtraditionalfieldmethods combined with digital outcrop data(LiDAR).Furthermore,threedrillcoresthatcoverc. 750 m of stratigraphy are being retrieved.Palynological analysis suggests a strongsedimentary facies dependence of thepalynomorphassemblage.Thefindingsofmarinedinoflagellate cysts suggests periods ofconnectivity between the proto-Gulf of Corinthand theMediterranean at an earlier stage thanpreviouslyreported.TheresultsmayprovevitalforunderstandingthestructuralevolutionofthebasinastheyimplythatbyLatePliocenetimethenorthernmarginoftherifthadalreadymigratedclosetoitspresentlocation.

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POSTER

LateToarciantoEarlyBajocianclimateandenvironmentalchangesinEuropeandEastGreenland–geochemicalrecordsfromcalcitefossilsandsediments

JesperAllanFrederiksen1,SuzannePultz1,GerdDietl2,StéphaneBodin3,PeterAlsen4,GüntherSchweigert5,ClemensVinzenzUllmann6andChristophKorte11DepartmentofGeologyandNaturalResourceManagement,ØstreVoldgade10,1350KøbenhavnK,Denmark.,2StaatlichesMuseumfürNaturkundeStuttgart,Rosenstein1,70191Stuttgart,Germany.,3UniversityofAarhus,DepartmentofGeoscience,Høegh-GuldbergsGade2,8000AarhusC,Denmark.,4GEUS,GeologicalSurveyofDenmarkandGreenland,ØstreVoldgade10,1350København,Denmark.,5StaatlichesMuseumfürNaturkundeStuttgart,Rosenstein1,70191Stuttgart,Germany,6CamborneSchoolofMinesandEnvironmentandSustainabilityInstitute,UniversityofExeter,UK

This study becomes the first author’s MasterThesis,andtheaimsaretousetheisotopevaluesfrom collected bulk rock samples and frompristine fossils to reconstruct climate andenvironmentalfluctuationsduringthelateEarlyand early Middle Jurassic (Late Toarcian–Bajocian) Middle European epicontinentalSwabo-Franconian andParisBasins, the FrenchSubalpineBasinandtheEastGreenlandJamesonLand Basin. Belemnite rostra and bulk rocksamples were collected in SW Germany in ZellunterAichelbergatthePliensbachstream(upperPosidonienschiefer Fm., Jurensismergel Fm.,lower Opalinuston Fm.), and in BalingenZillhausenattheWasserfallsection(OpalinustonFm.), and at the Roschbach section(Comptumbank, Eichberg Fm., andSubfurcatenoolith, Ostreenkalk Fm.) (seeQuenstedt1856-1858;Bloosetal.,2005).CoevalsamplesweretakenfromtheLaBaumesectioninSE France (Aalenian–Bajocian) (seeDeBaets etal., 2008), from different localities inLuxembourg, and from the Sortehat Fm. (onlyAalenian) in JamesonLand,EastGreenland(see

Krabbe et al., 1994; Dam & Surlyk 1998;Koppelhus & Hansen 2003). All fossils werescreened for diagenetic alteration (seeUllmannand Korte, 2015) using the Scanning ElectronMicroscope(SEM)andelementratios.Sr/Cavarybetween0.533and2.595mmol/molandMn/Cabetween 0.002 and 29.661 mmol/mol. Oxygen(varybetween-3.41and4.09‰PDB)andthecarbonisotopevalues(-11.11and1.90‰PDB)wererecentlymeasuredandaltereddatawillbeculledasthenextresearchstep.Organiccarbonisotopemeasurementsonbulkrocksamplesarecurrentlyinprogress.

POSTER

Surfaceanalysesoffossilleaves

MagnusA.R.Harding1andTaisW.Dahl11NaturalHistoryMuseumofDenmark,UniversityofCopenhagen,ØsterVoldgade5-7,DK-1350Copenhagen

Recent studies show that the metallome andchemicalcompositionoflivingplantsdependonthe geology aswell as nutritional quality of thesoils inwhichtheplantsgrew(e.g.Hustedetal.2004;Laursenetal.2011;Mieetal.2014).Fewstudies, however, have examined the chemicalmakeup of fossil plant material. In this study,μXRF,ToF-SIMS,LA-ICP-MSandFTIRtechniquesare applied to a fossil conifer (Cupressaceae)from theNaujâtMember,WestGreenland inanattempt to identify and distinguish pristineorganic matter preserved as well as thediagenetic history of the fossil. Moreover, thestrengths and weaknesses of the variousanalytical techniques are compared. Organicmatterwithin the fossilwas identified, but it isuncertainwhetherithasapristineorabacterialorigin.TheNaujâtconiferfossilispermineralizedin calcite with small spots of iron sulphidespresentmainlywhere the fossil is thickest. Thefossilisembeddedinasideriteconcretionformedin kaolinite-rich sediment. Based on theobservations,amodelforthefossilizationoftheplantisproposed.

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POSTER

Carinodens–anewadditiontotheLateCretaceousmosasaurfaunaofDenmark

JesperMilàn1,JohnW.M.Jagt2,JohanLindgren3andAnneS.Schulp21GeomuseumFaxe,Denmark,2NatuurhistorischMuseumMaastricht,TheNetherlands,3DepartmentofGeology,LundUniversity,Sweden

The small durophagous mosasaurine mosasaur(Reptilia, Mosasauridae) genus Carinodens isexceedingly rare in north European chalkdeposits,withpublishedfindslimitedtoasmallnumber of shed tooth crowns and two partialdentariesfromTheNetherlandsandBelgium,allassigned to Carinodens belgicus. A newlydiscovered isolated, shed tooth crown from theUNESCO world heritage site of Stevns Klintexpands theknowngeographicaldistributionofanother species, C.minalmamar, first describedfrom Morocco, to Denmark. The specimen wasfound within the uppermost metres of theMaastrichtian chalk deposits, thereby placing itwithin the last 50.000 years of the Cretaceous.The new tooth crown represents thenorthernmost occurrence of the genusCarinodens. Previous finds of mosasaur dentaland skeletal materials from Denmark have allbeen assigned to the hypercarnivorousmosasaurids Mosasaurus hoffmannii andPlioplatecarpus sp. Thus, the new specimenprovides important new information onecological niche partitioning amongst largemarinereptilesduringthelatestMaastrichtian.

POSTER

BiostratigraphyandpalaeoecologyofcalcareousnannofossilsintheLowerCretaceousMunkMarlBed,DanishNorthSea

SarahD.Møller1,EmmaSheldon2andJanAudunRasmussen31DepartmentofGeosciencesandNaturalResourceManagement,KøbenhavnsUniversitet,2GEUS,GeologicalSurveyofDenmarkandGreenland,3Fossil-ogMolermuseet,MuseumMors

The Lower Cretaceous Munk Marl Bed of theTuxenFormation(DanishCentralGraben)marksachangeinthedepositionalenvironmentwithinachalkunit.Herewe investigate thecalcareousnannofossils from this interval of the DanishBoje-2C well with emphasis on biostratigraphyand palaeoecology to better understand thepelagicenvironmentatthetimeofdeposition.Atotalofseventy-twosampleswereanalysedfromthe well. The samples correlate to the upperLower Barremian nannofossil zones BC14 andLK20B.Anacmeofnannoconid‘tops’isproposedasanewbiostratigraphicaleventcharacterisingthe middle part of the Munk Marl Bed. Highabundances of thermophile taxa suggest warmsurface water conditions at the time ofdeposition.Indicatorsofincreasedfertilityshowparticularly low abundances indicating adecrease in surface water fertility, presumablyrelated to an increased detrital input.Correspondence analysis ordinates samples inrelation to identified palaeoecological proxiesand reflects palaeotrophic levels in the surfacewaterwithinthesection.Theanalysisshowsthatthe calcareousnannofossils indicate aperiodofmoreoligotrophicsurfacewaterinthemiddleofthesection.

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POSTER

MiddleJurassicpalaeoenvironmentaleventsinEurope-evidencefrompalynologyandcarbonandoxygenisotopes

SuzannePultz1,JesperAllanFrederiksen1,SofieLindström2,StéphaneBodin3andChristophKorte11DepartmentofGeosciencesandNaturalRessourceManagement(IGN),UniversityofCopenhagen,DK,2GeologicalSurveyofDenmarkandGreenland(GEUS),DK,3DeparmentofGeosciences,AarhusUniversity,DK

During the early Middle Jurassic, several bioticand climatic changes took place. Amajor eventoccurred at the Aalenian to Bajocian transition,andisassociatedwithanegativecarbonisotopeexcursion in carbonate and organic matter(Bartolinietal.,1996;Hesselboetal.,2003).Thisnegative excursion is, in turn, succeeded in theEarly Bajocian by a poorly understood positivecarbon isotope excursion, associatedwith floralandfaunalturnovers(Sucheras-Marxetal.,2015;Bodin et al., 2017). In contrast, dinoflagellatesunderwentamajorevolutionandradiationfromthe Late Aalenian to Early Bathonian, andchangesinrelativesealevelarethoughttohavecontrolled the stratigraphic pattern ofdinoflagellate cysts (Wigganetal.,2017).Thesepaleoenvironmental perturbations are alsoreflected in the carbon isotopes of terrestrialorganic matter and marine carbonate, withlighter values in the marine palynofacies(Hesselbo et al., 2003). In the present study,currently inprogresspalynological and isotopicinvestigations of latest Toarcian to BajociansamplesfromthreedifferentregionsinEurope–(1) SE France (La Baume section), (2) SWGermany(sectionsinZellunterAichelbergatthePliensbachstream,andBalingenZillhausenattheWasserfall and at the Roschbach), and (3) in SSweden (Vilhelmsfält core) (Guy 1971) – arepresented.Theaimistodocumentthepresenceand abundance of marine and terrestrialpalynomorphsaswellas to identifycarbonandoxygen isotopes trends in the investigatedsuccessions inorder to replace themwithin theframework of Middle Jurassic climatic andenvironmentalchanges.

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Sablenickelisotopesmeasuredinsitufromfossilizedmicroorganisms

AnnaNeubuck,MarekTulej2,RetoWiessendanger2,MagnusIvarsson3,ValentineGrimaudo2,PavelMoreno2,CurtBroman1,AndreasRiedo4,WolfgangBach5,MartinWhitehouse6,PeterWurtz2.

1DepartmentofGeologicalSciences,StockholmUniversity,22PhysicsInstitute,UniversityofBern,Switzerland,3DepartmentofPaleobiologyandNordicCentreforEarthEvolution,SwedishMuseumofNaturalHistory,4LeidenObservatory,SacklerLaboratoryforAstrophysics,LeidenUniversity,TheNetherlands,5MARUM-CenterforMarineEnvironmentalSciences,UniversitätBremen,Germany,6DepartmentofGeosciencesattheSwedishMuseumofNaturalHistory Preciseinsitumeasurementsofnickelisotopesinfossilizedmicroorganisms holds great potentialfor differentiation between non-biologic andbiologic microstructures in rocks. Stable nickelisotopes are well known to be fractionated bybiologicalprocessesunderlaboratoryconditions.Less is known, however, due to instrumentalobstacles and alteration processes, if biologicsignatures of Ni isotope fractionation arepreserved in fossils in thegeologic rock record.Usingtransitionmetalisotopesasbiomarkersinmicrofossils has traditionally been difficultbecause of its usually low concentrationpreserved in the fossil. It has until now beentechnically impossible to reliably measure Niisotopicfractionationpatterninsituinfossilizedmicroorganisms, where the elementalconcentration has sometimes been as low as0.1wt%.Hereweshowboththatbiologicisotopicfractionation signatures are preserved inmicrofossils and that the instrumentaldevelopment has reached a milestone in beingabletomeasuresuchsignalsaccurately.Wealsodemonstratethatabioticsignaturesarestronglydeviatedfromthebiologicalsignatures,pointingout theeligibilityofusingstablenickel isotopesasbiosignatures.

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7.Climate7.1.ClimatefromthePalaeogenetotheAnthropocene-bridgingtimescalesandapproaches

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MioceneglacialeventsandtheirinfluenceonlithologydistributionwithintheDanishNorthSeaarea

KarenDybkjær1,ErikSkovbjergRasmussen1andEmmaSheldon11TheGeologicalSurveyofDenmarkandGreenland(GEUS)

During the Miocene, episodes of global coolingcausedrepeated,rapid,eustaticsea-levelfallsintheorderof25-50m.Inproximalsettingswithinthe North Sea Basin (onshore Denmark) thesesea-level variations affected the distribution oflithologies with deposition of well-sorted deltasandorbasinfloorfansduringtheglacialevents.These sanddeposits form important subsurfaceaquifersinthewesternpartofDenmark(Jylland).

Based on the dinocyst zonation of Dybkjær &Piasecki(2010)ithasbeenpossibletocorrelatethreesuccessive,prograding, fluvio-deltaicsandbodieswiththeearlyMioceneglacialevents;Mi-1a,Mi-1bandMi-2ofMilleretal.(1991).Inmoredistal areas (offshore Denmark), the glacialeventsdidnothaveany(significant)effectonthelithology, but can be recognised by increasedabundancesoffreshwateralgaeanddiatoms.

New data from the uppermost Miocene (upperTortonian and Messinian) have led to therecognitionofsomeoftheclimaticeventsknownfrom this time-interval - and to related sanddeposits. A Messinian glacial event, probablycorrelatablewith theMediterranean “Messiniansalinity crisis”, was recently recognised in theNora-1 well. This event correlates with aprograding depositional system and incision,

indicatingasea-levelfallof70-80m(Mølleretal.2009).

Identification and correlation of the Mioceneglacial events are important for understandinglithologydistributionandcanbefurtherusedforpredictionofpotentialreservoirsands.

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Eocenebryozoanbiotavsclimaticevents(SeymourIsland,WestAntarctica)

UrszulaHara11PolishGeologicalInstitute-NationalResearchInstitute

The earliest Antarctic late early EocenebryozoansoftheLaMesetaFm.,SeymourIslandare connected with the major phase ofcheilostome evolution; clear preponderance ofcerioporoidean cyclostomes along withnumerousmicroporoideans.Theinternalmouldsoftheloose,smallzooeciainthelowermostpartof this formation, includes the cheilostomes ofBeanidae, Catenicellidae, Savignyellidae, whichnowdays arewidely distributed in the tropical-warm, temperate latitudes in the shallow-watersettings (Hara 2015). 90% of taxa reveal themultilamellar growth-form connected with ashort-term episode in the lower part of Telm1,duringtheirlonginsituevolution.Thebryozoansfromthe(Telm4-5)arethemicroporoideansandthe first lunulitiform (free-living) bryozoans ofLunulites and Otionellina, ever reported fromAntarctica.Theirdisc-shapedcoloniesaretodayindicativeof tropics and subtropicsbut skeletalmineralogy is also important in view of thetransition of such bryozoans from calcitic tobimineralic to aragonitic on the K/T boundary.Recent, free-living lunulitiforms occur inwarm,shallow-shelfconditions, in temperaturesof10-29˚C,oncoarse,sandytomuddybottomwithlowto moderate deposition in fairly high velocitycurrents. Contrary to that, the bryozoansrecognized in the upper part of the formation

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(Telm7) are composed of the impoverishedbryozoan biota of scarse lepraliomorphs andfragmentedcyclostomes,whichareaccompaniedby the crinoids and brachiopods, gadiform fishremains, penguin bones and whales. The well-documenteddistributionofthebryozoansinthestratigraphicalprofileoftheLaMesetaFormationillustrates the climatic changes connected withtheEECO,MECOaswellastheEOT.

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Tracersofseaice,primaryproductionandmeltwaterinputs:distributionofbiogenicproxiesinaHighArcticfjordsystem,NortheastGreenland

MaijaHeikkilä1,KaarinaWeckström1,MikaelSejr2,PetraTallberg1,GuillaumeMassé3,AudreyLimoges4andSofiaRibeiro51UniversityofHelsinki,2AarhusUniversity,3UniversitéLaval,4UniversityofNewBrunswick,5GEUS

The coastal ecosystems of Northeast Greenlandare vulnerable to the enhanced melt ofcontinental and sea ice as a result climatewarming, however little is known of pastecosystemchangesintheregion.Wepresentthedistribution of an array biogenic proxies(dinoflagellate cysts, pollen, diatoms, biogenicsilica,C/Nandtheirisotopes,IP25,HBIIII)froma transectof13 surface-sediment samples fromYoungSound-Tyrolerfjord,NEGreenland(74°N),in order to assess their relevance as tracers ofpastchanges insea ice,primaryproductionandterrigenous inputs. The Greenland EcosystemMonitoring program provides a unique HighArctic time-series of hydrological, atmosphericandbiologicalmeasurementsfromthefjordsincethe mid-1990s, against which the sedimentsignatures can be compared. The proxy datashow an overall good agreement with themonitoring data. Organic carbon contents,diatom production, HBI III and heterotrophicdinoflagellatecystabundancewerehigherintheouter fjord, where turbidity is lower, salinity

higherandwatersmorenutrient-richcomparedtotheinnerfjord.Conversely,intheinnerfjord,these production proxies follow an oppositepattern.Theseasonalsea-iceproxyIP25andsea-ice-dwelling taxa are present in varyingabundances, which reflects the seasonalcharacter of the sea-ice cycle together withspecies-specifichabitatpreferencesofthesetaxa.Our results support the notion that futurewarming and freshening will likely have anegative impact on primary productivity andorganic matter sequestration. This implicationmay be assessed by reconstructing changesduring past warm periods using the newsedimentcorerecordsfromthearea.

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Investigatingphase-relationshipsbetweenicemargininstabilitiesandoceanographicconditionsinBaffinBayduringthelastdeglaciationandearlyHolocene

RebeccaJackson1,AnnedeVernal2,Marit-SolveigSeidenkrantz3,AndersCarlson4,ClaudeHillaire-Marcel2andMichalKucera51GeologicalSurveyofDenmarkandGreenland(GEUS)andMARUM/UniversitätBremen,2UniversitéduQuébecàMontréal,3AarhusUniversity,4OregonStateUniversity,5MARUM/UniversitätBremen

Freshwater forcing from Northern Hemisphereice sheets during the last deglaciation likelyplayed an important role in modulating deep-water formation, and thus global climate. Themechanisms of ice margin instabilities and itsexact phase relationship with climatic change,suchaspaleoceanographicvariation,arenotfullyunderstood.

Baffin Bay represents an important conduit forfreshwater transported into the Labrador Sea,released from the Greenland, Innuitian andLaurentideicesheets.Wetakeadvantageoftworadiocarbon-datedmarine sediment cores fromcentralBaffinBaythatspanthelastdeglaciationand early Holocene (ca. 17-10 kyr BP). These

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archivesprovideco-registeredrecordsofdetritalinput from the surrounding ice sheets andsufficient biogenic carbonate for thereconstructionofpaleoceanographicconditions.

Two distinct detrital carbonate-rich layers,originatingfromicesheetssurroundingnorthernBaffin Bay and dated at 14.2-13.7 kyr BP and12.7-11 kyr BP, indicate that ice sheet retreatevents occurred during both interstadial andstadial periods and were asynchronous withHeinrichevents.Despitepreviousevidenceforanoceanic trigger of these events, records hereindicate change in deep water properties andstrongerinflowofwarmerAtlanticwaterviatheWest Greenland Current postdated the firstevent.Thesecondeventwasnotprecededbyanymajor change in oceanographic conditions butlikely a response to a combination of aconsistentlystrongerWestGreenlandCurrentaswellasclimaticforcing.Resultssuggestthattherewere different mechanisms responsible for icemargininstabilityeventsinBaffinBayduringthelastdeglaciationandearlyHolocene.

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Paleoclimateandpaleoceanographydatabasedonisotope13Cand18Omeasurementswiththenewmeasurementtool

MagdaMandic11ThermoFisherScientific,Bremen,Germany

The contents of stable carbon and oxygenisotopes,13Cand18O,insecondaryprecipitatedcarbonatesandsedimentscanprovideimportantinformationaboutpaleoclimateconditionsofthearea. Environmental factors like temperature,concentration of atmospheric CO2, chemicalcomposition of water, isotopic composition ofwater, CO2 and deposited are influence theisotopiccomposition.Formanydecadesdifferentinstrumental methods involving generations ofthe isotope ratio mass spectrometers withdifferentperipheryunitsforsamplepreparation,have provided scientifically required highprecision, and high throughput of samples for

variety of different applications in paleoclimatereconstructions.

In this work we will present measurements ofδ13Candδ18Ofromsolidcarbonatesamples,DICandδ18Oofwaterwithnewlasertechnology,withcase study where Delta Ray was in the field(Karstic cave) performing formore than a yearcollectinghighfrequencydataonδ13Candδ18O.

We have demonstrated usage ofa ThermoScientific™ Delta Ray™ IRIS with URI Connectoncertified reference materials and confirmedthe high achievable accuracy and a precisionbetterthen<0.1‰forbothδ13Candδ18O,inthelaboratoryor the fieldwith sameprecision andthroughput of samples. With equilibrationmethod for determination of δ18O in watersamples,whichwepresentinthiswork,achievedrepeatability and accuracy are 0.12‰ and0.68‰respectively.

Applying newmethods formeasurement of thesamplesimportantforpaleoclimateinvestigationonecancometotheresultsalreadyinthefield.

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Deglacial–HolocenepaleoceanographyofHeraldCanyon,ChukchiSea

ChristofPearce1,MattO'Regan2,JayneRattray3,DavidHutchinson2,TomCronin4,NataliaBarrientos2,HelenCoxall2,IgorSemiletov5andMartinJakobsson21DepartmentofGeoscience,AarhusUniversity,2DepartmentofGeologicalSciencesandBolinCentreforClimateResearch,StockholmUnversity,Stockh,3EnergyBioengineeringandGeomicrobiologyResearchGroup,UniversityofCalgary,Calgary,Alberta,C,4U.S.GeologicalSurvey,RestonVA,USA,5TomskNationalResearchPolytechnicUniversity,Tomsk,Russia

TheHerald Canyon is a local depression acrosstheChukchiSeashelf,andactsasoneofthemainpathways for PacificWater to the Arctic Oceanafter entering through the Bering Strait. Weanalyzed sediment samples of two piston coresfromHerald Canyon, collected during the 2014

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SWERUS-C3ArcticOceanExpedition.Core2-PC1fromtheshallow(57mwd)flankcontainsthelateHolocene at high resolution (> 2m/kyr), whileCore4-PC1 fromthecentralcanyon(120mwd)extendsbackintimeto~13ka.Thelowerpartof4-PC1 contains an abrupt increase in biogenicsilica and a carbon isotopic shift towardsmoremarinevalues,whichareinterpretedasthesignalof the Bering Land Bridge flooding and waterexchangethroughtheBeringStrait(Jakobssonetal., 2017). Thismajor oceanic event is dated to~11ka and thus occurs in the very earlyHolocene, contrary to most previous earlierestimatessuggestingaYoungerDryasagefortheopeningof thegateway.ThechronologyofCore2-PC1isbasedon17radiocarbondatesandthe3.6kaAniakchakCFEIItephra,whichisusedasan absolute agemarker to calculate themarineradiocarbon reservoir age (Pearce et al., 2017).Analysisof sea icebiomarkersandphytosterolsindicate relatively stable sea ice conditionsthroughout the entire late Holocene, howeverendingwithanabruptincreaseofphytoplanktonsterols in the very top of both sedimentsequences which corresponds to the rapid iceretreatobservedinrecentdecades.

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Seaice,marineproductivity,andhumansettlementdynamicsintheNorthWaterPolynya-Qaanaaqregion(NWGreenland)duringthelateHolocene

SofiaRibeiro1,AudreyLimoges2,MartinNissen3,SteffenOlsen4,NajaMikkelsen1andGuillaumeMassé51GeologicalSurveyofDenmarkandGreenland,2UniversityofNewBrunswick,Canada,3DanishGeodataAgency,4DanishMeteorologicalInstitute,5TAKUVIK,LavalUniversity,Canada

TheNorthWater(NOW)isthelargestpolynyainthe Arctic, a large extension of recurrent openwaterssurroundedbyseaice,innorthernBaffinBay. This polynya is the most productiveecosystemnorthofthepolarcircle,anditsliving

resources have sustainedhuman settlements inbothArcticCanadaandGreenlandformillennia.WithintheframeworkoftheICE-ARCproject:Ice,Climate and Economics - Arctic Research onChange (EU FP7, http://www.ice-arc.eu/), weaimtoreconstructchangesinclimate,seaice,andmarine resources in the NOW region using anintegrated approach combining proxy recordsfrommarine sediment cores, remote sensing ofsea ice, andhistorical data.Wewill present thelatestresultsfromamulti-proxyinvestigationofsediment core records from the high ArcticInglefieldfjord(Qaanaaq)andfromanew5,4mhigh-resolution sediment core from the NOW,spanning the last ca. 3500 years. Our proxyresultswillbediscussedinthelightofhistoricaland archaeological sources in order to identifypossible links between past changes in climateand marine resource availability in this higharctic “oasis”withknowncultural transitions inGreenland.

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HolocenetemperaturetrendsintheNorthernHemispherehighlatitudes–model-datacomparisons

HeikkiSeppä1,YuruiZhang1,HansRenssen2andPaulJ.Valdes31DepartmentofGeosciencesandGeography,UniversityofHelsinki,Finland,2DepartmentofNaturalSciencesandEnvironmentalStudies,UniversityCollegeofSoutheastNorway,3SchoolofGeographicalSciences,UniversityofBristol,UK

Regionaldifferences inHolocene climate trendsin the Northern Hemisphere high latitudes areprimarilydeterminedbyorbital-scale insolationvariationsandmeltingicesheets.Previousinter-model comparisons have revealed that multi-simulation consistencies vary spatially. Wecompared multiple model results with proxy-based reconstructions in Fennoscandia,Greenland,northCanada,AlaskaandSiberia.Ourmodel-data comparisons reveal that data andmodels generally agree in Fennoscandia,Greenland andCanada,with the early-Holocenewarming and subsequent gradual decrease to0

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ka BP. In Fennoscandia, simulations and pollendatasuggesta2.0°Cwarmingby8ka,butthisisless expressed in chironomiddata. InCanada, astrong early-Holocenewarming is suggested byboth the simulations and pollen results. InGreenland, the magnitude of early-Holocenewarming ranges from 6.0°C in simulations to8.0°Cinδ18O-basedtemperaturereconstructions.Simulated and reconstructed temperatures aremismatched in Alaska. Pollen data suggest astrong early-Holocene warming, while thesimulations indicate constant Holocene cooling,and chironomid data show a stable trend.Meanwhile,ahighfrequencyofAlaskanpeatlandinitiation before 9 ka can reflect either hightemperature, high soil moisture or largeseasonality. In high-latitude Siberia, thesimulationsandproxydatadepicthighHolocenetemperatures,butthesignalsarenoisyowingtoa large spread in the simulations and betweenpollenandchironomidresults.Onthewhole,theHolocene climate trends in most regions(Fennoscandia,GreenlandandCanada)arewellestablished and understood, but importantquestions regarding the Holocene temperaturechange andmechanisms remain for Alaska andSiberia.

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AnevaluationofIRDasaproxyforglacierchange:resultsfromUpernavikIsfjord.

FlorVermassen1,DavidWangner1,LaurenceDyke1,AmalieCordua2,SabineSchmidt3,KurtKjær4andCamillaAndresen11GeologicalSurveyofDenmarkandGreenland,KøbenhavnK,Denmark,2InstitütfürGeologie,UniversityofHamburg,Hamburg,Germany,3EPOC,UMR5805,UniversityofBordeaux,Pessac,France,4NaturalHistoryMuseumofDenmark,KøbenhavnK,Denmark

The sudden increase of mass loss of theGreenland ice sheet at theonsetof this centuryhas spurred investigations regarding ice-discharge at marine terminating glaciers, aprocessthatisthoughttocontributeupto50%of

Greenland’stotalmassloss.Toevaluatewhetherthis recent increase of mass loss was anoutstanding event or occurs, centennial ormillennial timescales, sediment cores in fjordswith marine-terminating glaciers can beinvestigatedsincetheyconstitutehigh-resolutionsedimentological records that reflect pastchangesinglacierstability.

In glacimarine fjords, sand-sized sediment ispredominantly transported and deposited bymelting of sediment-laden icebergs. Therefore,ice-rafting can be reconstructed by quantifyingthe downcore variations in sand content. Eventhough the interpretation of IRD as a proxy forglacierstability(icebergproduction)iscommon,many glaciological and sedimentologicalcomplexities are involved in interpreting IRDrecords. A better understanding of thosecomplexitiescanbeachievedbyinvestigatingtherelationshipbetween IRDvariability and recentobservations of climatic and glaciologicalchanges.

In this study,we quantify the IRD variability offourshortcores(~2m)fromUpernavikIsfjord,WestGreenland.Ice-raftingisreconstructedbackto1930andcomparedtoclimaticmeasurementsandarecordofglacierterminuspositionchanges,derivedfromhistoricalexpeditionsandsatelliteimagery.Wediscussspatialtrendsof ice-raftingand the different processes that modulate itsvariability. This information aids the generalunderstanding and interpretation of IRD inpaleoceanographicresearch.

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A2000-yearrecordofoceaninfluenceonJakobshavnIsbræcalvingactivity,basedonmarinesedimentcores

DavidJ.Wangner1,AnneJennings2,FlorVermassen1,LaurenceDyke1,KellyA.Hogan3,KurtH.Kjær4andCamillaS.Andresen11GEUS–GeologicalsurveyofGreenlandandDenmark2INSTAAR-InstituteofArcticandAlpineResearch,Boulder,Colorado3BritishAntarcticSurvey,Cambridge,UnitedKingdom4NaturalHistoryMuseumofDenmark,Copenhagen,Denmark

The Greenland Ice Sheet has experiencedsignificantmasslossinrecentyears.Asubstantialcomponentofthisisattributabletotheretreatofmarine-terminating outlet glaciers, which lostmass through increased calving and meltwaterdischarge. Jakobshavn Isbræ is the mostproductive marine-terminating glacier inGreenland,yetrelativelylittleisknownaboutitshistorybeforethefirstinstrumentalobservationsoflocalclimaticconditions~140yearsago.

Three marine sediment cores were collectedfrom locations north-west to the mouth ofJakobshavn Isfjord in Disko Bay. These coreswereanalyzed to reconstruct changes inglacierbehavior in response to past climatic andoceanographic changes; this provides contextagainstwhichtoassessthesignificanceofrecentchanges. The sediments deposited at this sitereflect oceanographic and climatic changes aswell as the discharge of ice rafted debris fromJakobshavnIsbræ.

Radiocarbon dates of plant material combinedwith a 210Pb profile indicates that the corescoveratimespanof~2000years.X-Rayimagesandahigh-resolutiongrain size analyses revealclearchangesinthesedimentationregimesovertime.The influenceofoceanwater temperaturederivedfrombenthicforaminiferarecordaswellasthe impactofa floatingglaciertongueonthe

sediment output of Jakobshavn Isbræ isdiscussed.

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HoloceneoceanographicvariabilityincoastalsoutheastGreenland

LaurenceM.Dyke1,CamillaS.Andresen1,Marit-SolveigSeidenkrantz2,DavidJ.Wangner1andFlorVermassen11GEUS,DepartmentofGlaciologyandClimate,ØsterVoldgade10,DK-1350,KøbenhavnK,Denmark.,2CentreforPastClimateStudies,AarhusUniversity,Høegh-GuldbergsGade2,DK-8000,AarhusC,Denmark

ThecoastalwatersofsoutheastGreenlandaretheinterfacebetweentheAtlanticOceanandthevastGreenland Ice Sheet. Oceanographic processeshavebeenimplicatedintherecentlossoficefrommarine-terminating glaciers across the region.Oceanprocessesherearealsoimportantastheymodulate global thermohaline circulation; thisoccursboththroughtheinfluxofmeltwaterfromtheicesheet,andthroughmixingofwatermasseson the continental shelf. Understanding howtheseprocesseshavevariedinthepastiscrucialforpredictingfuturebehavior.

We present two complementary sediment corerecords of oceanographic variability from thecontinentalshelfofcentralsoutheastGreenland.Radiocarbon and lead-210 dating demonstratesthat these cores cover the last 5000 and 9000years respectively. We analysed benthic andplanktonicforaminiferatoreconstructvariabilityinwatermassesatboththesurfaceandseabed.We use independent, but complimentary,measurementsofsortablesilttoreconstructthestrengthofoceancirculationat theseabedandbuild a holistic picture of oceanographicconditionsfromthemid-Holocenetothepresent.

Combining our new results with records fromfurther north in the region yields a uniqueresourcewithwhich to assess the variability of

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oceaniccurrentsataregionalscale.Weusethisto examine the factors that have driven theoceanographic development of the region. Wethen identify how oceanographic changes insoutheastGreenlandhaveinfluencedoceanicandclimatic conditions across the wider NorthAtlanticregion.

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LateHolocenepaleoclimaticandpalaeoceanographicdevelopmentoftheeasternBaffinBayarea

KatrineElnegaardHansen1,IsabelleBilly2,PierreFrancus3,EleanorGeorgiadis2,JacquesGiraudeau2,PhilippeMartinez2,GuillaumeSt.Onge4,GuillaumeMassé5andMarit-SolveigSeidenkrantz11AarhusUniversity,2UniversityofBordeaux,3InstitutNationaldelaRechercheScientifique,4UniversitéduQuébecàRimouski,5UniversitéLaval

A738mlongmarinesedimentcore,AMD14-204CasqC,wasretrievedfromtheeasternBaffinBayduring a research cruise on board CCGSAmundsen in 2014. The study of benthicforaminiferal assemblages, XRF core scan dataandCT-scanssupportedbyradiocarbondatingofthis core allows the reconstruction of thepalaeoceanography and palaeoclimate of theeasternBaffinBayduringthelast~4800cal.BP.Several major changes in oceanographicconditionsandclimatearereconstructedduringthistimeintervalintheeasternBaffinBayarea,which also influenced the nearby UpernavikIsstrømglacier.Ourstudyrevealsthatrelativelywarmersubsurfacewatersprevailedduring thefinal phase of the warmer ‘Holocene ThermalMaximum’,linkedtotheentrainmentofrelativelywarmIrmingerCurrent(IC)waterintotheWestGreenlandCurrent(WGC).Thisrelativelystrongadvection of IC may also have resulted inrelatively strong melting of the UpernavikIsstrømglacier,causinginfluxofmeltwatertothearea.However,at~3100cal.BP,theonsetoftheNeoglaciation, the area experienced an abrupttransition to dominantly agglutinated benthic

species, indicating enhanced carbonatedissolution. Thiswas likely in part caused by areductionoftheinfluxofICwaterandincreasedentrainmentof theEastGreenlandCurrent intotheWGC. The reduction of IC water influx alsoallowed increased influx of the cold, corrosiveBaffin Bay Deep Water. These cold subsurfacewater conditions persisted throughout the lateHolocene,onlyinterruptedbyshort-livedclimatefluctuationssuperimposedonthiscoolingtrend.

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Spatiotemporaldifferencesinvarvestructureandpreservationoverthelast200yearsinLakeLehmilampi,EasternFinland

SariannaSalminen1,EevaHaltia1andTimoSaarinen11UniversityofTurku

Awidevarietyofstudiesconsideringvarvedlakesediments as a climate proxy have beenperformedinFinnishlakes.Nevertheless,noneofthemisconsideringspatialdistributionofvarveswithin an entire lake, although it is essential toacquiredatanotonlyfromthedeepestpointofalake but also from more shallow areas. Thedistributionofvarveswithintheentire lakehasonlybeenstudiedinafewlakesinEurope(Jennyetal.2013).

Inpreviousworkthechangesinthepresenceofvarveswithinthewholelakeduringthepast200years, arriving at a conclusion in changes inhypolimnetic hypoxia (2mg/l (Roberts et al.2009)),wereinvestigated.Asaresulttheextentof hypolimnetic hypoxia has clearly changedduring the past 200 years in the lake due toclimate.

In this study the differences in sedimentcomposition in varved and non-varved sectionsare studied with SEM (scanning electronmicroscopy), μXRF (X-ray fluorescence) and X-ray radiography to investigate the factorsinfluencingvarveformationinthelake.Theaimof this study is to investigate spatiotemporal

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differences in varve structure, formation andpreservationwithinthewholelake.

8.Quaternarygeology8.1.IceandclimatehistoryintheArcticandsubarctic

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A200kaglaciationhistoryfromNWSvalbard

HelenaAlexanderson1,MonaHenriksen2,HeidiT.Ryen3,JonY.Landvik2andGustafPeterson41LundUniversity,2NorwegianUniversityofLifeSciences,3NorwegianWaterResourcesandEnergyDirectorate,4GeologicalSurveyofSweden

Late Quaternary sedimentary units atKongsfjordhallet, NW Svalbard, represent fivecycles of glaciations and subsequentdeglaciationsduringhighrelativesealevels.Thehigh sea-level events are interpreted asglacioisostatically induced and imply precedingregionalglaciations,whichweconstrain in timeby luminescence and radiocarbon ages to justprior to~195ka,~130ka,~85ka,~60kaand~14ka.Combinedwiththestratigraphicalrecordfrom nearby Leinstranda (Alexanderson et al.2011) we identify six, possibly seven, majorglacial advances during the last 200 ka in theKongsfjorden region. Two of these occurredduring the Saalian and at least four during theWeichselian.

The results are based on detailedsedimentological, stratigraphical andchronologicalinvestigationsoftheuppermost15m of the 40-m-high Kongsfjordhallet coastalsections. The succession is dominated bysediments of marine and littoral origin,representing partial shallowing-upwardsequences due to isostatic rebound. Only onesubglacial till was recognized. Interestingly,alluvial and periglacial deposits, not commonlyrecognized in this type of setting, occur in thesequence. These include weathered coarse

alluvium, sandy channel fills as well ascryoturbatedsedimentsandsolifluctiondeposits.The sedimentary succession has beensummarised ina faciesmodel foranemergencecyclefollowingdeglaciation.

Our studyencompassesonly theupper15mofthe coastal cliff sections at Kongsfjordhallet(succession A of Houmark-Nielsen and Funder1999), and there is an additional ~20 m ofsedimentsbelowourUnit1,whichispromisingfor future studies aiming to go further back intime.

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ReindeerkilldatesrecordlateHoloceneglacierlakeoutburstfloodsinEastGreenland

AndersBjørk1,MortenMeldgaard1,JeppeMøhl1,KristianGregersen1,ShfaqatKhan2,RomainMillan3,KristianKjeldsen2,SvendFunder1,MikeWillis4,LaurenceDyke5,NicolajLarsen6andKurtKjær11NaturalHistoryMuseumofDenmark,2DTUSpace,3UniversityofCalifornia,Irvine,4UniversityofColorado,Boulder,5GEUS,6AarhusUniversitet

In the summers of 2004 and 2005 a surprisingfindoftheremainsofseveraldeadreindeerswasdone in East Greenland. The carcasses weremeltingoutofasnowbankinasmallvalleynextto the village Ittoqqortoormiit at the mouth ofScoresbysund fjord-system. The radio-carbonages of the 30 animals showed a surprisingspread with several episodes of reindeer-deposition within the last four thousand years.We argue that the only phenomena capable ofkilling and positioning the animals at the exactsamelocationovermultiplemillenniaareglacierlake outburst floods (GLOFs). In the catchment,glaciers and topography capable of creating

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GLOFsareindeedpresent.Thus,ourpileofdeadreindeer became an unlikely proxy of glacialpresence, and moved the onset of neo-glacialbuild-upintheregionbyathousandyears.

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Preliminaryresultsbasedon24new36ClexposuredatingsrevealsasynchronousdeglacialhistoryofTröllaskagipeninsula,centralnorthIceland

SkaftiBrynjólfsson1,NuriaAndrés2,DavidPalacios2andÞorsteinnSæmundsson31IcelandicInstituteofNaturalHistory,Akureyri,Iceland,2UniversidadComplutense,PhysicalGeography,Madrid,Spain,3InstituteofLifeandEnvironmentalScience,Reykjavík,Iceland

At present the Tröllaskagi peninsula, located incentralnorthIcelandhosts150cirqueandvalleyglaciers.Thelandscapeischaracterisedbysteepnarrowglaciallycarvedvalleysseparatedwithupto 1500 m high peaks and ridges. The glacialhistory of Tröllaskagi suffer from lack of directdating. Previous studies indicate Tröllaskagipeninsulawasmostlyicecoveredduringthelastglacialmaximum.Several lowlandendmorainesandraisedbeachesindicaterecurrentglacialre-advances during the deglaciation , which wascompletedabout10Kaago.Mostofthepresentglaciers are considered to have reachedmaximum Holocene conditions during the lateLittleIceAge.

We sampled24 rock samples fromerratics andmoraine boulders for 36Cl exposure dating inorder to improve theglacialhistoryof thearea.Preliminary results indicate asynchronousdeglaciation pattern over the peninsula. Somemountain ridges and summitswere deglaciatedat least about 16 Ka ago. Furthermore, somehighlandvalleysweredeglaciatedabout13-14Kaagowhileothersprobablyremainedglaciatedatleast until early Holocene. Finally we obtainedaverage ages 2.66 Ka and 0.7 Ka from two

moraines proximal to present glaciers whichweresuspectedtorelatetoLIAfluctuations.

Our preliminary results support recentresearches that suggest 36Cl exposure datingmethodasplausibletoimprovesignificantlythedeglacial history of Iceland, especially wherepresence of tephra and organic material fordatingislimited.

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AdvancesinDeglaciationonSvalbard

WesleyR.Farnsworth1,ÓlafurIngólfsson2,MichaelRetelle3,LisAllaart4,LenaHåkansson5,AndersSchomacker6,RikoNoormets7,SnorreOlaussen8,AlexanderProkop8andAleksandraSmyrak-Sikora81UniversityCentreinSvalbard(UNIS)&UiT,TheArcticUniversityofNorway,2UniversityofIceland&UniversityCentreinSvalbard(UNIS),3BatesCollege,ME,USA&UniversityCentreinSvalbard(UNIS),4UiT,TheArcticUniversityofNorway,5UniversityCentreinSvalbard(UNIS),6UiT,TheArcticUniversityofNorway&NaturalHistoryMuseumofDenmark,7UniversityCentreinSvalbard(UNIS),Dept.ofArcticGeology,N-9171Longyearbyen,8UniversityCentreinSvalbard(UNIS),Dept.ofArcticGeology,N-9171Longyearbyen,Norway

Despite warm regional fjords, a variety of datasuggest extensive glacier advances on Svalbardduring the Pleistocene-Holocene transition. Wepresent the first well-constrained (in age) endmoraine formed during the Lateglacial-earlyHolocene(LGEH) inSvalbard,DeGeerbukta,NESpitsbergen.The landformwasdepositedbyanoutletglacierre-advancingintoafjordextending4.4kmfurtherthanthelateHolocenemaximum.We compare the synchronicity of this glacieradvance to paleoclimate records and 15 otherproposed glacier advances from Svalbard.Furthermore, we introduce 35 additional LGEHglacier deposits identified through remotesensingwereglaciersalsoadvanced intoahighrelative sea level. Glacial deposits were wave-washedor cut by earlyHolocene raisedmarineshorelines, suggesting the landforms weredepositedbeforeorduringhighrelativesealevelstands, thus exhibiting a similar LGEH age.

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Contrary to current understanding, our newevidence suggests that the LGEH glaciers weremore dynamic, exhibited re-advances andextended well beyond the extensively studiedlate Holocene glacial expansion. Given thewidespreadoccurrenceoftheLGEHdepositsonSvalbard,wesuggestthattheculminationoftheNeoglacialadvancesduringtheLittleIceAgedoesnotmarkthemaximumextentofmostSvalbardglaciers since deglaciation; it is just the moststudiedandmostvisibleinthegeologicalrecord.

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10Beand26AlexposureandburialhistoriesforancientgranitetorsinarcticFinland.

AdrianHall1,MarcCaffee2,KarinEbert1,JakobHeyman3andJohanKleman11DepartmentofPhysicalGeography,StockholmUniversitySE10691StockholmSweden,2PurdueRareIsotopeMeasurementLaboratory,PurdueUniversity,525NorthwesternAvenue,WestLafayet,3DepartmentofEarthSciences,UniversityofGothenburg,POBox460,SE40530GöteborgSweden

The ice-divide zone of northern Finlandexperienced low erosion beneath successivecold-basedFennoscandianicesheets(Halletal.,2015).Oneindicatorofthisarethemanytorsthatoccuronhilltopsandflanks.Published10Beand26AlinventoriesfortwotorsummitsurfacesnearVuotsoindicate~0.8Myrofexposureandburial(Darmodyetal.,2008).Thesesamplescamefromtabulartorsthatmayhavelostgranitesheetstoglacialerosion.SchmidtHammervaluesarehigh,indicating limited weathering of these rocksurfacesdespiteapparentlylongexposure.Hencepublisheddatamayrelatetooneormorephasesof glacial erosion rather than to tor surfaceerosion. In contrast, nearby tors retain delicatesuperstructures and give low rock hardnessvalues,featuresconsistentwithlittleornoglacialmodification, more advanced weathering andlongerexposureof the tor summit surfaces.Wewillpresentnew10Beand26Alisotoperesultsforthese surfacesanduseMonteCarlo simulations

to derive Pleistocene exposure and burialhistories.Weexpectbedrockerosionratestobeamongst the lowest reported for the northernFennoscandianshield.

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ConstrainingtheevolutionofthelastEurasianicesheets:progresstowardsDATED-2

AnnaHughes1,RichardGyllencreutz2,JanMangerud1andJohnIngeSvendsen11UniversityofBergen&BjerknesCentreforClimateResearch,2StockholmUniversity

In 2016 we published an empiricalreconstruction of the evolution of the extent ofthe last Eurasian ice sheets, that is fullydocumented, specified in time, and includesuncertainty estimates (DATED-1; Hughes et al.2016). This was the culmination of a 10-yearefforttocompileandarchiveallpublisheddatesrelatingtothebuild-upandretreatoftheBritish-Irish, Scandinavian and Svalbard-Barents-KaraSeas ice sheets.Over5000dateswere assessedforreliabilityandused, togetherwithpublishedgeomorphology-based ice-sheet marginpositions, to reconstruct time-slice maps of iceextent for every 1000-years 25-10 ka and fourperiodsbetween40-27ka.Alluncertainties(bothquantitative and qualitative e.g. precision andaccuracy of numerical dates, correlation ofmoraines, stratigraphic interpretations) werecombined based on our best glaciological-geologicalassessmentandexpressedintermsofdistanceasa ‘fuzzy’margin.Since theDATED-1census (1 January 2013), the volume of newinformation(frombothdatesandmappedglacialgeomorphology) has grown significantly (e.g.32%increase in thenumberofdates),althoughthe spatial distribution of information remainssimilar. Here, we present work towards anupdated version of results,DATED-2 (census: 1January 2017), that attempts to further reduceandexplicitlyreportalluncertaintiesinherentinthe ice sheet reconstructions, and discuss theimplicationsoftherevisedmargins.

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LocalicecapsresponsetoHoloceneclimatevariabilityinKobbefjord,WestGreenland

NicolajK.Larsen1,AstridStrunk1,LauraB.Levy2,JesperOlsen3,AndersBjørk4,TorbenLLauridsen5,ErikJeppesen5andThomasA.Davidson51DepartmentofGeoscience,AarhusUniversity,2DepartmentofGeology,HumboldtStateUniversity,3DepartmentofPhysicsandAstronomy,AarhusUniversity,4NaturalHistoryMuseumofDenmark,UniversityofCopenhagen,5DepartmentofBioscience,AarhusUniversity

Thesensitivityofglaciersandicecaps(GICs) inGreenland toprolongedwarmperiods ispoorlyconstrainedandgeologicalrecordsdocumentingthe long-term glacial history are needed to putrecent observations into a broader perspective.Herewereporttheresultsfromthreeproglaciallakeswherefluctuationsinlocalglacierslocatedat different altitudes in Kobbefjord, southwestGreenlandhavebeenrecorded.Ourresultsshowthatthelakesreceivedmeltwaterfromtheinitialdeglaciationofthearea~9.2cal.kaBPuntil~8.7-7.9cal.kaBPwhenthemeltwaterinputceasedastheglaciersmostlikelydisappeared.Regrowthofglaciersbeganagainat~5.5cal.kaBPat~1,370ma.s.l.,~3.6cal.kaat~1,170ma.s.l.,and~1.6cal. ka BP at ~1,000 m a.s.l., clearly reflectingstrongaltitudinalcontrolof theGICresponsetoNeoglacialcooling.OurresultshighlightthatGICsin Kobbefjord, southwest Greenland areprimarily influenced by changes in summer airtemperatures andwinter precipitation and thattheyarefacingarapiddecaythatmostlikelywillresult in their disappearance within the nextcenturiesasaconsequenceofglobalwarming.

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DeglaciationpatternsoftheLakeDistrictIceLobeoftheScandinavianIceSheetinSEFinlandduringtheYoungerDryas

JuhaLunkka1,NikoPutkinen2andAnuSeppänen21GeoscienceResearchUnit,OuluMiningSchool.P.O.Box3000,FI90014UniversityofOulu,Finland,2GeologicalSurveyofFinland,P.O.Box97,FI-67101,Kokkola,Finland

Thedeglaciationpatternof theLakeDistrict IceLobe(LDIL)oftheformerScandinavianIceSheet(SIS)intheSalpausselkäzone,southernFinlandwerestudied.Glaciofluviallandforms(i.e.eskers,glaciofluvial deltas and subaquatic fans andsandurs) were mapped using Digital ElevationModel(DEM)datawith10metre-resolutionandLightDedectionAndRanging(LiDAR)datawith2metre-resolution.HillshadingwasusedtomakeaDEM-generated3D-landscapeinordertohelptherecognition of landforms and their surfacedeformation. Based on these observations icelobe re-advance and retreat phases, and theirextentacrosstheSalpausselkäzoneweredefined.

The results indicate that the LDIL of the SISretreated as far as 40 kilometres north of theproximalsideofthepresentSecondSalpausselkäridgemostlikelypriortotheYoungerDryas.Thisretreatphasewasfollowedbyare-advanceandthedepositionoftheFirstSalpausselkäinfrontoftheLDILicemargin.Subsequently, iceretreatedfurther north and the Second Salapusselkä infront of the LDILmarginwas formed. Opticallystimulated luminescencedates indicate that theSecond Salpausselkä was deposited during theYoungerDryas.

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MolluscsshowanearlyandexceptionalwarmHoloceneThermalMaximumaroundSvalbard,whichisnotfoundinclimatemodels

JanMangerud1andJohnIngeSvendsen11Dept.ofEarthScience,Univ.ofBergen,NorwayandBjerknesCenterforClimateResearch

Severalspeciesofshallow-watermarinemolluscsthatcannotpresentlylivearoundSvalbardduetothecold-climateoccurfrequentlyinraisedEarlyHolocenedeposits.Themostwarmthdemandingofthesespecies,Zirfaeacrispata,currentlyhasanorthern limit1000kmfarthersouth.Basedonradiocarbonagesofthisspeciesweconcludethatthe August temperatures on Svalbard were asmuch as 6 °C warmer than today during theperiod 10,200 to 9,200 calendar years ago(Mangerud&Svendsen2017).Thebluemussel,Mytilusedulis,re-appearedonSvalbardin2004,inresponsetotherecentwarmingoftheArctic.This happened almost 4000 years afterMytilusdisappeared from the shores of Svalbard,excluding a short re-appearance during theMedievalWarmPeriod900yearsago.After thelast Iceage,Mytilusarrived for the first time inSvalbardasearlyas11,000yearsago,indicatingthat the climate was then as least as warm astoday.

Ifwe, as an example, postulate that thewinterprecipitationpatternduringtheperiod10,200–9,2000 years ago was similar to the presentpattern, thena summerwarmingof6 °Cwouldhaveraisedtheequilibriumlinealtitude(ELA)onglaciersbyabout900meters,andallglaciersonSvalbardwouldhavemeltedaway.

Wealsonotethatclimatemodelssimulateamuchlater and not-so-warm Thermal Maximum

compared with our reconstruction when icesheets,oricesheetsandmeltwater,areincludedinthemodels(Zhangetal.2016).

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Localordistantcentreofuplift,acasestudyfromNorthwestIceland

HreggviðurNorðdahl11InstituteofEarthSciences,UniversityofIceland

Contemporarystudiesofglacio-isostaticupliftattheVatnajökullglacierinIcelandhaverevealedamoreor less instantaneousacceleratingratesofupliftashighas35mm·a-1duetonegativeglaciermass-balance. During the late Weichseliandeglaciation of Iceland, uplift rates exceeded160mm·a-1 when relative sea-level regressedfromthemarinelimitinWestIcelandsome14.7calkaBP.

GlacialstriaeinNorthwestIcelandarearrangedin an apparent radial pattern with the striaeorientated towards the outer coasts of NW-Icelandimplyingthatthestriaewereformedbyactively eroding glaciers retreating towards thecentreof thepeninsula.NumericalmodellingoftheWeichselianretreatoftheIcelandicIceSheet(IIS) has returned local ice-caps in NW Icelandwhen the IIS reached a temporaryminimum inBølling-Allerød times. Thus, the existence ofindependent late Weichselian ice-caps in NWIceland seems plausible and also that theyinfluenced glacio-isostatic uplift in the area,especiallywhenconsideringtemporalandspatialisostaticequilibriumduringdeglaciation.

Raised shoreline features are found throughoutlowland areas ofNW Iceland frompresent sea-level andup toor slightly above80ma.s.l. Theaim of this paper is to examine if altitudes ofraisedshorelinescanbeusedtodecideifglacio-isostaticupliftoftheNWIcelandwascontrolledbyreducedcrustalload(uplift)ofalocalicecap

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or if, and then to what extent, the uplift wasinfluenced by the wastage of the IIS in centralIceland.

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YoungerDryasicemarginretreattriggeredbywarmingoftheoceansurfaceincentral-easternBaffinBay

MimmiOksman1,KaarinaWeckström2,ArtoMiettinen3,StephenJuggins4,DmitryDivine3,RebeccaJackson5,RichardTelford6,NielsJ.Korsgaard7andMichalKucera51DepartmentofGeosciencesandGeography,UniversityofHelsinki,Finland,2DepartmentofEnvironmentalSciences(ECRU),UniversityofHelsinki,Finland,3NorwegianPolarInstitute,Norway,4SchoolofGeography,PoliticsandSociology,NewcastleUniversity,UK,5MARUM-CenterforMarineEnvironmentalSciences,UniversityofBremen,Germany,6DepartmentofBiology,UniversityofBergen,Norway,7NordicVolcanologicalCenter,InstituteofEarthSciences,UniversityofIceland,Iceland

TheGreenlandIceSheetstabilityislinkedtofast-flowing icestreams thatarestrongly influencedbyseasurfacetemperatures(SSTs)attheirfront(Hollandetal.2008;Nicketal.2013).Astheicemass loss from the Greenland Ice Sheet isaccelerating (Shepherd et al. 2012), there is aneed for high-resolution marine proxy data tounderstand interactionsbetween theoceanandthe ice sheet.Herewepresent the firstdiatom-based high-resolution quantitativereconstruction of sea surface conditions fromcentral-eastern Baffin Bay covering the periodfrom 14.0 to 10.2 kyr BP. Our reconstructionrevealswarmerseasurfaceconditionsfrom13.4kyr BP to the end of the Younger Dryas (YD)period (11.7 kyr BP) and strong interactionbetween the ocean and theWest Greenland icemargin. These warmer ocean conditions werecaused by an enhancement of Atlantic-sourcedwater inflow togetherwith increased insolationand amplified seasonality. Our sediment record

showsthatwarmeroceanconditionsplayedkeypartintheretreatofJakobshavnIsbræ,oneofthelargesticestreamsinWestGreenland,whichhasbeen shown to have collapsed at 12.2 kyr BP(Rinterknechtetal.2014).OurresultsshowthaticeretreatoccurredmainlybycalvingduringtheYD period while surface/subsurface meltdominatedduringawarmer climatebeforeandafter theYD.Our results emphasize theocean`ssignificant role for ice sheet stability under thecurrentclimatechange.

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MarineenvironmentalchangesinfrontoftheScandinavianIceSheetduringthelastdeglaciation

NadineQuintanaKrupinski1,AndreasMackensen2,YasminBokhariFriberg1,Karen-LuiseKnudsen3,Anne-SophieFanget3,JeroenGroeneveld4,EllenMartin5,Marit-SolveigSeidenkrantz3andHelenaFilipsson11LundUniversity,2AlfredWegenerInstitute,3AarhusUniversity,4MARUM,UniversityofBremen,5UniversityofFlorida

TheKattegat-BalticSearegionshowsevidenceofstrongcouplingwithNorthAtlanticclimateoverrecentglacial-interglacialcycles,but insufficientlong,high-resolutionBalticareaclimaterecordshave limited evaluating such links. New ultra-high-resolution sediment cores collectedduringIODPExpedition 347 can provide such records,including foraminiferal and molluscgeochemistry records reflecting seawaterenvironmental changes directly adjacent to theScandinavian Ice Sheet (SIS) during the mostrecentdeglaciation.

Wepresentbenthic foraminiferal stable isotope(δ18Oandd13C)andtraceelement(Ba/Ca,Mn/CaandMg/Ca)recordsaswellasmolluscSrisotopedata from IODP Site M0060 (located betweenSwedenandDenmark in thesouthernKattegat)toconstrainbottomwatersalinity, temperatureand oxygenation changes from ~18-13ka.Because of the large salinity changes (fresh tomarine)during thepast20ka in this region,we

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interpretδ18Oasreflectingsalinitychangesmorethan temperature here, while d13C reflectsventilation, productivity, and salinity. Ba/Ca,Mn/Ca, and Mg/Ca may indicate salinity,oxygenation, and temperature variations,although these proxies are less straightforwardtointerpretinthissetting.

Stable isotope results suggest fjord-like, poorlyventilated conditions during early deglaciation,withthreeclearphases:1)aninitialrapid,largefreshening event; 2) subsequent slower, step-wisefreshening(likelylinkedtothedecayoftheSIS); 3) more marine, ventilated, salineconditions after ~15.6ka. These events may belinked to regional and global climate changesduringthisperiodofglobalclimatechanges,andmayhelpusevaluate the interplaybetween theSISandclimateintheNorthAtlanticandbeyond.

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NewinsightsintotheglacialandclimatehistoryofthePolarUrals,ArcticRussia

CarlRegnéll1,John-IngeSvendsen1,HaflidiHaflidason1andJanMangerud11DepartmentofEarthScienceandBjerknesCentreforClimateResearch,UniversityofBergen,Norway

Here we present new results and discoveriesfromseveralfieldcampaignsinthePolarUralsofArctic Russia. This talk focus on the lateWeichselian and Holocene glacial and climatehistory as inferred from a 24 m long, partlyvarved, high resolution and exceptionally welldatedsedimentcorefromadeeplake(BolshoyeSchuchye)locatedintheinteriorofthemountainchain.Thecore,that isspanningthelast24,000years,provideauniquehighresolutionrecordoftheclimateandenvironmentalchangessincetheLast Glacial Maximum (LGM). Our results inferglacialinfluenceonlakesedimentationincludingannual rhythmites, i.e. varves, through theLGMuntilabout19kawhenthecontinuoussequenceof varves successively disappear and thesedimentationratedecrease.Weconcludethatalllocal glaciers within the catchment had melted

awayby15kaandtherearenoindicationsthataregrowth of glaciers took place during theYounger Dryas. A significant warmer climateprevailed during the Holocene period. ThecombinationofAMS14C-andvarvechronologyinthisstudyhasprovidedavaluablecontributiontoconstrain the age model for ongoingpalynological-, paleomagnetic, DNA- andcompound specific isotope (δ2H, δ18O) analysesalso conducted within the framework of theCHASE-(ClimateHistoryoftheArcticSeaboardofEurasia) project. Put together, this continuousand unprecedented high resolution recordeffectively supplement previous attempts toreconstruct pre-Holocene environmentalchanges based on fragmentary data frommoraines and exposed strata along river banksandcoastalcliffsaroundtheRussianArctic.

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Relativesea-leveldataasaconstraintofHoloceneicesheethistoryinFinderupLand,NEGreenland

AstridStrunk1,AndreasNilsson2,Marit-SolveigSeidenkrantz1,BenoirLecavalier3,GlennMilne4andNicolajK.Larsen11DepartmentofGeoscience,AarhusUniversity,Denmark,2DepartmentofGeology,LundUniversity,Sweden,3DepartmentofPhysicsandPhysicalOceanography,MemorialUniversity,St.John's,Canada,4DepartmentofEarthandEnvironmentalSciences,UniversityofOttawa,Canada

Here,wepresentanewrelative sea level (RSL)reconstructionforFinderupLand,NEGreenland,based on isolation basins to obtain moreknowledge about the Lateglacial and Holoceneglaciationhistory.ExistingRSLdataisingeneralsparse in NE Greenland and the RSL curvesproducedatnearby locationsarebasedonverylimiteddata1,2.Itisimperativetounderstandhowthe large ice sheets responded to a warmingclimate in the past, in order to make accuratepredictions of future sea level change.Reconstructionsofpastrelativesealevelchangesis a key parameter inmodeling global sea levelfluctuationsunderpastclimatechanges1,3,4,5.

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We present a new dataset of isolation lakescoveringelevationsfrom8-62ma.s.l.inwhichweidentify themarine to lacustrine environmentaltransition. We date this transition usingradiocarbon ages from foraminifera combinedwith paleomagnetic age correlation. Our newdatasetwillallowustoconstructaRSLcurveforFinderup Land, which in turn reflects theLateglacial and Holocene ice marginalfluctuations in NE Greenland. Furthermore, wecompareourresultswithexistingpredictionsofpastRSLintheareaproducedbytheHuy2(ref.6)andHuy3 (ref. 1) ice sheetmodels and discusspossibleimprovementsoftheicesheetmodelsbyincorporatingournewdataset.

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DeglaciationhistoryofwesternNorwayinferredfrom10Be-datingoferraticsand14C-datesfromsedimentcores

JohnIngeSvendsen1,JanMangerud1andJasonP.Briner21Dept.ofEarthScience,UniversityofBergenandBjerknesCentreforClimateResearch,2Dept.ofGeology,UniversityatBuffalo,USA

We report new results from an ongoing fieldcampaign in southern Norway aiming atreconstructing the glacial and climate historysince the Last Glacial Maximum (LGM). Theinferred ice sheet history is based on a largenumber of cosmogenic nuclide exposure ages(10Be)fromglaciallytransportedbouldersaswellas sediment records from lake basins. We findthat all coastal mountains in the studied areawereicecoveredduringtheLGM,atwhichtimethe Scandinavian Ice Sheet was flowingwestward, independent of the underlyingtopography.Later,thefastflowoftheNorwegianChannel Ice Stream led to a lowering of the icesurface. The highest mountain peaks along theHardangerfjordenbecameicefreeasearlyas~20ka. Following the collapse of the NorwegianChannelIceStream,theicemarginstabilizedjustoutsidetheoutermostcoast.Amajorwithdrawaltook place ~15 ka, possibly in response to the

Bøllingwarming(Gumpetal.2017,Mangerudetal. 2017). The retreat was later interrupted bytwore-advances that culminated~14ka (OlderDryas)andduringtheendofYoungerDryas.Wefind 10Be- dating a very useful tool for makingthree-dimensionalicesheetreconstructions.Thefront of the ice sheet seems to have beensurprisingly steep. In the Bergen area the icesurfaceappears tohavereachedanelevationofmore than 700 m only some 15 km inside thefront. However, in low-lying areas radiocarbondating of basal lacustrine sediments providesmore precise and accurate dates of thedeglaciation.

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TheMineralAssemblageofGas-chargedsedimentsfromVestnesaRidge,NWSvalbard–ataleofcrystallizationanddissolution

ChristophVogt1,SimoneSauer2,AivoLepland3andJochenKnies41Crystallography,Geosciences,UniversityofBremen,Germany,2CAGE–CentreforArcticGasHydrate/UiTTromsø&TheGeologicalSurveyofNorway,Trondheim,Norway,3CAGE/UiTTromsø&TheGeologicalSurveyofNorway,Trondheim,Norway&UniTallinn,Lettland,4CAGE/UiT-Tromsø&TheGeologicalSurveyofNorway,Trondheim,Norway

We present a full-pattern quantitative phaseanalysisofx-raydiffractiondata(QXRD,Vogtetal.,2002)fromsedimentstakenwithintheactivemethane seep sites of Vestnesa Ridge, NWSvalbard.The4coringpositionswerecontrolledbyremotelyoperatingvehicle(ÆGIR6000)withthree siteswithin the active seep sites and onereferencesiteoutsidethemainactivity.Hence,acleardifferentiationbetweenactiveandinactivewithrespect tomethanegas fluxcanbeshown.While the reference core can be related towellknowsedimentaryeventsinthevicinityoftheWSpitsbergenshelfandYermakPlateau–whicharerelated to warm Atlantic water influx and/ordeglaciation of the Svalbard ice sheets - gas-hydrate influenced cores contain particularcarbonate mineral phases. Mg-rich calcites and

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aragoniteshavebeen freshlyprecipitated in thevicinity of a sulfide methane transition zone(SMTZ) triggered by anaerobic methaneoxidation (AOM) and sulfate reduction due tohighmethanefluxthroughthesediments.

TheQXRDallowsalsofortheinvestigationofFe-,Mn-oxidesand–sulfidesprobablyprecipitatedinthe transition zones under changing redox-conditions. Combined with sediment and porewater geochemistry, the authigenic mineralassemblage indicative for a gas-hydrateinfluenced sediment can be described in muchdetail. While geochemical processes can bequantitatively viewed, the high resolutiondeterminationof authigenicminerals alsohelpsto understand the past history of methaneemissionsinthisArcticgashydratesystem..

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Fromfjordtoland–HoloceneclimateoftheFemmilsjøenarea,NESpitsbergen

LisAllaart1,AndersSchomacker2,MatthiasForwick3,MichaelRetelle4andLenaHåkansson51UiTTheArcticUniversityofNorway&UniversityCentreinSvalbard,2UiTTheArcticUniversityofNorway&NaturalHistoryMuseumofDenmark,3UiTTheArcticUniversityofNorway,4BatesCollege,ME,USA&UniversityCentreinSvalbard,5UniversityCentreinSvalbard

TheoverallaimoftheprojectistoreconstructtheHoloceneclimateandglacialhistoryofnortheastSpitsbergen, based on a holistic approachincluding collection and integration of marine,terrestrialandlacustrinedata.Theareaofmaininterestisthe8kmlonglakeFemmilsjøeninNESpitsbergen,aswellas itssurroundingsandtheadjacent part of northernWijdefjorden. Marinesedimentcoresandswathbathymetrydatawerecollected justoffFemmilsjøen in thesummerof2017. Lacustrine cores are to be collected in2018. Weexpectthatdataseriesfromdifferentarchiveswith restrictedspatialdistributionwillreflectthevariousfeedbackmechanisms(e.g.theinteraction between ocean-atmosphere,

atmosphere-sea-ice, precipitation-ice-masses,increasedrunofffromglaciersandsolarforcing)ofthedifferentelementsintheclimatesysteminthat particular area. This will help to solvequestionsaswhethertheLatePleistocene-EarlyHolocenefjordtemperaturesincreasedfirstandsubsequently theglacierson landretreated-orviceversa.Furthermore,weaimtoidentifyifthesame climatic signals occur in both archivessynchronously. Preliminary results from theprojectwillbepresented.

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Sea-iceintheIceland-NorwegianSeaduringthelast50-60000years:firstresultsfromtheIS-4Cmarinecore

ErnaÓskArnardóttir1,EstherRuthGuðmundsdóttir1,JónEiríksson1,ÍvarÖrnBenediktsson1andYanguangLiu21InstituteofEarthSciences,UniversityofIceland,Askja,Sturlugata7,IS-101Reykjavík,Iceland,2FirstInstituteofOceanography(FIO),StateOceanicAdministration,Qingdao,China

Sea ice coverage in the North Atlantic plays animportantroleintheArcticclimatesystem.

The aim of the study presented here is toreconstruct and time sea ice coverage in theIceland-Norwegian sea during the Weichselianwiththepurposeofincreasingourunderstandingofclimateandoceanographicchanges.Theareaishighly affected by the cold southward flowingEast Greenland current and a branch of thewarmer north-westward flowing Norwegiancurrent, creating a complex zone of temperateandcoldwaters.

A 430 cm long marine sediment core, IS-4C,retrieved from 1598 m water depth in theIceland-Norwegiansea,northeastof Icelandhasbeen investigated with regard to quantity andsource of ice rafted debris (IRD) aswell as theabundance of planktonic foraminifera. Theseproxies have been counted at every 2-3 cmthroughoutthecore.Radiocarbondatingindicatethattheupper251cmofthecorerepresentthe

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last42000yearsandtheVeddeAshispresentintheuppermost 30 cm.Moreprecise chronologywith radiocarbon dating, tephrochronology andcorrelation of oxygen isotopic records fromGreenlandicecoresandtheNorthAtlanticdeepseaisinprogress.

IRD has been identified to three maincomponents; crystals, rock fragments andash/tephra. Planktonic foraminifera have beencountedandidentifiedtospecies.Theseproxiesdisplayhighamplitudevariationsthroughoutthecoreindicatingvariableseaiceflux.Alowseaicefluxisrecordedbetween184cm(39500yr.BP)and294cmindicatinganinterglacialperiod.Theinvestigationisongoing.

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AnewrelativesealevelcurvefromMestersvig,NEGreenlandbasedonisolationbasins

FrankBauer1,AstridStrunk1,SarahWoodroffe2,AnneSophieSøndergaard1andNicolajK.Larsen11DepartmentofGeoscience,AarhusUniversity,HøeghGuldbergsGade2,8000AarhusC,Denmark,2EnvironmentalResearchCentre,DepartmentofGeography,UniversityofDurham,SouthRoad,Durham,UK

Our ability to model the past response of theGreenland ice sheet to climate change isfundamentally dependent on the quality anddistribution of geological observations of icemargin history and relative sea level (RSL)observations.InGreenland,theextensiveice-freecorridor provides an excellent opportunity todevelop a network of well constrained RSLobservations that can provide powerful glacio-isostatic adjustment (GIA) constraints over thepost-glacial period. In southern Greenland, theRSL observations are in many places wellconstrained in contrast to northern Greenlandwhere thedataquality and spatial resolution ispoorer.Inthisstudy,wepresentanewRSLcurvefromMestersvig,NortheastGreenland.Weusedsediment cores from seven isolation basinscollected at different elevations to identify the

change from marine to lacustrine sedimentsusingamultiproxyapproachincludingXRFcorescanning, magnetic susceptibility and diatomanalysis. The marine-lacustrine isolations weredated using terrestrial macro fossils. Our newresultswill be compared toexistingRSL curvesfromtheareaandwith the latestRSL-based icesheetmodelofGreenland.

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PutoranaicesheetadvanceoversouthernTaimyr,NWSiberia,duringtheLateSaalian(MIS6)

IvarBenediktsson1andPerMöller21InstituteofEarthSciences,UniversityofIceland,2DepartmentofGeology,LundUniversity

PreviousstudiesinNWArcticSiberiasuggestthatlocal icecapsaroundtheKaraSeashelfmergedthere repeatedly to form a Kara Sea Ice Sheet(KSIS). When assembled to a large ice sheet,initial northward flow from the ByrrangaMountainsontheTaimyrPeninsulareversedasthe icesheet furtherexpandedsouthwards.Themost extensiveglaciationoverTaimyroccurredduring the Taz/Late Saalian (MIS 6), duringwhich the KSIS advanced from NW onto thePutorana Plateau south of Taimyr. However,stratigraphic sites along theBol’shayaBalaknyaRiver(situatedonsouthernTaimyr)suggestthattheTaz/LateSaalianexpansionoftheKSISfromNW was preceded by ice coming from thePutoranaPlateautothesouth,aconclusionbasedon our site BBR 16. This site reveals a finingupwardssequencefromfluvialsandstoshallowglaciomarine mud with shell fragments, datedwith ESR to 171 ka BP. This sequence isglaciotectonically deformed and unconformablyoverlain by subglacial traction till. Theglaciotectonicdeformationaswellasclastfabricsin the overlying till, indicate stress applicationfromsoutherlydirections.OurpreliminarymodelsuggestsamarinetransgressionduetoagrowingPutorana ice sheet, before it overrode southernTaimyr during the Late Saalian (MIS 6). Thisoccurred at the same time as a KSIS advanced

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fromthenorthbeyondtheByrrangaMountains.TheKSISsubsequentlymergedwiththePutoranaice sheet and eventually pushed the maximumextent of Late Saalian ice well south of thePutoranaPlateau.

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Faciesmodelforareboundcyclebasedonmid-lateQuaternarysedimentsintheKongsfjordenarea,NWSvalbard

MonaHenriksen1,HelenaAlexanderson2,HeidiT.Ryen3,JonY.Landvik1andGustafPeterson41NorwegianUniversityofLifeSciences,2LundUniversity,3NorwegianWaterResourcesandEnergyDirectorate,4GeologicalSurveyofSweden

Raisedmarinedepositsfoundincoastalareasofthe Arctic have been instrumental inreconstructing past sea-level change andglaciations during the Quaternary. This isbecause the high relative sea level indicated bythemarine sediments is largelydue to isostaticloading and thus implies a preceding regional(ice-sheet scale) glaciation. Kongsfjordhallet isoneof several sites in theKongsfjorden area inNW Svalbard with such deposits, and wheresuccessionsofQuaternarysedimentsareexposedinupto40mhighcoastalcliffs(Houmark-Nielsen&Funder1999).Here,wepresentresultsfromamore detailed sedimentological andstratigraphicalinvestigationoftheuppermost15m of Kongsfjordhallet.While subglacial tills arescarce, marine and littoral sediments arevolumetrically dominating, representing partialshallowing-upward sequences. Interestingly,wealso findalluvialandperiglacialdeposits,whichare not commonly recognized in this type ofsettings.

Basedonthisrecordwehavefurtherdevelopedthe facies model for rebound cycle byAlexandersonetal. (2011).An idealizedrecord,representing glacial advance and overriding(facies A), deglaciation with isostatic reboundandsuccessivelyshallowerwater(faciesB-E)andeventually fluvial and periglacial processes

(faciesF)onice-freeland.Evenifonlyafewofthefacies are actually found per sequence, it stillimpliesaregionalglaciation.AtKongsfjordhallet,five cycles of glaciation and subsequentdeglaciation during high but falling relative sealevels are recognized. These are dated byluminescencetorangeinagefrom~190katothelast deglaciation (Alexanderson et al., thisvolume).

POSTER

TheWeichselianchronostratigraphicalframeworkoftheKongsfjordenTroughMouthFan,W-Spitsbergen

DanielHesjedalWiberg1,HaflidiHaflidason2andJanSverreLaberg11DepartmentofGeosciences,UiT–TheArcticUniversityofNorwayinTromsø,N-9037Tromsø,Norway.,2DepartmentofEarthScience,UniversityofBergen,Bergen,Norway

The high-latitude Kongsfjorden Trough-MouthFan (TMF), situated on the continental marginwest of Svalbard was fed by the Kongsfjordenpaleo-ice stream system. A placement, which isideally suited for recording glacial advances totheshelfbreakand thereby thedevelopmentofthe Svalbard Ice Sheet through time. During asurvey in 2010, a regional seismic grid wasestablished, consisting of 17 high-resolutionseismic 2D lines (TOPAS). There were alsoretrieveda12.65meterlongsedimentcorefromthesouthernpartoftheKongsfjordenTMFat846mwater depth. Our preliminary conclusion fitswell with the earlier proposed developmentmodels, which indicates that during theWeichselian glacial (117 – 11.6 ka), paleo-icestreams from the west coast of Spitsbergenadvanced to the continental shelf-break threetimes.Thenewdataacquiredallowus to studythe last two advances in greater detail thanpreviously available. The upper half of the coredisplays a very varied character, with layerscomprising ice rafteddebris (IRD) inter-beddedwith hemipelagic sediments,where the interval

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between2–5mhavebeendatedwithAMS14C.Ananomalous layer (at270-335cm)havebeenestimated tohaveanagebetween23,3–25ka,and is interpreted to comprise sediments fromthelastglacialmaximum(LGM).Thelowerhalfofthecoreappearsvisuallyfairlyhomogenous,buthave been interpreted to consist of alternatinglayers of GDFs and IRD related to the secondadvance during themid-Weichselian, estimatedtohaveoccurredfromabout70ka.

POSTER

EvolutionofGreenland’sglaciersandicecapsinthe20thcentury

NielsJ.Korsgaard1andMiskaLuoto11UniversityofHelsinki,DepartmentofGeosciencesandGeography

About 20,000 glaciers and ice caps (GICs)surround the Greenland Ice Sheet. These GICscover7%oftheglaciatedareainGreenlandbutstore less than 1%of the total ice volume. It isestimatedthat14-20%ofthetotalicelossfromGreenland between 2003-2008 could beattributedtotheGICs,thereforetheycontributefarmoretoglobalmeansealevelrisethantheirsize relative to the Greenland Ice Sheet wouldsuggest. They could make a significantcontributioninthe21stcentury,astheyaremoresensitiveclimateindicatorsandadjusttheirsizeinresponsetoclimatechangemorerapidlythanice sheets. Estimates for the 20th century thatpredatesthemodernageofremotesensing,userecords from half a score of GICs to obtainestimates of the mass loss for Greenland as awhole. This has implications for ourunderstanding of past glacier evolution and itscoupling to climate, and hence also limits ourabilitytopredictthefuture.Thisprojectaimstoproducean improvedobservationaldataset forphysicalandstatisticalmodellingoficelosswithregionalgranularity.Therecordwillextendbackto the Little Ice age, when the GICs began toretreatfromtheirmaximumpositions.Dataandmodelswillbedevelopedtofacilitateananalysisof factors driving GIC evolution in the 20th.Finally, the data will be used as input for

inversion modelling of glacier evolution of asubsetoficecapsenablingaforwardsimulationoffuturebehavior.

POSTER

PaleoceanographicoceansurfaceconditionsinKongsfjorden,Svalbardoverthelast400years

TiiaLuostarinen1,ArtoMiettinen2,KatrineHusum2,DmitryDivine2,SeijaKultti1,OutiHyttinen3andRahulMohan41DepartmentofGeosciencesandGeography,UniversityofHelsinki,2NorwegianPolarInstitute,Tromsø,Norway,3DepartmentofGeosciencesandGeography,UniversityofHelsinki;GeologicalSurveyofFinland,Espoo,4NationalCentreforAntarcticandOceanResearch,MinistryofEarthSciences,Goa,India

Marine subfossil diatom assemblages fromKongsfjordenareusedtoinvestigateseasurfacetemperatures(SST)andseaicevariabilityinhightemporal resolution. The oceanographicconditions in Kongsfjorden are strongly relatedto the characteristics of the West SpitsbergenCurrent(WSC),transportingAtlanticWater(AW)andthereforeheatandsaltintotheArcticOcean(Svendsenetal.,2002).ChangesintheAWinflowcanhaveamajor impacton theenvironmentofthe Svalbard area (Ślubowska-Woldingen et al.2007).

A49cmlongmarinesedimentcorewasanalyzedfor diatoms and grainsize at 1.0 cm intervals.Diatoms were abundant in the top 16 cm. TheAMS14Cdatessuggestthebasalageofca.400calyr. BP. The diatom-based SST reconstructionbased on the North Atlantic surface sedimentsamplecalibrationdataset(Miettinenetal.2015)andWAPLStransferfunctionmethod(TerBraakand Juggins 1993) indicates temperaturevariation between 4.1 to 6.0 ˚C with a meantemperature of 4.8 ˚C. The qualitative sea icereconstructionisbasedontheMarginalIceZone(MIZ) diatom assemblage. Factor analysis withthe North Atlantic diatom factors based onAndersen et al. 2004 was used to estimate the

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variability of water masses. The preliminaryresultsshowacoolingtrendinbothSSTandseaice since the Little Ice Age, and a very recentwarming during the past decades. Grain size isdominatedby fine fraction, but in theupper15cm coarse fraction increases up to 40 %,indicatingchangeindepositionalconditions.

POSTER

Characteristicsofwave-builtsedimentaryarchivesinBuorKhayaBay(71°N/130°E),SiberianArctic,Russia.

LasseSander1,RuneMichaelis1,SvenjaPapenmeier1,SergeyPravkin2andKarenH.Wiltshire11Alfred-Wegener-Institute,List/Sylt,Germany,2ArcticandAntarcticResearchInstitute(AARI),St.Petersburg,Russia

Progradedsequencesofbeachdepositspreservevaluablepaleoenvironmentalinformationonthelong-term variability of the (wave-) climateforcing driving centennial to millennial coastalevolution.BuorKhayaBay,NESiberianArctic,islocated at the transition between theVerkhoyansk mountain range and the ArcticOcean and is one of the few places along theRussian arctic coast, where wide beach-ridgesystemsexist.TwofieldsitesinBuorKhayaBaywerevisitedduringanexpeditioninAugust2017inordertoobtainbaselineinformationtoassessthe potential of the systems for thereconstructionofHolocenesealevelandpastsea-iceextent.Theinnerpartsofthebayareice-freeforthreetofourmonthsduringtheshortborealsummer.Thewaveforcingofthesystemishencea functionof thedurationof ice-free conditionsand fetch across the open sea surface. Bothsystems are composed of several sets of beachridgescomposedofsand-tocobble-sizedshalesoflocalorigin.Themorphologicalarrangementoflandforms and the characteristics of the beachdeposits evidence (1) extensive periods ofcontinuousprogradation,and(2)unconformitieswith changes in ridge orientation suggesting

fluctuations in the directional components ofenergysupplyandsedimentdelivery.

The project is at an early stage of investigationand we present first insights into a new andpromising area of investigation. Work will becontinuedinsummer2018.

POSTER

IcemarginalfluctuationsoflocalicecapsinMcCormickFjord,NWGreenland

AnneSofieSøndergaard1,NicolajKrogLarsen1,AstridStrunk1andJesperOlsen21Dept.forGeoscience,AarhusUniversity,Denmark,2Dept.forPhysicsandAstronomy,AarhusUniversity,Denmark

Knowledge about the glacial history of theGreenlandIceSheetanditsdynamicresponsetopast climate variability is important to put thecurrent changes into context. In southern andeastern Greenland, a number of recent studieshave documented the ice marginal response toHoloceneclimatevariability (Lowelletal.2013,Larsenetal.2016),butfromnorthernGreenlandthereareveryfewobservations.

Inthisstudy,weuseamultiproxyapproachtotryand constrain the Holocene glacial history inMcCormickFjordinnorthwestGreenland.Duetothe occurrence ofmoraines and the absence ofmarinecontentinseveralretrievedlakecores,wespeculatethattheareamighthasbeensubjectedto an early Holocene ice advance that dammedthearea fromthe inflowofmarinewaters fromthefjord.

During the field season 2016 and 2017 weretrievedsedimentcoresfrom5lakesindifferentelevations, samples for cosmogenic exposuredating from twomoraines, shell fragments andmossesfromthemarginofanearbylocalicecap.Here we present C14 ages and XRF data of 6sedimentcoresandC14datesofmosssamples -the rest of the samples are scheduled to beprocessedinearlyspring2018.

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With the collected data,we expect to obtain anoverview of the deglaciation history inMcCormick Fjord.Wewill discuss the ages anddatainrelationtoexistingclimaterecordsfromtheareaandputthenewresultsintocontext.

8.2. Glacial processes, depositsandlandforms

ORAL

Palaeo-icestreamsinNE-Iceland:anewprojectandthefirstfindings

ÍvarBenediktsson1andÓlafurIngólfsson11InstituteofEarthSciences,UniversityofIceland

Current understanding of the configuration,geomorphological imprint, dynamics andrecessional history of palaeo-ice streams inIcelandislimited.Anewprojectaimstoadvanceour knowledge of palaeo-ice streams in NEIceland by investigating the glacial landformassociations and sedimentary records in theVopnafjörður, Bakkaflói, Þistilfjörður andJökuldalsheiði areas, using multiple glacialgeological, geomorphological, remote sensing,geophysical/geotechnical and chronologicalmethods.Theprojectisdesignedtoelucidatetherelativetimingandspatialdistributionoffasticeflow,theabsolutetimingofice-stream/ice-sheetrecession and thinning, and the mechanismscontributing to fast flow and the genesis ofstreamlinedsubglacialbedforms.Theprojectcanthereby provide insight into marine-ice sheetinstability and the vulnerability of marine-terminating ice streams to sea-level rise, andfurther our understanding of ice sheetdeglaciation dynamics. An important benefit ofthis project will be the value of its results forconstraining numerical models aimed atilluminating subglacial landform developmentandtheevolutionoftheIcelandicesheetduringthelastdeglaciation.

Preliminarymappingsuggeststhattheflowsetsof several apparently cross-cutting former ice

streams are preserved in the glacial landformrecord.Thisincludesonsetzoneswithreticulatedridges and hummocky topography, and trunk-flow zones with elongate subglacial bedforms,rhombohedral ridge-networks and regularly-spaced transverse ridges. Reconnaissancefieldwork in 2017 indicates that elongatesedimentarybedformsconsistofdeformationtilland sorted sediments, and that rhombohedralandtransverseridgesaremainlycomposedoftill.Future excavations and GPR surveys aim atrevealing the internal structure of theselandforms.

ORAL

Interpretationofglaciotectoniccomplexesfromanalysisofthin-skinnedthrust-faultstructuresinseismicsections,anexamplefromtheJammerbugtineasternNorthSea.

LarsOleBoldreel1andStigA.S.Pedersen21IGN,KU,2GEUS

Duringthelastdecade,anumberofglaciotectoniccomplexeshavebeenrecognizedintheNorthSea(Andersen 2005, Bendixen 2016, Larsen &Andersen2005,Novak&Leth2015,Pedersen&Boldreel2017).Themappingofthesecomplexesare merely depending on interpretation ofqualified seismic data,which enables structuralinterpretation. This presentation demonstratesthe complexity of seismic interpretation ofglaciotectonic structures by the investigation oftheJammerbugtGlaciotectonicComplex.

TheJammerbugtGlaciotectonicComplex,easternpartof theNorthSea,occupiesanareaofmorethan300km2 locatedabout10kmoffshore thewest coast of northern Denmark. The bedrockincludedinthecomplexcomprisethemainpartof theCretaceousChalkGroupintheNorthSea.Thedetachment surface in theproximalpart ofthe complex occurs in Lower Cretaceousgreensandabout400mb.s.l.Inthecentralpartofthe complex the thrusting ramps the strongreflectorsatthebaseoftheChalkGroupandthe

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detachmentsurfacecontinuesinthelowerpartoftheUpperCretaceouschalkthroughoutthedistalpart.

The Eemian–Early Weichselian SkærumhedeGrouponlapthedeformedbedsattheboundaryto the tectonicdepressionnorthof thecomplexindicating a Saalian age of the glaciotectonicdeformation.Thecalculationofthedisplacementduring balanced cross section constructiondemonstratesthatthethrustsheetsinthetailingend of the complex had their source in theSkagerrak Sea. Thus, we suggest that the holecaused by displacement of thrust sheetscontributed to formation of the Skagerrakdepression.

ORAL

Computersupported3DmodellingoftheHanklitglaciotectoniccomplex,Mors,Denmark

EmblaGaldal11UniversityofCopenhagen

TheHanklitcoastalcliffisaglaciotectoniclocalitywhereanexcellentcross-sectionthroughathrustfault complex is exposed. The structuralarchitecture and structural features of theglaciotectonic complex is modelled in the 3Dmodellingsoftware,LeapfrogGeo.

The structural elements in theHanklit Complexconsist of thrust sheets interpreted to be theresult of the Norwegian ice advance in a pro-glacial glaciotectonic deformation about 30-28,000 years ago. It consists of a 60m thicksuccessionofEocenediatomiteoverlainby15mof glacial deposits. The Hanklit Thrust Sheetextendsformorethan1kmalongtheW-Estrikeandisdisplacedformorethan300mtothesouth(Klint & Pedersen, 1995). The Hanklit ThrustSheet is thrusted across the foreland featurenamed Gullerup Thrust Sheet, whereas theSalgerhøj Thrust Sheet describes thenorthernmost thrust element ramping up anddisplaced upon the back of the Hanklit ThrustSheet.InthefrontalpartoftheSalgerhøjThrust

Sheetahanging-wallanticlineisdevelopedwithoverturnedlimbs.Thishanging-wallanticlinecanbefollowedfornearly10kmalongthecrestofthehighesthillsonMors.Abalancedcrosssectionisprovided. The depth to the décollement zone isdeterminedandthedisplacedalongtheshallowdippingrampandflatiscalculated.

The Hanklit Thrust Fault Complex is a well-documentedthrustfaultstructure,andthemodelis a good illustration of the thin skinned thrustfault,andcanalsobecomparedtostructuresthatoccurs in mountain ranges like the Juramountains.

ORAL

Diagnosingicesheetgroundinglinestabilityfromlandformmorphology

SarahGreenwood1,LaurenSimkins2andJohnAnderson21DepartmentofGeologicalSciences,StockholmUniversity,2DepartmentofEarthScience,RiceUniversity

Marine-based ice sheet stability is largelydictated by processes at or near the groundingline,wheremarineandglacialprocessesandthetopographic setting govern the duration ofgrounding line occupation and sensitivity toretreat.Landformsthatarebuiltatthegroundingline, such as grounding zone wedges andrecessional moraines, are inscribed extensivelyonformerlyglaciatedcontinentalmargins.Theselandforms directly mark former grounding linepositions over a prolonged period of retreat(thousands of years), represent the history ofsedimentation during the occupation of eachposition, and offer high potential for extractinginformationaboutgroundinglinedynamics.

We characterise the morphological traits andspatial distribution of thousands of groundingline landforms from the Ross Sea continentalshelf, which mark Antarctic Ice Sheet retreatsince the Last Glacial Maximum. Recessionalmorainesindicateaconsistencyofgroundinglineprocesses/setting and regularly forced retreat,

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whilegroundingzonewedgesarehighlyvariablein size and shape, developing both asymmetryand sinuosity during landform growth. Weattributegrowthofsinuositytolateralvariabilityin sediment delivery along the grounding line,linked to basal meltwater drainage. Thisdevelopmentofsinuosityovertimeiscommonlyassociatedwithlarger-magnituderetreatevents.A ‘stable’ grounding line position of relativelylong duration may thus be linked with an‘unstable’retreatevent.Landformconstructionissurprisingly insensitive to the local topographicsetting.Weexploretheprocessescontrollingtheproduction of contrasting grounding linelandformmorphologiesand,consequently,whatthese morphologies reveal regarding the(in)stabilityofaretreatingicesheet.

ORAL

DetailsinglacialterrainsdetectedfromDigitalTerrainModelsbringsnewlightupontheDanishglaciallandscape

MichaelHoumark-Nielsen11CentreforGeoGenetics,NaturalHistoryMuseum,UniversityofCopenhagen,Denmark

Previously unnoticed landforms of formerglaciated terrains in Denmark can now berevealed from studies using Digital TerrainModels(DTMs)providedbytheDanishGeo-dataAgency.Theremovalofbuildings,vegetationetc.fromDEMswith25m,10mand1.6mgridsallowexposure of details in landforms not earliersubjected to investigation. GIS-based studies ofhillshadedDTMs–onlandaswellasontheseafloor –combined with Quaternary geologicalmappinganddatafromopenexposuresaswellastheuseoftherichliteratureontheDanishglaciallandscape and its origin, gives new insight intoglacial landforms, that was formed along thelowland fringes of the Scandinavian Ice Sheetduringthelasttwoglaciations.

In this lecture focus will be on subglaciallandforms and their distribution around the

country. Here single or multiple generations ofstreamlinedterrainwithincreasingsizerangingfrom tens of meters to tens of kilometres arepresented. Other subglacial features includeeskersandtunnel-valleys.Examplesaregivenonthe combination of easily accessible on-landfeaturesandobscured terrainspartlyburiedonthe sea floor into a more whole appearance ofglacial landforms. In order to establish ameaningful and modern model of the ice agelandscapes in Denmark, subglacial terrains arebut one of many pieces of the puzzle and theymust be seen in relation to other glaciallandforms such as terminal moraines, dead-iceland forms and features related to proglacialerosionandlongtimeperiglacialreshaping.

ORAL

Mappingofglaciotectonicstructuresandassociatedsedimentarydepositionwithgroundpenetratingradar

PeterRollJakobsen1,HansLercheandCecilieSkovsøAndersen1GEUS

The analysis of glaciotectonic structures andgeologicalsettingisbestdoneinoutcrops,butastheyarelimitedbothinoccurrenceandinlateralextent, geophysical methods are often used tointerpret thegeology.Groundpenetratingradarhas proven to be an excellent method todetermine sedimentary structures as well asdeformationstructures.

Examples of structural analysis are given fromsmallcompositeridgesinthenorthwesternpartof Jylland created during the general retreat oftheMainGlacialAdvanceinthelateWeichselian.Other examples are given from NorthwestSjællandwheretwogeoradarinvestigationswerecarriedoutintherimofthelargeend-morainesfroma re-advanceof theYoungBalticAdvance,about17.000yearsago.

The radar profiles are differentiated into radarfacies with distinct reflection characteristics.

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Glaciotectonicdeformationssuchas thrustsandfolds are interpreted from the GPR data.Furthermore syn-tectonic and post-tectonicsedimentation is interpreted from the radarprofiles.

The examples show that themorphology of theridges investigated is controlled by thedeformation structures, and thatpenecontemporaneous sedimentary processeshavesmoothenedthemorphologycreatedbythedeformations.

ORAL

Geomorphologyanddistributionofsubglacialtriangularhummocks(murtoos)inSwedenandFinland

MarkD.Johnson1,JoniMäkinen2,GustafPeterson3,AnttiOjala4,Jukka-PekkaPalmu4,KariKajuutti2,ChristianÖhrling3andElinaAhokangas21UniversityofGothenburg,2UniversityofTurku,3GeologicalSurveyofSweden,4GeologicalSurveyofFinland

TriangularorV-shapedhummocksof subglacialorigin have been identified in Sweden andFinlandduetotheincreasedresolutionprovidedby LiDAR imagery. Their triangular shape isdistinctive and recognizable as a clearlyidentifiable landform. These forms have beenpreviously mapped in some cases as dead-icehummocks, but geomorphic relationships witheskers, flutesandDeGeermorainesshowtheseto be subglacial. Good examples of these formsoccurnearMurtoojärvi,Finland,andweproposecallingthesenewlandforms‘murtoos.’Individualmurtoosarediamondandtriangularshapedwiththe axis of the triangle parallel to regional iceflow.Murtooshavealongitudinalspacingon50to200m,andtheirwidthsareontheorderof50to100m.Theyareasymmetricwithagentleup-icesideandasteeperdown-iceside.Often,theyhaveashingledappearance.Inmanycases,theyoccurinpatchesinanice-flowparallelpathwitheskers defining corridors we believe to be ofsubglacialmeltwaterorigin.

Murtoos are composed primarily ofheterogeneousdiamictonwithminoramountsofbeddedsand.

MurtoosarecommoninFinlandandSwedenandwepresentamapoftheirdistribution.Theyseemtobemostcommonwhereice-retreatrateswerehigh during deglaciation, and they are absentwhere extensive frozen-bed conditions werepresent.

ORAL

Theframeworkofglaciotectoniccomplexesandtheirpositionintheglaciodynamicsequencestratigraphy

StigSchackPedersen11GEUS

Theanalysisofglaciotectoniccomplexesusestheclassification of architectural surfaces. Thesecomprise four orders of surfaces (Pedersen2014). The first order includes the décollementzone and the topographic surface,which definethebottomandthetopofcomplexes.Thesecond-ordersurfacesarethethrust-faults,whichboundthethrustsheetsandduplexesthatconstitutetheinternal framework of tectonic complexes. Thethird order comprises foldedbeds appearing intheinternalstructureofthrustsheets.Thefourthorder includes all small-scale structures likejointsandfaultswithminordisplacement,whichare important for the prediction of dynamicdevelopment(Pedersen2000).

For the interpretation of the dynamicdevelopment, three macroscopic regimes aredefined: thedistal, thecentraland theproximalpart of glaciotectonic complexes (Pedersen2005).Inthedistalregimeclosetotheforeland,flat-lyingthrust-faultsdisplacethinthrustsheets.Inthecentralregime,steepdipsof thrust faultsoccur together with hanging-wall anticlines.Towards the proximal part of complexessuperimposed deformation of duplexes occur,which result in vertical orientation of surfaces.Glaciotectonic complexes may includesuperimposed deformation related to

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development in one event or superimposing ofseveral events. Glaciodynamic events aredifferentiated by application of glaciodynamicsequence stratigraphy, which combinesdepositional and structural features (Pedersen2012).

ORAL

Subglacialtilldeformation:lessonsfromlaboratoryexperiments

JanA.Piotrowski1,MiaBeringHoldensen1,WłodzimierzNarloch2,SimonCarr3,AndersDamsgaard4andNicolajKrogLarsen11DepartmentofGeoscience,AarhusUniversity,DK-8000AarhusC,Denmark,2DepartmentofGeologyandHydrogeology,NicolausCopernicusUniversity,PL-87-100Toruń,Poland,3SchoolofGeography,QueenMaryUniversityofLondon,LondonE14NS,UK,4GeophysicalFluidDynamicsLaboratory,PrincetonUniversity,Princeton,NJ08540,USA

Inadetailedstudyofmega-scaleglaciallineations(MSGLs)leftbyaWeichselianpalaeo-icestreamin Poland, Spagnolo et al. (2016) analysedmultipleparametersoftheland-formingtillandconcludedthatitoriginatedbyacombinationoflodgementandthin-skinneddeformationwhosecumulativeeffectwastheformationoftheMSGLfield.

To advance our understanding of till formationand deformation postulated by Spagnolo et al.(2016)weconductedaseriesofexperimentsonthistill inalargering-shearapparatusintendedtomimicsubglacial shearing (BeringHoldensen2017). Undisturbed, oriented samples formicromorphological analyses were taken atdisplacementincrementsof0,9,18,36,72,144,288,576and1152cm.

Till microstructures mapped on thin sectionsacross the zoneof shearing gave intriguing andhitherto unmatched insights into thedevelopment and evolution of till propertiesduring the shearing under controlled boundaryconditions. The deformation signatures oftenvaried non-systematically between the sampledincrements.

Three-dimensional microtomographic scanningshowed intervals of relatively stable till fabricsinterveningwithphases of fabric re-orientationtowardsnewequilibria.Shearstressesduringthedeformationshowedadistinctcyclicitypossiblyindicating formation and collapse of grainbridges.

Collectively,weinterpretthering-sheardataasasignature of permanent and sometimesunsystematic evolution of till structure with ageneral trend towards more ductile and lessbrittledeformationwithincreasingstrain.Theseresults bear on the reconstruction of pastsubglacial processes and we advocate extremecautionwith interpreting the history of naturaltillsbasedonthemicromorphologicalsignaturesalone.

ORAL

Glaciallandformevolutionintransitionalcold–warmbedsubglacialconditionsinthecentralpartofScandinavianIceSheet,innorthernFinland

PerttiSarala11GeologicalSurveyofFinland,P.O.Box77,96101Rovaniemi,Finland/OuluMiningSchool,Univ.Oulu

On-going glaciomorphological mapping inFinland based on airborne LiDAR (LightDetection And Ranging) interpretation hasrevealed new data that is useful for theglaciodynamic examination in the glaciatedterrain.OneofthekeystudyareasinFinlandhasbeentheKuusamoIceLobeareaclosetotheLateWeichselian ice-divide zone in Finnish Lapland.The glacial morphology of the ice lobe iscomposedmainlyofmorainemorphologiessuchas the glacial streamlined lineations of theKuusamo drumlin field in the eastern part anddifferenthummockyandribbedmorainesinthewesternpart, i.e.atthecoreoftheice lobe.Thedrumlin field was formed under surging typeglacial movement during Younger Dryas whilethecorepartoftheglacierremainedcold-based.

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Glaciofluvial deposits (eskers and deltaformations) occur in places representing lastdeglaciationphase.Particularly,ribbedmorainesrepresent the depositional formations formedunder subglacial conditions at the transitionalzonebetween thewarmandcoldbasedglacier.However, an erosional, subglacial meltwaterchannel network cutting the ribbed moraineformationsbeforethedepositionofglaciofluvialdeposits and smoothly lineated surface ofmorainicterrainsbyglacierreworkinggivesnewknowledgeoftheformationphasesofsubglacialmoraine formations in the core part ofcontinental glacier. As the subglacialmeltwateractivitythatformedtheerosionalchannelsystemandlaterchannelfillssuchaseskerswasworkedafterribbedmoraineformation,theoriginoftheribbed moraines must be earlier process,happenedclosetocold-basedcorepart.

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ActiveretreatofaLateWeichselianmarine-terminatingglacierrevealedbylarge-scaleglaciotectonicsinMelasveit,westernIceland

ThorbjörgSigfúsdóttir1,ÍvarÖrnBenediktsson2andEmrysPhilliips31DepartmentofGeology,LundUniversity,Sweden&InstituteofEarthSciences,UniversityofIceland,2InstituteofEarthSciences,UniversityofIceland,3BirtishGeologicalSurvey,Edinburgh,UK

Large and complete glaciotectonic sequencesformedbymarine-terminatingglaciersarerarelyobservedonland,hamperingourunderstandingof the behaviour of such glaciers and theprocessesoperatingattheirmargins.DuringtheLate Weichselian in West Iceland, marine-terminating glaciers deformed glaciomarinesediments.Theseformationsarenowexposedin>5kmlongcoastalcliffsintheMelasveitdistrict,recording past glacier dynamics and theinterrelationship between glaciotectonic andsedimentary processes under/in front of amarine terminating glacier. The sedimentologyand glaciotectonic architecture of the coastal

cliffs reveals a series of subaquatic morainesformed by a glacier emanating fromBorgarfjörður to the north. The style ofdeformation demonstrates that these moraineswere primarily built up by ice-marginal/proglacial thrusting and folding ofmarine sediments as well as deposition andsubsequent deformation of ice-marginalsubaquaticfans.Thesouthernmostandlargestofthemorainesisover1.5kmwideandmorethan30 m high and is interpreted to indicate themaximum extent of the Borgarfjörður glacier.Generally, the other moraines becomeprogressively younger towards the north,designating an advances or still-stands of theglacier as it oscillatedduringanoverall retreat.Glaciomarine sediments rapidly accumulated infrontof theglacierand filled in thedepressionsbetween the moraines when the glacier finallyreceded from the area. Previously obtainedradiocarbondates from the deformed sequencesuggestthatthesemoraineswereformedintheYounger Dryas. This study highlights thedynamics of marine-terminating glaciers andmay have implications for the interpretation oftheir sedimentological and geomorphologicalrecords.

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GlaciotectonicanalysisofthegeologyintheNEpartofSjælland,Denmark,basedoninterpretationofvibroseismicdataalongthewestbankofEsrumSø

LineWinsløw1,StigA.S.Pedersen2andLarsO.Boldreel11CopenhagenUniversity,2GEUS

In the northeastern part of Sjælland, twooutstandingmorphologicalelementsarepresent:the composite hill ridges characterizing theterraininGribskovandtheelongateddepressionlodging Esrum Sø. A simple glaciodynamicinterpretation of their formation is that theyrepresent a hill-and-hole pair with Esrum Sørepresentingtheholefromwherethematerialfor

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the composite hills in Gribskov derived. Thisinterpretationsatisfies thegeneralN–S trendofthemorphologicalelements.

However, thenorthernpartofEsrumSø trendsSE–NW parallel to the buried Esrum-Alnarpvalley suggesting a tectonic origin of the lakemorphology. For the investigation of thishypothesis, a 6.3 km vibro seismic profile wascollected along the western bank of the lake.Duringtheanalysisoftheseismicprofile,alargeglaciotectonic complex was recognized. Thecomplex comprises five sections, whichcharacterizethedistaltotheproximalstructuraldevelopment.Thetranslationofthecomplexwasfromanortherly toasoutherlydirectionoveradécollement surface,which stepwise rises from95 m b.s.l. in the northern proximal regionshallowing toward the southern distal region.Theglaciotectoniccomplexcomprisesrampsandflats with related hanging wall and footwallstructures.

TheglaciotectoniccomplexdevelopedduringtheadvanceoftheScandinavianIcesheetintheLateWeichselian (30,000-20,000 B.P.). During theinitialphase,glaciofluvialsedimentsaccumulatedproglacially. These were later thrusted intopiggyback duplexes. Following the recession oftheice,aglaciolacustrineenvironmentappeared.In a final phase, a superimposed glaciotectonicdeformation occurred concluding thedevelopmenttheglaciotectoniccomplex.

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SubglacialorPro-glacialDeformedMiddle-LateWeichselianRidgesinJyderupSkov,Odsherred,Denmark

CecilieSkovsøAndersen11FormerstudentatUniversityofCopenhagen

The aim of this study is to investigate theglaciotectonicdeformationoftheice-pushridgeson the outer edge of the Vig-Hønsinge Arc inJyderup Skov, Odsherred, Denmark. Bymeasurements of Ground Penetrating Radar(GPR) reflections profiles across the structures,

theprojectwillaimtoproduceageologicalmodelwith emphasis on a structural analysis ofdeformed meltwater sediments. The ridges areparallel to the terminal moraine of the Vig-HønsingeArcformedbytheBælthavReadvanceandarelocatedontheproglacialmeltwaterplainaheadof theterminalmoraine.Theridgeswereinvestigated by six 250 MHz GPR linesperpendicular to the ridges and one GPR linestrikingparalleltotheridges.TheGPRlinesweresuccessfullyrecordedandneededonlyverylittleprocessing and patience with estimating themigrationvelocity, asdiffractionsweremany.8Facies have been determined from the radarstratigraphicanalysis.Twofaciesofglacio-fluvialsand and gravel,which are folded and thrustedrespectively indicating both ductile and brittlestyledeformation,with complex imbricate fans.Additionally, deformed seasonal outwash,channels,till,kames, landslidesandcoversandsare interpreted as well. The GPR lines aredeformationalshortenedby7%onaverage.Twodifferentscenariosaresuggestedtoexplainthisdeformation; A: A surge and sustained advanceandB:Recessiononanannualscale.Basedonthedistribution of the radar stratigraphic facies isscenarioBinterpretedtobethemost likelyonetohavehappened.

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NewsubglaciallandformsdetectedfromLiDARdata

KariKajuutti1,JoniMäkinen1,ElinaAhokangas1,AnttiOjala2andJukka-PekkaPalmu21UniversityofTurku,2GeologicalSurveyofFinland

High-resolution DEMs produced from LiDARprovidearevolutionarytoolforthemappinganddocumentation of glacial landforms over wideareas (e.g. Johnson et al. 2015). The mainresourceforthisstudywastheMaankamaramapservice (http://gtkdata.gtk.fi/maankamara/) ofthe Geological Survey of Finland (GTK) whereLiDARdataissupplementedwithbasemapsandmaps of the Quaternary deposits as well asbedrock,striationandthehighestshorelinedata.

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Indeed, while studying the deglaciation of thepastScandinavianicesheetaftertheSalpausselkäIIIstageinSWFinland(Kajuuttietal.2016),ourattention was drawn to formations beingsurprisinglyregulartrianglesinshape.

Eventhoughthetriangularlandformsareclearlyidentifiable from LiDAR-based DEMs, they arealmost impossible to detect frommap contour-lines,otherremotesensingimagesoreveninthefield within forest covered areas. The trianglesconsistoftillandaretypically100–200mlongand 2 – 5 m high. Our hypothesis is that thetriangular landforms and related other featuresbelongtorouted,large-scalesubglacialdrainagesystems forming a continuum betweenchannelized (eskers) and more widely spreadsmall-scale distributed subglacial drainage(Mäkinenetal.2017).

We have started co-operation with Swedishresearchers(cf.Petersonetal.)aimingtoajointpublicationthatwillshowthedistributionofthetrianglesinbothcountriesandmoreoverexpandourknowledgeoftheirsedimentologyandorigin.The name for the new landforms will bepublishedbothinourforthcomingpaperaswellasintheNGWMmeeting.

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Usinglarge-scalepatternsandmorphologyofsubglacialmeltwatercorridorstogaininsightintothespatialorganisation,formationandevolutionofmeltwaterdrainagebeneathicesheets

EmmaLewington1,StephenLivingstone1,AndrewSole1,ChrisClark1andSarahGreenwood21TheUniversityofSheffield,2StockholmUniversity

Whilespatio-temporalvariationsintheefficiencyof the subglacial drainage system have beenidentifiedasakeycontrolonicesheetdynamics,the inaccessibility of the bedmeans its precisecharacter and evolution remains poorlyunderstood. Palaeo-bedforms provide one

solution to this, enabling the reconstruction ofrelict networks over large areas. Suchinvestigationshavebeenfacilitatedbythereleaseof freely available, high-resolution digitalelevationmodels(e.g.ArcticDEM).

This study focuses on subglacial meltwatercorridors (SMCs), characterised as elongatedtracts of hummocky sediments often associatedwith eskers, glaciofluvial sediments and erodedbedrock. Similar features have been recognisedbefore (e.g. Ramptonet al.,2000; Uttingetal.,2009; Peterson et al., 2017) but theirdistribution over ice-sheet scales has yet to beconsidered. This is an important considerationfor determining the formation of these featuresandconfirmingtheirlinktosubglacialmeltwateri.e. identifying the source, magnitude anddurationofflowrequired.

We use a large-scale mapping approach tounderstand the spatial pattern of palaeo-subglacialflowbeneathlargepartsoftheformerLaurentide and Fennoscandian ice sheets. Anautomatedmethod for identifying andmappingthese features is developed based on the highdegreeofroughnesswithinthesechannelswhichdistinguishes them from the surrounding bed.The outputs of this approach are compared totraditional manual techniques and detailedmorphologicalinvestigationstoprovideinsightsinto the nature of the drainage system and tocontextualise limited observations ofcontemporarysubglacialmeltwaterdrainage.

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SedimentologyofthenewsubglaciallandformsdetectedfromLiDARdatainSWFinland

JoniMäkinen1,KariKajuutti1,AnttiOjala2,Jukka-PekkaPalmu2andElinaAhokangas11DepartmentofGeographyandgeology,UniversityofTurku,2GeologicalSurveyofFinland

New triangular-shaped glacial landforms havebeenidentifiedanddescribedfromLiDAR-basedDEMs in SW Finland (Kajuutti et al. 2016;

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Mäkinenetal.2017).Ourhypothesisisthattheyand related other features belong to routed,large-scalesubglacialdrainagesystemsformingacontinuum between channelized (eskers) andmore widely spread small-scale distributedsubglacialdrainage.

We present the first sedimentologicaldescriptionofthenewtriangularlandformfromSW Finland and tentatively discuss thedepositionalenvironmentandrelatedprocesses.The general sediment characteristics includestratified gravel-sand core covered by loosesandy/gravelly, massive/matrix-supporteddiamictons interbedded with disturbed,laminated sand beds. The paleoflow pattern islobe-shapedwithboulder-richmargin.Maximumsizeofthebouldersinthesedimentisca.1mandthe clasts are angular to edge-rounded. Thesediment characteristics do not fit into currentconceptionofsubglacialglaciofluvialdepositsortills,butrathersupport thecontinuumbetweenthese as also indicated by the morphologicalcharacteristics.

Ongoingco-operationwithSwedishresearchers(cf. Peterson et al. 2017) will expand ourknowledgeonthesedimentologyandgenesisofthese new landforms. Their name will bepublishedbothinourforthcomingpaperaswellasintheNGWMmeeting.

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SedimentologicalandmorphologicalimplicationsfortheunderstandingofmurtooformationinSweden

GustafPeterson1,MarkD.Johnson2andChristianÖhrling31DepartmentofEarthSciences,GothenburgUniversity,Göteborg;GeologicalSurveyofSweden,Uppsala,2DepartmentofEarthSciences,GothenburgUniversity,Göteborg,3GeologicalSurveyofSweden,Göteborg

During glacial landform mapping in southernSweden, a new distinct landformwas detected,which we refer to as murtoos. The landformappearance is a V-shaped hummock, generally

pointing down ice with an asymmetric verticalprofilealongitsaxis.TheLiDARDEMofSwedenhas been surveyed for murtoos, and theycommonly throughout the country, mostfrequentlynorthoftheYoungerDryasicemarginandinareasdeglaciatedduringBølling-Allerødinthe south. We have excavated murtoos at fourlocalitiesandhavestudiedtheinternalstructurethrough detailed sediment description. Thedistribution, geomorphology andsedimentologicalpropertiesofmurtooscollectedhereprovideanopportunitytounderstandtheirgenesis.

Murtoosizesareroughly10-100meterswide,5to 50 m long, and 2-10 meters high. Theindividual murtoos have an overlappingappearance and occur as fields. In places,elongated fields trendparallel to theoverall iceflowdirection.Commonly,Murtoosoccurincloserelationtoribbedmoraineand,inplaces,theyaredraped by eskers and overprinted by flutes,indicating murtoos form subglacially. Murtoospredominantlyconsistofaheterogeneoussandygravelly diamicton,with angular to sub-angularclasts.Lensesofsortedsedimentsareintermixedinthediamictonandbouldersarecommononthesurface. Further, their distribution in Swedensuggestsaformationduringperiodsofrapidiceretreat. We list multiple hypotheses, their prosandcons,anddiscuss themtoshed lighton theformativeprocess.

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AnewglacialdepositsandfeaturesdatabaseofFinland

NikoPutkinen1,PerttiSarala1,SatuPutkinen1,Jukka-PekkaPalmu1andAnttiE.K.Ojala11GeologicalSurveyofFinland

Renewing of the glacial deposits and featuresdatabase isgoing-on intheGeologicalSurveyofFinland(GTK). It includesbothanewdefinitionof the landform categories and mapping workbased on the 2-metre resolution LiDAR (LightDetectionAndRanging)datainterpretationwithArcGIS software. Preliminary sources for map

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polygons and lines are: 1. LiDAR-DEM dataprovidedbyNationalLandSurveyofFinland,2.GTK’s Quaternary geological 1:20 000 and 1:200000data,3.aggregate,engineeringgeologicaland groundwater aquifer investigations. Themulti-year project aims to produce 'the bestmappingdataforeachlocationinFinland'withacost-effective,minimal fieldwork approach. Themapping process combines both the maingeologicalunit(deposit)andanew,landsystems-based glacial geomorphological featureinformation. Recent studies have shown thatpreviously detected large mega-scale glacialfeatures, such as mega flutings, drumlins, endmoraine complexes and glacial melt watersystemsshowupinLiDAR-baseddigitalelevationmodels(DEM)ingreaterdetailthaneverbefore(Putkinen et al., 2017). The newmap databasewill significantly improve mineral exploration,groundwater studies, land use planning andmanagement. Inthe future, thedatabasewillbelinkedtothenationwidestratigraphicalunitsandbe extended to the national subsurface 3Ddatabase.Theglaciodynamicthemesincludedinthe database are: Glacifluvial deposits, glaciallylineated terrains and various types of othermorainetypesreferredtomuchslower ice flowvelocities or different glaciermargin landforms(ribbedmoraines,hummockymoraines,DeGeermorainesandendmoraines).

8.3. Open session Quarternarygeology

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RepeatedfluvialsedimentationduringthelatePleistoceneinKitinenvalley,Sodankylä

AnnikaKatarinaÅberg1,AnuKaakinen1andVeli-PekkaSalonen11DepartmentofGeosciencesandGeography,UniversityofHelsinki,P.O.Box64,00014Helsinki

New studies confirm (Sarala et al. 2015, 2016,Lunkkaetal.2015)thatWeichselianglaciationinCentral Lapland has been more complex thanpreviously assumed. Three to four interstadialshave been suggested based on the existence ofintertill sorteddepositsandpollenassemblagesof organic layers. In addition, subtill fluvialdeposits have now been discovered in testsectionsofKärväsniemi,inSodankylä,indicatingthattheareawasice-freeduringEarlyandMiddleWeichselian. The Kärväsniemi site consists ofthreetillbedsandfoursortedsedimentunits.TheOSL ages of the lower fluvial deposit varybetween67-79ka,suggestingdepositionduringOdderade (MIS 5a). The upper sorted deposit,interpretedasfluvialbarandchannellagdeposit,may have deposited duringMiddleWeichselianinterstadials (MIS 3). These two subtill sorteddeposits, separated by a thin till unit, could bealso correlated to Tärendö I and Tärendo II(Hättestrand & Robertsson 2010) of theRiipiharjustratigraphyinnorthernSweden.ThesorteddepositsinKärväsniemicanbecorrelatedwiththelacustrinedepositsofSokli(Helmensetal.2007).

A 3Dmodel of surficial depositswas generatedalong with a GIS database and GPRinterpretations to study sedimentation in theKärväsniemi area (Åberg et al. 2017). ThesedimentationhistoryinKärväsniemihasatleastthree phases of fluvial deposition, disturbed bydepositionofthreetillunits.Thenon-destructive

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contactsoftheoverlayingtillssuggeststhattheywere deposited from a stagnant frozen-bed icesheetindicatinganoverallweakglacialerosioninKärväsniemi.

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AninterglacialdepositfromCopenhagen,Denmark:marineisotopestage7

OleBennike1,JensGalsgaard2,JoakimStielKorshøj2,GeoffreyLemdahl3,KirstyPenkman4andRichardPreece51GEUS,2GEO,3KalmarUniversity,4YorkUniversity,5CambridgeUniversity

DuringtheconstructionofanewMetrostationinCopenhagen, fossiliferous organic sedimentswere encountered. An investigation wasundertaken on the organic sediments, whichoccurredbeneathasuccessionofalowertillbed,glaciofluvial sand and gravel, an upper till bedand glaciofluvial sand. The organic sedimentswererichinplantfossilsandtheflorashowthattheregionwasforestedbutincludedsomelight-demanding species. The flora includes Najasminor,whichtodayhasanortherngeographicalrange limit in Germany. Shells of freshwatermolluscs were frequent, but the diversity wasrather low. Bithynia opercula were abundant,allowing the sediments to be put into anaminostratigraphicalframework.Theaminoacidracemisation ratios indicate that the organicsediments formed during earlyMIS 5e ormorelikely during MIS 7. The older attribution isconsistentwithOSLagesof206and248ka.TheassemblagesfromTrianglenaresimilartothosereported from deposits recovered during theconstruction of the free port (1.4 km away) inCopenhagen in 1892, except that CorbiculawasnotfoundatTrianglen.ThepresenceofCorbiculaindicates a pre-Eemian age. AAR data fromBithyniaoperculafromthefreeportwerealmostidenticaltothosefromTrianglen,indicatingthatthe twositesarecontemporary.Wesuggest theTriangleninterglacialbeusedasalocalnamefortheMIS7interglacialdeposits.

ORAL

Abagofsandfromtheice-concealed,31kmlargeHiawathacraterinNorth-WestGreenland:samplesoftheimpactplume,ejectablanketandcraterfloorfromarecentmeteoriteimpactthroughtheGreenlandicesheet

AdamA.Garde1,TodE.Waight2,ChristianWeikusat3,CarstenGuvad1,SvendV.Funder4,KurtH.Kjær4,IainMcDonald5,JetteD.Møller6andGernotNehrke31GeologicalSurveyofDenmarkandGreenland,Denmark,2DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,Denmark,3AlfredWegenerInstituteforPolarandMarineResearch,Bremerhaven,Germany,4CentreforGeoGenetics,NaturalHistoryMuseum,UniversityofCopenhagen,Denmark,5SchoolofEarthandOceanSciences,CardiffUniversity,U.K.,6NaturalHistoryMuseum,UniversityofCopenhagen,Denmark

Hand-picked, sand-sized grains from a recentglaciofluvialsedimentfromtheHiawathaGlacierdraining the Hiawatha impact crater, InglefieldLandinNorth-WestGreenland,providerarenewinsightintomeltingandcrystallisationprocessesand unusual incorporation of organic carbon inthe uppermost parts of a large, young impactstructure.

ThebulksandcompositionmimickstheregionalPalaeoproterozoic, granulite-facies paragneissbedrock. Predominating {10-13}, {10-12}orientationsofshocklamellaeinquartzindicatea threshold shock pressure of >16 GPa. Yellow,green,brownandblack,variablycarbon-bearingglassfragmentshavefeldspar-,biotite-orgarnet-like compositions and high volatile contentssuggestingdirectmelting of theseminerals andadmixture of H2O and organic carbon.Microporphyritic to microcrystlline particleshave similar and occasionally crustal-melt-likecompositions. Microliths of euhedral, zonedand/or skeletal feldspar, orthopyroxene,clinopyroxene, ilmenite and cordierite suggestrapid crystallisation and partial quenching. An

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ellipsoidal grain with radial crystallites mayrepresentameltdropletfromtheimpactplume.Ejecta blanket? microbreccias with glassy ormicrocrystalline matrix contain abundantbedrockmineralsplinters.

Sand-sizedcarbonaceousgrainsandcentimetre-sizedcharcoalfragmentspickedfromglaciericepreserve conifer cell structures; their highlyvariable reflectance corresponds to150-1200°Cheating. Raman graphite-o-peak spectra ofcarbon in microbreccia matrix, glass andmicrolithcoatingslikewiseshowawiderangeofordering without evidence of metamorphicoverprinting, unlike carbon in the NorwegianGardnos crater (Parnell & Lindgren 2006). TheHiawatha carbon was probably derived fromPleistocenetreetrunksburiedundertheice;theicesheetlikelyprotectedthemfrombeingblownawayduringtheinitialimpactphase.

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TheLastGlacialandHoloceneSeismostratigraphyandsedimentationhistoryoftheLakeBolshoyeSchuchye,PolarUral,ArcticRussia

HaflidiHaflidason1,JulieLundekvamZweidorff2,RichardGyllencreuz3,John-IngeSvendsen2andSlavaGladysh41Dept.ofEarthScienceandBCCR,UniversityofBergen,Allégt.41,POBox7803,N-5020Bergen,Norge,2Dept.ofEarthScienceandBCCR,UniversityofBergen,Allégt41,POBox7803,N-5020Bergen,Norway,3DepartmentofGeologicalSciences,StockholmUniversity,10691Stockholm,Sweden,4I.S.GrambergVNIIOkeangeologia,SonicGroup,190121,St.Petersburg,RUSSIA

The seismostratigraphic studies of the 11 km2and the 136 m deep Lake Bolshoya Schuchye,Polar Ural, Arctic Russia, have unrevealed thatthelakeisapparentlypreservinguptoa130-150m thick pile of seismostratigraphic laminatedsediments.With aid of a Sparker array seismicandsubbottomprofiling(SBP)surveysadensegridofprofileshavebeencollectedallowingthesediment distribution and the geometry of the

sedimentunitstobemappedoutinsomedetails.Three regional seismic horizons have beenidentifiedandcorrelatedwiththewelldated24mlongcoreretrievedfromthelake.Thedetailedtime constrain available on the upperstratigraphicunitsinthelakeofferalsoexcellentpossibility to calculate the development insediment fluxes in thisPolararea fromtheLastGlacialMaximum(25kaBP)tothepresentday.The detailed grid of seismic survey has alsoallowed the total sediment volume in the lakebasin to be calculated and integrated with thewell dated core the age of the initialsedimentation in the lake basin has beencalculatedtohavestartedc.55kaBP,withafewthousand years uncertainty. Identification ofsubmerged delta inside the lake basin suggestthat the lake level must have dried in and belowered with at least 26 m below the presentlevelduringtheLGMperiod.ThisfindingofferanewinsightintotheclimateconditioninthePolarUralarea,ArcticRussia,duringtheLGMandtheearlydeglaciationperiod.

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SandydepositsfromaPreborealglacierlakeoutburstflood(NedreGlomsjø),southeasternNorway

LouiseHansen1,FredrikHøgås1,LarsOlsen1andGeorgiosTassis11GeologicalSurveyofNorway

ThemajoroutburstfloodfromglacierlakeNedreGlomsjø in southeastern Norway, has beenknown for decades. Previously describeddeposits include pronounced boulderaccumulations upstream and vast fine-grainedflooddepositsfardownstream.Inaddition,newLiDAR data from the middle reaches of theGlomma valley has revealed spectacular megabars and erosional features related to thedramatic flood event (Høgaas & Longva 2016).The LiDAR data provide a basis for furtherinvestigationof the event and its impacton thelandscape and the valley fill. Sedimentologicalinvestigationofasandydunefieldprovidesnew

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insight into the variety of deposits from theoutburst flood. The dunes were previouslydescribed as of aeolian origin. However, faciesanalysisshowsthatthedepositsweredepositedin association to the outburst flood. Beside theassociation with water-lain facies, such as e.g.diffuse, climbing ripple lamination, a diagnosticfeature seems to be water-escape structuresdefinedbynumerous(sub)verticaltrackscuttingthrough the bedding including the foresets ofmega-scalebedforms.Thetracksareinterpretedas a result of a significant drop in hydrostaticpressure as the flood levels were lowered andtriggeredareleaseofexcessporepressureinthesediments.Thestudyextendstheunderstandingof the outburst flood as an extreme, landscape-defining event. In addition, the study hasimportant impact on the understanding of theregionspostglaciallandscapeasother,previouslydefinedaeolianfieldsmayshowtooriginatefromthe flood,andcomparablesedimentary featureshavebeenobservedatStarmoennaturereserve.

ORAL

TheQuaternaryoftheislandofFalster,SWDenmark

PeterRollJakobsen1andKnudErikKlint21GEUS,2GEO

TheislandofFalsteriscoveredbythegeologicalmapsheetsGeologicalmapofDenmark1:50.000Stubbekøbing andNykøbing Falster. During thegeological mapping new data was collectedregarding Quaternary stratigraphy,morphologyandtheevolutionofthelandscape.

The pre-Quaternary deposits on Falster areMaastrichtienchalkandPaleogeneClay.Thepre-Quaternary surface is influenced by NW–SE-striking faults that act as weakness zones, andburiedvalleysareincisedintothechalksurface.At Stubbekøbing, the course of the Fribrødreåvalleyiscontrolledbyafault.

TheoldesttillunitonFalsterisseeninboreholesand is interpreted as the Ristinge Klint TillFormation(c.50000yearsago).

AtPomlenakkeandonFarøsectionsshowa tilldepositedbyaglaciercomingfromNE,whichisinterpreted as the Midtdanske Till Formation(LateWeichselian24000–20000yearsago).Itiscovered by two Baltic tills – Øst Jylland TillFormationandBælthavTillFormation(19000–16000 years ago). A characteristic boulderpavement is seen at the base of the lower unit.The boulders are often more than 1 m indiameter.

Themostpronouncedgeomorphologicalelementis thepushmoraineVæggerløseArc, formedbyanadvancefromeast.Aneskerstretchesfromthenorth-easternmost part of Falster and almostdown to Nykøbing Falster. A small meltwaterplainisassociatedwiththeesker.IntheNorthernpart smooth ridges with a NW-SE trend areinterpreted as older marginal moraines,subsequentlyoverriddenbyglaciers.

ORAL

AlargeyoungimpactcraterbeneaththeIceinNorthwestGreenland

KurtH.Kjær1,NicolajK.Larsen2,SvendFunder1,MichaelHoumark-Nielsen1,AdamGarde3,MarkFahnestock4,IanMcDonald5,OlafEisen6,JosephMacGregor7,AndersBjørk1,VeitHelm6,EskeWillerslev1,MatheuMorlighem8,JeremieMouginot8,HenningHaack9,KristianK.Kjeldsen10,HorstMachguth11,TobiasBinder6,JohnPaden12andShfaqatAbbasKhan101CentreforGeogenetics,UniversityofCopenhagen,2Dept.ofGeoscience,AarhusUniversity,3GeologicalSurveyofDenmarkandGreenland,4UniversityofAlaskaFairbanks,5CardiffUniversity,6AlfredWegenerInstitute,7NASA,8UniversityofCalifornia,9GeobiologyandMineralsSection,UniversityofCopenhagen,10DTUSpace,11UniversityofZurich,12UniversityofKansas

DuringEarth’shistory,cataclysmicimpacteventshave been linked to major climate change andmass extinctions. Here, we report on thediscovery of a large impact structure hiddenbeneath Hiawatha Glacier in northwestGreenland.Beneathnearlyakilometreoficeliesa31-kilometre-wide,circularbedrockdepression

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withanelevatedrimandasubduedcentralpeak.Outwash sediments from the largest riverdraining from the glacier catchment containsshocked quartz and other unweathered impactgrains. Geochemical analysis shows that theimpactorwasaPt-rich ironasteroid thatwouldhave had a diameter of c. 1.5 km in order toproduce a crater of the observed size.Radiostratigraphic, morphological andgeochemicalevidencesuggestthattheHiawathaimpacttookplacebetween38and11.7kyrago,whichwouldmake it the largest known impactexperienced bymodern humans. Our discoveryhaspotentiallywide-rangingimplicationsforourunderstandingoftherecenthistoryofEarth.

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Provenanceand10BesurfaceexposureageofLateWeichselianglacialerraticbouldersinsouthernNorway

HenrietteLinge1,LukasBecker1,JennyEidsvåg1andDerekFabel21DepartmentofEarthScience,UniversityofBergen,2ScottishUniversitiesEnvironmentalResearchCentre

Bouldersandcobblesofnon-locallithologies(i.e.erratics) are foundon all types of substrates ineast-central southern Norway. The onlyexception is surfaces formed after the lastdeglaciation. Hence, erratics are found insuperimposed on surfaces of bare bedrock,blockfield, till, glaciofluvial and glaciolacustrinematerial. The erratics must have been glaciallytransported at some point, either as isolatedclasts or as till. Boulders resting on fragilesubstrates, such as sediments or weatheredbedrock, are characteristic for areas with pastcold-based,low-erosiveicesheets.

Wepresentapreliminarysynthesisoffivestudiesthatusedprovenanceanalysisoferraticboulderstoreconstructregionalice-flowdirectioneastofthe present day main water divide. Theinvestigatedmountainsallhaveerraticmaterialfrom source areas to the N and NNW. The

westernmost mountains Kolla, Knutshøa andBlåhøe (Becker 2013), as well as Heidalsmuen(Tvedt2013),alsohavematerialoriginatingfromsource areas in the SW. The mountainsStorsølnkletten (Eidsvåg 2013) and Tron (Hult2011)locatedinthecentralpartofthestudyarea,and Søre Sølen (Kvamme 2012) in the easternpart,haveadditionalboulderstransportedfromsourceareasintheS-SE.

Inaddition,wereport10Besurfaceexposureagesfrom 36 glacially transported boulders in thestudyarea.10Beagesrangefrom7.7±0.5to66.1±1.9ka,butclusteraround11ka.Theagesmustbe considered minimum ages as they are notcorrectedforsnowcover,weatheringorisostaticrebound.

POSTER

MineralogicalanalysisoftillbytheGreenlandIceSheet,Kangerlussuaq,WestGreenland

KarinGrodzinsky1,Eva-LenaTullborg2,JohanHogmalm1andIgnasiPuigdomenech31DepartmentofEarthSciences,UniversityofGothenburg,Gothenburg,Sweden,2TerralogicaAB,Gråbo,Sweden,3SwedishNuclearFuelandWasteManagementCompany,Stockholm,Sweden

Till sampled from terminal moraines close toKangerlussuaq at west Greenland are analyzedthrough mineralogical observations along withchemicalcompositiondataincludingSr-isotopes.Thisstudyfocusontheweatheringprocessesandinteraction between glacial meltwater and till.ScanningElectronMicroscope,XRDandleachingexperimentsare,amongothermethods,usedtostudy chemical weathering and reactions. Forexample,mineralssuchaspyriteandbiotiteshowweathered edges with loss of sulfur andpotassium, respectively. Some feldspars maypresent caved surfaces which could indicateweathering processes. Leaching experimentsindicaterelatively fast interactiontimebetweenwater and till, and the data are compared tochemical compositions of moraine ponds andporewatersamplesandevendeepgroundwater

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from the same study area. These comparisonsincrease our understanding of the course ofeventsandreactionsfortheglacialmeltwateronits way from the glacier and further down thebedrockandinthewatershed.

Thestudyhasbeencarriedoutasacomplementto the Greenland Natural Analogue ProjectconductedbytheCanadianNuclearManagementOrganisation, the Finnish Posiva Oy and theSwedishNuclearFuelandWasteManagementCo.(ClaessonLiljedahl,L.etal.2016).Theaimoftheprojectwastoinvestigatehowglacialconditionswouldaffectadeeprepositoryforspentnuclearfuelduringfutureglacialperiods.

POSTER

SedimentarycharacteristicsofapossibletsunamidepositintheLeirfjordenarea,NorthNorway

LouiseHansen1,ReidulvBøe1,HaraldSveian1andKatrineHusum21GeologicalSurveyofNorway,2NorwegianPolarInstitute

A material-extraction site near Leirfjorden inNorthNorway reveals a composite stratigraphyof interbedded glacial and marine deposits. Acoarse-grained, crudely stratified event bed isinterpreted as a possible tsunami deposit. It isunderlain by marine deposits reflectingreworking of glacial deposits by waves andgravitationalprocessesafterglacierretreat.Theevent bed is divided into four main intervalsreflecting different stages of the sedimentationprocess. From the base upwards, these areirregular, poorly sorted sand and gravelinterbeddedwithmassive fine sandoverlainbythin-bedded silt and sand with clasts. Thesuccession of facies reflects flow processes ofvariedconcentrationalternatingwithsuspensionsedimentationofsand.Siltyintraclastsandpoorsorting testifies to short and episodictransportationandfastsedimentation.Thebedisoverlain by subtidal sediments. Thesedimentologicalcharacteristicsofthebedshowsome similarities to previously described

tsunamidepositsfromNorwaybuttherearealsodifferencessuchasabsenceofbiogenicmaterialexceptforafewreworkedforaminifers.Thehighelevationoftheinferredtsunamidepositatc.75m a.s.l. precludes a relation to the Storeggatsunami and it must be older. As there is norecordofanolder,regionaltsunami,alocaleventis suggested. A marine sparker survey inLeirfjordenrevealsamajormass-wastingdepositthataccumulatedinthefjordshortlyafterthelastdeglaciation.Thismass-wastingcouldbealikelysourceforalocaltsunami.Failureisexplainedbyhigh sedimentation rates and emergencefollowing glacier retreat,maybe combinedwithseismicity.

POSTER

LateGlacialandHolocenedevelopmentwithinthesourcedepressionoftheVejrhøjend-moraine,NWSjælland,Denmark

PeterRollJakobsen1,OleBennike1andJakobWalløeHansen21GEUS,2UNESCOGlobalGeoparkOdsherred

The prominent arcuate end-moraines in NWSjælland are the backbone of the geology ofGeopark Odsherred. The largest andsouthernmost of the end-moraines, the Vejrhøjarc,isaglaciotectonichill-holepairlandform.Thesourcedepressionmakesupthe innermostpartof one of Europes largest reclaimed areas, theLammefjord.ItconstitutesabasinthathasbeenfilledwithLateGlacialandHolocenedeposits.Aspartofalargeoutreachprogrammethebasinwasinvestigated in a drilling campaign and groundpenetratingradarinvestigationswasusedinthesandyareas.

Inthedeepestrecognizedpartofthisbasin,25mof sediment has been deposited. Macro fossilsshow that the basin initially was a Late Glaciallake, where sand and clay is deposited. ThefreshwaterlakeenvironmentcontinuedintotheHolocene,andpeatwasdepositedattheshoresofthelake.

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During the Atlantic transgression the area wasflooded, and the present surface is now 3.8 mbelowsealevel.Intheinitialphaseofthechangeof environment from freshwater to marine,brackish sediments are deposited in form oflaminatedgyttjadeposits. In thisphasesomeofthe lake deposits where redeposited.Subsequentlyafullmarinesequencedepositedinthebasinasmarinegyttjawithnumerousshells.

Attheedgeofthebasinmarinesandisdeposited,and oyster banks developed at relative shallowwaterdepth.

POSTER

LakesedimentanalysisoftheNedreGlomsjøoutburstfloodevent,SoutheasternNorway

HelleDalingNannestad1,IvarBerthling1andFredrikHøgaas211DepartmentofGeography,NorwegianUniversityofScienceandTechnology,NO-7491Trondheim,NORWAY,2GeologicalSurveyofNorway,PostalBox6315SluppenNO-7491Trondheim,NORWAY

Sedimentcoresfromlakeandmirescanprovidegeologicalarchivesofpalaeofloods.Byanalysingthesedimentwecanbetterourunderstandingofthenatureandimpactoflargefloodevents.Thisstudy aims to constrain the run-up height andtiming of the outburst flood from glacial lakeNedreGlomsjøattheendofthelastIceAge.Coresfromfourlakebasinswillbeexaminedforgrainsizedistribution,totalorganiccarbon(TOC)andmacrofossilcontent.Inadditiontothis,weaimtoprovideageochemicalprofile(usingXRF)ofthefloodlayer and properly constrain the event intime by radiocarbon dating macrofossils foundabove and below the flood sediment.Geochemical data will serve as a geomarker inorder to identify the flood layer elsewhere.Theprobable flood layer stands out as a light, fine-grained layer in all of the retrieved cores. Theupper boundary towards the organic gyttja assharp,whichsignalsthatsedimentationstoppedabruptly. Preliminary results indicate that the

floodinundatedbasinsmorethan50mabovethevalleyfloorinourstudyarea.

POSTER

Lateglacial–earlyHolocenegeomorphologybetweenLakeVänernandLakeVättern,southernSweden

ChristianÖhrling1,GustafPeterson2andMarkD.Johnson11DepartmentofEarthSciences,UniversityofGothenburg,Gothenburg,Sweden,2GeologicalSurveyofSweden,Uppsala,Sweden

The arrival of Light Detection and Rangingderived elevation models enables efficient andaccurate mapping of landforms. The region incentral Sweden between Vänern and Vätterncontains landforms created during two of themost important events during the lateQuaternary of Sweden; the Younger Dryas coldintervalanddrainageoftheBalticIceLake.

Here,wepresenta1:220000scalegeomorphicmap of this region covering approximately 18000 km2. Fifteen landform units have beenmapped; end moraines, De Geer moraines,drumlinoids, crag-and-tails, hummock tracts,irregularridges,eskers,deltas/sandurs,outwashcomplexes, meltwater channels, boulderbars/sheets, the Timmersdala ridge, raisedshorelines, sanddunesandprominent landslidescars.

Themappedglacialgeomorphologydeepenstheunderstanding of the deglacial history by therevelationofpreviouslyundetectedgeomorphicfeatures and their relations, for example theabundanttracesofmeltwatererosionmanifestedas channels and hummock corridors, andpreviously unreported ice-marginal lines.Perhaps most striking is that all of these ice-margin positions aremarked by distinct lobatemoraines where they were formed above thehighestshoreline.

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Thismapprovidesa‘settable’forfutureresearch– e.g. glacier modeling, georesources, geologichistoryandgeoheritage.

POSTER

WeichselianStratigraphyandDeglacialDepositsfromKuusivaara,Sodankylä,CentralFinnishLapland

MarkusT.O.Valkama1,SeijaKultti1,AnnikaK.Åberg1,EmiliaKoivisto1andVeli-PekkaSalonen11UniversityofHelsinki

Central Finnish Lapland exhibits limited glacialerosionduringtheWeichselian.Therefore,thetillunitsofEarlyandMiddleWeichselianstadialsarepreserved in many places (eg. Helmens et al.2007, Lunkka et al. 2015). This studydescribeslithostratigraphy from Kuusivaara, which issituated140kilometresnorthofRovaniemi,east

of river Kitinen. During deglaciation, the studyarea was first occupied by the Moskujärvi IceLake(207m.a.s.l.)andlaterbytheAncylusLake(186 m.a.s.l.) Stratigraphy and glacial depositsfromtheareawerestudiedfromsixtestpitsandconducting fifteen kilometers of groundpenetrating radaracquisition. Sediment logswere made from test sections and fourteensediment samples were analysed for theirgranulometric properties. Preliminaryobservationssuggest thatweatheredbedrock iscoveredbyaprobablyEarlyWeichseliantillwithsandy sediments and a distinct soil horizon ontheir top, which may represent an interstadialdeposit.Theuppertillisastratified,loosesandymelt-out deposits overlain by aeolian sands,gravityfloworshorelinedeposits.Stratigraphicalevidence can be applied as a key to interpretlandscapeevolutionbasedonLiDARimages.

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9.Economicgeology9.1.Circulareconomy

ORAL

Turninganthropogenicstocksintoeconomicviable‘ore’reserves–majorchallengesfortheCircularEconomy

PerKalvig1,RuneJ.Clausen2,TonnyB.Thomsen3andJonasNedenskov41CenterforMineralsandMaterials(MiMa),GEUS,2CentforMineralsandMaterials(MiMa),GEUS,3Dep.EconomicGeology,GEUS,4AmagerResourceCentre(ARC)

Classical mineral exploration and resourceassessment techniques are inadequate tools forassessment of the financial viability ofanthropogenic end-of-life stocks. In order todevelop ample mining technologies andbeneficiation flow-sheets that provides for aviable exploitation of secondary raw materialsthereisafundamentalneedforcharacterizingthecomposition and properties of secondary rawmaterials.

Example; the Danish WtE plants produce c.600.000 tpa of bottom ashes that potentiallyconstitute important secondary multi-elementresources,whichisgenerallyconsideredaswasteby plant-owners, and left to be utilized byentrepreneurs.Theentrepreneursapplyascrap-metalapproachtoextractsomeofthemetals,andtheremainsareusede.g.inroadconstruction.Inorder to reduce leakages, somechallengesneedtobetargetedandovercome:

Challenge 1: Physical and chemicalcharacterization of the heterogenic resource.Metals mainly occur as primary alloys andsedondaryalloysdevelopedintheincineration.

Challenge 2: Representative sampling of theheterogenicflowofthe‘ore’material,copingwithawiderangeofparticle sizesandshapesof the‘oreminerals'.

Challenge3:Estimationofthegradesandin-situ‘ore’-value,arecritical fordevelopinga ‘mining’set-upandbeneficiationflowcharts.

Challenge 4: Estimation of the dynamic reservetonnage.

Challenge 5: Estimation of project viability: thein-situ ‘ore’-value/’ore-concentrate’. Absence ofparameters characterizing the ‘ore’ and the‘mineralconcentrate’,aswellasnon-transparentprice schemes, prevents the development offeasibilitystudies.

Inconclusion; inadequateresourceassessmentsare major obstacles for addressing and closingleakagesinthecirculareconomy.

ORAL

CharacterizationofRawMaterialsandRecycledStoneWoolWasteforProductionofStoneWoolMelt

VickieSchultz-Falk1,PeterArendtJensen2,KarstenAgersted3andMetteSolvang11ROCKWOOLInternationalA/S,2DepartmentofChemicalandBiochemicalEngineering,TechnicalUniversityofDenmark,3DepartmentofEnergyConversionandStorage,TechnicalUniversityofDenmark

Stone wool waste is generated either duringproduction,whereedgesarecutoffintheshapingprocess, or during renovation or demolition ofbuildings. Stonewool is produced by forming amelt that is spun into fibers. The rawmaterialsinclude mineral raw materials as well assecondary raw materials i.e. waste from otherindustries. It is also possible to re-melt stonewoolwasteand thusrecycle thewastematerialbackintotheproductionprocess.

This study investigates the differences in heatresponse of a conventional stone wool rawmaterialmixandofstonewoolwaste.Thestudycombined Differential Scanning Calorimetry

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(DSC), X-ray Diffraction (XRD) and Hot StageMicroscopy (HSM).Thematerialsarecomparedin terms of thermally induced processesoccurringinthematerials,meltingtemperature,crystallinityandenergyconsumptionassociatedwithheatingandmeltingofthematerials.

DSCrevealsthattherawmaterialmixandstonewool waste have fundamentally different heatresponses: the raw material mix decarbonizesandthewoolcrystalizesbeforebothmelting.XRDis used to investigate the crystallinity of themineralrawmaterialsandthecrystalsformedinthestonewoolwasteuponheating.HSMrevealsthatstonewoolwaste initiatesmeltingat lowertemperaturesthantheconventionalrawmaterialmix.

Understanding the differences between theconventionalrawmaterialmixandtherecycledstonewoolwastewillultimatelyhelptooptimizetheproductionprocesstowardsrecyclinglargeramountsofstonewoolwaste.

POSTER

Utilizationofbiocharasacovermaterialinminewasteareas

PerttiSarala1andRaijaPietilä21GeologicalSurveyofFinland,P.O.Box77,96101Rovaniemi,Finland/OuluMiningSchool,Univ.Oulu,2GeologicalSurveyofFinland,P.O.Box77,96101Rovaniemi,Finland

Goodmineralwaste coverages and landscapingsolutions in northern mining industry will bedevelopedandtestedintheproject‘Utilizationofbiocharindrycovermaterialandlandscapingofmine waste areas’ (Biopeitto) funded by theEuropeanRegionalDevelopmentFund.Fromtheperspective of sustainable development andregional well-being, the solutions that willminimizethecostsforenvironmentandincreasethe local livelihoodsshouldbedeveloped in thenorthern region itself. Testing biochar, minewastesandotherrestmaterialsasthecomponentofmineralwastecoverintailingsandwasterockpile solutions are environmentally important.

Thetestsaimatfindingthebestwaystoimprovecover material’s long-term durability andstability, prevent erosion, and improve thesustainability of water management, carbonbalanceandnutrienteconomy.Benefitoftheuseof biochar is its’ local production whichdiminishes the transport and storage costs andopens new possibilities to develop localentrepreneurship.Tailingsareproducedinlargequantitiesbytheminingindustryanditmightbemoreeconomicalandbeneficialtousethewasteas a resource than treat it as awaste.Availablematerialsneeded to improve tailingspropertiessuchaswood,fibreandbiosludgebutalsootherrest materials from other industries should betestedtoenhancetheirvalorisation.Theprojectis led by the Geological Survey of Finland andotherresearchpartnersaretheNaturalResearchInstituteFinlandand theOuluMiningSchooloftheUniversityofOulu.

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9.2.Mineralresourcesanddeep-seaminingininternationalandnationalseabedareas

ORAL

Deep-seamineralresourceswithinNationalJurisdiction

HaraldBrekke1,GeorgyCherkashov2andPedroMadureira31NorewegianPetroleumDirectorate,2VNIIOkeangeologia,UniversityofSt.Petersburg,3EMEPC

AccordingtotheUNConventionontheLawoftheSea, the continental shelf is the area of seabedthatisunderthejurisdictionofthecoastalstates,which in some cases may extend beyond 200nauticalmiles.According to theConvention, theexploitation of any continental shelf resourcesbeyond200nauticalmilesissubjecttoaroyaltyto be paid through the International SeabedAuthority.In most parts of the world, thecontinental shelf consists of an inner, shallowpart and an outer, deep-sea part. Oil and gas,placers and aggregates are associated with theshallow parts of the continental shelf, whilepolymetallicmineral resourcesare found in thedeep-sea parts and likely to be relevant forroyalty payments. In wide platform areas, likethose of the Atlantic, oil and gas may also besubject to such payments. The polymetallicminerals are regarded as potential sources ofnickel,copper,cobalt,manganese,zinc,lead,gold,cobalt,tellurium,andpossiblyREEs.Estimatesofthemineral resourcesof thedeepseaand theirpartition between the continental shelf and theinternational seabed are still very uncertain.Recently published studies indicate that,dependingonthetypeofmineral,between20%to50%oftheresourcemaybelocatedwithinthecontinental shelf areas. Recent test mining byJapanandthedevelopmentoftheSolwara1MineinPapuaNewGuineaindicatethatsulphideswillbethefirstdeepseamineraltobeexploited,andthatitwillhappenwithinthecontinentalshelf.

ORAL

Explorationofseafloormassivesulfides:currentstatusandperspectives.

GeorgyCherkashov11VNIIOkeangeologia,StPetersburg,Russia

Seafloormassivesulfide(SMS)depositspresentthethirdtypeofashortlistofdeep-seamineralsafter ferromanganese nodules and cobalt richferromanganese crusts. The discovery ofhydrothermal vents and associated massivesulfides in the end of 1970s had not onlyfundamentalbut also economic importanceduetoextraordinaryconcentrationsofmetalsbeingdischargedfromhotventstotheseabottom.ThemajorcomponentsofSMSareCu,Zn,Pb,AuandAg. The high grades of suchminor high/green-techcomponentsasSe,Te,Ge,Bi,As,Cd,Ga,TlandInarealsodetectedinSMSdeposits.

Most of SMS deposits are localised in the areabeyond the national jurisdiction whichadministratingbyInternationalSeabedAuthority(ISA). Currently 6 contracts for exploration ofSMSdeposits are signedbetweenStatesPartiesand ISA for theareas in theAtlantic and Indianoceans. Different geological and geophysicalmethods are used for the prospecting of activeand inactiveSMSdeposits.The firstexplorationcontractshouldbecompletedin2026.

SMSdepositslocalizedwithinEEZarethesubjectfor exploration study as well. Most of thesedeposits which distribute along the island arcsystemsinthePacificarewellexploredandevenreadytobemined(e.g.OkinawaTrough,BismarkSea). The technologies for futuremining are inprocessofbeingdesignedandmethodsofmetalsextractionfromSMSalreadyexistbeingsimilartothat of land-based volcanogenicmassive sulfidedeposits.

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ORAL

SulfidemineralogyoftheLoki’sCastlehydrothermalvent,ArcticMid-OceanRidge

KristianDrivenes1,BenSnook1andKurtAasly11NorwegianUniversityofScienceandTechnology

Samples from the active Loki’s Castlehydrothermal vent were collected from theseafloor by ROV during the MarMine cruise in2016. The hydrothermal vent sites consist ofblacksmokersystems,andassuchhavediversemineralogy with highly heterogeneous macroandmicrotextures.Thesamplescurrentlyunderinvestigationrepresentchimneycollapsebrecciaratherthanmassivesulphidefromthecoreofthedeposit. Sulfide mineralization in the whitesmokermaterialislimitedwithminorsphalerite,galenaandpyrite.Thelesscommonblacksmokermaterial is dominated by silica and sulfategangue, with sulfides occurring as lenses andpatches of fine-grained material and, locally,largergrains.

In the sulfide-rich areas, the sulfides occur inmineralogically and metallogenically distinctzones on the cm scale. The Fe-rich zonescomprises intergrownpyrite andmarcasite, theZn-richzones comprises sphalerite, and theCu-richzonescomprisesanisotropicCu-Fe-Sphase,likely isocubanite, with both sharp submicronlamellae and larger exsolutions of chalcopyrite.Minorpyrrhotiteandgalenawasobserved.Thereis significant overlap between the zones,especially the Zn-rich andCu-rich zones,wherethe isocubanite replaces sphalerite. Thesphalerite is infectedwith chalcopyrite disease,butunder theopticalmicroscopeseveralgrainsandzonesappeartobeinclusion-free.However,SEM investigations show lamellae in sphaleriteless than 100 nm wide, oriented in the samecrystallographic planes as chalcopyrite lamellaeinneighboringisocubanite,indicatingthatnotalllamellaeinsphaleritemaybevisibleintheopticalmicroscope.

ORAL

Uncertaintiesingrade,tonnage,anddistributionestimatesforseafloormassivesulfidedeposits

JohnWJamieson1andRolfBPedersen21MemorialUniversityofNewfoundland,DepartmentofEarthSciences,2K.G.JebsenCentreforDeepSeaResearch,UniversityofBergen

The economic potential of deep sea mining isultimately dependent on the size, grade, anddistribution of ore deposits on the seafloor.Forseafloor massive sulfide (SMS) deposits, therehave been several studies that have reportedquantitative estimates of the resource potentialatbothglobalandregionalscales(includingtheNorthAtlantic),andtheseresourceestimatesarebeingutilizedtodrivepolicydecisionsrelatedtothe economic potential of SMS mining, andassociated exploitation and environmentalregulations.However, thegeologicaluncertaintyassociated with these resource estimates issignificant. Development and regulatorydecisionsmustultimatelybetiedtonotonlythegrade and tonnage estimates of individualdeposits, but also an understanding of theassociateduncertaintyoftheseestimates.Inthispresentation,wewilldiscussthecurrentstateofknowledgeof thesize,gradeanddistributionofSMS deposits.We will focus on how theseestimates are determined, the evolvinguncertainties related to these estimates, andstrategiesthatshouldbeimplementedtoreducethese uncertainties, including approaches toexploration,samplinganddrilling.

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ORAL

Deepseamineralresourcesintheinternationalseabedarea

PedroMadureira1,HaraldBrekke2andGeorgyCherkashov31EMEPC,2NorwegianPteroleumDirectorate,3VNIIOkeangeologia,UniversityofSt.Petersburg

AccordingtotheUNConventionontheLawoftheSea, the seabed and subsoil areas of the worldoceans are divided into two parts: theinternationalseabedunderthejurisdictionoftheInternational Seabed Authority (ISA), and thecontinental shelf under the jurisdiction of thecoastalstates.Theresourcesoftheinternationalseabedarea(termed“theArea”),aremanagedbytheISAonbehalfofthemankind.Today,thereisan increasing interest for themineral resourcesof the deep ocean because of the demand forcertainmetals needed in green technology. ThemostpromisingmineralresourcesintheAreaforsupplyingglobalneedsarepolymetallicnodules,polymetallic sulphides and ferromanganesecrusts.Theyareregardedaspotentialsourcesofnickel,copper,cobaltandmanganese(nodules),ofcopper,zinc,leadandgold(sulphides),andofcobalt, tellurium,manganese andpossiblyREEs(crusts).Currently, the ISAhave28Contractorscarrying out exploration activities in the Area,rising from eight before 2011. Estimates of themineral resources of the deep sea are still veryuncertain. However, exploration and scientificstudiesinrecentyearsindicatethattheCoandNiresourcesofthedeepseaexceedsthoseonshorebytenandfourtimes,respectively.InthecaseofMn and Mo, the resources of the deep oceanmatch thoseonshore.Noonehas so far startedany commercial exploitationof these resources.TheISAiscurrentlydevelopingitsregulationsforexploitation, starting with the nodules. Theseregulationsshouldbecompletedby2020.

ORAL

TheSevenSistersHydrothermalSystemontheArcticMid-OceanRidge

AFAMarques1,RBPedersen1,DLRoerdink1,TBaumberger2,CEJdeRonde3,RGDitchburn3,IHThorseth1,IOkland1,MDLilley4,MWhitehouse5andADenny11K.G.JebsenCentreforDeepSeaResearchUniversityofBergen,Norway,2PacificMarineEnvironmentalLaboratory(PMEL),NationalOceanicandAtmosphericAdministration(NOA,3GNSScienceNewZealand,4SchoolofOceanography,UniversityofWashingtonUS,5SwedishMuseumofNaturalHistory,StockholmSweden

Wepresentnewfindingsontheshallow,hybrid,seafloor hydrothermal system (known as theSeven Sisters site) with epithermal-stylemineralization that is hosted by maficvolcaniclasts on the slow spreading NorthernKolbeinsey ridgeon theArcticmid-ocean ridge.Thesystemliesontopofaflat-toppedvolcanoat~130 m depth from which relatively hightemperature (up to 200°C) phase-separatingfluids vent from smoking craters and uniquepinnacle-like edifices on top of mounds. Thehydrothermal mineralization at Seven Sistersmanifestsas replacementofmaficvolcaniclasts,directprecipitationfromthehydrothermalfluid,andasvaporelementalsulfursublimates.Bariteisubiquitousandisreplacedbypyrite,whichisthefirstsulfidetoform,followedbyZn-Cu-Pb-Agbearing sulfides, sulfosalts and silica. Themineralized rocks at Seven Sisters containappreciable amounts of ‘epithermal suite’elements with secondary alteration minerals.VentfluidshaveapHof~5andareBaandmetal-depleted. Sulfide and secondary alterationmineralogy, fluid and gas chemistry, as well asd34Sand87Sr/86SrisotopevaluesindicatethatmineralizationatSevenSistersissustainedbytheinput ofmagmatic derived fluidswith seawatercontribution. Radiometric dating of baritesuggeststhatthishydrothermalsystemhasbeenactiveforatleast4670±60years.

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ORAL

PreliminarycharacterisationofpotentialseafloormassivesulphideorefromtheLoki’sCastledeposit,ontheArcticMid-OceanRidge.

BenSnook1,KristianDrivenes1,KurtAasly1andGavynRollinson21NTNU,2UniversityofExeter

Ensuring efficient ore characterisation isnecessaryforallstagesofmineplanning,therebystreamlining deposit identification, resourceextraction, mineral processing and wastemanagement. It provides information forcompositional, chemical, textural and mineralliberation considerations, and tracks theeffectiveness of mineral processing. As such,defining the most effective assessmenttechniques for new ore types is of highimportance.

In response to growing demand [1], potentialnew sources of copper and zinc have beenidentifiedinthedeepsea,fromseafloormassivesulphides(SMS)[2,3].OnesiteunderNorwegianjurisdictiondemonstratinggoodpossibilitiesforSMSmineralisationisLoki’sCastle,whereactivehydrothermalventingoccursat2400mdepthonthe slow spreading ArcticMid-Ocean Ridge [4].The site consists of two mounds, eachapproximately 150 m across and 30 m high,capped by 5 active chimneys releasing 320° Cfluids [4]. During the 2016 MarMine cruise [5]boulderswerecollectedfromthemounds’flanks,which represent collapsed chimney fragmentsthat have formed debris flows. The vent sitesappeartoconsistofbothwhiteandblacksmokersystems,andassuchhaveadiversemineralogywith highly heterogeneous macro and microtextures.

We report initial approaches to determininganalytical techniques to characterise SMS ore;petrography, geochemistry, and automatedmineralogy. Preliminary results indicate thattypicalsulphidemineralassemblagesinsampleswith elevated Cu and Zn grades comprise finegrainedchalcopyrite,isocubanite,sphaleriteand

pyrite,oftenwithcomplextextures:chalcopyriteovergrowths on isocubanite; sub-micronlaminations of chalcopyrite within isocubanite;micronscalechalcopyriteblebswithinsphalerite.

ORAL

CHARACTERISEINGMINERALREPLACEMENTSREACTIONSINCU-FE-ZN-SMINERALSFROMTHEARCTICMID-OCEANRIDGEUSINGSEM,EBSDANDOPTICALMICROSCOPY

BjørnEskeSørensen1,KristianDrivenes1andGertNolze21NTNU,DepartmentofGeoscienceandPetroleum,2BundesanstaltfürMaterialforschung,Berlin.DepartmentofMaterialsEngineering

Ore minerals in samples collected from blacksmokersatLoki’sCastleattheArcticMid-Oceanridgeshowcomplex intergrowthandexsolutiontextures.Cu-Fe-Smineral(s)appearinsphaleriteasseveralµmsizeroundedinclusions,orasfinelamellae parallel to {001}. Sphalerite (sph)(Zn,Fe)S is replaced by a Cu-Fe-S phase(isocubanite), which itself has exsolutions ofmostly submicron lamellae(chalcopyrite?). Thematrixphaseisisotropic,appearspinkishyellow,and has a composition close to cubanite(CuFe2S3). The lamellae are less pinkish, andhavecompositionsclosetochalcopyrite(CuFeS2,tetragonal). In addition, a second set ofexsolutions appears as wavy laths.Understanding the relations between themineralizing phases are imperative tounderstandthegenesisofthedepositsandhencealso to make realistic models of the economicpotential.

Further work will reveal more details on therelationshipbetweenthephases.Afterpolishingwith Ar-ions the pattern of isocubanite andsphalerite were indexable, however becausesphalerite and isocubanite have very similarstructurestheycouldonlybedifferentiatedusingthe combination of optical andbackscatteredelectron imaging, EDS (energy-dispersive

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spectroscopy) and EBSD. However, the EBSDreveals topotaxial relations between sphaleriteandisocubanitethatpreservestheorientationofthe host, reinforces the interpretation thatisocubanite replaces sphalerite rather thangrowing together with sphalerite. Differentmethodsof indexing thepatternsand improvedcollectionmay enableus todistinguish also thechalcopyrite lamellae from the host isocubaniteandsphaleritethoughthechalcopyritestructureisverysimilartothehostphases.

9.3. Open Session: EconomicGeology

ORAL

ParageneticevolutionofhydrothermalREEmineralisationintheOlserum-Djupedalarea,SESweden

StefanS.Andersson1,ThomasWagner2,ErikJonsson3andRadoslawM.Michallik11DepartmentofGeosciencesandGeography,UniversityofHelsinki,2InstituteofAppliedMineralogyandEconomicGeology,RWTHAachenUniversity,3GeologicalSurveyofSweden,DepartmentofMineralResourcesandDepartmentofEarthSciences,UppsalaUniversity,Uppsala,Sweden

TheREEmineralisationintheOlserum-Djupedalarea is located at the border of thePalaeoproterozoic Västervik sedimentaryformation and c. 1.8 Ga granitoids belonging tothe Transscandinavian IgneousBelt (TIB) in SESweden.Themineralisationisdominatedbythephosphates monazite-(Ce), xenotime-(Y) andvariablyREE-bearing fluorapatite.Thesemostlyformed, along with subordinate (Y,REE,U,Fe)-(Nb,Ta) oxides, during an initial hydrothermalstage. During a subsequent stage, allanite-(Ce)formedlocally,andsecondarymonazite-(Ce)andxenotime-(Y)alsoformed,mainlybyleachingandremobilisationofREE from fluorapatite. Similarcoupled dissolution-reprecipitation processessubsequently also affected primary monazite-(Ce), xenotime-(Y), and minor (Y,REE,U,Fe)-(Nb,Ta)oxidephase(s).ThismobilisedREE,Th,Uand Nb-Ta, and caused the formation ofadditional xenotime-(Y), monazite-(Ce),fluorapatiteandvariableamountsofallanite-(Ce)– ferriallanite-(Ce), uraninite, thorite andcolumbite-(Fe) (Andersson et al., 2018).Bastnäsite-(Ce)andsubordinatesynchysite-(Ce)characterise the youngest REE mineralisationstage, and formed from the low-temperaturealteration of allanite-(Ce) and ferriallanite-(Ce).We interpret the paragenetic sequence toessentially be the result of decreasing

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temperatures, from an initial high-temperaturehydrothermal stage (≥600°C) to a low-temperature stage (<<400°C). In addition, localdifferencesinfluidchemistry,particularlytheCacontent,aswellasfluidoxidationstate,facilitatedthe dissolution-reprecipitation processes, andultimately governed the stability of the REEmineralsintheoreassemblagesoftheOlserum-Djupedalarea.

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CriticalmetalmineralisationinSweden:overviewandhighlights

ErikJonsson1,KarinHögdahl2,MartiyaSadeghi1andNikolaosArvanitidis11GeologicalSurveyofSweden(SGU),DepartmentofMineralResources,Box670,SE-75128Uppsala,SwedenandDepartmentofEarthSciences,UppsalaUniversity,Uppsala,Sweden,2DepartmentofEarthSciences,Mineralogy,PetrologyandTectonics,UppsalaUniversity,Villavägen1

Critical metals, as part of what is presentlydefined by the EU(https://ec.europa.eu/growth/sectors/ raw-materials/specific-interest/critical_en) asCritical Raw Materials (CRM), are increasinglysought for from both primary and secondarysources.TheSwedishpartoftheFennoscandianShield,with itsmajororeprovincesBergslagen,Skellefte district and Norrbotten, contains asignificant number of primary sources,mineralisations with variably well-knownpotential for critical metal production.Traditional by-product critical metals such asantimony,cobaltandindiumarevariablyknown,the latter confined to some skarn-associatedsulphide-oxide mineralisations in westernmostBergslagen, while the former mainly occurshosted by accessory sulphosalts in polymetallicsulphide deposits in several regions, chiefly inBergslagen and the Skellefte district. , Cobalt isrepresented by several different deposit typesincluding e.g. skarns and volcanosedimentary-associatedmassive sulphides.While tungsten isknown from a number of deposits, these aretypifiedbutnotlimitedtoskarn-hostedscheelite,

which account for the most important andrecentlymineddeposits,locatedinnorthwesternBergslagen. Elevatedgallium and germaniumcontentsareassociatedwithrareearthelements(REE)-rich iron oxide skarn deposits inBergslagen,andthepotentialforREEisrelativelygood,intheseandothertypesofmineralisations,asrecentlynotedbyGoodenoughetal.(2016),inseveralareasfromsouthernSweden(NorraKärrandOlserum),viaBergslagen,to,a.o.,theKirunatype apatite-iron oxide ores of Norrbotten. TheREEsinSwedenwillbeoutlinedinmoredetailinan upcoming SGU report, based on work donewithintheEURAREproject(www.eurare.eu).

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TowardsReal-TimeOreGradeEvaluationusingLaser-InducedBreakdownSpectroscopy

LasseKangas1,RoelvanToorenenburg1andJussiLeveinen11DepartmentofCivilEngineering,AaltoUniversity,Espoo,Finland

Onminingoperations,Grade-controlisbasedonlaboratory measurements from blast-holesamplesorappropriatetypeofwelllogging(e.g.gamma logging) to characterizeeachblock.Theproblems with these techniques are that theyslow,costlyandtheresultsarenotimmediatelyavailable.Toovercometheseissues,itisessentialto develop new sensor technologies that canprovideelementalandmineralogicalinformationreal-timeandon-site.

Here, a case study using Laser-InducedBreakdownSpectroscopy(LIBS)andsamplesofParainenlimestonequarryispresented.Theaimof the research was to resolve, if LIBSmeasurements can be used to characterize theore body during the blast-hole drilling. ThequalityparametersthatareusedinParainenforthe ore grade evaluation are Ca/Si+Al and themagnesiumcontentofthesamples.Thesamplesconsisted of drill cuttings samples from threedifferent blast-holes and four bulk samples ofdifferentoregradescollectedfromthestockpiles.

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The bulk samples were crushed, sieved andresorted to get the same grain size distributionwith the drill cuttings. The cuttings and thecrushed bulk samples were measured by freefalling them via funnel to mimic the movingparticlesinthedrilltube.

The results from the LIBS measurements werevalidatedusingsynchrotronX-raydiffractionandgamma logging from the blast-holes. OurpreliminaryresultssuggestthatLIBScanbeusedas an on-line analyzing technique during thedrilling process. The ore type and anapproximationof theoregradecanbedetectedfromthespectraldata.

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Non-invasiveandnon-destructivequantificationofwollastoniteinlimestonesusingRamanspectroscopy

KatiLaakso1,LasseKangas1,SaaraKaski2,HeikkiHäkkänen3andJussiLeveinen11DepartmentofCivilEngineering,AaltoUniversity,Espoo,Finland,2DepartmentofChemistry,UniversityofJyväskylä,Jyväskylä,Finland,3DepartmentofBiologicalandEnvironmentalScience,UniversityofJyväskylä,Jyväskylä,Finland

Wollastonite is an economically importantmineral that is used to manufacture plastics,ceramicsandotherproducts.Finlandiscurrentlyamong the top producers ofwollastonite in theworld, and the largest in Europe. Finnishwollastonite is sourced from the Ihalainendeposit in Lappeenranta, southeastern Finland.Here, wollastonite is extracted fromPaleoproterozoic (1.9 Ga) limestones that alsohostindustrial-gradecalcite.Processingoftheserocks requires certain mineralogicalcompositions (e.g.: 21% of wollastonite) thatdetermine the processing quality of the rock.Currently, labor-intensive laboratory analyticaltechnology is commonly used for themineralogical characterization of rocks. Laser-spectralmethodshave thepotential topartiallyreplace such technologies, and for this end,

Raman offers a fast, non-invasive and non-destructivealternative.

To test the ability of the Raman technology toclassify wollastonite-bearing limestone rocksinto different quality categories, three sampleswere acquired from the Ihalainen deposit andthese samples were scanned using a Ramansetup.Differentdataanalysismethodswerethenapplied to map the spatial distribution andrelativeabundancesoftheminerals.Theresultswere validated using the scanning electronmicroscopy (SEM) system of the GeologicalSurveyofFinland.

Thepreliminaryresultssuggestthattherelativequantity and the spatial distribution ofwollastonite can be mapped using high spatialresolution Raman data. The ongoing study willnext focus on acquiringmore samples from thestudy area, and using these samples, to furthertest the potential ofRaman for the detection oftheprocessingqualityofrocks.

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Zn-Pb-Cusulfide-bearingglacialsandstoneerraticsnearRaaheonthewesterncoastofFinlandasindicatorsofPaleozoicbasemetalmineralizationatthebottomoftheBothnianBay

ErikNilsson1,EeroHanski2,HannuHuhma3,YannLahaye3,TimoMäki4,HughO'Brien3andKariStrand21GeosciencesandEnvironmentalEngineering,LuleåUniversityofTechnology,Sweden,2OuluMiningSchool,UniversityofOulu,Finland,3GeologicalSurveyofFinland,Espoo,Finland,4FirstQuantumMineralsLtd.,Pyhäsalmi,Finland

Over the past tens of years, sandstone erraticsvariably enriched in Zn, Pb and Cu have beencollectedfromthecoastsouthofRaahe,buttheirsource has remained unclear. In these non-metamorphosed and non-deformed erratics,detrital grainsofquartzandminor feldspararecementedbycalciumcarbonate,which ispartly

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or wholly replaced by ore minerals, includingsphalerite, galena, pyrite, marcasite, andchalcopyrite. Analyzed boulders have yieldedtotal base metals contents between 1 and 10wt%. The FeS content in sphalerite is low andvariable,rangingcommonlybetween0.5-15mol-%,whichisinharmonywithitscoexistencewithpyrite.

Galena shows very radiogenic Pb isotopecompositions, with 206Pb/204Pb falling in therange of 20.55−21.06 and 207Pb/204Pb between15.90and15.94.Thesecompositionsaresimilarto those measured for the Laisvall Pb-Zn MVTdeposit in the Swedish Caledonides, beingconsistent with a similar Ordovician age of oreformation.However,Sisotopeanalysesofpyriteyieldedmostlynegativeδ34Svaluesfrom−15.6to−7.6, which are distinctly different from thegenerallyheavysulfurisotopecompositions(ave.+24) reported from the Laisvall-type deposits.These results togetherwith somemineralogicaldifferences(presenceofchalcopyrite,absenceoffluorite and barite) suggest that the boulderswere not derived from the eastern front of theCaledonianorogenbuttheirsourceoccursmuchcloser, likely being a so-far-undiscovered basemetaldepositundertheBothniaBay.

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Cu-MomineralizationepochsinNWIranandtheirtemporalrelationshipwithmetallogeniczonesofneighboringLesserCaucasusandCentralIran

VartanSimmonds11ResearchInstituteforFundamentalSciences,UniversityofTabriz,Tabriz,Iran

The Tertiary Urumieh–Dokhtar magmatic arc(UDMA) in Iran represents the northeast-wardsubduction of the Neo-Tethyan oceanic crustbeneath the central Iranian domain during thelate Mesozoic-early Cenozoic. It coincides withtheporphyrycoppermetallogenicbelt,including3metallogeniczonesinNW(Ahar-Jolfa),central

andSEparts,whichhostmanyporphyrycopperdeposits (PCDs) and prospects. The Ahar-Jolfametallogenic zone includes the Qaradagh andSheyvardagh batholiths and many smallerintrusions and includes porphyry, skarn andvein-typemineralizations.Thiszonesharesmanymagmatic, geodynamic and mineralizationfeatures with the neighboring South ArmenianBlock (SAB), where the Meghri-Ordubadcomposite pluton of Eocene-Miocene age hostsmany porphyry Cu-Mo deposits. By comparingthe measured Re-Os and U-Pb ages ofmineralizations inNW Iran [1,2,3,4,5], it canbeconcluded that porphyry mineralizations haveoccurredinthreeepochsoflateEocene(~35Ma),middleOligocene(31-25Ma)andearlyMiocene(22-20 Ma). Mineralizations here coincide withthe third epoch of suchmineralizations in SAB,which are associated with Eocene to Mioceneintrusions,whiletheoldermiddleJurassic-earlyCretaceousandupperCretaceousepochsofSAB[6] have no reported counterparts in Iran. Thefirst epoch of NW Iran postdates all Eocenemineralizations in SAB. The second epoch iscoeval with Paragachay and the first-stage ofKadjaranPCDs.Thethirdepochisyoungerthanall mineralizations in SAB, except the secondstage of Kadjaran PCD. These epochs are olderthannearlyallPCDsandprospectsinCentralandSEIran,revealinganoldtoyoungtrendalongtheUDMA.

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2DelementalmappingofpyritebyLA-ICP-MS:anapplicationinvisualizingAuenrichmentprocess

LingliZhou1,BalzKamber1,GuotaoSun2andQingdongZeng21IrishCentreforResearchinAppliedGeology,GeologyDepartment,TrinityCollegeDublin,2InstituteofGeologyandGeophysics,ChineseAcademyofSciences

Pyrite is commonly associated withmineralization in deposits forming in differentenvironments. The spatial distribution of tracemetals inpyritecanbeheterogeneous,andmay

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contain genetic information. With thedevelopmentof2DtraceelementmappingwithLaserAblationInductivelyCoupledPlasmaMassSpectrometry (LA-ICP-MS) it is nowpossible toreveal, in much greater detail, the interiorcompositionaltexturesofpyrite,andthuspermitinvestigation of themineralisation process thatrecordedinthecrystallizationhistoryofpyrite.

Here we report two cases of 2D elementalmapping of pyrite in investigating Aumineralisation process. Pyrite samples werecollected from a quartz pebble conglomerate ofthe fluvial Mississagi Formation, Canada (thebasal part is Au abundant), and from theQingchengzi Pb-Zn-Au-Ag ore field, NE China,respectively. The trace element maps reveal acommonexistenceof core-rim structure for thepyritefromMississagiFm.Thedetritaloriginofpyriteisreadilydemonstratedfromroundingofindividual grains and cores and the revealedtruncated texture of originally rounded detritalfragments.Goldisfinelydispersedinthedetritalcores/grains, indicating a significant amount ofAu was suspended in the river flows for theenrichment. Two distinct episodes of goldenrichment are distinguished from the elementmaps of pyrite from theQingchengzi Pb-Zn-Au-Ag deposits: an early syn-sedimentary stagewheninvisiblegoldisconcentratedindiageneticpyrite, and maybe re-mobilized and re-concentrated later; and a later hydrothermalstagewheregoldformsaseitherfreegoldgrains,orasinvisiblegoldinthepyrite.

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REE-enrichmentinPalaeoproterozoicbandedironformations,Bergslagen,Sweden:primaryprecipitationorhydrothermaloverprint?

MarcusBrismo-Ploetz1,KarinHögdahl2andErikJonsson31DepartmentofEarthSciences,UppsalaUniversity,Villavägen16,SE-75236Uppsala,Sweden,2Dept.EarthSciences,UppsalaUniversitySwedenandGeologyandMineralogy,ÅboAkademiUniversity,,3GeologicalSurveyofSweden,Uppsala,SwedenandDept.EarthSciences,UppsalaUniversity,SwedenandDepartment

ofEarthSciences,UppsalaUniversity,Uppsala,Sweden

In the Svecokarelian bedrock of south centralSweden, and specifically, the Bergslagen oreprovince, hematite-dominated banded ironformations (BIF) constitute one of three majortypesofironoxidedeposits.Recently,duetotheincreasedcriticalityofrareearthelements(REE)through their applications inmodern industrialand low-carbon/energy saving technologies,severalprojectshavebeenundertakentoexploretheir potential distribution in previouslyunknowndepositsanddeposittypes.AmongtheresultingdiscoverieswereREE-mineralisedBIFs(e.g. Jonsson & Högdahl 2013). In the Högforsmines,silicate-dominated[e.g.cerite-(Ce)andFe-analogue of västmanlandite-(Ce)] REEmineralisation was interpreted to have formedfrom epigenetic processes resulting in localisedREE-enriched skarn replacing carbonateinterlayers,i.e.apost-depositionalhydrothermaloverprint. Subsequent sampling and analyticalwork revealed REE-enrichment in other BIFdepositsinthispartofBergslagen,e.g.attheNyaBastnäs field (8500 ppm REEtot), Storgruvan(1300 ppm REEtot), and Myrbacksfältet (8000ppm REEtot). The main REE hosts here areallanite-(Ce), REE-enriched epidote, and cerite-(Ce).Thesedepositsarelocatedinclosevicinityto REE-rich skarn deposits in the REE-line(Jonsson & Högdahl 2013), but REE-anomalousBIFshavealsobeenidentifiedoutsideofthisarea.TheBIF at Forsbo, located further to thenorth,has a REEtot of 1800 ppm, mainly hosted bymonazite-(Ce). A post-depositional, epigenetic,yet pre-tectonic origin for the the REE-enrichment in the BIFs along the REE-line issuggested by geological, mineralogical andtextural evidence. The phosphate-hosted REEmineralisation in the Forsbo BIF, on the otherhand, appears to potentially having formedthroughprimaryprecipitation.

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POSTER

CharacterisationoftheKivilompoloMolybdenumMineralisation,PeräpohjaBelt,NorthernFinland

MatthewGoode1,Jukka-PekkaRanta2,HolgerPaulick3andEeroHanski41UniversityofOulu,MScStudent,2UniversityofOulu,DoctoralStudent,3UniversityofOulu,ProfessorofEconomicGeology,4UniversityofOulu,OuluMiningSchoolDeanofEducation

The Paleoproterozoic supracrustal PeräpohjaBelt hosts several poorly studied metaloccurrences. One of these includes theKivilompolomolybdenitemineralisation,initiallydiscoveredinthe1950´s.Mineralisationoccursinboudinagedquartzveinswithingneissicgranitesadjactenttothe1.99Gapre-orogenicKierovaaragranite (Ranta et al. 2015). The ore mineralsconsistofabundant,coarsegrainedmolybdeniteflakes, in addition to pyrite, pyrrhotite andchalcopyrite.Mineralisation occurs in a roughly3kmlongzoneand,basedondrillholes,extendstoadepthofatleast150m(Yletyinen1967).

Preliminary singlemolybdenite Re-Os dating ofthemineralisationgivesanageof1.99Ga(HollyStein pers.comm), which is consistent with theadjacent Kierovaara granite. The precise age ofthe host granite is not known, but the closeproximity of the Kierovaara granite wouldsuggest a similar age. Discovery of high-gradePalokasAu andRompasAu-Umineralization inthePeräpohjaBelthasgivenimpetustostudythisoccurrence.

Combined outcrop and boulder mapping wascarriedoutinJuneof2017inordertodeterminethe extent of the mineralised zone. Detailedpetrographical analysis of the host rock andmineralised zone will be carried out to betterunderstandthenatureoftheoccurrenceandtherelationship between deformation and themineralisation.Wholerockanalysisofanumberof channel samples will be carried out todetermine the presence or absence of amineralisedhaloaroundthedeposit.U-Pbdatingofzirconfromthehostrockwillprovideaprecisecontrolontheageofthemineralisation.

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Au-Ag-(Bi-Te-Se)-enrichedpolymetallicveinmineralisationsinSWSweden:oremineralogyandthermalevolution

ErikJonsson11GeologicalSurveyofSweden,DepartmentofMineralResources,Uppsala,SwedenandDepartmentofEarthSciences,UppsalaUniversity,Uppsala,Sweden

Polymetallic Au-Ag-(Te-Se)-bearing quartz (-carbonate) veins formed in association withlarge-scalecrustaldeformationprocessesduringthe c. 1 Ga Sveconorwegian orogeny and itsaftermatharewidespreadinSWSweden,chieflyin Dalsland and Värmland. Previously, oremineralogicaldatahavebeenreportedforsomeVärmland veins (cf. Alm& Sundblad 1994, Alm2000, and references therein), whereasinformation on the Dalsland veins has beenoverall lacking.Thepresent studyformspart ofanattempttoincreasetheknowledgeofthenobleand critical metals-rich deposits in this region;within this framework, new observations fromtheVärmskogveinswerealsosuppliedbyNysten(2013).

Inmostofthestudieddeposits,theoccurrenceofAg-Bi-Te-Se-rich minerals is interpreted tomainly represent unmixing during cooling of ahigher-Tsulphidephasecarryingabundanttracemetals;mostly represented by bornite, but alsogalena,chalcociteandchalcopyrite.Observations,including the presence of exsolved Bi-richminerals such as wittichenite (Cu3BiS3) andmiharaite(Cu4FePbBiS6)suggestsuchhighinitialtemperatures; Bi-rich bornites able to exsolvesuch phases have been termed “bismuth-saturated”andform>400°C(cf.Cooketal.2011).Theidentificationofaccessoryoreminerals(andtextures) suchasaltaite (Ag2Te), argentopyrite-sternbergite (AgFe2S3), clausthalite (PbSe)-galenasolidsolutions,empressite(AgTe),hessite(Ag2Te; both twinned and untwinned), Hg-amalgams, jalpaite (Ag3CuS2)-galenaintergrowths, matildite (AgBiS2) in galena,

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mckinstryite [(Ag,Cu)2S], native tellurium,naumannite (Ag2Se)-sulphide intergrowths,stibnite (Sb2S3), stromeyerite (AgCuS), petzite(AuAg3Te2) reaction rims, anduytenbogaardtite(Ag3AuS2) combine to reveal an extensiveevolution at decreasing temperatures, fromaboveandaround300°C,tobelow100°C.

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CrustalstructureandhostinglithologyaccountforthespatialdistributionofgoldmineralisationinSWFinland

JaakkoKara1,TuomasLeskelä1,IiroPitkälä1,JanneHokka2,PietariSkyttä1,MarkkuTiainen2,HannaLeväniemi2andMarkkuVäisänen11DepartmentofGeographyandGeology,UniversityofTurku,2GeologicalSurveyofFinland

New gold occurrences have been recentlydiscovered in the Häme Belt, southwesternFinland (Grönholm and Kärkkäinen 2012,Tiainen et al. 2017). The Geological Survey ofFinlandand theUniversityofTurku launchedatwo-yearcollaborativeprojecttoinvestigatethelinkbetweenthespatialdistributionof thegoldmineralisations, the regional-scale bedrockstructureandthehostinglithologies.Theprojectalsoaimsat trainingyounggeoscientistswithinthefieldofeconomicgeology.

Two months of field work carried out in thewestern part of the study area in 2017concentrated on structural mapping tocharacterizethekinematicsofthemajorN-SandE-W trending shear zones, and structural andlithological mapping of the Uunimäki goldmineralization(Kärkkäinenetal.2016), locatedclose to the intersection of the shear zones.Moreover, conductedmapping and sampling ofmaficintrusiverocksprovidesmaterialtostudythegeochemicalsignaturesandfertilitiesofmaficrocks which seem to host several known goldmineralizationsinthetargetarea.

Thenext stage of the project involvesU-Pb agedeterminationstodatethegold-hostingintrusive

rocksandtheshearzoneactivities,andshiftingofthespatialfocusonthecentralandeasternpartoftheHämeBelt.Thematically,wewillapplythemethodsofprospectivityanalysistounderstandtheexplorationpotentialforgoldmineralisationswithinthearea.

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AccessorymineralswithintheSAM–apreliminarycasestudy

MichalRuszkowski1andJaninaWiszniewska21DepartmentofGeology,UniversityofWarsaw,ŻwirkiiWigury93,02-089Warsaw,2PolishGeologicalInstitute-NationalResearchInstitute,Rakowiecka4,00-975Warsaw

Suwalki Anorthosite Massif (SAM) is a part ofMesoproterozoic, beltiformmagmatic AMCG[anorthosite - mangerite - charnokite - graniterapakivi]suite known as a Mazury Complex(Wiszniewska J., 2002).Fe-Ti-V large oredeposits were established within SAM.NanoconcentrationsofREE(La,Ce,Nd),PGE,AuandzirconmineralsareoftenpresentinsulphideFe-Cu-Co-Nidispersedmineralisation.Theirsizeranges from10-150µmor in some cases up to250µm.

Hydrothermal concentrations of unusualzirconium elongated forms have been observedwithin the polymetallic SAM mineralization,suggesting their hydrothermal origin (Bin F.,2009).Zirconsformalsodispersedgrains,whichareof igneousorigin and thin fillings, filamentsandrimsaroundoreminerals.Thinzirconrimsareof80-250µminlengthand4-30µminwidthand they accurate imitate the shape of oreminerals. The biggest form was observed inuntypical zircon form of “blown candle flame”structure. Enrichment of large quantities of Hf(0,5-0,8 mass %) were measured by SEM-EDSmethod.Widerpartsof thinzirconrimsaroundore minerals were prepared for agedeterminationsandisotopicanalysesbySHRIMPIIemachineatPGIinWarsaw.

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Numerous small inclusions of Te (0,4-0,7 mass%) were measured in hydrothermal sulphides,especiallyinmillerite.Theyaregroupedinsmallforms, which are directed along flow of hotsolutions.2-4µminsizeofsingleinclusionswereobserved.

New results of accessory minerals inpolymetallic mineralisation may increase ourknowledgeoftheevolutionofdocumentedSAM.

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PlatinumGroupElementMineralizationoftheRF-4drillcore,ReinfjordUltramaficComplex,Troms,Norway

LarsTollefsrud11NorwegianUniversityofScienceandTechnology(NTNU)

TheReinfjordUltramaficComplex(RUC)isapartoftheSeilandIgneousProvince(SIP).TheSIPisgivenanageof560-570Ma(Robertsetal.2006),andisapartoftheKalakNappeComplex.Thus,the SIP is a part of theMiddle Allochton of theCaledonian thrust nappe. The RUC comprisesrocks that of dunitic, wehrlitic and olivine-clinopyroxeniticcompositionand is surroundedbymetasedimentsandgabbro.Chemicaldataoffour drill cores from theRUC (RF-1, RF-2, RF-3andRF-4)displayplatinumgroupelement(PGE)anomalies in the upper third part of the drillcores.

Detailedworkon thePGEmineralization in theRF-1 drill core of the was performed EvenNikolaisen (2016). Nikolaisen discovered thatmajority of the platinumgroupminerals (PGM)werepresentastellurideshostedbybasemetalsulfides(BMS).

The writer desires to continue the work byNikolaisenby investigatingthePGMintheRF-4drill core. The RF-4 drill core is located on thefootwall of what is likely to be a normal fault,whiletheRF-1drilloreistakenfromthehanging

wallofthesamefault.ThewriterwillinvestigatethedistributionandchemistryofthePGMtogaina better understanding into the ore formingprocesses. Scanning electronmicroscopy (SEM)and electron probemicro analyzer (EPMA)willbeutilized, aswell as transmitted-and reflectedlight microscopy for studying base metalsulfides.Thermodynamic software such asPerpl_x and MELTS may be used to modelstabilityofsilicatesandsulfides.

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10.Engineeringandenviromentalgeology10.1.GeohazardsintheNordicandArcticregions

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ArtificiallysupplyofwaterforreleaseoftheVeslemanneninstabilityatManneninRomsdalen,westernNorway

LarsHaraldBlikra1,LeneKristensen1andGustavPless11TheNorwegianWaterResourcesandEnergyDirectorate

Permanent monitoring and early warningsystems were established at the unstable rockslope Mannen in 2009. The instrumentationincludes a comprehensive surface network inaddition to120mdeep instrumentation in twoboreholes. A periodic ground-based InSARcampaignin2014identifiedlargedisplacementsin a small portion of Mannen (Veslemanneninstability).Thevolumeisbetween120.000and180.000 m3. The possible runout area includessomefewhouses,afarmandtherailway.Stagesof increased velocities in 2014, 2015 and 2016ledtoevacuationofpeople,animalsandclosingof the railway. These events have attracted amassivemedia interest.Thishas shown tobe achallenging situation for the evacuated people,the municipality and for NVE having theresponsibilityforthemonitoring.

NVEdecidedtoartificiallyaddwaterinordertoreducethestabilityandpossiblyreleaseapartorthe entire Veslemannen instability, and wasperformed two times in October 2017 duringperiodswerepeoplewereevacuated(redhazardlevel).Thedisplacementsbeforetheexperimentwasalreadysignificantandtheadditionalwatersupply had an effect in terms of increaseddisplacements. However, the area stabilizedagain when temperatures lowered below zeroandtheprecipitationcameassnow.

There are a series of challenges related to“helpingnature”intermsofartificialtriggeringoflandslides.Thisincludesthemediaattentionandcommunication issues related to evacuatedpeople,municipalityandother

ORAL

Anautomaticwatchofaslope,Lacàl’Eau-Claire,Nunavik

ArmelleDecaulne1andNajatBhiry21CNRS,LETGUMR6554,Nantes,France,2UniversitéLaval,Centred'étudesnordiques,Quebeccity,Canada

TheslopetopographyandtalusmorphometryinLac à l’Eau-Claire (56°20’N; 76°17’W) indicateinheritedandactivegravityprocesses.Evidenceofrecentactivityhasbeenobservedduringfieldinvestigations. However, the identification ofgravityprocessesonslopesremainsdifficult, asnoeventhaseverbeenreportedandnowitnessis able to relate any event in this remote area.Nevertheless, Lac à l’Eau-Claire is traversed byCree and Inuit hunters and fishermen all year-round, and a well-known place for trap. Lac àl’Eau-ClaireisalsopartoftheTursujuqNationalPark, and welcomes tens of tourists each year.Gravityprocessesthusbecomenotonlyphysicalprocesses,butraisehazardandriskissues.

In an attempt to better know the year-roundgravity processes acting on Caribou slope, weinstalled in August 2016 an automatic camera.Thisslopehasbeenselectedbecauseitpresentsfresh scattered boulders indicative of recentslopeactivity;furthermore,theapicalrockwallisheavily affected by frost weathering and deepcracks are opening on the uppermost of therockwall. From the collection of 2855 pictures,we are able to survey gravity movements andsnowcoverevolutionontheslope.

ThecameraatCaribouslope,andthreeotherondifferent slopes, is now operating. Additionalcameras surveying slopes and slope processeshave also been installed in other places

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encountering gravity processes in Nunavik: inTasiapikvalley,south-eastofUmiujaq;andoverthe road leading to the airport inKangiqsualujjuaq.

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ArtificiallytriggeringofRockFallinNorway.Methods,consequencesandlessonslearned.

UlrikDomaas1andTrondVernang11NorwegianGeotechnicalInstitute

Securingroads,housingareas,constructionsitesandprotectivework from rock fallmay involveartificially blasting, scaling and other means inaddition to ordinary protectiveworkwith rockbolts,wireropenets,wireropefencesanddams.Foreseeing the consequences of artificiallyreleaseofrockfallforhumanactivitiesbelowaredifficulttoevaluateduetothecomplexityofsuchactivity. Making evacuation plans withoutknowingtheexactoutcomeofrockfallreleaseisnecessary to do before executing the rock fallrelease. Improved planning, hazard zoning,involvement of local authorities, police andrescueteamcangiveasuccessfuloutcome.Closecooperation with entrepreneurs and decisionmakers during thework is vital. Information inpeoples meeting and in local newspapers isnecessary. Triggering of loose rock withmoderate volumes may cause larger rock fallvolumethanexpected,producingdustcloudandrock fragment splashing far beyond knownrunout.Rockfallmaterialmayalsotriggerdebrisflow days after the event itself.Removing looserockswithwaterorfreehangingironballunderhelicopter is efficient to clear an unstable area.Useofairpilloworrubbermatsmaybeefficienttoreleasesingleblocsbutcanbedifficultinsteepmountainsides.Systematicassembledknowledgeofmethods,cases,andunforeseenconsequencesfromartificiallytriggeredrockfallsisneededandwillbebeneficialtoallsidesoftheindustry.

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ContinuouslymonitoringofGámanjunni3,26Mm3unstablerockslide,Kåfjord,northernNorway.

GudrunDreiåsMajala1,LarsHaraldBlikra1,LeneKristensen1andIngridSkrede11NVE

Gàmanjunni 3 is classified as a high-risk objectbased on the movement, structures and theconsequences of the rockslide. As a high-riskobject,theunstablerockslideneedcontinuouslymonitoring.

ThesectionforrockslidemanagementinNVEareinchargeofallunstablerockslopes(7inpresent)thatareclassifiedashigh-riskobjectsandsomeobjects that needs periodic monitoring. NGU isresponsibleforthemappingandclassificationoflargerock-slopefailures.

Gámanjunni 3 is a 26 Mm3 large unstablerockslide located in Kåfjord, northern Norway,and is the third monitored site in themunicipality.Gàmanjunni3hasamovementof2-6 cm/year towards W-SW and has a fullydeveloped wedge with a 150 m verticaldisplacement.AlargerockslidefromGámanjunni3willcrossthevalleyanddamtheriver.

Since October 2016 NVE have established 10GPS-antennas, 3 different web cameras, 4platforms for helicopter and a weather stationthat forms the monitoring network. A ground-based radar in the valley further monitor therockslide.Inordertoimprovethesignalfromthesatellite radar (InSAR), corner reflectors areplaced in the unstable area. Investigations interms of resistivity and seismic surveys havebeen performed in order to build a bettergeological model. Run-out modelling, dam-breach analysis and flood modelling arecompleted.

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Permafrostrockwallsinnorway-Thermalregimeandgeomorphologicalprocessesintimeandspace

BerndEtzelmüller1,FlorenceMagnin1,KristinS.Myhra2,BenjaminJacobs3,MichaelKrautblatter3andSebastianWestermann11UniversityofOslo,2WesternNorwayUniversityofAppliedSciences,3TechnicalUniversityMunich,Germany

The role of the ground thermal regime ongeomorphological processes in settingsassociated to steep slopes has receivedconsiderable attention in the past. It is evidentfrom recent studies that e.g. rock walls have aprofound effect on the thermal regime inmountain sides, a.o. influencing rock wallstability, weathering regimes and glacier-permafrost interaction in space and time. Thispresentation discusses the importance of thethermal regime in space and time ongeomorphologicalprocesses insteepslopes.Wecombine direct observations of air, ground androck wall temperatures with numericalsimulations. We present results from boththermal(2Dtransientthermalmodel-CryoGRID2D) and thermo-mechanical modelling alongwith Electrical Resistivity Tomography (ERT)validation of different sites dominated byunstablerockslopesinNorway.Weanalysehowthermal gradients in rock walls may influenceimportantgeomorphologicalprocessesrelatedtoweathering, talus developments, materialaccumulation and ice aggregation in coarsematerial. On longer time scaleswe hypothesisethat permafrost dynamics associated withglaciation and deglaciation phases may haveinfluencedthedevelopmentandstabilityoflarge-scalevalleysystems.

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Artificialtriggerofthelarge-scaleChapfrockinstabilitybytwoblastingsin2001/2002,BerneseOberland,Switzerland.

UeliGruner11Kellerhals+HaefeliAG,Bern,Switzerland

Alargeunstablerockmassofabout250’000m3called Chapf near Innertkirchen (BerneseOberland, Siwtzerland) was continuouslymonitored during 50 years. The Grimsel Passroad is situated about 1‘000m below and wasthus endangered. The movement wasaccelerating from about 1 cm/year up to 0.6cm/dayduringtheyears1999to2001.Thereforethe Canton of Bern decided to take emergencymeasures.First,thecollapsewasintendedtobetriggered by infiltrating water into the openjoints, as the movements reacted strongly toprecipitation. The watering had to be stoppeddue to the seasonal decrease of the availablewater. Finally, the unstable rock mass wasremovedbytwobigblastings.

Theremovalwascarriedout in twosteps fromthe top to the bottom. In a first step, 156boreholes up to 95m deepwere drilled in theupperhalfoftheabout150mhighrockwall.Witha digital elevation model based on aerialphotographs and laser scanning a 3D-model ofthe jointswaselaborated inorder todeterminethe explosive charge. The blasting in October2001 with a total of 19'000 kg of explosivdenudatedabout150’000m3ofrock.

ThesecondblastinginAugust2002wasplannedwith a similar approach as 2001 (21’000 kg ofblastingcharge).About110’000m3ofrockwereblasted.Bothblastingswereverysuccessful:ThestablerockwalloftheChapfwasnotaffectedandconsequently this area does not endanger theGrimselPassroadanymore.

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GeologicalobservationsofthelandslideofJune17,2017inKarratFjord(centralWestGreenland)

PierpaoloGuarnieri1andErikVestSørensen11GEUS-GeologicalSurveyofDenmarkandGreenland

OnJune17,2017alandslideoccurredalongthesouthern slope of the 2180m-highUmiamakkuAuffaa in the Karrat Fjord, central WestGreenland(Lat.71º38’).Therockmassslidintothe Kangilleq Fjord generating a tsunami thatseverely damaged the village of Nuugaatsiaqlocated35kmtothesouth-west.TheKarratFjordregionispartofageologicalmappingprojectinthe Uummaanak region between the GeologicalSurvey of Denmark and Greenland (GEUS) andthe Government of Greenland. During fieldoperations conducted in 2015-2017 a largenumber of oblique, high-resolution stereo-images were acquired for photogrammetricstudies coupled with geological observationcoveringtheentireregion.Thisallowsustostudythegeologyandstructureof theregion in threedimensionsand ingreatdetail.Detailedobliquephotos along the southern flank of UmiamakkuAuffaawerecollectedin2015, twoyearsbeforethe rockslideevent, andagain in July2017,onemonth after the disastrous event. This gives usunique control of the geological and structuralsettingbeforeandafter the landslideeventandfurthermoreallowsustoestimatethesizeofthelandslideprecisely.Thegeologyofthatparticulararea is represented by quartzites, amphibolitesand meta-pelites belonging to thePalaeoproterozoicQeqertarssuaqFormation.3D-photogeology in theGEUSPhotogrammetry-Laband field data shows strongly foliated meta-volcanic andmeta-sandstone rocks dipping 20°to the SW. The downslope setting toward thefjord and the tectonic layering suggest alithological and structural control for thelandslidemechanism.

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Cosmogenicnuclidedatingofrock-slopefailuredepositsandrockslopedeformationinTromscounty,northernNorway

ReginaldL.Hermanns1,MartinaBøhme1,JohnGossse2andSamuelNiedermann31Norgesgeologiskeundersøkelse,2Dalhousieuniversity,3GeoForschungsZentrumPotsdam

SystematicmappingforunstablerockslopeshasbeencarriedoutinTromscountysince2007and129unstablerockslopeswererecognized(morethanonethirdofallknowninNorway).Despitethis large number, the 1810 Pollfjellet rockavalancheistheonlyhistoriceventinthecounty.Wedateddepositsofrock-slopefailuresandrockslope deformation by cosmogenic nuclide (CN)dating.Mostofthedepositsofrock-slopefailuresdate to shortly after deglaciation in this region.However,agesalsospantheentireHolocene.

FourslidingsurfacesthatdissecthighaltitudeflatsurfaceshavebeensampledforCNdating.Twoofthese top surfaces have been dated to be olderthanLGM,whilefortheremainingtworesultsareexpected soon. Two of those surfaces aredissected by deep-seated gravitational slopedeformations (DSGSDs). Both topmost slidingsurfaceshaveagesintheupperpartthatpredateLGM.BothDSGSDshavecollapsedepositsalongtheirfootthatdateshortlyafterdeglaciation.Theother two top surfaces are dissected byrockslides. Both became activewithin or at theend of the thermal maximum within theHolocene.Noneofthosearerelatedtoanyrock-slopefailuredeposit.Ourdatathussuggestthatrock-slope deformation in Troms county is aprocessthathasbeenactivefrombeforetheLGMand DSGSDs can survive glacial cycles in cold-basediceenvironments,whilerockslidesratherseemtobephenomenathatstartedandpeakedafterdeglaciationandmaintainonalowconstantratewithintheHolocene.

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Destabilisationandtemporaldeformationpatternsofrock-slopeinstabilitiesinNorthernandWesternNorway

PaulaHilger1,ReginaldL.Hermanns2,KristinS.Myhra3,BerndEtzelmüller4andJohnC.Gosse51GeologicalSurveyofNorway;UniversityofOslo,2GeologicalSurveyofNorway;TechnicalUniveristyTrondheim,3HøyskolepåVestlandet,Sogndal;UniversityofOslo,4UniversityofOlso,5DalhousieUniversity,Halifax,Canada

Morethan300activerockslopesdemonstratingpostglacialdeformationaremappedinNorway,whereofsevenareclassifiedashigh-riskobjectsbecauseoftheirslidingratesandpotentialimpacton infrastructure. In addition to post-glacialstress increase, we expect water pressure andaltitudinal permafrost dynamics to significantlyimpactthesegravitydrivenslopeprocessesalongcomplexpre-existingbedrockstructures.

To improve understanding of the potentialinfluenceofpost-glacialpermafrostdynamicsonrock-slopefailures,weuseterrestrialcosmogenicnuclide(TCN)datingalongthreeslidingsurfacestoderivethetimingofinitialfailureandpotentialsliding patterns since the onset of deformation.Preliminary TCN ages of the Mannen andRevdalsfjellet 2 instabilities in western andnorthern Norway respectively, suggest thatsliding started close to the Holocene ThermalMaximum,whenmountainpermafrostpresencewasataminimum.Thisindicatesthatpermafrostthawingmay have contributed to the timing ofthese rock-slope instabilities. The preliminaryresults of Revdalsfjellet 1, which is an adjacentbut independently moving rock body toRevdalsfjellet 2, suggest a movement onsetduring strong temperature fluctuations in themidHolocene.

Recent acceleration of deformation at theMannen site could be connected to late stagepermafrost thawing at the lower boundary ofaltitudinal permafrost, whereas relatively slowdisplacement rates at the Revdalsfjelletinstabilities connected to their low elevation of

600 m a.s.l. seem to be dissociated fromcontinuous permafrost. The different timing oftheinitialfailureatthetwoadjacentinstabilitiesdemonstrates the structural complexity of thesitesandimportanceoflocalsettings.

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Monitoringactiverockfallandavalancheevents

LeneKristensen1,IngridSkrede1andLarsHaraldBlikra11NVE

Movementsinreleaseareashavebeenmeasuredprior to both rock fall events and snowavalanches in Western and Northern Norway.Our results indicates that bothpriormovementand acceleration phases can be identified rockfallsandavalanchesandmaypotentiallybeusedasearlywarning.However–inseveralinstanceswe have measured large movements andaccelerations that stopped due to changedconditions(meteorologyetc.).

Themovements have beenmeasured primarilyusing ground based InSAR systems (LiSALab),while change detection and analysis has beenaided using point clouds from terrestrial laserscans. In combination the datasets allows fordetailed detection of howmovement relates torockstructures.

Theexamplespresentedareapartofaresearchproject, aiming to obtaining acceleration curvesof different types of slide events. NVE isresponsibleforalltypesofgeohazardrelatingtoslides (rock, clay, avalanches etc.) as well asflooding in Norway. The Section for RockslideManagements primary responsibility ismonitoring of seven high risk rock slides inNorway, and periodic monitoring of less riskyobjects. We base the monitoring on theassumption that large rock slopes develop overtime and accelerates prior to failure. In theproject we extend the methodology andequipmenttostudyothertypesofslides.

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Measurementsofmovementinsourceareascangreatly aid a visual inspection of stability andprovideabasisforhandlingcrisissituationsafterslidestobuildingsorinfrastructure.FurthermoreisincreasesNVEspreparednesstohandlevarioustypesofgeohazards.

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SensitivitytocoastalerosioninsouthernSwedenshowninamapviewer

KärstinMalmbergPersson11GeologicalSurveyofSweden

Arisingsea level isexpectedtocauseincreasedcoastal erosion in southernmost Swedenwherethe postglacial isostatic uplift is negligible. Topredict where coastal erosion will be mostintense and which areas are most sensible toerosion, detailed geological data are necessary.The coast of Skåne displays great variation ingeologyandtopographyandwhilesomepartsarehighly sensible to erosion, other parts are veryresistant.

TheGeologicalSurveyofSwedenhascarriedoutcombined land- and sea-based geologicalmapping along the coastline of Skåne. Thecollected data on land include beach sedimentcomposition, beach morphology, sedimentstratigraphy, signs of active erosion andconstructionsforcoastalprotection.Informationcollected on the sea floor includes surfacesediment composition, detailedbathymetry andpatterns of erosion and deposition caused bywavesandcurrents.

The information has been used to classify theshoreline into different coastal types withdifferent sensitivity to erosion (MalmbergPerssonetal.2016).Anattempttoestimatetheerosion conditions after aone-metre riseof thesealevelhasalsobeenmade.Themostcommoncoastal type today is sandy beaches withalternatingerosion/accumulationbutinbalanceoveranextendedtime(31%ofthecoast).12%ofthecoastissubjecttoneterosion.

Thesefeatures,andmoreinformation,areshownin a map viewer:https://apps.sgu.se/kartvisare/kartvisare-skanestrand.html

The information can be used for e.g. coastalphysical and marine spatial planning and forstudyofsedimentsandsedimentaryprocessesincoastalenvironments.

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Integratedanalysisofpast,andpotentialfuturerockslopefailuresofvarioussizefromRombakstøtta,Norway

OddAndréMorken1,ReginaldHermanns2andPaulaHilger11NGU,2NGU,NTNU

Catastrophicfailureoflargerockslopeshasledtofatalities in Norway several times per century.TheGeologicalSurveyofNorway(NGU)carryoutsystematicmappingofpotentiallyunstablerockslopes in Norway. In this context, a hazardanalysis and preliminary consequenceassessment of the unstable rock slope atRombakstøtta,hasbeencarriedout.Additionally,afragmentationcycleanalysis,usedtoassessthefragmentationoftherockmassduringa failure,and to separate rock fall deposits from rockavalanche deposits, has been developed andtested.

Thestudyareaisinanorthfacingslopealongafjord,withinthearcticcircleandclosetothecityof Narvik. Based on delimiting lineamentsobservedinthefield,aerialphotos,photo

panoramas and digital elevation models, eightfailure scenarios are defined. Application ofNGU´s hazard analysis as well as volumeestimationandrun-outanalysisweredoneforallscenarios. Four of the scenarios havemodelledrun-out reaching vital infrastructure and thefjord.

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The fragmentation cycle analysis has beendevelopedandappliedinspiredbyCharrièreetal.(2016).Results suggest that the rock avalanchedeposits at Rombakstøtta underwent 0-3fragmentation cycles during failure andtransport. And that rock fall deposits generallyexperienced more than 4 fragmentation cyclesduringfailureandtransport.

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ThetriggeringfactorsoftheMóafellshyrnadebrisslideinnorthernIceland:intenseprecipitation,earthquakeactivityandthawingofmountainpermafrost

ÞorsteinnSæmundsson1,CostanzaMorino2,JónKristinnHelgason3,ConwaySusan4andHalldórG.Pétursson51DepartmentofGeographyandTourism,UniversityofIceland,Askja,Sturlugata7,101Reykjavík,Icel,2SchoolofEnvironment,Earth&Ecosystems,TheOpenUniversity,MiltonKeynesMK76AA,UK,3IcelandicMeteorologicalOffice,AvalancheCentre,Suðurgata12,400Ísafjörður,Iceland,4LaboratoiredePlanétologieetGéodynamiquedeNantesUMR-CNRS6112,2,ruedelaHoussinière,BP92,5IcelandicInstituteofNaturalHistory.BorgumviðNorðurslóð,602Akureyri,Iceland

On the 20th of September 2012, a large debrisslideoccurredintheMóafellshyrnaMountainintheTröllaskagipeninsula, centralnorth Iceland.Theslideinitiatedafteranunusualwarmanddrysummer followed by a month of heavyprecipitation. Furthermore, the slide originatedafter a seismic sequence. The main source ofmaterialwasice-richtalusdepositsperchedonatopographic bench. Blocks of ice-cementeddeposits broke off the frontal part of the talusconeandfellontothetalusslopebelow.Furtherdownslope, the landslidematerialbecameover-saturated,causingittoevolveintoadebrisslide.Weestimate that the totalvolumeof thedebrisslide isaround500,000m3andthat itsprimarycause was intense precipitation. We cannotexcludetheinfluenceoftheseismicsequenceasacontributing factor. The presence of ice-cementedblocksintheslidedepositsshowsthat

thawing of ground ice could have played animportant role as a triggering factor. Ice-cementedblocksofdebrishavebeenobservedinthe deposits of two other recent landslides innorthern Iceland, in theTorfufellMountain andthe Árnesfjall Mountain. This suggests thatdiscontinuouspermafrostisdegradinginIceland,duetoclimatechange.ThisstudyhighlightsthatgroundicethawcouldrepresentanewsourceofhazardinIceland.Theknowledgeofthedetaileddistributionofmountainpermafrostontheislandispoorlyconstrainedandshouldbeapriorityforfutureresearch.

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GeomorphologicEvidenceandTimelineReconstructionofHoloceneJökulhlaupsalongtheHvítáRiverandGullfoss,Iceland

GretaWells11UniversityofTexasatAustin

Gullfoss is one of Iceland’s most visited touristsites,atwo-tieredwaterfallwheretheHvítáRiverplunges32metersintotheHvítárgljúfurcanyon.Thissystemisonelineofevidenceforpaleofloodsthat surged across the region ~9500 years BP.Overaspanof100-200years,aseriesof floodsdrainedtheice-dammedglaciallakeKjölurinthesouthwestern highlands. The largest eventsreachedan estimatedmaximumpeakdischargeof3x105m3s-1,rankingthemamongthelargestknown floods in Iceland and on earth.MostresearchonIcelandicjökulhlaupshasfocusedonfloods generated by volcanic and geothermalactivity beneath the southernmost ice caps; butthe little-studiedKjölur floods, not triggeredbyvolcanogenic processes, may provide a betteranalog for most global glacial lake outburstfloods.A pioneering study by Tómasson (1993)reconstructed the Kjölur paleofloods based ongeomorphologic evidence and paleolakestrandlines. This project builds on previousresearch by employing new methods to betterconstrain flood timing, magnitude, and routing.This presentation has three main goals: 1)

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present new and synthesized geomorphologicfieldevidence;2)outlineasamplingstrategyforgeochronological analyses; and 3) situate theKjölur jökulhlaups in the broader context ofcatastrophic flood geomorphology in Iceland.This research will yield insight into drainagedynamicsofice-dammedproglaciallakes,whichpose an increasing hazard worldwide due torapidclimate-drivenglaciallakeexpansion.Ithasexcellent potential to bridge the gap betweenacademic researchandpublic outreach throughcommunicationtoahighnumberofinternationalvisitors.

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AstructuralandInSARstudyoftheunstablerockslopeinOksfjellet,Troms

MarieBredal1,SteffenG.Bergh2,LarsHaraldBlikra3andTomRuneLauknes41GeologicalSurveyofNorway(NGU),2UiTTheArcticUniversityofNorway,3NorwegianWaterandEnergyDirectorate(NVE),UiTTheArcticUniversityofNorway,4NorutNorthernResearchInstitute

OksfjelletisoneofmanyunstablerockslopesinTroms,Norway.Duetothehazardandriskposedby potential slope failures, it is important toobtain precise deformation measurements. Inthis study, a combination of field observationsand InSAR data was analyzed to betterunderstandthegeologicalstructuressusceptibleforslidinginOksfjellet.

Field mapping in Oksfjellet revealed a ductileshear zone/thrust that is interpreted to haveformed during the Caledonian nappeemplacement.Mappedfractures,trendingNE-SWand NW-SE, coincides with regional Mesozoicbrittlestructures.

SatelliteInSARdata(TerraSAR-XandRadarsat-2)revealed subsidence of the unstable slope at arate of 4 ‒ 5 mm/year. Additionally, satelliteInSARdatadetectedsubsidenceofalargerarea,atarateoflessthan1mm/year,thatisthoughtto relate to active down-faulting. Results from

Ground-Based InSAR revealed displacementestimates at rates of mm/day, indicating thatseasonal changes related to water and iceinfluencesthestabilityoftheunstablerockslope.

Based on structural measurements anddisplacement patterns detected by InSAR, thedeformation in Oksfjellet is interpreted to becontrolled by a complex interaction betweenductile and brittle structures, following acommon deep seated sliding surface betweenfoliation/thrust and fractures. The combinationofInSARdataandfieldmappingprovedvaluablein order to assess displacement patterns atdifferent temporal and spatial scales. ThiscontributedtoanimprovedunderstandingoftheevolutionoftheunstablerockslopeinOksfjellet.

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TheKassenandHåkånesetrockslopeinstabilitiesalongfjordlakesinTelemarkshowlargepostglacialgravitationalstrainbutnopresentdaydeformation,SouthernNorwayTheKassenandHåkånesetrockslopeinstabilitiesalongfjordlakesinTelemarkshowlargepostglacialgravitationalstrainbutnopresentdaydeformation,SouthernNorway

KajaKrogh1,ReginaldL.Hermanns2,TrondEiken3,JohnGosse4,MartinaBøhme2andIvanaPenna21NorwegianUniversityofScienceandtechnology,Norway,2GeologicalSurveyofNorway,Trondheim,Norway,3UniversityofOslo,Oslo,Norway,4DalhousieUniversity,Halifax,Canada

The Kassen and Håkåneset rock slopeinstabilities lie along fjord lakes. The Kasseninstability lies at the tip of a plateau dippingsteeply towards Bandak lake. The instabilitystretches2,5kmE-W.Itsupto100-m-highsteepback scarp separates undeformed crystallinebedrock from strongly desintegrated rockmass

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breaking the slope in various compartments. Inthe central part a depression exists, that hasdescended an additional 25-50 m. Below that,bathymetric data reveal a 13.4-million-m3 largerock-avalanche deposit on the bottom of lakeBandak. Preliminary cosmogenic nuclide agesindicatethatthetopofthemountainmeltedoutoftheiceat14.1kaandwasmainlyactiveintheearlypartoftheHolocene.Differentlythetopofthe Håkåneset rock slope instability lies midslope but similarly the up to 75-m-high backscarp separates strongly deformed and crackedrock mass from stable rock mass. Bathymetricdata of Tinnsjø lake reveal that the instabilityextendsdownto~330mbelowlakelevel.Atthefoot both a 40-m-high pressure ridge within aterrace and several generations of slide scarswithin this terrace suggest that the instabilityreachesdowntothelakebottom.

Kinematicfeasibilitytestsatbothlocationsshowthat simple failure modes are possible in thesteepest slope parts but bi-planar sliding isfeasible at both locations for largercompartments. Displacement rates determinedbydGNSSshowvelocitiesbelowsignificancelevel(< 2mm/yr) for the past years suggesting thatbothrockslopesstabilizedincomparisontothepronouncedpostglacialdeformation.

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StabilityAnalysisofPreikestolen(Rogalandcounty,Norway)

KatrineMo1,ReginaldHermanns2,MartinaBöhme3andPierrickNicolet31NorwegianUniversityofScienceandTechnology,2NorwegianUniversityofScienceandTechnology,GeologicalSurveyofNorway,3GeologicalSurveyofNorway

The hike to Preikestolen is one of the mostpopular trails in Norway, with more than ahundred thousand visits each year. Despite thepopularity, thestabilityof therock formation isnot yet determined. The Geological Survey ofNorway (NGU) is now mapping potentialunstablerockslopesinRogalandCounty.Hence,

Preikestolen is included as one of the maininvestigationobjects.Themasterthesis“StabilityanalysisofPreikestolen"isapartofthisproject,and will be based on data collected by NGU inadditiontostudentwork.

In September 2017, the rock formation wasscannedfromfourdifferentangleswithagroundbased LiDAR scanner. These scans will be puttogether to create a detailed 3D model ofPreikestolen.Inaddition,two3Dmodelswillbecreated using photogrammetry. Onemodel willbebasedonphotostakenfromhelicopterandtheotheronefromdronephotos.Thesemodelswillbecomparedtofielddatainordertotestwhichremotesensingdatagivetheclosestresultsandcanbeusedbestasastandardmethod.Further,the3D-modelswillbeinvestigatedinColtop-3Dto gather structural data measurements. Thesemeasurementswillbeusedincombinationwithstructuraldatafromfieldworktodoakinematicfeasibilitytest.Further,thestressdistributionintherockformationwillbemodelledwithRS2.Togatherinputdata,severaltestareplannedintherockmechanics laboratoryatNTNU.Eventually,alldatawillbediscussedtogiveafinalevaluationofthestability.

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Assessment of risk posed by slopefailures at a coastal cliff inHyllestadmunicipality (Sogn og Fjordane,Norway)

VegardNes1,ReginaldHermanns2,IvannaPenna2andJonRunarDrotninghaug11NTNU,2NGU

In the last years, the Norwegian GeologicalSurveyhasbeenmappingunstablerockslopesinSogn og Fjordane county. Several of themdevelopedonfjordslopes,whichimpliesthat inadditiontothedirectimpacts,theconsequencesrelated to displacement waves need to beaddressed. In this context, slope instabilitiesalonga6kmcoastal cliff inAafjordenhasbeen

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identified, and two of them are currently beingmonitored(NGU,2017).Theaimofthisworkisto give a complete overview of the unstableslopespresentalongthecoastalcliffofAafjorden,as well as their main controlling factors byincludingtheresultsofarecentsurvey.

Themappingwascompletedthroughfieldwork,and interpretation of photogrammetric modelsand a 1m resolution DEM. The mechanism offailuresisbasedonsitemeasurementsaswellasstructure detection with COLTOP3D. VolumeestimatesoftheunstableblockswerecalculatedusingCloudCompare.

Our analysis shows that there are 8 unstableblockswithvolumesupto170000m3alongthecoastal cliff of Aafjorden that can lead toconsiderable displacement waves, as alreadyoccurred in 1992 (Harbitz, 2001). ThedetachmentsarecontrolledbysteepN-SandE-Wstriking joint sets in the western domain, andjointsetdipping70degreestowardseast intheeasterndomain. The kinematics of theunstableblocks have exposed both potential toppling-failuresandplanarfailures.Futureworkincludestheriskassessmentofallthepotentialscenarios,using the methodology developed by NGU(Hermanns,etal.,2013).

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MonitoringofsurfaceprocessesinGråfonnfjellet,Raumamunicipality,Norway

PierrickNicolet1,IvannaPenna1,ReginaldHermanns2,OddAreJensen3,LenaRubensdotter1andSiljeØrenSkei41NorgesGeologiskeUndersøkelse,Trondheim,2NorgesGeologiskeUndersøkelse,Trondheim;NorgesTeknisk-NaturvitenskapeligeUniversitet(NTNU),3Norgesvassdrags-ogenergidirektorat,4NorgesTeknisk-NaturvitenskapeligeUniversitet(NTNU),Trondheim

LooserockmassesremainontheheadscarpsandafterhistoricandprehistoricrockavalanchesonGråfonnfjelletmountain, Innfjorddalen,Norway.This material is remaining after at least three

post-glacial rock avalanches that have beendepositedinInnfjordalen(Scheileretal.2016).Atthis site, in addition to the rock avalanchedeposits, a large colluvial fan can be observed(Skei 2016). The objectives of this work are todescribethesourceofsedimentsandthesurfaceprocessescontributingtothedevelopmentofthefan. This study takes advantage of permanentmonitoring equipment (3 cameras and 1meteorological station) and periodicmeasurements (LiDAR, photogrammetry,gigapixel pictures) to study the slopeprocessesthatareactivenowadays.Anareaof intensivelyfracturesrocks,thatremainsintheheadscarp,isshown to be the main source of sediments.Indeed, 93 negative differences (e.g. missingblocs) have been observed between 2014 and2016 on the gigapixel pictures in this area. Inaddition, 63 positive or composite differences(e.g.depositedblocorsedimentstransportedonashortdistance)havebeenidentifiedinthesamearea,whichsuggestthatthesedimentsareoftentransported only on a short distance.Furthermore, the permanent camera placed inthe valley permits to identify several snowavalanches that remobilize sediments down tothe lower parts of the fan. During snow meltseason or precipitation events, materials aretransported in form of debris flows along twomainchannels.Furtherworkisneededtobetterrelate the observed events with themeteorologicalconditions.

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10.2. Open session Engineeringandenviromentalgeology

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Themodellingofice-marginalcomplexesandsaltstructuresusing3Dlayermodels

ThomasBreumAndersen11GEO,GeodataandSubsurfacemodels,Maglebjergvej1,2800Kgs.Lyngby

Among the most challenging geologicalstructures to interpretandmodel in theDanishareaaretheicemarginalcomplexeswithcomplexstacked internal structures and areas with saltdomesintrudingNeogeneandQuaternarystrata.The geology will reflect complex tectonics thatmustbeinterpretedandturnedintoasequenceoftectoniceventsinordertorepresentthisina3Dmodel.

Thedevelopmentofareliableconceptualmodelis essential in this work and thisconceptualization must encompass a thoroughanalysis of all data sources available includingdrillings, geophysics, geomorphology, previousinvestigationsect.representingacross-disciplineinvestigation.

Thedevelopment of a geological 3Dmodel thatreflects the conceptual geology and tectonicstructures requires special techniques whenusing layer models including sophisticatedpositioningofdigitalization-points,interpolationand adjustment procedures in order to developsteeply dipping or vertical strata, faultlines orsaltdomes thatmaybedeveloped as truedomestructuresorhorststructures.

Examples will be shown from well-knowngeologicalDanishgeologicalsitesastheRøsnæsIcemarginal complex, Thyborøn (RønlandSaltdiapir) and Suldrup Saltdiapir where thesemethods have been used in connection withground water modelling projects and forgeotechnicalpurposes.Themodellingtechniquetakesthelayer-modelmethodtoitslimitsbutthis

typeofmodelcanbeintegratedwiththeoverallgeologyofanareafairlyeasyincontrasttoasitespecificvoxelmodel.

ORAL

GeochemistryofdepositedminetailingsinRepparfjorden,northernNorway,andtheireffectonbottomfauna.

MalinAndersson1,TorErikFinne1,HildeTrannum2,KristinePedersen3,AnitaEvenset3andPaulRenaud31GeologicalSurveyofNorway,2TheNorwegianInstituteforWaterResearch,3Akvaplan-niva

Submarine tailing disposal (STD) involves thedischargeofminetailingsbelowtheseasurfaceasanalternative toon-landdeposits.Norway,acountrywithdeep,shelteredfjords,isoneofthefewcountriesintheworldwherethesedisposaloperations are in use. This study investigated afour decade old mine tailing deposit inRepparfjorden, originating from copper oreprocessing in the 1970's. Bathymetry from thisprojectrevealedthatthedepositisstillpresentlyalmostintact.Theissueisofinterestasthemineislikelytoreopenin2019.

Themine tailings are, in relation to the naturalmaterials lying under the tailings and on top,clearlyenrichedintheelementsAu,Ba,Bi,Cr,Cu,Hf, Ni, Re and Zr, but also depleted in theelements:Be,Cd,Cs,In,Li,Nb,P,Pb,Rb,S,Sc,Vand Zn,therefore establishing the chemicalsignature of the tailing material. To be able tocomparegeochemical resultsandexecute faunaexperiments, newly fabricated flotation tailingswere produced. The old tailing deposit differsconsiderably from these,which couldbedue todifferencesinorematerialorflotationprocess,orchemical changes during deposition. Thesedifferences make chemical predictions for afuturedepositdifficult.

The bottom fauna study revealed differences inthenumberofspeciesandindividualspresentinthesurfacesedimentsdependingontheinfluence

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ofthetailings.Dependingonthedepthoftailingson top of surface sediments, a decrease inbiomass amount was evident during a re-colonisationexperiment.

ORAL

Developmentofadirecttensiletestmethodformicrotexturalfracturestudies

KarinAppelquist1,MathiasFlansbjer2,LinusBrander1,LoviseSjöqvist1,JanErikLindqvist1andCamillaLindström11RISECBI,2RISEMechanicsResearch

Traditional macroscale rock strength testsgenerally aim at characterizing and comparingdifferent rock types in a standardized way.However,thesemethodsrarelyshedlightonthecrack development in relation to the materialstructure. Often the loading situation andspecimen geometries are complex, resulting indifficulties identifying the contribution ofdifferent synchronous deformation processes.Examplesarecompressiveloadingtests,inwhicha combination of compression and shearingoccur,andLosAngeles tests, inwhichcrushing,abrasion, tension and shearing occursimultaneous. Due to this shortcoming, a newmethodology which combine detailed crackingmonitoring techniques with mechanical rocktests – allowing the examination of differentisolateddeformationmechanisms–ispresented.

Themethodologycombinestensilestagetestingofarockspecimenwithcontinuousmonitoringofthe cracking processes by Digital ImageCorrelation and Acoustic Emission. Aftercompletion of tensile test, examination ofmicrocracks and fractures by fluorescenttransmission microscopy is conducted. Thismethodology enables the spatial and temporalvisualization of the cracking processeswithin arocksample,onmicro-andmesoscale,linkingthecracking processes (e.g. initiation, reactivation,propagationandbridgingofmicrocracks,andthefinal development of the open fracture) to rocktexture and microstructure. The methodology

hasbeendemonstratedon28samplesfromthreegranitic rocks of different textures andstructures. The strength of the methodology istheincreaseinknowledgeofcriticalparametersaffectingcrackingprocessesinrockmaterialsandhow these are related to the rock micro- andmesostructure.

ORAL

ConstructiongeologicalmapofStockholm-andexampleofgeo-datarecycling.

PhilCurtis1andClaesMellqvist11SGU

The original construction geological map ofStockholmwasproducedduringthe1970sandisstill widely used today in the early planningstagesofnewinfrastructureprojects.Althoughitwas digitized in 1997 it has not been updatedsince its original publication. The GeologicalSurvey of Sweden (SGU) has been working onsuchanupdatethatincludestheincorporationofgeological data from existing infrastructureprojectsfromexternalsourcessuchas(SwedishTransportAdministration)Trafikverket and theconstruction industry. The new map is to beissuedonthewebina2Dformatforeaseofuse,however, much of the visualization andinterpretationprocesshasbeenperformedin3Dandtheresultswillbeavailableforviewingonaseparatewebsite.

ORAL

WeaknessZonesintheBedrock-GeophysicalStudiesinCityArea

TaijaHuotari1andMaritWennerström11GeologicalSurveyofFinland

As the amount of underground building in cityareasgrowstheneedforinformationofbedrockunder the ground surface is increasing.

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Problematic features for undergroundconstruction might be weakness zones in thebedrock.Informationonthelocation,orientationandpropertiesofweaknesszonesbeforestartingconstructionwill improvethescheduleandcostestimates of the project, as well as usuallyreduces the construction costs. Thepotential ofdifferent geophysical methods were tested todetect weakness zones in the bedrock in theproject called ‘Intrageo’ (Huotari &Wennerström, 2017). Further, the geophysicalresultswereintegratedwithstructuralgeologicalinterpretationofweaknessesinthebedrock.

The investigations were carried out atHannusjärviandFinnooinEspooontheplannedrouteforthe2ndphaseoftheWestMetro,aswellas in the area of the new undergroundwastewater treatment plant of HSY (HelsinkiRegionEnvironmentalServicesAuthority)waterservices at Blominmäki, Espoo. Bothinvestigation areas are located in the Helsinkimetropolitanarea inFinland. In2ndphaseWestMetro targets the measurements wereconcentrated on tests of ground geophysicalmethods.Theaimwastotestdifferentmethodsalong the same survey profiles to performintegrated interpretation and to evaluate theusability of different methods. In Blominmäkitests concentrated on geophysical drill holemeasurementsandmagneticmeasurementswithdense line spacing in the most fractured rockarea.Petrophysicalproperties,aswellastherocktypeand structural features,were studied fromdrillcoresamplesforthesakeofcomparisonandverification.

ORAL

Digitalarchiveforstronggroundmotionsrecordedinearthquakesequences

EvangelosKatsanos1andVictorAmboBoserup11DepartmentofCivilEngineering,TechnicalUniversityofDenmark

Numerous structures and infrastructuressystems have been recorded to encounterextensive damages or total collapse due tosuccessiveearthquakegroundmotionsoccurredin short time spans. A list of recent earthquakesequences, found to be detrimental for bothhumans and the building stock, comprises ofseismic events from Amatrice-Italy (2016) andKumamoto-Japan (2016), Gorhka-Nepal (2015)and Tōhoku-Japan (2011). Nevertheless, thecurrent seismic codes prescribe the structuraldesign on the basis of a single “design”earthquakewaivingthesequentialseismiceventsthat may increase the seismic vulnerability ofstructures. It is, thus, importantto focusonthishazardous phenomenon in order, eventually, tomitigateitsconsequences.Overthelast15years,the effects of earthquake sequences on thestructuralperformancehavebeenelucidated[1-3].However,theuseofrealstrongmotionsfromsuccessive ground shakings is commonlyrestrictedtoasingleearthquakesequenceeventthat may dominate (or bias) the structuralresponseresults[4].Additionally,theartificially-developed earthquake sequences may derivequestionable seismic demand [5]. Hence, thisstudyisdedicatedtocompileadatasetincludingalmost 7000 suitably selected strong groundmotions,whichwererecordedworldwideduringearthquake sequences and foundof interest forstudies addressing the structural responseimposed by multiple earthquakes. The datasetcompiled provides metadata related toseismological characteristics and strong groundmotion parameters while, when necessary, therecordswereprocessed(i.e.,base-linecorrectionand frequency-based filtering). Finally,systematic analysis of the selected motionsrevealed trends on the basis of the several

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parameters associated with the successiveearthquakes.

ORAL

ThequaternaryhistoryattheHornsRev3site.

JoakimStielKorshøj11Geo

In 2013 Geo was contracted to carry out preinvestigations for Energinet, for the offshorewindfarm Horns Rev 3. The pre investigationsrevealedaburiedlandscape,withdislocatedfloesofMioceneclays.

TheHorns Rev 3 bank is composed of a rathercomplex sequence of Postglacial and glacialsediments, including glacial floes of Tertiarysediments. The area was not covered by iceduringtheWeichselglaciation.Thesea-levelwasapproximately 120 m below current sea-level.TheonlydepositsfromWeichselthatisobservedintheareaisfrommeltwaterriversflowinginthelower lying areas. Two Postglacial units havebeen deposited during the Flandriantransgression. Deposits consist of non gradedsand and organic clayey silt and clay. Thedeposits are generally loose/soft, locally theorganiccontent ishigh,here theyaredescribedasorganicclay(gyttja).Somesmallerdepositsofpeathavebeenobserved,oneofwhichwasdatedbyC14determination.ThepeatlayerwasfoundinthebottomofthePostglacialsequenceandwasdated to between 8211 and 7791 years BC. In-between the meltwater deposits smaller tilllayers are seen, as well as floes of Tertiarysediments.

Tertiary deposits have been found as floesinterbedded in themeltwater deposits and twoborings stopped in Tertiary deposits. Sincedrillingstoppedintheselayers,itisnotpossibletosayiftheyarepartsoffoldedTertiarysedimentby Saalian or earlier glaciations, floes or if theTertiarysedimentsareinsitu.

ORAL

Risksofarsenicexposurethroughagriculture

KirstiLoukola-Ruskeeniemi1,JuhaKaija1,TimoTarvainen1,TarjaHatakka1,RiittaKeiski2,AuliTurkki2,JanaPinka3,IsabelJordan3,FabienneBattaglia4,Marinale-Guedard5,CeliaJones6,ProsunBhattacharya7,SirpaKurppa8,IngoMüller9,GrzegorzSiebielec10andJoseSolisVeliz111GeologicalSurveyofFinland,2UniversityofOulu,Finland,3GEOSIngenieurgesellschaftmbH,Germany,4BRGM,France,5LEBAquitaineTransfert,France,6Kemakta,Sweden,7KungligaTekniskaHögskolan,Sweden,8NaturalResourcesInstituteFinland,9LfULG,Germany,10InstituteofSoilScienceandPlantCultivation,Poland,11NationalUniversityofEngineering,Peru

Arsenic is a toxic and carcinogenic semi-metalwhichcanenter intoagriculturalsoilandwaterduetohumanactivitiesorfromnaturaldeposits.AgriAsWater JPI project started 1st April 2017and evaluates arsenic contamination in Europefocusing in two study areas with intenseanthropogenic pollution. Research institutes,universities and companies from five EUcountries participate in the project. AgriAssummarizes national and European databases(e.g., Tarvainen et al. 2013) and developsrecommendationsandguidelinesforsustainablemanagement of arsenic risks in agriculturalareas.TheFrenchstudysiteisahistoricalareaofdestructionofWWIchemicalweaponslocatedinasensitivezoneforagricultureandgroundwater.TheGermansiteischaracterizedby800yearsofmining. Arsenic removal technologies will bedeveloped and demonstrated in both areas.Biological tools will be applied to manageecological, environmental and human risks.Dissemination activities will follow theprocedures of the successful LIFE + projectASROCKS which developed guidelines for rockaggregateproduction in arsenic-rich areas (e.g.,Parviainen et al. 2015). In the first stakeholderworkshop organized in Freiberg in September2017, interaction and discussions betweenfarmers,authoritiesandresearcherswereactive.

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The authors thank EU and the Academy ofFinland, Agence Nationale de la Recherche,Bundesministerium für Ernährung undLandwirtschaftandForskningsrådetFORMASforfunding, in the frame of theAgriAsConsortiumfinancedunder theERA-NETWaterWorks2015 Cofunded Call. This ERA-NETis an integral part of the 2016 Joint Activitiesdeveloped by the Water Challenges for aChangingWorldJointProgrammeInitiative.

ORAL

2,5D Open Source Modeling of RockAggregate Resources in the HelsinkiMetropolitanArea

SamppaMäkelä11UniversityofHelsinki

Theobjectiveofthisstudyistodevelopamethodof appraising rock aggregate resources, usingopendataandopensourcetools.TheavailabilityofaggregatesinFinlandismostlydeterminedbycompeting land use and restrictions onextraction. Therefore, it is important todetermine the extent of available resources,especiallynearareasofhighdemand.

Thestudyareaconsistsof the14municipalitiesintheHelsinkimetropolitanarea,atotalof3841km2.Thedatausedareopenaccess,providedbyGSF and NLS. These are combined in a GIS toidentifylocationswhereextractionofaggregatesis possible. Geology, limitations and the highestand lowest point of possible extraction aredetrmined. These are used to estimate theavailable resources and locate the economicallyfeasiblesites.Datausedincludeadigitalelevationmodelandlayersongeologyandlanduse.

The results show that competing land use hassterilized most aggregate locations in the area.Remaining locations are concentrated on theedges. However, some potential sites remain.Field evaluations and comparison to previousstudiesshowthatthemethodissoundandabletolocatepossiblelocalities.

The model is fast in coarsely determiningaggregate volume. It is highly suitable forfocusing expert fieldwork. Land use in the areacontinues to sterilize new locations. To avoideconomic and ecological damage, a plan shouldbe implementedforsecuringthisresource.Thismayincludethereservingof locations,reducinguse, checking legislation on production andrecyclingusedaggregates.

ORAL

DevelopingofGeothermalDistrictHeatingsolutionsfor4townsinPoland

KirstiMidttømme1,BeataKępińska2,LeszekPająk3,BaldurPétursson4,JanKocbach5,IngvarHenne5,UsmanDar6,Jørgen.BSkauge6,ÓskarP.Einarsson7andFriðfinnurKDaníelsson81ChristianMichelsenResearch(CMR),2MineralandEnergyEconomyResearchInstitute,PolishAcademyofSciences(MEERIPAS),3MEERIPAS,4Orkustofnun,5CMR,6SwecoNorge,7Verkis,8Alvarr

Poland possesses proper geothermal energy tosupply low-emission thermal energy.Polish,Icelandic and Norwegian experts collaborate todevelopgeothermaldistrictheatingsolutionsforfour towns in Poland. Three of the towns,Konstantynów Łódzki, Sochaczew, andPoddębice, are located in sedimentary rockscentralPolandinthePermian-MesozoicSzczein–Lodz Miechow. The last town, Lądek Zdrój issituated incrystalline rocks inSudetMountainsclose to the boundary to Czech Republic. Thetown is one of the oldest Polish health resortsusingthermalwater.

A10MWthgeothermaldistrictheatingplantwasestablished in Poddebice in 2013, substitutingfossil energy. The geothermal well of 2101 mdepth is extracting water of 70 °C from LowerCretaceous sandstones. Maximum flow rate is252m3/h. Thewater is discharged into the Nerriver and it is a challenge to satisfy therequirementofamaximumtemperatureof35°Conthewaterdischarged.Thereisalsoaneedfor

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better understanding of the effect of long-termgeothermalexploitation

A new geothermal well of 2800m depthextractingwaterof70C fromLower Jurassic isplanned as an additional energy source forKonstantynów Łódzki incooperated in theexistingŁódźdistrictheatingsystem.

TheauthoritiesinSochaczewplansageothermaldistrict heat pump solutions utilizing water of40°CfromLowerCretaceoussandstone.

A new geothermal well of 2500 m depth isplannedinLądekZdrójproducingwaterof70°Cfromfracturezones.

The joint Polish/Icelandic/Norwegian projectwasfundedbyEEAGrant.

ORAL

GeologicalstudiesofthepossibleHelsinki–Tallinnunderseatunnelroute

KeijoNenonen1andOssiIkävalko11GeologicalSurveyofFinland

GeologicalSurveyofFinland(GTK)andEstoniangeological Survey (EGS) conducted geologicalstudies and acoustic-seismic surveys of thepossible linings for an undersea railway tunnelbetweenHelsinkiandTallinn.

Thesurveysprovidedadetailedoverviewofthegeologicalstructureoftheseafloorbasementanddeposits between Finland and Estonia. A newfinding was that the crystalline Proterozoicbasement sea floor continues all the way toNaissaar and to the shallows near the Estoniancoast.A thick layer (100-150 m) of softsedimentary rocks from Cambrian - Ordovicianage (sandstones, claystone and limestones)covers the hard granitic bedrock on the city ofTallinn area. Presently ongoing FinEst Linkproject between Finland and Estonia examinesthepossibilitiesofbuildinga100kmlongrailwaytunnel.Thegeologicalfindingsprovidesnewand

useful information for furtherdetailedengineeringgeologicalsurveys.

The FinEst link project examines the technicalandeconomic feasibility of theundersea tunnelandthe logisticsolutions inadditionto itscost-effectiveness and economic, environmental andsocialimpacts.Resultsaretobeexpectedduringthepresentyear2018.Theviabilityofplanningthe tunnel can be assessed only after receivingtheseresults.

Theresearchworkonthefeasibilityofthetunnelproject was enabled by EU funding under theInterregCentralBalticprogramm.TheprojectisledbytheHelsinki-UusimaaRegionalCouncil incooperationwiththeCityofHelsinki,theFinnishTransport Agency, the City of Tallinn, theEstonian Ministry of Economic Affairs andCommunications and the Harju CountyGovernment

ORAL

Nytborearkivserdagenslys-Øgetadgangtilprivateborearkiver

MikkelWendelboeToft11Cand.scient

Geohar skabtennyonlineadgang til videnomundergrunden.Formåleteratsikreatfagfolkpåtværs af organisationer kan arbejdemed bedstmuligt udgangspunkt så projekterne bliver løstmesteffektivtogmedmindstrisiko.Idetteoplægvil vi fortælle om strategien bag frigivelsen afvirksomhedens data, samt om de tekniskeproblemstillinger som vi bliver mødt af underudviklingenafetsætheltnyeservices.Desudenperspektiveres der mod potentialet ved aftilgængeliggøre andre virksomheders data.Initiativet er blandt andet motiveret af Statensbeslutningomatstillesitkortgrundlaggratistilrådighed, hvilket har skabt helt nyeforudsætninger i markedet. Vi har udviklet enrække værktøjer som, via bagvedliggende 3Dmodeller af undergrunden, kan lave virtuelleboringer,udstille3Djordartskortifladesnit,samtgøredetmuligtat lavehurtigeogbrugervenlige

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profilsnit af høj kvalitet. Ved at udstilleværktøjerne online, søger vi at skabemaksimaltilgængelighed, og mulighed for højbrugervenlighed. Et interessant potentiale itendensenmedåbningaf adgangen tildata ideprivate virksomheder, er værdien vedsammenstilling af data fra andre kilder. Ensammenstillinggørdetmuligteksempelvisatserelationen mellem registreret jordforurening,arealanvendelse eller befæstelsesgrad, og denoverfladenære geologi. Mulighederne foranvendelse er utallige, og når først brugeren isærligefagdomænerfåradgang,såvurdererviatanvendelsesmulighedernevilspirefrem.

POSTER

DevelopmentofadatabaseforstratigraphicinformationonQuaternarydepositsattheGeologicalSurveyofNorway(NGU)

LouiseHansen1,BoNordahl1,AlexandraJarna1andInger-LiseSolberg11GeologicalSurveyofNorway

ANationaldatabaseforsuperficialdepositshaveexisted inNorwayfordecadesand isdevelopedandhostedbytheGeologicalSurveyofNorway.The database is the basis for web servicespresenting Quaternary map information atdifferent scales and associated products andservices (www.ngu.no). The maps are used insociety for various purposes from research topublic planning. Stratigraphic information haspreviously only been presented as a somewhatcomplicated text strings locally on analogueQuaternary maps, or in associatedreports/articles.Therehas,tillnow,notbeenanydatabasetoreceivestratigraphicinformationinastructuredway.AsthereisagrowingneedintheNorwegian society for subsurface geologicalinformation there is also a need for thedevelopment of a stratigraphic database. Aprototype of a stratigraphic database ispresented.Animportantaspectofthedatabaseisthat it can host varied types of stratigraphicinformation from different sources. The newly

developed National Database for Groundinvestigations(NADAG)isapotentialsourceforvaluable stratigraphic information from e.g.linked drill reports. Well organized andstandardized stratigraphic information in adigitalformatisneededforextendingthepresentdaygeologicalmapproductsintothesubsurface,and for furtheranalysesandmodeling.Possiblewebsolutionsarepresented.

POSTER

ProvenanceandContaminationHistoryoftheParanáDelta,Argentina

JaneIhrfors1,MatildaSchütz1,RodneyStevens1,JuanPabloMilana2andClaudioParcia31UniversityofGothenburg,2UniversidadNacionaldeSanJuan,3UniversidadNacionaldeSanMartin

Thisisasedimentologicalandgeochemicalstudydocumenting sediment provenance andcontamination of the Paraná Delta front duringthe last150years.TheParanáriversystemisapristine landscape home to several endangeredspecies and South Americas second largestdrainage basin containing some of the world’slargestwetlands. The basin has been cultivatedfor a long time but with an expanded humanactivity during the last century with increaseddeforestation and industrialisation. Therefore,studiesintheParanácouldgiveanindicationonhow the Amazonswill be affected by increasedhumanimpact.Previousstudiesofthedeltafronthavemappedanddatedbeachridges(Medinaetal, 2013). A transect sampled perpendicular tothese provides a historical record of the deltaprogressionanddevelopment.Theaimistoseehowthechangeofclimateandhumanactivityinthe catchment area have affected the sedimentprovenance at the delta front. The samples areanalysed usingmethods to identify themineralcomposition in the clay and sand fractions toreveal their provenance and roughly estimatingeach sub-basin’s sediment supply to the deltafront. Sediment geochemical trends over thesampledtimeline,withaparticularemphasison

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heavymetalcontents,areinterpretedintermsofprovenanceandcontamination,whichinturnarelinked to human impact through deforestation,afforestation, population growth, urbanisationand industrial activity.In general, the delta-forming processes themselves need to be re-evaluatedontheParanáDeltasincethesearealsoaffected by changing climate and increasinghumanimpact.

POSTER

InvestigationsofclaydepositsasbarrierforafinalrepositoryforDenmark'slow-andintermediatelevelradioactivewasteinsubsurfaceto500mdepth.

BertelNilsson1,PeterGravesen1,StigA.SchackPetersen1andMereteBinderup11GeologicalSurveyofDenmarkandGreenland(GEUS),ØsterVoldgade10,1350Copenhagen,Denmark

TheDanishradioactivewastefromtheresearchstation Risø must be stored on Danish landterritory (exclusiveGreenland). The radioactivewaste is consisting of the waste from thedecommissioningofthenuclearfacilitiesatRisø,andtheradioactivewasteproducedinDenmarkfromhospitals,universitiesandindustry.

TheGeologicalSurveyofDenmarkandGreenlandhasuntil2011beenresponsibleforthegeologicalstudies ofnear-surface areas (100-200 meterdepth) for the repository. The task has been tolocate and recognize non-fractured clays orPrecambrian bedrocks with low permeabilitywhichcanisolatetheradioactivewastefromthesurroundings. Six potential areas have beenlocatedbasedonthemostfavorableconditionsinrelation to geology, hydrogeology, natureprotectionandclimatechangeconditions.

Fiveof thesix localitiesPaleogeneandNeogeneclaysareconsideredassuitableasthelastbarrierin the repository based at these criteria: 1.Theclay layer shall be at least 50-100 m thick, 2.Theclay layersshall have a continuoushorizontaldistributionintheselectedarea.3.Theclay layers shall be low permeable withoutfractures and with very low groundwatercontent. 4. The selected area shall be withoutgroundwater and drinking water interests. Thelast locality was located in Precambrianbasementrocks.

In2018newtechnicalstudieswillbecarriedouttodeterminepossiblefuturelocationsforadeepgeologicalfinalrepositoryat~500meterdepth.Astheexistingdataandpreviousstudiesdonotmake it possible to conclude where a deeprepositorycanbeplaced.

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11.Hydrogeology11.1.Groundwater transport incold,changingclimates:theory,experiments,models

ORAL

Modellingsnowmeltinfiltrationinaseasonally-frozensoilmonitoredbyelectricalresistivitymeasurements

HelenKristineFrench1,AndrewBinley2andCliffVoss31NorwegianUniversityofLifeSciences,2LancasterEnvironmentCentre,LancasterUniversity,UK,3U.S.GeologicalSurvey,MenloPark,CA94025USA

Infiltration during snowmelt can be highlyheterogeneousduetotheformationoficeontheground surface below the snow cover. Insituationswheresnow is contaminated, suchasalong highways and airports due to de-icingagents, the area that takes part in the earlyinfiltrationwilldeterminetheretentiontimeandpotential for degradation in the unsaturatedzone. In 2001, French and Binley (2004)observedahighlyvariablesnowmeltinfiltrationover a small area at Gardermoen, Norway,monitored with time-lapse electrical resistivitymeasurements.Inthisstudy,wewanttotestthesuitabilityofanewlydevelopednumericalmodelfor water and heat transport including phasechange (modified version of SUTRA_ICE,described inMcKenzieetal.,2007) inavariablysaturated soil against field observations.Monitoredweatherandsnowmeltdatadefinedthe boundary conditions of a simulatedunsaturated profile with seasonal freezing. Thedependency of capillary pressure andpermeability onwater saturation is taken fromthe van Genuchten equation. Soil physical dataand heterogeneity was based on local soilmeasurements. Different infiltration scenarioswere tested. Soil temperatures, TDRmeasurements of soil moisture, a tracerexperiment conducted at an adjacent site andchanges in electrical resistivity were used to

validate the model of infiltration and thawing.The model was successful in reproducing thethawing and soilmoisturepatternsobserved inthesoil,andhencelookslikeapromisingtoolforpredicting snowmelt infiltration andmelting ofgroundfrostinasandyunsaturatedsoil.

ORAL

Numericalsimulationsoftemperature-dependenttransportinwasterockpilesinpermafrost-dominatedenvironments

DanielePedretti1andLeslieSmith21GeologicalSurveyofFinland(GTK),2UniversityofBritishColumbia(UBC)

Waste rock piles (WRPs) contain unsaturatedmaterials that can yield water with elevatedsolute concentrations as a consequence ofsulphide mineral oxidation.Tracer tests can beused to provide insight to transport propertiesthat affect the evolution of the effluent waterqualityovertime.Incoldenvironments,flowandtransport are also affected by variably freezingconditions within the pile, a process thatcomplicatestheinterpretationoftracertests.

This contribution describes a numerical modelsimulating conservative solute transport in ahomogeneousWRPwithtemperature-dependentboundaryconditionsandvariablyfreezingcycleswithinthepile.Theconceptualmodelisbasedonthe experimentalwaste rock piles at theDiavikDiamondMineinnorthernCanada,locatedinanareaofcontinuouspermafrost.

The results illustrate the key role of an explicitsolution of temperature-dependent flowconditions to evaluate the seasonal and annualreleaseofsoluteloads.Themodelillustratestheannual drainage cycles in the core of the pile,whichwerehypothesizedtobecharacterizedbydistinctspringflushesandsteadydeclineinflowprior to freeze-up. Solutes move within the

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unfrozencoreofthepileevenwhentheexternalportion of the pile starts to freeze. Thetemperature boundary conditions affect the(transient) flow geometry within the piles, andcancomplicatetheinterpretationoftracertests.In particular, an apparent dual-porosity-likeeffectisproducedonsolutebreakthroughcurvesevenwhen the pile is physically simulated as ahydraulically and geochemically homogeneoussingleporositydomain.

ORAL

GroundwaterlevelsrealtimemonitoringandvisualizationsoftwaredemonstratedforPrecambrianvalleysedimentaquifersinOstrobothnia,WFinland

NikoPutkinen1,HolgerKessler2,BenWood2,ElinaLindsberg1,HarriIssakainen1,TeroRönkkö1,EsaKauniskangas1andMiikkaPaalijärvi11GeologicalSurveyofFinland,2BrittishGeologicalSurvey

OldburiedPrecambrianvalleysinOstrobothnia,Kurikka, W Finland play a major role in thegroundwater system andwill ensure the futuremunicipaldrinkingwatersupplyforover150000people. Several year’s of intensivehydrogeological studies include70boreholes tothe bedrock, ~200 km gravity measurements,numerous seismicprofilesin the100km2 studyarea. According to the reported results, it ispossible to conclude the bedrock structurespromote the most conductive hydrogeologicalunits interlinks between faults, fractures andotherstructures, the topographyof theglaciallyeroded bedrock surface and the overlyingweathered bedrock surface and 50-100m thickhighly variable glacial deposits include severalconfined - semi confined sand and gravelsedimentaquifersandclayeytillandmarinesiltaquitards.

InthisprojectGTKandBGSareworkingtogetherforwater companies on developing free–to-usegeological software for use in hydrogeological

investigations and environmental monitoring.Data(e.g.gw-levels)willbecollectedinthefieldin real-time using an innovative sensortechnique.Theprojectwilldevelopvisualizationcapabilityforthisdataandinterpolationroutineswillbeadded,allowinganalysisoftrendsacrossmonitoring sites. Connections toGTK corporatedatabases will be established, making dataexploration simple and intuitive for GTKgeoscientists and the supervising authority.Sharing real time groundwater data inGroundhogDesktop,andvisualizinginteractivelyinmaps,logsandcross-sections,willsignificantlyhelp environmental agencies to monitor andcontrolthesustainableuseofwater.

POSTER

Subpermafrost Groundwater andPingosinAdventdalen-EvaluatingtheImplication of Holocene PermafrostFormationinNearCoastalAreas

MikkelToftHornum1,PeterEngesgaard2,SørenJessen3andAndyHodsonProfessoratUNIS1MasterstudentatUCPH,guestmasterstudentatUNIS,2ProfessoratUCPH,3AssociateprofessoratUCPH

In previously glaciated areas of the Arctic,substantial isostatic rebound and associatedrelative sea-level fall have lead to Holocenepermafrost formation in formershallowmarineareas. The study area for this work isAdventdalen in Svalbard, a glacial valley forwhich an extensive amount of research ongeologicalandpermafrost-relatedsubjectsexists.The implications of this landscape’s history forsubpermafrost groundwater is investigated inthreeways:1)ElectricalResistivityTomography(ERT)surveysaroundapingoenablelocationofintrapermafrost groundwater flow paths. 2) Adecoupled 1D/2D heat and groundwater flowmodel provides quantitative estimates of thepotential discharge from the subpermafrostgroundwatersystemaspermafrostaggrades.3)Artesian springs at three pingos facilitatehydrogeochemical interpretation of controllingprocessesalonggroundwaterflowpaths.Results

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fromtheflowandheattransportmodelssuggestthatthepermafrostthicknesshasnotyetreachedequilibrium,andsofrozengroundmightstillbedevelopinginthelowestpartofthepermafrost.Thisimpliesthatgroundwaterdischargefromthesubpermafrost aquifer could be driven bypermafrost aggradation, leading to the artesiansprings seenat thepingos.However, the springwater analyses show complexhydrogeochemistry probably due to freeze andthaw processes, although a common source isprobableandasubpermafrostoriginseemsmostlikely.Onthebasisof themodelresultsandtheERT, a new conceptual model of open-systempingoformationwillthereforebepresented.

11.2. Groundwater – surfacewaterinteraction;chemicalandquantitative impacts on rivers,lakes, wetlands, fjords andcoastalareas.

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GroundwaterdischargeandrechargepatternsincomplexaquifersysteminamineexplorationareainNorthernFinland

SusanneCharlottaÅberg1,KirstiKorkka-Niemi1andVeli-PekkaSalonen11DepartmentofGeosciencesandGeography,UniversityofHelsinki,P.O.Box64,00014Helsinki

AprominentCu-NishowingnamedtoasSakattihasbeendiscoveredinSodankylä(Brownscombeetal.2015),closetoKitinenriverandbelowtheNatura 2000 protected Viiankiaapa mire.Understandingof the interactionof surface andgroundwater is essential for sustainable oreexploration and development. However, thecomplexity of the sedimentation history of thesurficial deposits makes the groundwateroccurrences scattered and elusive. The mirehydrologyanditsrelationshipwithgroundwaterrecharge–discharge patterns is also crucial formirevegetation,buthasseldombeenstudiedinFinland (Laitinen et al. 2005). Understandinggroundwater-surface water interaction areas isalso important when protecting habitats ofgroundwaterdependentecosystems(GDE).

MODFLOW-NWTmodelwasutilizedfordefiningthe groundwater recharge and dischargepatternsandtorelatethemwithGDEsinthearea.Hydrostratigraphicunits of themodel basedonthe previously created conceptual sedimentarymodel (Åberg et al. 2017). At the same timeannual groundwater table fluctuation wasstudied frommonitoring wells for definition toinitial recharge rates. The recharge parameterswere calibrated with parameter estimation.Hydraulic conductivities were manually

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calibrated with interpolation from previous k-value calculations. The model results indicatedthatmajorflowdirectionistowardstheKitinenriver.Themodelunderestimatedthedistributionof the discharge zone within mire area. It alsoslightly overestimated the recharge rates. Thefluxes from the bedrock are needed in order toget more reliable results. Flow modelling wasfound to be effective tool for evaluating theconceptualsedimentarymodel.

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CoastalgroundwaterinWesternSweden:Hydrogeologicalandsocietalchallenges

RolandBarthel1,MarkusGiese1,EzraHaaf1,IngmarGeuze1andMichelleNygren11DepartmentofEarthSciences,UniversityofGothenburg,Gothenburg,Sweden

Groundwater at the Swedish coast occurs infractured bedrock or in isolated, shallowquaternary sedimentary formations. Thoseresourcesareoflimitedinterestforpublicwatersupply.However,alargeandgrowingnumberofpoorly regulated private wells create anincreasingpressureongroundwaterinattractivecoastalareasandonislands.

The “Koster” archipelago forms amicrocosmofcoastal groundwater problems in Sweden.Koster's geology is dominated by fractured,crystalline bedrock, occasionally overlain byquaternary deposits. With around 300permanent residents, and up to 6,000 summerguestsinpeakholidayseason,theexistingwatersupplybasedon800privatewellsreachesalimit.Water availability forms an obstacle to futuredevelopment and the current situation isregardedasbeingunsustainable.

Groundwater on Koster was monitored over aperiodof1.5years.Allobservationsweremadeinabout220private,pumpedwells.350sampleswere analysed for major ions and metals.Groundwater levelsand insituphysicochemical

parametersweremeasuredatsixoccasions,anddataloggerswereinstalledin10wells.

Studies dealing with saltwater intrusion infractured (bedrock) aquifers are rare. Thehydrogeological assessment on Koster thusreveals interesting new insights into coastalgroundwater in crystalline rock formations.However, thedominatingmanagementproblemonKosterappearstoberatheracombinationofalack of national regulations and an overlycomplex framework of responsibilities. Thiscontribution attempts to combinehydrogeological and societal aspects and drawssomewider-rangingconclusionson the relationbetween hydrogeological research and itsapplicationindecisionmakingprocesses.

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SpatialvariabilityofwaterandnutrientfluxesingroundwaterdischargingtoRingkøbingFjord

CarlosDuque1,JoelTirado-Conde2,SachinKaran3,JanjaSvetina1,SørenJesen2andPeterEngesgaard21AarhusUniversity,2UniversityofCopenhagen,3GeologicalSurveyofDenmarkandGreenland(GEUS)

River and groundwater discharge to coastalwaters bring nutrients that may causeeutrophication, algal blooms or hypoxic events.The quantification of nutrient discharge tocoastal waters is essential for themanagementthese areas and it is especially relevant inestuarieswithalimitedflushingbyseawater.Thequantificationof thegroundwatercomponent ischallengingsinceittakesplacesinthesubsurfaceand under the water. Often it is estimatedindirectly based on water budgets or regionalnumericalmodelsonthescaleof theestuaryorstudy area. Likewise, the quantification ofnutrient loading is usually carried out byassuming an average concentration.Nevertheless,itiswellknownthatgroundwaterdischarge,aswellasnutrientconcentrationsarehighly variable over short distances. Thisintroducesuncertainties in thequantificationof

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coastalnutrientexports.Inthiswork,thespatialvariabilityofthegroundwaterdischargeandthegroundwater nitrate and phosphorusconcentration to Ringkøbing Fjord is measureddirectlyatthehorizontalandverticalmeterscaleto assess the range of variability that can beconsideredat theseenvironments.Thedataarecompared with the hydraulic conductivitymeasurements to investigate the potentialcorrelations between fluxes, nutrientconcentrationlevel,andhydraulicconductivityatvariabledistancesfromshoreanddepthsbelowtheseafloor.

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UseofWaterStableIsotopesandEndMemberMixingAnalysistoMapandQuantifyGroundwaterExchangewithLakes

PeterEngesgaard1,IngeborgSolvang2andEmilKristensen31DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,Denmark,2MulticonsultNorgeAS,avd.Bergen,Norway,3FreshwaterBiologicalLaboratory,DepartmentofBiology,UniversityofCopenhagen,Denmark

Groundwater-lake exchanges are important inordertoestablishwaterbudgetsforlakes.

We used water stable isotopes (18O) to mapdischarge and recharge zones. In groundwaterdownstreamof lake rechargezones (lakewaterseeping to groundwater) one expects to find asignal similar to that of the lake (typicallyenrichedin18Ocomparedtogroundwater)andingroundwaterdischargezones,oneexpectstofindagroundwatersignal.

However, concentrations are ‘noisy’ due torainfall-evaporation processes, groundwaterflow, changes in residence time etc. An EndMember Mixing Analysis accounting for endmember uncertainty (rainwater, groundwaterandlakewater)wasusedtomapseepagezonesat Lake Tvorup Hul in National Park Thy,Denmark. A two-component analysis (Electrical

Conductivity (EC) and 18O) was also used tobetter constrain the analysis under theassumption that EC behaved as a conservativetracer.

The4halakeislocatedinsandydeposits.18OandECweremeasuredin30wells(depthof1.25m)around and close to the lake. End memberconcentrationsanduncertaintyweredeterminedby sampling groundwater in wells on thedischargeside,aswellaslakewaterandrainfall.

18O andECwere robust tracers able to identifydischarge (South) and recharge (West, North)zones.OntheEasternshoretheanalysisshowedamixtureofdischarge/rechargeexplainedbytheproximity to a water divide and/or a morecomplex geology with near-surface clay andchalk.Theidentifiedseepagezonesagreewithaniso-potential map and spot measurements ofseepage.

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Anintegratedandcoupledsurface/subsurfacewatermodeltoestimatelakehydrologicandbiogeochemicalbudgetsoverNorthernlake-richregions

ZacharyHanson1,JacobZwart1,AlanHamlet1,StuartJones1andDiogoBolster11UniversityofNotreDame

Lakesareintensebiogeochemicalprocessorsandplay key roles in the global carbon cycle.However, to date large-scale models rely onmultiplying a mean observed areal rates byregional or global lake surface area, treating alllakesasthesame.Thisignorestheheterogeneousnature of these systems and their static naturerenders them incapable of predicting how lakecarbon cycling will change under future globalchangescenarios.Torectifythis,wedevelopedaprocess-basedmodel incorporating surface andgroundwater hydrology, physics, and ecology.Themodelcanbeappliedoverlargegeographicregionstohindcastandforecast lakehydrologic

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and carbon fluxes. We applied our model tosimulate lake levelsanddailycarbonfluxesandpools for 3675 lakes in theNorthernHighlandsLakeDistrict(NHLD),Wisconsin,USAfrom1980-2010. The model produces patterns consistentwith observations. We show that variability inlake carbon fluxes are related to some simplehydrologic metrics, such as the fraction ofhydrologicexportasevaporation.Thiscan thenpredict important carbon processes and fluxesfor the region. Hydrologic characteristics wereevenly distributed across lake sizes; therefore,median areal lake carbon emissions and burialacrossthelakesizegradientweresimilar,whichmeant that large lakes constitute anoverwhelminglylargeproportionofthetotallakecarbon flux for the region. Preliminary resultsforecasting behaviors over the next 50 yearsunder climate change suggestdramatic changesinhydrologicandbiogeochemicalcharacteristicsintheregion.

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Investigatinggroundwatercontributiontolakesinclaydominatedcatchments

JacobKidmose1,DavidLajerJuulKristensen2,CatharinaSimoneNisbeth2andSørenJessen21GeologicalSurveyofDenmarkandGreenland,2UniversityofCopenhagen

Groundwater discharge to lakes is normallyinvestigated in geological environmentsdominated by permeable, high hydraulicallyconductive sediments, which can facilitate thegroundwater-surface water interaction. Thisincludes, for example, lakes set in glacialmeltwater outwash planes comprising coarse-grainedsandyaquifers.Inotherinvestigations,asand, chalk, or other water baringhydrogeologicalunits,areincontractwithsomepartsofthelake,eitherinabathymetricaldeeperpart, or in a horizontal zone of the lake. Fewstudies has been carried out in hydrogeologicalsettings where the upper 10-20 meters nearsurfacegeologyaredominatedbylowpermeable

materials as clays. Groundwater inputs, orexchanges with lakes in such hydro-geologicalsettings are generally believed to be small andtherefore often ignored in water balancecalculations.

The presented study investigates thegroundwatercomponentinthewaterbalancefora lake locatedon the islandofFunen,Denmark.The lakerestsupon20meterof lowpermeabletill moraine clay which overlays an artesianaquifer, as indicated by piezometric heads andthe occurrence of a spring located on a smallisland on the lake. Evaluation of the waterbalancecombinesresultsfromcontinuouswaterquantitativeandqualitativemeasurementsat11surface inlets, 1 outlet and at the spring.Furthermore, in order to understand thephysiography of the lake–aquifer system,geophysical surveys are conducted. Themeasured water fluxes shows an importantdischargeofgroundwatertothelake,supportedby isotopic analysis. Groundwater modelling isused tovalidate themeasuredwaterbalanceofthelake.

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Geo-hydro-ecologicalfactorsaffectingthedistributionofendangeredspeciesofViiankiaapamire,inoreprospectingsite

KirstiKorkka-Niemi1,AnneRautio1,PaulaBigler1andSusanneÅberg11UniversityofHelsinki,Departmentofgeosciencesandgeography

Potential impacts of ore prospecting, aswell asminingdevelopmentactivities,areoftenrelatedtosurfaceandgroundwaterresourcesandtheirinteractions. A prominent Cu-Ni-PGE sulphidediscovery named Sakatti has been discoveredbelow the Natura 2000 protected Viiankiaapamire, in Northern Finland. It is important tounderstand thepossible associationof themirevegetation with groundwater–surface water

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interactions,aswellasthegeochemicalfeaturesofthelocalbedrock.

This study aims to answer the question of howmuch the hydrological and hydrogeochemicalfactors control the patterns of endangeredvegetationinViiankiaapamire.Especiallyintheareas rich in Hamatocaulis vernicosus,groundwater recharge-discharge patterns havebeencompiledon thebasisofdata collectedbyfield studies, thermal infrared (TIR) remotesensing and laboratory analyses. Groundwaterflow patterns have been determined bymeasuringwatertablesinobservationwellsandpeat layers.Water samples (N=137) have beentakenfromgroundwaterandfrompeatlayer,inorder to determine the variations in waterchemistry including stable isotopes, dissolvedsilica,mainions,pH,EC,DOCandtraceelements.TIR survey using unmanned aerial vehicle hasbeen used in order to observe groundwaterdischarge locations in themire and to assess ifendangered species prefer groundwaterinfluencedhabitats.

Temperature anomalies were detected,indicatingcoldgroundwaterdischargingintothesoilsurfaceatsomelocationsinthestudiedmire.Groundwater and surface water chemistryrevealed significant vertical and horizontalvariation. Geochemical stratification in peatlayers could be observed in pH, EC, stableisotopesandsomedissolvedelements.

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Lacustrinegroundwaterdischargeanditsrelevanceforeutrophication

JörgLewandowski1,KarinMeinikmann1,GunnarNützmann1andDonaldO.Rosenberry21Leibniz-InstituteofFreshwaterEcologyandInlandFischeriesandHumboldtUniversityBerlin,2USGeologicalSurvey,Denver,Colorado,UnitedStates

Eutrophication is still a major threat to lakes.Typical anthropogenic nutrient sources includefertilizers, manure and sewage. As a first steptowards an effective lake management all

nutrient import pathways need to be preciselyquantified.Nutrient loadingviasomepathways,for example streams, can be easily quantifiedquite accurately. The estimation of nutrientimport to lakes by lacustrine groundwaterdischarge (LGD) is usuallymuchmore difficult.WediscusssomereasonswhyLGDhasoftenbeenunderestimatedanddisregardedinlakenutrientbudgets. We give a brief overview ofmeasurement techniques, and present volumes,concentrations and loads reported in literatureforLGD.Mostmeasurementtechniquesarebasedon separate determinations of seepage volumeand nutrient concentration of exfiltratinggroundwater, and thenmultiplyingboth values.Concentrationsofgroundwatercompoundsvaryalong the flow path from the catchment to thelake.Especiallytheaquifer-lakeinterfaceisoftenconsideredareactivezone.Wedescribethefateofnitrogenandphosphorusontheirsubsurfacepathwayfromthecatchmentthroughthereactiveinterface into the surfacewaterbody.Asa casestudy we present results from Lake Arendsee(Germany) where LGD is the major driver ofintenseeutrophicationinthelake.Morethan50% of the total P load is of groundwater-borneorigininthiscase.

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"Translating"adensity-independentgroundwatermodelintoaSEAWATmodel

ThomasLjungberg11DepartmentofGeoscience,AarhusUniversity.

Incoastalregions,thehigherdensityofthesalinegroundwater influences the flow pattern of thelighter fresh/brackish groundwater as itmakesitswaytothesea.Inordertogetthebestpossibleunderstanding of the flow patterns whenmodellingsuchcoastalaquifersitisnecessarytotake the density difference into account, e.g. bysettingupaSEAWATmodel.However,SEAWATcan easily become unstable if the cell volumesacrossthemodelarenotuniform,anditdoesbestifseveralmodellayersrepresenteachgeological

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unit[Guo&Langevin,2002].Theserequirementsmake it difficult to assign values of hydraulicparameterstothemodel,asthegeologicalunitsrarely are uniformly distributed across themodelled area. Besides this, when consideringdensity differences and solute transport, thecomplexity of the calculations means that theruntimeofsuchamodelismuchlongerthanforadensity-independentmodelof the samesystem.InmyMaster's thesis Isetupa5-layerdensity-independent MODFLOW model with non-uniform cell volumes, and calibrated it frommeasurements of hydraulic head. Subsequently,this model was "translated" into a 10-layerdensity-independent model with uniform cellvolumes, and then further developed into aSEAWAT model, and it was shown that thesethreemodelsproducedverysimilarresults,asfarashydraulicheadsgo. In this talk Iwillpresentthe technique thatwas used for translating themodel, and show that the models do indeedproducesimilarresults.

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DevelopingmethodstoassessquantitativeandchemicalcontactbetweengroundwaterandthevarioussurfacewaterbodiesinrelationtoupdateofriverbasinmanagementplansinDenmark

BertelNilsson1,LarsTroldborg2andLærkeThorling31GeologicalSurveyofDenmarkandGreenland(GEUS),ØsterVoldgade10,1350Copenhagen,Denmark.,2GeologicalSurveyofDenmarkandGreenland(GEUS),C.F.MøllersAllé8,Bygning1110,,Denmark.,3GeologicalSurveyofDenmarkandGreenland(GEUS),C.F.MøllersAllé8,Bygning1110,8000,Denmark.

TheEuropeanWaterFrameDirective(WFD)setsoutobjectivesforthewaterenvironment.Theseinclude the protection of, enhancement andrestoration of surface water, groundwater andgroundwater dependent terrestrial ecosystems(GWDTE).

TheGeologicalSurveyofDenmarkandGreenlandhas in collaboration with Aarhus Universityrecently started developing methods to assessthe chemical and quantitative interactionbetween groundwater bodies, rivers, lakes,coastalwaterandGWDTE.Thetaskistoreviewnational monitoring programs in terms of howwell the data collection on hydrological andchemical data capture the potential interactionbetween the around 400 Danish groundwaterbodies and surfacewater bodies. The hydrauliccontact between the groundwater, rivers, lakesand coastal water will be quantified using anationalhydrologicalmodelforDenmark.Resultsandexperiencesobtainedonthevariouspartsofthe hydrological cycle will be presented. TheworkisfundedbytheDanishEPA.

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UsingthestableoxygenisotopeofphosphateasatracerforvariousphosphorussourcestoLakeNørresø,Denmark.

CatharinaS.Nisbeth1,DavidWO’Connell2andSørenJessen11UniversityofCopenhagen,Dept.ofGeosciencesandNaturalResourceManagement,Copenhagen,Denmark,2DepartmentofCivilandEnvironmentalEngineering,TrinityCollegeDublin,CollegeGreen,MuseumBui

Eutrophication of freshwater ecosystems is inparticular sensitive to phosphorus input. Thus,identifyingthedifferentphosphorussourcesandtheir relative fraction of the total phosphorusloadisessentialforrestorationandimprovementof eutrophic aquatic ecosystems. Analyzing theoxygen isotopes of phosphate (δ18Op) ofphosphate in the various PO4 fractions couldprovidethenecessaryknowledgefortracingtheorigin of the different phosphorus sources.Furthermore,δ18Opcouldalsobeusedtoidentifywhich sources are most significant in thedegradation of the associated freshwaterecosystemsat a local scale.Themethodutilizesthat the P-O bond in the orthophosphate, isresistanttoinorganichydrolysisattemperatures

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and pH levels found in natural abiotic aquaticecosystems.Subsequently, theδ18Opwill reflecttheisotopicsignatureofthesources1.However,biological activity alters the source δ18Opsignatures,whichleadstoanisotopicequilibriumbetweentheambientwaterandthephosphate2.

This method is contingent upon an extendedknowledgeoftheδ18Opsignaturesfromdifferentphosphate sources. Nonetheless, the varioussource signatures have not yet been entirelyevolvedandmoreresearchhastobeconductedinordertoconstrainthesesignaturesfurther.

Thisstudyfocusesonidentificationoftheδ18Opsignaturesforthemainphosphatesourcestotheeutrophiclake,Nørresø,inDenmark.Theaimwasto i) identify which of the phosphate sourcesconstituted the largest fraction of the totalphosphateinputtothelake,andii)investigateifsomeofthesources in factcamefromthesameplaceoforigin.

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Trophicstatecontrolofgroundwater-fedecosystemsbygroundwater-bornephosphorus

CatharinaSimoneNisbeth1,JacobKidmose2,KaarinaWeckström3,KasperReitzel4,BentVadOdgaard5,AiaAistrupEriksen5,OleBennike6,BertelNilsson2,LærkeThorling7,SuzanneMcGowan8,AndersSchomacker9,Marie-LouiseSiggaard-Andersen9,DavidLajerJuulKristensen1andSørenJessen11DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,2DepartmentofHydrology,GeologicalSurveyofDenmarkandGreenland,3DepartmentofEnvironmentalSciences,UniversityofHelsinki,4DepartmentofBiology,UniversityofSouthernDenmark,5DepartmentofGeoscience,AarhusUniversity,6DepartmentofMarineGeology,GeologicalSurveyofDenmarkandGreenland,7GroundwaterandQuaternaryGeologyMapping,GeologicalSurveyofDenmarkandGreenland,8SchoolofGeography,UniversityofNottingham,9NaturalHistoryMuseumofDenmark,UniversityofCopenhagen

Understanding P cycling in the terrestrialhydrosphereisimportanttomanageecosystems.We conduct a cross-disciplinary study ofgroundwaterPcyclingbycomparingthecurrentwaterandPbalanceofa70halake(Nørresø,Fyn,Denmark)inaclayeytilldominatedlandscapetothe lake’sHolocenetrophichistory,asretrievedfrom sediment cores. The diatom and pigmentrecordsofcoresampleswith14Cagespredatinghumaninfluence(>6000yrBP)indicatethatthelake was never P-poor but rather meso- toeutrophic. The current lake water balanceindicates a ~35% groundwater contribution,while~65%comesfromabouttenditchstreamsand direct precipitation. A groundwater-fedspringat1melevationabovelakelevelexistsonasmallislandandshowsthatthereisanartesianaquifer beneath the confining till. Furthermore,metre-scale circular iceholesduring thewintersupportsgroundwaterdischargetothelakefromanartesianaquiferviadiscretedischargezonesinthelakebed.Thespringwaterisanoxic,ferrous,and contains 130 µg P/L. Similar water qualityand total-P contents of 150-390 µg/L areobservedinartesianglaciofluvialsandprobedbywatersupplywellsdistanced0.5to2.7kmfromthe lake. If the P concentration of the spring isrepresentative for the artesian aquifer, theaquifer’s groundwater discharge constitutes~90%oftheexternalsourceofPtothelake.Thecombined data suggest that geogenic Pmay bemobilized within and transported throughaquifers andmayultimately control the trophicstateofgroundwaterdependentecosystems.

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Transportandtransformationofnitrateinariparianwetland

RasmusJesPetersen1,ChristianPrinds1,BoVangsøIversen1,CharlotteKjærgaard2,SørenJessen3andPeterEngesgaard31DepartmentofAgroecology,AarhusUniversity,2SEGES,3DepartmentofGeosciences,CopenhagenUniversity

Even though riparian wetlands have beenintensivelystudiedduringthepast30yearsthese

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areasstillfunctionasa“blackbox”withregardsto removal of nitrogen input from surroundingareas. To comply with regulations of theEuropean Water Framework Directive, Danishagricultureistoreducetheloadofnitrogenfromagricultural fields to fresh water bodies. Oneinitiativeismovingfromauniformregulationofnitrogenapplication toaspatiallydifferentiatedregulationwherelessfertilizershouldbeappliedto vulnerable areas. This leads to theidentificationof vulnerableand robust areas, inwhichriparianwetlandsplaysanimportantrole.

Thepresentcasestudyinvestigatesthetransportandtransformationofnitrateenteringariparianwetland via drain water from surroundingagriculturalareas.Thedrainpipesarecutoffatthe hillslope and drain water irrigates thewetland.Dependingonthesaturationstateofthewetlandsoilsand theamountofwaterenteringduring precipitation events, a part of thewaterinfiltratesintothewetlandsedimentsandtravelstowardsthestream.Someoftheinfiltratedwatermaybecaughtbydrainswithinthewetlandsoilsand transported directly to the stream. Theremainingwater can be either evapotranspiredortransporteddirectlytothestreamviaoverlandflow. Preliminary results show an efficientdenitrification of nitrate infiltrating into thestudied wetland soils. The nitrogen removalefficiencyatdifferentdrainoutletsseemsthentobe largely controlled by the amount of drainwaterinputrelativetotheinfiltrationcapacityofthewetlandsoil.

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Mappingsurfaceflowinlow-gradientareaswiththermalremotesensing

ChristianPrinds1,RasmusJesPetersen1,ReneLarsen1,MogensGreve1andBoVangsøIversen11AarhusUniversity,Dept.ofAgroecology

Thermal infrared (TIR) imagery has long beenused for mapping groundwater-surface waterinteractions and mainly for locating areas ofgroundwater seepage in lakes and shorelines(Rundquistetal.1985,Banksetal.1996).Inthis

study,weusedthemethodforlocatingdischargefromtiledrains into lowlandsandwaterbodies(lakes,streams,ditchesetc.).Tiledrainsareoneofthemainendpointsfornutrientsappliedtotheagricultural fields and a fast conduit. Whenstudying the function of riparian lowlands andwetlandsasnutrientbufferzones, it isessentialtoknow1)thelocationofdrainageinputintothebuffersystemand2)theflowpathofthewater.The TIR imagerywas collected by aUAV (eBeefrom SenseFly) with a thermal camera(ThermoMap from SenseFly) at early spring in2016 and 2017. The surveys are conducted incold periodswhere discharging drainagewater(and groundwater) are warm anomaliescomparedtothecoldsoil.Weherebyobtainmapsof the area’s thermal signature at the time offlight.Thedrainageoutletsareeasilyobservedassharppoint sourcesofwarmwater andsurfaceflows are also remarkably clear making TIR ausableapproachformappingofflowdirectioninlow-gradientareassuchasriparianlowlandsandwetlands.Theflowsystemscanbecomparedtotopographically modelled surface flow usinghigh-resolution DEMs and flow directionalgorithms.

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Usingland-basedandwaterbornehydrogeophysicalmethodstoinfergeologicalcontrolsongroundwaterdischargetoalake

EvaSebok1,SachinKaran2andPeterEngesgaard31DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen;COWIA/S,2GeologicalSurveyofDenmarkandGreenland(GEUS),DepartmentofGeochemistry,3DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen

Thegeologicalheterogeneityofstreamandlakesediments can lead to spatially heterogeneousgroundwaterdischargetosurfacewaters,whichcan be detected by Distributed TemperatureSensing(DTS).Theheterogeneityofunderwatersediments can also be mapped by waterbornegeophysical surveys such as floating electrode

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Electrical Resistivity Tomography (ERT).However,ERTandDTSmeasurementsarerarelycombined to detect the spatial variability ingroundwater discharge to surface waters. Theaimofthisstudywasthereforeto:(1)testtheuseofDTSinadeeperlakeenvironmentupto4mofwater depth and (2) assess if sedimentheterogeneity indicated by waterbornegeophysical surveys can result in potentialdischargepatternsdetectedbyDTS.

LakeTissøisthefourthlargestlakeinDenmarkwithasurfaceareaof12.3km²,maximaldepthof13mandapresentsurfacewaterextractionof5million m³/year. At the Eastern lakeshorepotential locations of groundwater discharge inthe near-shore region were mapped by DTS.Sediment properties were surveyed with bothon-land and waterborne ERT and the resultingresistivitydatawereusedas input toa2D flowmodel aimed to test the potential dischargelocations interpreted from the DTS survey. Ourresults show that potential patterns ofgroundwater discharge agree well with thelocation of a higher resistivity/coarsermaterialzonedetected60-140moffshore.Thenumericalflow model also confirmed that the surveyedsediment distribution can result in dischargepatternsdetectedbyDTSmeasurements.

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PotentialforLakeBankFiltrationatLakeTissoe,Denmark

FranciskaAmalieKøhn1,EvaSebok2andPeterEngesgaard11DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,2DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen;COWIA/S

In collaboration with Kalundborg Forsyning(KALFOR), COWI is currently investigating thepotential of Lake Bank Filtration (LBF) at LakeTissø, Denmark. Challenges associated withpumpingupgroundwaterinclosevicinitytothelake are the temporal variability in thegroundwater-lakeseepage,wherecloggingofthe

lakebed,aswellasthedrasticchangesofthelakestage throughout the year (160 cm), mayinfluence LBF efficiency. Several field methodswere applied to understand the temporalbehaviorofthetransientseepagepatternsandtoinvestigatethe(in)filtrationpotentialofthenear-lakearea.Basedondata(hydraulicconductivityvalues,boreholeinformation,resistivityprofiles,sedimentsamples)aboutthegeologicalsettingofthe area, a conceptual 2D/3D geological modelwas developed in GeoScene3D. In addition tohydraulic field and tracer data the geologicalmodel was used to develop a 2D/3Dhydrogeologicalconceptualmodeltoexaminethegroundwater-lakeinteraction.Finally,a3Dflow-and multiple tracer transport model wasdevelopedinMODFLOWandMT3DtoexploretheimpactsofapumpingtestcarriedoutatthefieldsiteforassessingthepotentialforLBF.

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AnevaluationoftoolstostandardisegroundwaterresourceassessmentforcoastalareasinSweden

IngmarGeuze1andRolandBarthel11DepartmentofEarthSciences,UniversityofGothenburg,Sweden

Groundwater problems in coastal regions areusually not associated with the sparselypopulated shores of water-rich Scandinavia.However, the combination of local geology andthe specific conditions of water usage createchallenges even there.Along the Swedish coast,much of the groundwater occurs in fracturedbedrock or in relatively small, shallow, andisolated Quaternary sedimentary formations.Those aquifers are usually not consideredrelevant as water resources and have thuspreviously not received much attention fromwaterauthoritiesorresearchers.Nevertheless,apossible long-term solution to the increasingpressure on water resources could be foundwithin the utilisation of these groundwatersystems.

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Noattempthasbeenmadetoreviewandevaluatethe results of individual investigations carriedout by differentmunicipalities in coastal areas.Thus thestatusof coastalgroundwatersystemsin Sweden remains unclear and a standardmethodology that could be applied forgroundwater resource assessment in Swedishcoastal areas does not exist. Hydrogeologicalinvestigations involve high costs, meaning thatperformed investigations should yield reliableresults that fill multiple uses. With the projectpresentedhere,anattemptismadetodevelopastandard methodology for the specifichydrogeological conditions on the Swedishcoastline.

Wepresentfirstlytheresultsofanonlinesurveycarried out among Swedish coastalmunicipalities, illustrating the various types ofproblems, methods of investigation used andmeasures taken. We secondly review variousmethodscommonlyapplied,inconjunctionwithaproposalforastandardmethodologythatmaybeapplicableonanationallevel.

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Formationofsaltwaterintrusionsinthelow-lyingcoastalareasduringtheHoloceneinSouthernJutland

RenaMeyer1,PeterEngesgaard1andTorbenO.Sonnenborg21DepartmentofGeosciencesandNaturalResourceManagementUniversityofCopenhagen,Denmark,2GeologicalsurveyofDenmarkandGreenland(GEUS),Copenhagen,Denmark

Aquifersinlow-lyingcoastalareasarethreatenedby saltwater intrusions, as a result of low headgradients, high abstraction rates and landmanagement,andclimatechange.Understandingthe evolution and driving mechanisms ofsaltwater intrusions can help to adapt watermanagement strategies to mitigate the impact.The 1700km2-large study area in the borderregionbetweenDenmarkandGermany,adjacentto the Wadden Sea, has undergone a complex(hydro-)geologicalevolution; lying in theglacial

foreland likely under permafrost conditionsduringLGMandexperiencingarelativeriseinsealevel during the Holocene. Airborneelectromagneticsurveysindicatesaltwaterupto20km inland. Reclaimed from theWadden Sea,these low-lyingareashavebeenprotected fromfloodingbydikesforthelast200yearsandhavebeen heavily drained. In order to identify theoriginanddynamicsofthesaltwaterandtheroleof heterogeneous geology, a 3D regional-scaledensity-driven flow-and-transport model wasused.Theformationofsaltwater intrusionswassimulated during the Holocene taking intoaccount changing conditions causedby floodinganddikeconstruction.Theresultsrevealthatthesaltwater originate from a combination ofremnant (pre-Holocene) seawater, Holocenetransgressionandrecentdrainage.Mainfeaturescontrolling the progression of the modernseawater into the coastal aquifers are buriedvalleys providing preferential flow path forsaltwater in combination with an extensiveMioceneclaylayerhinderingsaltwaterintrusionand land management with dike constructiontransformingtheshallowaquiferfrombeingsaltsaturatedduringfloodingtobeingrefreshedafterthedikewasbuilt.

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TemperatureprofilestomeasuregroundwaterdischargetoRingkøbingFjord.

JoelTirado-Conde1,CarlosDuque2,SachinKaran3andPeterEngesgaard11DepartmentofGeosciencesandNaturalResourceManagement.UniversityofCopenhagen,2DepartmentofGeoscience.AarhusUniversity,3DepartmentofGeochemistry.GeologicalSurveyofDenmarkandGreenland(GEUS)

Groundwater discharge or upwelling plays animportantroleintheecologicalandhydrologicaldynamics in coastal areas, bringing freshwaterinputstosalinewatersystems.However,locatingitboth in spaceand timeaswell asquantifyinghowmuchgroundwaterflowsupwardtocoastalareas requires a big effort since these are very

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heterogeneous systems. Seasonal changes inrainfall, temperature and water level lead totemporal variability, while variations in thehydraulicpropertiesandhydrologicalprocessescan generate spatial heterogeneity, making theprocess of measuring those fluxes complicatedand requiringmultiplemeasurements to obtainaccurate results. Furthermore, the non-steadyposition of the fresh water-salt water interfaceincreases the uncertainty surrounding theseprocesses. Using temperature as a tracer, thegroundwaterinputstoasurfacewaterbodycanbecalculatedbymeansofsolvinganalyticallytheconduction-convection equation, shorteningconsiderablytheamountoffieldworkneededtoobtain groundwater upwelling fluxes. In thiswork groundwaterupwelling in theRingkøbingFjord coastal area was obtained using twomethods:directupwardflowmeasurementsandindirectflowcalculationswithshallowfjordbedtemperatureprofiles.Thesetwodifferentsetsofdata are compared in order to assess theirfeasibility to map and quantify upwelling.Addressingthestrengthsandweaknessesofeachmethod,weaimtobetterconstrainthereliabilityoftheminordertoimprovethequalityofthedatacollectionprocess.

11.3. Integrated HydrologicalModeling

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Assessingtheimpactofmodelstructureonuncertaintyinintegratedhydrologicalmodelling

MichaelButts1,SílviaLeirião1,DouglasGraham1andJeremyKobor21DHI,AgernAlle5,DK2970Denmark,2NowatO’ConnorEnvironmental,Inc.,POBox794,Healdsburg,CA95448,USA

Understanding and quantifying modeluncertainty is essential for decision-making inwaterresourcesmanagement.Modeluncertaintycomes from the forcing data (rainfall,evapotranspiration), the boundary conditionsandtheparameters.Italsoarisesfromthemodelstructure, including the process descriptions,numerical approximations, and geologicalmodels. Inpractice,we trade-off thecomplexityof the model required to capture the relevantcatchmentprocessesagainsttheaccuracyneededtomakereliabledecisions.

In this paper, we examine the impact ofmodelstructure on model calibration and predictionuncertaintyinthreecasestudies.Thefirststudyassesses the impact of land use change in theNapaValley,USA.Wepresentamodelframeworkthatallowsforarangeofmodelstructures,whichweusedtocalibrateinseparatestepsthesurfacewater and then the groundwater. In the secondcase,wesystematicallyexploreddifferentmodelsand model structures for rainfall-runoffprocessesintheBlueRiver,USA.Inthiscase,theuncertaintiesinthepredictedflowsduetomodelstructure were larger than uncertainties fromboth the rainfall and the model parameters.Finally, we are currently using the samemodelling framework to investigate the impacton model structure and calibration on anintegrated hydrological model of the Hindscatchment,NewZealandwherechangesinwaterallocation and land use may result inunacceptable flow reductions in an extensive

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coastal spring system. The aim is to exploredifferentfacetsofriskcalculationbasedonBayesequation to determine whether the proposedchangesleadtounacceptableflowreductions

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Cannewdrainconceptsimprovelocaldrainflowperformanceincatchmentscalemodelling(MIKESHE)?

IdaBjørnholtKarlsson1,AnkerLajerHøjberg1andBoVangsøIversen21GeologicalSurveyofDenmarkandGreenland(GEUS),2InstitutforAgroøkologi,AarhusUniversitet

Nitrate leaching to groundwater, surface waterandoceansareanincreasingissueforareaswithintensiveagriculture.Thedrainageflowsystemisimportantforthetransportationofwaterbutalsoworks as a potential fast track with limitedreduction fornitratepollutants.As theneed forcatchmentmodelsthatcansimulateandpredictnitratetransportanddegradationgrows,sodoesthe necessity for models able to adequatelyrepresentdrainageflowonlocalscale.

Inthisstudy(TReNDS,Højbergetal.2016-2018)theaimistotestwhetherornotknowledgeaboutthemechanisms controlling drain flow creationcanbeusedtodevelopnewdrainconcepts;thatcan improve local scale performance. Theconceptsmustbefoundedindataobtainableoncatchment scale; as they potentially should beincorporatedintonationalmodellingschemes.

AfullydistributedhydrologicalMIKESHEmodelforthe101km2Norsmindecatchment,Denmarkisused(Hansenetal.,2014;Heetal.,2015).Thecatchment is dominated by agriculture and anextensive drainage network. The concepts arebuilt on thesesofdifferentiatedoccurrenceandparameterization for different drain types (tile,natural and urban drain); and importantvariables (such as TWI and clay content in thesoil, (Iversen, 2016)) controlling the generationofdrainflowthatcanbeaccountedforwithinthelimitations in the MIKE SHE model concept.Measureddrainagefromeightdrainflowstations

(Kjærgaard et al., 2011-2015) are used forevaluatinganygainoftheimplementationofthedrainconceptsondynamicsandquantity.

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IntegratedhydrologyintheCOHERENTproject

MortenAndreasDahlLarsen1,KirstenHalsnæs1andMartinDrews11TechnicalUniversityofDenmark

The COHERENT project, funded by InnovationFund Denmark, was instigated on Nov. 1 andaddressesrisksinthecoastalzoneofbothnaturaland anthropogenic origin and the interplaybetween them. The presentation will presentwork led by the presenting author whichspecifically addresses the impact ofinland/watershedhydrologyonnaturalhazardsinthecoastalzone,mostoftenfloodingeventsoncoastal cities, and the interactions withadaptation practices, urban development andmanagement.Thetopicishighlyrelevantduetoprojected increases in frequencies andmagnitudesofnaturalhazardsinthecoastalzoneunder current climate change potentiallyresultinginhighsocialandeconomiccosts.

Thephysical impact of coastal flooding ismadeupofmainlytheimpactofthestormsurgeitselfaswellaswaves,tidesandageneralincreaseinsea level and the assessment of potentialadaptation measures can be complex. Thevulnerabilitycanhoweverincreaseforthefluvialpart with higher stream flow and groundwaterlevel,withtemporalscalesintheorderofdaystoseasons. Another influence comes from thepluvial side when rainfall events occursimultaneously,withtemporalscalesintheorderofminutestodays.Akeyobjectiveoftheworkistherefore to assess the influence of inland-watershed hydrology on the risk hazards forcurrent and future conditions within the threecases of the project; Skive, Ringkøbing andAabenraamunicipalities.Akeyobjectiveiscloseinteractionwithmunicipalitiesandstakeholders

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to reflect applied conditions and assess trueprojectedurbandevelopmentgoals.

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Awatershedscaleapproachtomodelironconcentrationinriver

MarkusSaari1,HannuMarttila1,PekkaRossi1andHeiniPostila21Waterresourcesandenvironmentalengineeringresearchunit,UniversityofOulu,2Waterresourcesandenvironmentalengineeringresearchunit,UniversityofOulu

Numerous studies have reported increases iniron concentrations in freshwaters especially inboreal regions. The significant role of iron inbiochemicalprocessesandelementcyclesmakesthis matter of concern among researchcommunity. With infrequent sampling (weeklyinterval)inmainriverswehavelimitedprocessunderstanding to evaluate main drivers behindtheirontransportinwatershedscale.Toenhancethis, we usedwatershed scale SWATmodel fortypical clayey soiled and agriculture dominatedriver basin in Southern Finland. In this type ofwatershed, themobilityof iron isdominatedbythe erosion and transportation of suspendedsolids,especiallyclayparticles.Thestronglinearcorrelation between TSS, turbidity and ironconcentration was utilized to model irontransportation in watershed scale. Successfulmodel calibration and validation allowed us tostudy main sources for iron transport andseasonal dynamics. Based on the modellingresultsthemostcrucialtimesforirontransportarelateautumnrainfallswhichcausesignificanterosiononagriculturallands.Wefurtherusedthemodel to predict future land use and climatechange scenarios and possibilities to mitigatetheirjointeffectstoirontransport.

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Estimatedvariationinpesticideleachingthroughgreensandfairwaysbasedondetailedfate-descriptionsin12-cmsoilprofiles

SachinKaran1,NoraBadawi1,AnneM.D.Jensen2andAnnetteE.Rosenbom11GeologicalSurveyofDenmarkandGreenland(GEUS),DepartmentofGeochemistry,2UniversityofCopenhagen,DepartmentofGeosciencesandNaturalResourceManagement

Leaching resulting from treating golf courseswith pesticides is presently not well known.Although studies have shown that 90-100% ofappliedpesticidescanbemicrobiallyremovedinturfswithasurfacenearthatchlayer,thisisnotubiquitous.Theretardationofpesticidesinsoilsiscompoundspecific,butalsocontrolledby thehydrogeological setting that for fairways caninclude the presence of wormholes. Thus,potential rapid preferential flow and transportmaymakefairwaysmorevulnerableinregardstoleaching.

Based on both detailed fate (degradation andsorption)andhydrogeologicaldescriptionsoftheupper 12-cm soil profile of golf courses, theleachingpotentialoftebuconazole(TBZ)throughsix greens (three USGA and three push-upgreens) and of MCPA through three fairways(low, medium and highly fertilized) wereestimated numerically using COMSOLMultiphysics.Allthegolfcourseswerelocatedinareas characterized as macro porous clay tillsettings. The impact of fate processes on theleachingpotentialof:

·TBZas:

-ananalyticalgradecompound,

-acommercialformulation,

-acommercialformulationincombinationwithasurfactantproduct

·MCPAas:

-ananalyticalgradecompound

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-acommercialformulation

was evaluated numerically for greens andpreferential transport for fairways given thepresence of a wormhole. The preliminarysimulationresultsindicatethat

-TBZhas a high potential for leaching throughthegreensinhighconcentration

-MCPAhasalowpotentialforleachingthroughthefairwaysgivenahighdegreeofdegradationintheupper12cm.

11.4.OpensessionHydrogeology

ORAL

Skåningshave-anewmajorwell-fieldontheislandofLolland(S.Denmark).Developmentandhydrogeology.

KristianBitsch1,KarlJørgensen2andMikaelJørgensen31Rambøll,HannemannsAllé53,DK-2350CopenhagenS,2MunicipalityofLolland,Jernbanegade7,DK-4930Maribo,3NIRAS,Sortemosevej19,DK-3450Allerød

TheIslandofLollandliesinthesouthernpartofDenmarkandcomprises1242km².TheIslandisveryflathavinganaverageof7minaltitudeandamaximumof30mabovesealevel.ThesurfaceoftheIslandisdominatedbyglacigenesedimentsof late Weichselian age, clayey tills andglaciofluviatile outwash sediments formingdiscontinuous basins. The prequaternary areMaasthrictian-CampanianchalksinthenorthandPaleocene clays to the south. Non-salinegroundwater forms a shallow lens with amaximumdepthof50min thenorthern2/3oftheisland.Thewatersupplystructureisbasedon4 municipal and 25 community waterworks,deliveringatotalof2+1millionm3peryear.Anew infrastructure project demands up to 450000m3/year.100000m3/yearcanbedeliveredbytheexistingwaterworks.Inthecentralpartofthe islandawidespread layerofoutwashsandswasrecognized.Theareahadjustbeensubjectedto an intensive geological and geophysicalmapping using all existing well data, seismicprofilingandextensiveSkyTemmapping,whichhadbeenusedtomakeanewregionalgeologicaland hydrologicalmodel of the area. Thismodelwas used as the basis for producing a detailedwell fieldmodel later improvedwith additionaldata from MRS soundings and 6 new wellsincludingamajortestpumping.Thisledtoanewmodelandanabstractionstrategyminimizingtheimpact on the surrounding wetlands includingthelargeNATURA2000area,theMariboLakes.

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ORAL

InvestigatingcontrolsongroundwaterdroughthazardinScandinavia

EzraHaaf1,PekkaM.Rossi2,BjørnKløve2andRolandBarthel11DepartmentofEarthSciences,UniversityofGothenburg,Gothenburg,Sweden,2WaterResourcesandEnvironmentalEngineeringResearchUnit,UniversityofOulu,Finland

Drought has historically been a minor issue inSweden and Finland, countries of high waterabundancy.However, since late2015 into2017large parts of Sweden and Finland have beenclassifiedwithmedium tohigh risk fordroughtimpact according to thedroughtmonitorof theJRCoftheEuropeanCommission.InSweden,theSwedish Geological Survey (SGU) has reportedfalling groundwater levels through theirmonitoring program, particularly during thesummer in Southeastern Sweden. By spring of2017, this problem had intensified andgroundwater drought had been registered inlarge parts of the country. Impacts on societyhavebeenrulesonwateruse,irrigationbanandprivate drinking water wells running dry incertain regions. In Finland, groundwater levelshavebeenperiodicallyreportedtobelowduringthe2000sbasedon themonitoringnetworkbyFinnish Environmental Institute, which hascausedworriesinwaterusage.AlthoughsomeoftheSwedishaquifersarerecoveringasofautumn2017, the drought is still persisting in manysystems. The current understanding of severityandpersistenceaswellaspropagationofdroughtinto groundwater for Swedish and Finnishgroundwater systems is very limited. Here, weinvestigate patterns of groundwater droughtshistoricallyandgeographically.Furthermore,weexplainthesensitivityandpersistencebasedongeologicandenvironmentalcontrolsfordifferenttypesofgroundwatersystemswithdecisiontreelearning.

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SustainableWaterResourcesinIranianQanats

FatanehHajatpourBirgani1andRodneyStevens11DepartmentofEarthSciences,UniversityofGothenburg

Qanatsarewater-transporttunnelswithalowerslope than the groundwater surface theyintersect, typically in arid regionswith alluvial-fan geomorphology. Since the traditional qanattechnique (Persian origin in 1st millennium)relies solely on gravitational drainage to assessdeepgroundwaterresources,theyaresuitableinruralareas,andtheover50,000activeqanatsintheMiddleEastareacrucialsupplyfordrinkingandagriculturalwaterfornumerouspopulationcenters.Qanatsustainabilityisrelatedtochangesinclimate,populationandland-use.Importantly,groundwater lowering by excessive pumpingdecreases or stops qanat discharge. We haveconsidered the qanat sensitivity to theseinfluencesbycharacterizingthegeomorphologic,geologic, climatic and resource-managementassociationsinselectedcasestudies.Debris-flowalluvial fans can be expected to have steepergroundwater gradients than do stream-floodfans.Thisisduetothegreatersurfaceslopeandthelowerhydraulicconductivityassociatedwithfine-grained, debris-flow deposits. The internalstratigraphycanfurtherreflectthefanevolutionover time and further influence reservoircharacter. This poster presents a problemanalysisofqanatresources,theirfuturepotentialand vulnerability. The study is a part of theKERMIT project (Knowledge Exchange forResource Management and International Trust,see separate abstract by Stevens et al., thisvolume),which uses the endemic knowledge ofrefugees inSweden todevelopcasestudiesandcooperation networks both within Sweden andabroad.

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POSTER

FracturemineralsinvestigationsatKyläniemi,SouthernFinland:Paleohydrogeologicalimplications

MinjaSeitsamo-Ryynänen11DepartmentofGeosciencesandGeography,UniversityofHelsinki,Finland

In crystalline bedrock environments, a bulk ofgroundwaterflowoccursinchannelsprovidedbyfracture networks. Isotopic compositions ofprecipitated fracturemineralscanbeutilizedtogain information about the origin, age andcompositional evolution of the deepgroundwatersincrystallinebedrock.

The aim of this study is to investigate thehydrogeochemicalevolutionofgroundwaters inthe crystalline bedrock at Kyläniemi, located inSouthern Finland near Salpausselkä end-moraines. Fracture mineral samples containingcalciteand/orpyritewerecollectedfromwater-conductingfracturesattheupper∼500mofthebedrock. These fracture filling calcites occur asthin ∼200–350 μm crusts on open fracturesurfaces, and the pyrites as small euhedralcrystals.

In addition to optical microscopy and chemicalcomposition analyses, the calcite fillings areanalyzedfortheisotopiccompositiononcarbonand oxygen, and the pyrites for the isotopiccomposition on sulfur. The δ18O values of thelatest calcite generations are expected to showvalues indicating the influence of glacial meltwaters.Theδ13Cvaluesofcalciteandδ34Svaluesof pyrite should demonstrate the evolution ofredoxenvironmentfronts.

Theresultsofthisstudyarecomparedtothoseofprevious studies conducted at Olkiluoto(Sahlstedtet al.2010,2013,2016)which is thechosen geological repository site for spentnuclearfuel.UnlikeOlkiluoto,theKyläniemisiteroseabovethesea-levelinearlyHolocene.Thus,late-stage groundwater evolution is unaffectedbybrackishwaterintrusionsrelatedtoYoldiaSeaandLittorinaSeastages.

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Stablewaterisotopesinsnow:ChangesthroughouttheseasoninFinse,Norway

EvelienvanDijk11UniversityofOslo

Herewepresentchangesofstablewaterisotopeswithin the snow pack throughout one seasonfromtheFinseareainsouthernNorway.

Stablewaterisotopeshavebecomeakeyelementinhydrologicalandatmosphericresearchtopics.Theycanbeusedtogetanunderstandingaboutthe changes in the snow pack throughout thesnow season. For this study, 215 samples fromseveralsnowpitswereanalyzedforstablewaterisotopesthroughoutthesnowseason2016-2017.Siteswereselectedby lookingat thesnowdriftpatterns and snow accumulation to get anundisturbed stratigraphy. The LagrangianparticlemodelFlexpartwillbeusedtomodelthemoisturesourcesforthissnowpacktogetafullerunderstanding of the snow processes and theatmospheric part of the hydrological cycle. Assnow is a water storage it is important tounderstand which processes play a role withinthesnowpackduringaccumulationandmeltandhow these processes influence the deformationand melting. By understanding how the snowmeltphaseschange,betterpredictionsaboutthespring floods can be estimated. Modeling themoisture sources is important to give a betterunderstanding of the atmospheric part of thehydrological cycle. The atmospheric part of thecycleisnotyetfullyunderstood,andbyusingtheisotopiccompositionofsnowtotrackairparcelsback in time a better understanding can beaccomplished.

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12.Geophysics12.1.OpensessioninGeophysics

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DataacquisitionintheNorthande-infrastructurebytheEPOS-Norwayteam

KuvvetAtakan1,ValérieMaupin2andtheEPOS-NorwayConsortium31DepartmentofEarthScience,UniversityofBergen,Norway,2DepartmentofGeosciences,UniversityofOslo,Norway,3seehttps://epos-no.uib.no

Integrating multidisciplinary transnationalinfrastructuresisakeychallengeforsolidEarthScience. EPOS (European Plate ObservatorySystem) is a European project to integrateexistingresearchinfrastructureswithinthefieldsofseismology,geodesy,geophysics,geology,rockphysics and volcanology in Europe.Within thisframework,theEPOS-Norwayprojectisworkingin several directions, from developing new e-infrastructuretointegrateNorwegianSolidEarthdatatoimprovingthemonitoringcapacityintheArctic,includingNorthernNorwayandtheArcticislands of JanMayen, Bear Island and Svalbard.Two main recent developments will bepresented.

A prototype of the e-infrastructure to visualizeandanalyzegeophysicalandgeologicaldatawillbedemonstrated, andwewill alsopresenthowwe are working to implicate the scientificcommunityinthedevelopmentofthesoftware.

Wewillalsoreportontheresultsfromthesurveyconducted in August-September 2017 todeterminetheexactlocationsofthesixplannedco-locatedseismologicalandgeodeticstationsonSvalbard. The survey was conducted with thevessel Ulla Rinman who set out fromLongyearbyen with a crew of scientists andtechnicians from UiB, Kartverket and UNIS.Svalbard is currently experiencing increasedseismic activity in Storfjorden and continuedseismic activity inNordaustlandet, and thenew

stations could greatly increase ourunderstandingofthisactivity.

ORAL

VerydeepstructuralcontrastsacrosstheNorthernTornquistZone

NielsBalling11DepartmentofGeoscience,AarhusUniversity,Aarhus,Denmark

The Tornquist Zone defines a major tectoniclineament across Europe. It extends from theBlack Sea to the North Sea and separates oldPrecambrian cratonic units to the east andnortheast from younger Phanerozoic tectonicunits in Central and Western Europe. In itsnorthernpart, this tectonic zone splits into twomain elements, the Sorgenfrei-Tornquist Zone(STZ),trendingnorthwestfromaroundtheislandof Bornholm to the Skagerrak Sea, and, furthersouth, the Thor Suture between palaeo-continents,BalticaandAvalonia.

Thispresentation is focusedontheSTZ.Here,awiderangeofgeophysicalstudiesrevealmarkeddifferences in crustal and upper-mantlestructure.FromshieldunitsinsouthernSwedento deep basins in Danish areas, we observepronounced crustal thinning, increased surfaceandupper-mantleheatflowanddifferentgravityand magnetic field anomalies. From traveltime(Medhus et al. 2012; Hejrani et al. 2015) andsurface wave (Köhler et al. 2015) tomography,verydeepstructuralcontrasts,downto250-300km,arerecentlyrevealedalongtheSTZaswellasfurther north. A marked, narrow lithospheretransition zone is outlined with high upper-mantle P- and S-wave velocity below Swedishshield areas and low velocities below DanishBasin and most of southern Norway. Despitemarkedly different crustal structure betweenDenmark (deep basins) and southern Norway(Scandinavian Mountains), similar low upper-mantle velocities are observed. These resultsemphasize the significance of the STZ and the

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importance of including deep structuralinformation in understanding different tectonicevolution and associated contrasting geologicalenvironments.

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MagneticcharacteristicaofPaleogenesedimentsinJutland,Denmark.

ClausBeyer1,PerNørnberg2andClausHeilmann-Clausen21CB-Magneto,2InstituteofGeoscience,ÅrhusUniversity

During the last decades we have carried outpalaeomagneticworkontheCenozoicsedimentsinDenmark.Eocenesediments investigatedare:The Ølst Formation, including the basal EoceneStolleKlintClay,RøsnæsClayandLillebæltClayFormations, and twoupperEocenemembersofthe Søvind Marl Formation: the Moesgård andKysingmembers. Themagnetic properties varyaccording to the geochemic environment,biogenic factors and mineralogy, particularlyconcentrationofmagnetite.

The Stolle Klint Clay has a weak remanentmagnetisation due to the anoxic depositionalenvironment, with its organic content causingdegradation iron oxides. The overlying ØlstFormationhasastronger,welldefinedremanentmagnetisationduetoitsfavourableenvironmentforpreservationofironoxides.Inbothunitstheremanent magnetisation is sitting inmultidomainegrains.Achangetohigh-intensitymagnetisation occurs in the Røsnæs Formationdue to that the magnetic grain fractions aredominated by single domaine grains (>90%)throughouttherestoftheEoceneuptillthebaseof the Moesgaard Member. Separation of themagnetic phase and subsequent analysis bytranslucent scanning electron microscoping(TEM) identifiedmagnetite grains smaller than50nanometers,similartotheonesproducedbymagnetotacticbacteria.Theiroccurrence in thisstratigraphic interval may be due to the warmclimaand/orthemarinesedimentaryfacies.Theresult is an excellent palaeomagnetic recordingwhich makes it possible to define secondary

magnetic components and use them for datingQuaternarytectonicepisodese.g.atAlbækHovedwhereEocenesedimentsweretiltedbytheice.

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CrustalstructureacrosscoastalNordland(Norway)fromteleseismicreceiverfunctions

AnneDrottning1,ChristianSchiffer2,StéphaneRondenay1andLarsOttemöller11UniversityofBergen,2DurhamUniversity

The uplift and erosional history of the coastalNordland region, innorthwesternNorway, is ofgreat scientific interest as it may have causedhydrocarbons to accumulate differently thanexpected across the area (Nyland et al. 1992).Elucidating this history requires a solidunderstandingofcrustalstructureintheregion.Tohelpaddressthisneed,26broadbandseismicstationsweredeployedacrosscoastalNordlandfrom 2013 to 2016, as part of the broaderNEONOR2project.Here,wepresentpreliminaryresults of an inversion of teleseismic receiverfunctions computed at these stations, with theaim to map the crustal velocity structure andMoho depth beneath the region.We employ anautomated workflow based on the methods ofSchiffer (2015) and Svenningsen and Jacobsen(2007), which inverts simultaneously receiverfunction waveforms and Ps polarizations atdiscretefrequenciestoobtainSvelocitystructurein the crust and uppermost mantle. The dataqualityishighlyvariablefromonestationtotheother.SomestationsyieldaveryclearMohopulseat relatively shallow depths (~20-30 km).Conversely, other stations return ringy receiverfunctionsthatareeitherassociatedwithcomplexcrustallayeringor,morelikely,withstrongnear-station noise and scattering. The robustness ofthe method and the results is tested withsyntheticdatasets.ThemostrobustresultsfromhighsignaltonoiseratiostationsareintegratedintoregionalmapsofseismicvelocitiesandMohodepth.

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The3DstressfieldofNordland,northernNorway-insightsfromnumericalmodelling

SofieGradmann1,MKeiding1,OOlesen1andYMaystrenko1GeologicalSurveyofNorway,Trondheim,Norway

TheNordlandarea inNWNorway isoneof thetectonicallymostactiveareasinFennoscandia.Itexhibits patterns of extension, which are incontradiction to the first-order regional stresspattern that reflects compression from ridge-push. The regional stress field stems from theinteractionofridgepushandGIA(glacialisostaticadjustment);thelocalstressfieldmainlyresultsfromgravitationalstresses,aswellastheflexuraleffectsofsedimenterosionandre-deposition.

Wedevelop3Dfiniteelementnumericalmodelsof crustal scale, using existing geometricconstraints from previous geophysical studies.Internal body forces, induced by variations indensity,topographyorMohodepth,alreadyyieldsignificant deviatoric stresses, which are oftenomittedinstressmodels.Weshowthatthesecanstronglyinfluencethenear-surfacestressregime.Similarly, existing weakness zones (such asfaults)controlthelocalstressfield.

We apply the far-field stress fields (GIA, ridge-push,sedimentredistribution)aseffectiveforceboundary conditions to the sidesorbaseof themodel. This way, we can account for all stresssourcesatonce,butcanalsovarythemseparatelyinordertoexaminetheirrelativecontributionstotheobservedstressandstrainratefields.

Wecompareourmodelstothestressandstrainobservations derived from different recentseismologicalandgeodeticdatasets.

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RelativerelocationofearthquakesalongthenorthernNorthAtlanticridgeusingRayleighwaves

ChristianGrudeKolstad1,ValérieMaupin1,TormodKværna2,StevenGibbons2andAsbjørnBreivik11DepartmentofGeosciences,UniversityofOslo,Norway,2NORSAR,Norway

Earthquake activity alongmid-oceanic ridges isparticularlydifficulttomonitorduetothelackofnearbystations.Precise locationofearthquakesis however required in order to reach a betterunderstanding of the relation between theseismicactivity and the tectonicmechanismsatplay during the geological history of the mid-oceanicridges.

We present the results from the relativerelocation of 153 shallow moderate-sizeearthquakes along the North Atlantic Mid-OceanicridgefromIcelandtoSvalbard.Rayleighwaves are usually a major and well-recordedseismic phase for mid-oceanic earthquakes.Nearby earthquakes produce very similarRayleigh waveforms even when recorded atratherdistant seismological stations, and cross-correlationprovidesagoodmeasurementoftheirtime delays. Injected in a double-differencealgorithm, this can be used to relocate theearthquakes relative to each other. The meandistance shift is found to be about 8km. Visualinspection shows a better alignment of theseismicityafterrelocationandplottingonahigh-resolution sea-bed map shows that theearthquakeslocationsarebetterconsistentwithtectonicfeaturesafterrelocation.Therelocationis also compared with an independent studymade in the same area that uses a Bayesianapproachtorelocatetheseismicactivitybasedona large set of recordings of regional Pn and Snarrivals.

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High-resolutionseismicinvestigationsoftheCaledonianLowerAllochthonandbasementtransitioninJämtland,Sweden

PeterHedin1,ChristopherJuhlin1,HenningLorenz1andAlirezaMalehmir11Dept.ofEarthScience,UppsalaUniversity,Uppsala,Sweden

During August-September 2017 we acquiredhigh-resolution reflection seismic data in theJämtland region of west-central Sweden toincrease our understanding and knowledgeregarding mountain building processes. Ofparticularimportanceisthenatureandextentofdeformation within and across the lowermostallochthonousunitsoftheCaledonides,themainorogenic décollement and underlyingPrecambrian basement of the FennoscandianShield.TheLowerAllochthonhoststructuresthatstrikeparallelwiththeorogeniccompressioninthisregion.Therefore,deformationzones,faultsandfracturesystemsinthenearsurfacearealsoof interest since they may be important incontrolling the current hydrogeologicalenvironment and influence ground watercirculation and the transportationofpollutants.The study area is in close connection with aplanned2.5kmdeepboreholeof theCollisionalOrogenyintheScandinavianCaledonides(COSC)project (Gee et al., 2010) andprevious regionalseismic(Juhlinetal.,2016)andmagnetotelluric(Yan et al., 2017) studies, which will allowinterpretationinaregionalcontext.

Inadditiontothesemorescientificobjectives,thecurrent project presents an opportunity toevaluate and develop equipment andmethodology for efficient and versatileacquisition of high-quality multi-purposereflectionseismicdata.Weuseda500kgBobcat-mounted drop-hammer as the seismic source.Recording was done along two perpendicularprofilessimultaneously,using1Cand3Cwirelessunits (20 m separation) and a high-resolutionseismiclandstreamercomprising100fullydigital3CMEMSsensors(2-4mseparation).

Thedata are currentlybeingprocessedand thefirstresultswillbepresentedattheconference.

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SeismologicalobservationsofLandslideandTsunamiinKarratFjord,Greenland,June172017

TineB.Larsen1,TrineDahl-Jensen1,PeterVoss1,JohnClinton2andMeredithNettles31GEUS,Copenhagen,2ETHZürich,3ColumbiaUniversity,NewYork

On June 17, 2017, a large landslide occurred inNW Greenland, around 20 km from the smallvillageofNuugaatsiaq,population100inKarratFjord.Theslideslippedintothefjord,inducingalarge tsunami, which inundated much of thevillage, producing widespread destruction – 11houseswere swept out to sea, and four peoplelosttheirlives.

Theslidegeneratedseismicenergyequivalenttoa magnitude 4.1 earthquake, visible across theglobe. Careful examination of the seismicwaveformsindicatesnotriggeringtectonicevent.The landslide lit up all 30 GLISN stations(http://glisn.info).Onestation,NUUG, is locatedin the village of Nuugaatsiaq and recorded theseismic energy generated by the slide andresponded to the ground tilt induced by thefluctuating water levels from the resultanttsunami.

ThetimeseriesfromNUUGclearlyrecordsboththe slide and the resulting inundation events.Seismic waves from the landslide reaching thetownhadadurationofabout5minutes.Thislongdurationandtherelativelymonochromatic,long-periodpartofthesignalthatslowlyincreasesinamplitude are indicative of complex landslidesignals. The long-period, large-amplitudetsunamiwaves are seen in the seismograms assignalswithaperiodof3min,lastingforover3hours.

The long-period signals observed across theGLISN network, and around the globe, are

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consistent with a landslide source. The long-periodsignalsuggestsfailureoccurredintwoormorestages.

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TowardsanewglobalcrustalmodelderivedfromrapidreceiverfunctioninversionofGLImERdata

ChristianSchiffer1,StéphaneRondenay2,AnneDrottning2andLarsOttemöller21DepartmentofEarthSciences,DurhamUniversity,2DepartmentofEarthScience,UniversityofBergen

Teleseismic receiver functions provide arelatively easy way to image structure in theEarth’s subsurface. Despite its general ease ofuse, themethod often requires substantial userinput to yield stable and robust results. This isalsothecasefortheinversemodellingofreceiverfunctions,whichcanyieldhighlyvariableresultsdepending on the choice of independentconstraintsandmodelparameterisationused intheinversionworkflow.Asaconsequence,large-scale applications to global datasets have beenlimited. We developed a generalised receiverfunction inversion approach to obtain robustestimates of the crustal and uppermost mantleshear-wave velocity structure. The automatedand rapid inversion technique uses thepolarisation of incident P-waves in conjunctionwiththeoriginalreceiverfunctionwaveformstoconstrain the S-wave structure beneath seismicstations.Weapplyittoaglobalreceiverfunctiondatabase, GLImER (Global LithosphericImagining using Earthquake Recordings), withtheaimtoconstructanewglobalcrustalmodelconsistingof thousandsof individual1Dcrustalmodels. We use previous global estimates ofMoho depth and intra-crustal structure asstarting models and refine these during theinversion. The greatest improvement of ourapproachoverexistingoneswillbetheadditionalinformation it provides about layering andabsolute S-wave velocity in the upper mantle.FutureworkincludestheintegrationofabsoluteP-wave velocity from teleseismic S-wave

polarisations into the inversion workflow,something that should yield important newconstraint on the composition of the crust anduppermostmantle.

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LateMesoproterozoic,SveconorwegianorogenicmantlepreservedbeneathSWFennoscandia,reflectedinseismictomographyandassessedbythermalmodelling

TrondSlagstad1,YuriyMaystrenko1,ValerieMaupin2andSofieGradmann11GeologicalSurveyofNorway,Trondheim,Norway,2CentreforEarthEvolutionandDynamics,UniversityofOslo,Oslo,Norway

The Late Mesoproterozoic SveconorwegianorogenyinSWFennoscandiacomprisedaseriesofgeographicallyandtectonicallydiscreteeventsbetween 1140 and 920Ma, involving accretionandpartial subductionof continental fragmentsbehindanactivecontinentalmargin(Slagstadetal.,2017).Today,thisregionischaracterisedbylowseismicvelocitiescomparedtootherpartsofFennoscandia(Medhusetal.,2012;Gradmannetal., 2013).A channel-like zonewithparticularlylowvelocitiesinthelithosphericmantlebeneathSWNorwaycoincidesspatiallywiththeinferredSveconorwegian continental-margin arc. Basedonresultsfromthermalmodelling,wearguethatthe channel-like, low-velocity zone, at least inpart,reflectsthethermal(radioactive)effectsoftherefertilisedmantlewedgeofthiscontinentalmagmaticarc.Similarly,thegenerallylowseismicvelocities in the interior of the orogen areinterpreted to reflect refertilisation due tosubduction of continental material (cf.Hieronymus&Goes,2010).Thermaleffectsfromyoungertectonicevents,suchasPermo-Triassicrifting or late Palaeozoic Caledonian orogenesiscanbeallbut ruledout. In contrast,hotmantlematerial derived from the Iceland plume mayhave an effect on temperatures beneath SWNorway,butisunlikelytoproducetheobservedtomographicvariations.Thegeologicalrecordin

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SW Fennoscandia suggests that active-marginmagmatism terminatedas a resultof rapid slabroll-backand trenchretreatstartingatca.1Ga.The rapid shift from active- to passive-marginprocesseswas probably critical to preserve themantle wedge, and their identification cantherefore shed light on how active-marginprocessesterminatedinancientorogens.

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Geologicalcharacterizationofclayeytillusingcross-boreholegroundpenetratingradar.

EspenBingSvendsen1,MajkenC.LoomsZibar1,KurtKjær2,LarsNielsen1andBertelNilsson31UniversityofCopenhagen,2NaturalHistoryMuseumofDenmark,UniversityofCopenhagen,3GEUS

Approximately 40% of Denmark is covered byclayey till. Knowledge of the water flow andtransport pathways through these glacialdeposits is necessary in order to sustainablyexploitandprotectourwaterresources.Inclayeytill, the presence of macropores dominates thetransport pathways as they create a three-dimensionalnetworkofpathways thatenableamuch faster water and contaminant transportthan through the surrounding fine-graineddiffusion-limitedclaymatrix.Thesemacroporesexist as fractures, biopores from burrows androots,aswellassandlenses.Themacroporesarenon-trivialtomapandatpresent,alow-costnon-invasive technique for mapping such networksdoes not exist. We aim to use existing groundpenetratingradar(GPR)toolstodevelopsuchatechnique for geological characterization ofclayey till. This study will present preliminaryresults from Havdrup, Eastern Zealand, first offour field sites, and will focus on correlationbetween cross-hole GPR data and XRF core-scanner acquiredmajor and minor elementvariation.

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3Dgeomodellingworkflowusinghighperformancecomputing–thevuonosandkerettidepositsinOutokumpuMiningarea,easternFinland

EevaliisaLaine1,HeidiLaxtröm1,JanWesterholm2andJohanErsfolk21GeologicalSurveyofFinland,2ÅboAkademiUniversity,FacultyofScienceandEngineering

TheOutokumpudistricthostinganumberoforebodiesis located within the PalaeoproterozoicNorthKareliaSchistBelt.Miningactivitystarted1913andseveralmineshavealreadybeenclosed(e.g.Keretti/OutokumpuandVuonos)butserveas valuable data sources for ore exploration.Project GECCO combines expertise in highperformance computing and geomodelling, andaims to develop tools for faster geologicalcommon earth model (CEM) modelling in apowerfulcomputingenvironment.

This paper demonstrates the GECCO workflowfor the area containing historical Keretti andVuonos massive Cu-Zn-Co and disseminated Nisulphide ore deposits hosted by a distinctlithological assemblage, the Outokumpuassemblage, consisting of peridotite andserpentiniteenvelopedbyCr-bearingcarbonate-quartz rocks. Geological structures andlithological heterogeneity of the Outokumpuassemblageweremodeledbyusinggeostatisticalsimulations constrained by drill core data,geological cross sections and fault zones.Hundreds of simulated realizations weresummarizedasstochasticgeological3Dmodels,i.e.,3Dvoxetspopulatedbyprobabilitiesforeachrock type. The calculated gravity and magneticresponseswereused to validate the alternativegeological 3D voxelmodels and comparedwiththeVuonos-Keretti3Dmodelbuiltbytraditional3D modelling. High performance computingusingGPUforsimulationandvisualizationmadeitpossibletomakegravityandmagneticforwardmodelling in real time.The suggested approachgives a possibility to analyze uncertaintiesassociatedwithgeological3Dmodelsspacedonsparsedatasets.

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GeophysicalmodellingoftheLekaOphioliteComplex

AlexanderMIchels1,SuzanneMcEnroe1andChristineFichler11NorwegianUniversityOfScienceandTechnology

The~497MaLekaOphioliteComplex (LOC)onthe island of Leka in central Norway is one ofnorthern Europe’s most complete ophiolitescomplexes.The LOC is comprised of oceaniclithosphere that formed near the margin ofLaurentia in a subduction-initiated setting, wasobductedontoLaurentiaintheearlyOrdovician,and later transferred to Baltica as part of theupper allochthon in the Scandian Orogen. TheLOC has excellent exposures of partiallyserpentinized mantle rocks, crustal cumulatedunites and wehrlites, the petrologic andgeophysical paleo-Moho, gabbro, sheeted dykesandpillowbasalts.Herewepresentamodel forthestructureoftheLOCbasedonitsgeophysicaland petrophysical properties. This is the firstgeophysical study of the LOC that utilizes bothgravityandmagneticdata.Newground-magneticsurveys combined with a recent aeromagneticsurvey by NGU are use to model the LOC, andinvestigate the enhanced magnetizationassociated with the major faults.The Bouguergravityhighnearthecenteroftheislandis50.5mGalwithamagnetichigh2800nT.Usinggravitysurveys, new aeromagnetic data and thepetrophysical properties of 564 rock samples,three model sections that transect the islandnorthwest to southeast were created. Depth ofthe base of the model was constrained by thegravity data while magnetic data was used toconstraincontactsandstructureswithintheLOC.Thenewmodelssuggestthedepthofthecomplexisnear2kmandtheultramaficpartof theLOChasasynclinalstructure.

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Whythemantletransitionzonedoesnotappeartobethinnedatplumesites

ThorstenNagel1,ErikDuesterhoeft2andChristianSchiffer31DepartmentofGeoscience,AarhusUniversity,Denmark,2DepartmentofGeoscience,Christian-AlbrechtsUniversity,Kiel,Germany,3DepartmentofEarthSciences,DurhamUniversity,Durham,UK

Deepmantleplumesandassociatedhighthermalgradients are expected to cause an upwarddeflection of phase transitions defining thelower-upper mantle boundary and an overallthinningofthemantletransitionzoneinreceiverfunction data. We use forward calculation ofmineral assemblages, seismic velocities, andreceiver functions to explain the commonabsenceoftheseobservationsbymeansoflargetemperature-dependent variations of seismicvelocitiesinthelowermantletransitionzone.Athigh thermal gradients, primitive mantlecompositionsdisplayassemblagesdominatedbymajoriticgarnetandpericlase.Associatedseismicvelocitieswouldbe5-10percent lowerthan forwadsleyite- or ringwoodite-rich assemblagescharacteristic for undisturbed thermalconditions. The identified low-velocity zone atupwelling sites could cause a miscalculation ofthelower-upper-mantleboundaryintheorderof20 kilometers. Our results also confirm andexplainexistingpropositionsoflowvelocitiesinthelowermantletransitionzoneatplumesites,whicharebasedon theobservationofnegativeconversionsinreceiverfunctiondatain500-600kilometersdepth.

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POSTER

TheseismicsignatureoftheMantleTransitionZoneindifferentgeodynamicscenarios

ChristianSchiffer1,KenniPetersen2,ThorstenNagel2andErikDuesterhoeft31DepartmentofEarthSciences,DurhamUniversity,2DepartmentofGeoscience,AarhusUniversity,3InsituteofGeosciences,KielUniversity

TheMantleTransitionZone(MTZ)isdefinedbyaseries of phase transitions that form thetransition between upper and lowermantle. Atabout410km,olivinetransformsintowadsleyite,at510kmintoringwooditeandatabout660km,ringwoodite and garnet decompose intobridgemaniteandpericlase.Thesephasechangescause high-amplitude seismic discontinuities asthey represent abrupt density and associatedseismic velocity steps. The exact pressure anddepth at which these occur are dependent oftemperature and composition. Therefore,deflections of the phase transitions are to beexpected when cold, depleted subductedlithosphereorawarm,possiblyenrichedmantleupwellingarecrossingtheMTZ.

These depth-changes for different geodynamicscenarios is one of the most common ways tostudy lower-upper mantle mass exchange,commonly interpreted from receiver functionimages. We explore the imaging capability ofreceiver functions of the MTZ for differentsubduction and upwelling scenarios using anintegrated petrological-modelling-seismologicalapproach to create realistic receiver functionimages of the MTZ phase transitions. Inparticular,wedevelopself-consistentnumericalmodels coupled to the most advancedthermodynamic databases to derive realisticdensities and seismic velocities. The generatedsnapshotsarethebaseforfull-waveformseismicmodelling and subsequent receiver functionprocessing. Using this synthetic modellingapproach,wewill explore theeffectofdifferentstation layouts, noise and dimensions ofanomalies.

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TowardsaFinnishSeismicDatabase–TamingtheNationalSeismologicalDDSS

TommiVuorinen1,AleksiAalto1andIlmoSalmenperä11InstituteofSeismology,UniversityofHelsinki

Institute of Seismology, University of Helsinki(ISUH)isresponsibleformaintainingtheFinnishnationalseismologicalnetwork(HE).Inadditionto HE network, ISUH actively collects andemploys continuous waveform data from otherseismicnetworksacrosstheNordic-Balticregion.In addition, data is also gathered andmanagedfrom various temporary network installationsandactiveseismicsoundingprojects.Thesedataand the accompanying metadata streams arecombined, analysed and processed, and latercombined with the results of the neigbouringcountries (where applicable), to provide data,dataproductsandserviceswhichcanbeutilizedbyresearchers,variousagenciesandthepublic.

ISUH is actively participating in the pan-European solid-earth Research InfrastructureEPOSwhichwillsetdatamanagement,licensingand distribution standards for the providedDDSS.InordertoaddresstherequirementssetbyEPOS and the practical necessities ofmanagingbig data, ISUH is developing a database-drivenSeisComP3-compatible solution that willfacilitatemorediverse,standard-basedaccesstoavailabledataanddataproducts.

Thedatabasewillalsoenablethedevelopmentofnew services and software,whichwill help notonlyindatamanagementandcurationbutalsoinprocessing raw data streams into usableproducts. Indeed, quality of certain data& dataproducts have already been improved and newsoftware has entered testing during thedevelopment and implementation phase of theproject.

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13.Highandlowtemperaturegeochemistry,cosmochemistryandgeochronology:

13.1. Geomicrobiology of thepastandpresent

ORAL

OceanredoxconditionsbetweentheSnowballs–geochemicalconstraintsfromArenaFormation,EastGreenland

TaisW.Dahl1,EvaL.Scheller2,AlexanderJ.Dickson3,DonaldE.Canfield4,ChristophKorte5andKasperKKristiansen51NaturalHistoryMuseumofDenmark,UniversityofCopenhagen,Denmark,2DivisionofGeologicalandPlanetarySciences,CaliforniaInstituteofTechnology,Pasadena,USA,3DepartmentofEarthSciences,UniversityofOxford,UnitedKingdom,4UniversityofSouthernDenmark,OdenseM,Denmark,5InstituteofGeologyandNaturalResources,UniversityofCopenhagen,Denmark

The emergence of animal ecosystems is largelybelieved to have occurred in increasinglyoxygenated oceans after the termination of theSturtianandMarinoanglaciations.Thistransitionhasledtoseveralhypothesesforthemechanismdrivingoceanoxygenationandanimalevolution.One hypothesis is that enhanced weatheringincreased oceanic nutrient levels, primaryproductivity and organic carbon burial, andultimately oxygenated the atmosphere andoceans. Another hypothesis suggests that ananimal-driven reorganization of the marinebiogeochemicalcyclesmighthaveoxygenatedtheoceans. Through molybdenum (Mo), carbon,sulfur isotopes and iron speciation results fromthe Arena Fm, East Greenland, this studyconstrains ocean redox conditions after theSturtian deglaciation and before the majorradiation of animals. Carbon and sulfur isotopestratigraphy is used to correlate the Arena Fmwith other formations worldwide between theSturtian and Marinoan glaciations (~720–635

Ma).ThelowerpartoftheArenaFmconsistsofblack shales deposited under locally euxinicconditions as evidenced by high proportions ofhighlyreactiveironandpyrite.Theseblackshalesdisplay muted Mo enrichments, low Mo/TOCcompared to overlying shales and Phanerozoiceuxinic sediments. The δ98Mo values areconsistent with other Cryogenic euxinic basinsandwell below that of themodern oceans. Thecombinationoflow[Mo]andδ98Mosuggeststhatwidespreadanoxiaprevailedintheoceansatthistime. These results are consistent with mostother studies from this time suggesting thatocean oxygenation was not linked to SnowballEarthdeglaciation,butwasdelayeduntilanimalseffectivelyenteredthescene.

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Primordialcellularoxygensensingkeytoanimalevolutionintheoxicrealm

EmmaHammarlund11LundUniversity

Microbes sense environmental oxygen throughmechanisms that since have been inheritedthrough evolution all the way to vertebrateanimals[1]. The inherited and modifiedmechanisms in animals now couple to cellresponsesthatarecrucialforthemaintenanceoftissue.However, towhat extent an evolution oftheoxygensensingmechanismsmatteredfortheevolutionanimalsremainslargelyunexplored.

Oxygensensingmechanismshaveprimarilybeenexploredinthefieldoftumorbiology,sincetheyassociate with tissue hypoxia[2] and themaintenance of cancer stem cells. Cancer stemcellspossessthecapacitytoformnewtissue.Inthese studies, the hypoxia-inducibletranscription factors (HIFs) are central, by howthey are guided by ambient tissue oxygenationandhowtheyassociatetostemcell-likefeatures(stemness)[3]. Insights from tumor biology, on

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how HIFs regulate tissue formation, emphasizethatrefinedcontrolofprimordialoxygensensingmechanismsmustplayaroleforlargelifeintheoxic environment. Indeed, by acknowledging afew observations from the fields of stem cellsscienceandtumorbiology, itappearsaparadoxthat animals renew tissue in the oxicenvironmentatall.

Based on transdisciplinary observationsregarding the role of the oxygen sensingmechanisms – inherited from microbes – Ipresentamodelofevolvingstemnesscontrolthatmay have facilitated animals to enter anddiversify in the oxic environment. The modelchallenges the view that an increased extent ofoxic niches resulted in the Cambrian explosion.Implications of the model is compared toobservationsinthegeologicalrecord.

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Microbialelementcyclingandtransport:fromancientsedimentarybasinstothePlastisphere

NicoleR.Posth1,SergueiChiriaev2,ElenaGorokhova3,ThomasR.Neu4andJakobStrand51Geology,DeptofGeosciences&NaturalResourceManagement,UniversityofCopenhagen,DK,2SDUNanoSYD,IRCA,MadsClausenInstitute,SDU,Sønderborg,3DeptofEnvironmentalScience&AnalyticalChemistry-ACES,StockholmUniversity,4MicrobiologyofInterfaces,HelmholtzCentreforEnvironmentalResearch(UFZ)Magdeburg,5DeptofBioscience,AarhusUniversity

Microorganisms play a key role inbiogeochemical processes in aquaticenvironments, closing all major element cyclesand influencing element transport and burial.Experiments with modern, model organismshavebeenusedtoconstraintheroleofmicrobesin ancient aqueous environments. Both theacquiredknowledgeand theanalyticalmethodsusedinthesestudiesoftheEarth´spastarealsouseful to clarify the role of microorganisms incontemporaryandfutureevolvingenvironments.

Thepollutionofoceansthroughplasticdebrishasemerged as a new global challenge. Theintroduction of these synthetic particles toaquatic systems raises environmental healthconcerns, but these particlesmay also alter thetransportandburialofmicrobialorganicmatterandinfluenceglobalbiogeochemicalcycles.Bothin thewater columnand sediment, bacteria arefound as free-living cells or surface-orientedbiofilms.While biofilm found onmarine plasticimplies a new ecological niche, named thePlastisphere, our knowledge of marine plastic-microbeinteractionisstillnascent.Plasticactsasa vector for microbial communities, offers asurfaceforabioticandbioticelementcycling,andmayevenbeamicrobialcarbonsource. Indeed,microorganismsmayplayakeyroleindegrading,transporting and incorporating (micro)plasticintobiogeochemicalcycles.Inthisnewstudy,wecombine microbial community profiles,bioimaging, isotope, and elemental analysis toelucidate plastic-associated element cycling.Focuson the interactionbetweenmicrobes, theplasticsurfaceandtheirenvironment,aswellastheeffectoftransportanddiagenesiswillinformthe influence of these particles on elementcycling.

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Mechanisticinsightintomicrobialformationofironoxides:implicationsfordevelopmentofbandedironformationsandouratmosphere

KarinaK.sand1,StanislavJelavić1andJamesJ.DeYoreo21DepartmentofChemistry,UniversityofCopenhagen,Denmark,2PhysicalSciencesDivision,PacificNorthwestNational,Laboratory,Richland,WA,USA.

Microbial control over mineralization is awidespread phenomena that has shaped thenear-surface mineralogy and chemistry of theearth, oceans and atmosphere. However, themechanisticunderstandingof these interactionsispoorlyconstrained.Wequantitivelyaddressedthe mechanisms behind the controls that

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microbial extracellular polymeric substances(EPS) exert in directing mineral formation andtransformation.Wecapturedthecollectivebondbehavior of model and natural EPS duringinteraction with the two common iron oxides,hematite and ferrihydrite. Subsequently, weappliednucleationtheoriestothemeasurementsand obtained information on the mechanisticcontrols for iron oxide formation on thepolymers.OneofthemainfindingsisthatEPS,aswell as less complex polysaccharides, stronglybind iron species and iron oxides to such anextent that they modulate the interfacial freeenergy of the iron oxide-polymer system, thuspromotingnucleationon thepolymermatrixbydecreasing the nucleation barriers. Thesefindingshaveimplicationsformineralformationin both oxic and anoxic conditions and mayexplainthemechanismsbehindthedevelopmentofbandedironformations(Lalondeetal.,2012)and oxygen buildup during the Great OxidationEvent(Canfield,1998).

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Porespacesealingusingmicrobiallymediatedcalciteprecipitation:alabtofieldscalestudy

DominiqueJ.Tobler1,MarkO.Cuthbert2,MichaelS.Riley3,StephanieHandley-Sidhu4andVernonR.Phoenix51Nano-ScienceCenter,DepartmentofChemistry,UniversityofCopenhagen,Denmark,2SchoolofEarthandOceanSciences,CardiffUniversity,UnitedKingdom,3SchoolofGeography,EarthandEnvironmentalSciences,UniversityofBirmingham,UnitedKingdom,4SchoolofGeography,EarthandEnvironmentalSciences,UniversityofBirmingham,UnitedKingdom.,5CivilandEnvironmentalEngineering,UniversityofStrathclyde,UnitedKingdom

Microbially driven calcite precipitation (viaureolysis) has shown great potential in a widerange of applications, including solid-phasecapture, concrete crack remediation, soilstabilisationandcarbonsequestration.Here,thisprocessisinvestigatedasameansofreducingtheprimary porosity and/or secondary fracture

porosityofhostrockssurroundingnuclearwasterepositories in order to control or preventradionuclide transport. To determine a suitablefield injection approach, a series of bench scaleexperimentswereundertakeninthelaboratory.First,batchexperiments focusedonthekineticsofcalciteprecipitationasa functionofbacterialmass,ureaandCa2+concentrationandanaerobicvs aerobic conditions. Results showed that theureolyticbacteriaperformedequallywellunderbothoxygenpoorandoxygenrichconditions.Inthe next stage, flow-through experiments invariousmedia (sand columns, rock cores)werecarried out to examine the homogeneity andextent of thepore space fill along the column/core as a function of injection strategies. Itemerged thata staged injection strategy,wherewe alternate between bacterial and reactantinjection, yields the most homogeneous calcitefill, reducing overall porosity by up to 45 %.Ultimately, thisapproachwastestedat the fieldscale, ledbyUniversityofBirmingham,tosealafractured rock (dacite) at ~28 m depth, in aquarryinLeicestershire,UK.Withinfewinjectioncycles, the single fracture was substantiallyplugged by calcite, yielding a significanttransmissivitydecreaseoverseveralmeters.

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13.2.Bio-mineralinteractions

ORAL

Crystallizationkineticsofapatitemodelsystems

HenrikBirkedal11DepartmentofChemistry&iNANO,AarhusUniversity,Denmark

Theformationofbiomineralsremainsshroudedinmystery.Aplethoraofmechanismshavebeenproposed [1,2]. To obtain detailed insights intotheformationofsuchminerals,wehavepresentresultsofstudiesofapatiteformation.

We use in situ X-ray diffraction to mapcrystallization kinetics [2-5] and found that athighpHapatite forms fromamorphous calciumphosphate precursors. Choices of pH andcounterions have significant impacts oncrystallization kinetics and the shape of theresultingnanocrystals.

We show that using dense organic gels affordchemicalgardentypeformationofhollowtubeswith apatitic (andotherminerals dependingonchoice of conditions) walls [6] while couplingsedimentationandparticleaggregationresultsinlarge transparent nanocrystal aggregates [7].Organicadditiveschangecrystallizationkineticsand crystal size/shape [3,4,7] and may evendramaticallyalterthecrystallizationpathwaybyintroducingmetastablemesoscopic states priorto nucleation [8]. These results illustrate thecomplexnatureof(bio)mineralformation.

ORAL

In,onorinbetween:trackingthepersistenceofproteinsinthepast

MatthewCollins11UniversityofCopenhagen

It is a time of great change in the use ofbiomolecules in archaeology and geology. As ayoung lecture at the Fossil Fuels andEnvironmental Geochemistry Institute inNewcastle,Iwasusedtothinkingthatitwassmallrobust molecules which typified organicgeochemistry. Today leading ScandinaviaArchaeologistKristianKristiansen(Gothenburg)isarguingthathisdisciplineisundergoingathirdscience revolution, in which genetics allied toisotope geochemistry and data modelling iscastingasidepostmodernnotionsandreturningto older concepts of cultural change. Of thesethree pillars, both bigger geochemical datasetsand better modelling strategies were foreseen,the explosion in genetic data was not. Geneticsand proteomics are now potential tools forarchaeologists and geoscientists becauseextraordinarytechnologicaladvances,drivenbythe biosciences, are luckily well suited to thefragmented remains which accumulate overtime. Using new genomic methods, the lastdecadehasrevealedhowremarkablywell largefragile organic molecules persist and can berecoveredandinterrogated.

Proteins survive longer thanDNA - therefore ifgenomics has revolutionised archaeology willproteomics revolutionise geosciences...? Er, no,probablynot.NeverthelessinthispresentationIwill explore what we know about proteinsurvival. How long do proteins survive intogeological time, where and how does theysurvive, and what use might they be uponrecovery? As I am speaking in the bio-mineralinteractions session, it probably comes as nosurprisethatitismineralswhichseemtokeytoansweringthesequestions.

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ORAL

Biomimeticapproachtomaterialdesign

AnneRathNielsen1,DanielJ.Murray2,BehzadRad2,SusanL.S.Stipp3,RonaldNZuckermann2andKarinaK.Sand41UniversityofCopenhagen,DepartmentofChemistry,MaterialsChemistrySection,2MolecularFoundry,LawrenceBerkeleyNationalLab,California,USA,3MaterialsChemistry,Nano-ScienceCenter,DepartmentofChemistry,UniversityofCopenhagen,Denmark,4Geography&EarthSciences,AberystwythUniversity,UK

Biomineralising organisms are experts incontrolling the interplaybetweenpolymersandminerals to obtain strong and functionalmaterials. The use of bio inspired polymers tocontrolanddirectgrowthof calciumcarbonate,couldprovideapathwaytowardsthefabricationof novel tough and strong compositematerials.An important step in this direction is to gaincontrolof thecalciumcarbonatenucleationandgrowth processes, which requires thoroughcharacterization of the organic/inorganicinteractions.

Bio inspired peptoid polymers (N-substitutedglycines) can be synthesized with precisionsequencecontrolandareknowntoformultrathintwo-dimensionalnanosheets [1].Arecentstudyhasshownthatnanosheetswithsurfaceexposedacidic chains can template formation of stableamorphousCaCO3(ACC)[2].Thishasinspiredusto investigate the CaCO3 nucleation rates andgrowthonfunctionalisedsubstratesasafunctionoftimeusingacustombuildflowcellsystem.Weused model systems of chosen self-assembledmonolayers(SAMs)tomaptheeffectofspecificfunctional groups as well as studied directnucleation and growth on immobilized peptoidpolymers.

This study provides insight into the differentenergy barriers provided by the differentsurfaces.Knowledge of the kinetics andthermodynamicsofthecrystallisationprocessisan important first step for guiding the

crystallizationtowardsfabricationofbioinspiredcompositematerials.

ORAL

Sub-micronresolutiondiffractionandfluorescencetomographyrevealsbonemicrostructure

NinaWittig1,SimonFrølich1,MieBirkbak1,JonasPalle1,MajaØstergaard1,KathrynSpiers2,JanGarrevoet2andHenrikBirkedal11DepartmentofChemistry&iNANO,AarhusUniversity,Denmark,2DESYPhotonScience,Hamburg,Germany

The structures of many materials includingbiominerals are highly complex. Understandingtheir structure is challenging and calls formethods with sensitivity across several lengthscalesin3D.MultimodalX-raytomographiesaresuch techniques [1]. Here, we apply diffractionscattering computed tomography (DSCT) torevealthecrystallinepropertiesandfluorescencetomography(FT)toprobeelementdistributionsinboneusinga400nmX-raybeam.

Bone displays essential structural featuresrangingfromthenano-tomacro-scale.Thelinksbetween bone structure and function remainpoorlyunderstood.Theosteonisabuildingblockin human long bones. In osteons, mineralizedcollagenfibrilsarearrangedinatwistedplywoodstructuresurroundingaHaversiancanal.Whileithas been shown that the indentation modulusvariesperiodicallywiththeosteonlamellaeandthatthisispositivelycorrelatedwiththemineralcontent [2], it remains uncear how themineralphase’spropertiesvariesacrosstheosteon.Thesame holds for oligo elements such as Sr. Tounravel the structure of osteons, wecombineDSCT and FT with sub-micronresolution. This experiment combines thecapabilities of diffraction and fluorescencewiththose of computed tomography to allow forreconstruction of a diffractogram and afluorescence spectrum in each volume elementwithinthesample[1].Theresulting>1.5milliondiffractograms were Rietveld refined usingMultiRef [3] to obtaintypical crystallographic

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parameters, including unit cell parameters,profile parameters etc. This revealed distinctvariations in mineral properties and elementdistributions with distance from the osteoncenter.

POSTER

Quantificationofmolecularbonding:Implicationsfororiginoflifeandtheironcycle

StanislavJelavić1andKarinaKSand21UniversityofCopenhagen,Nano-ScienceCenter,DepartmentofChemistry,Copenhagen,Denmark,2AberystwythUniversity,Geography&EarthSciences,Aberystwyth,UnitedKingdom.

Mineral-polymer interactionsarevital formanylifeformshaveprobablyplayedasignificantrolein the origin of life through polymerization ofnucleotides.Toformfunctionalbiopolymers,thepreexistingmonomershadtobepreconcentratedfrom dilute prebiotic solutions and thethermodynamic barrier to polymer formationhad to be surpassed. Both these processes hasbeen found to be encouraged by mineraladsorption.Elementcyclesofcarbonandironarealso strongly impacted by mineral-polymerinteractions. E.g. microbial production of ironoxidesoccursonsuchavastscalethatitimpactstheglobalironcycleandhasbeenresponsibleformajorbiogeochemicaleventssuchasthecreationof an oxygen-rich atmosphere. Despite thesignificance of the polymer-mineral interaction,littleinsightintothethermodynamicandkineticproperties of the polymer-mineral bond isavailableatamechanisticlevel.

Dynamic force spectroscopy (DFS) can directlycapture the bond behavior of interacting bondsbetween molecules and mineral surfaces. Wehave used this atomic force microscopytechniquetoinvestigatethethermodynamicandkinetic bond parameters describing bondbehaviorandenergeticsofnucleotideadsorptionandRNApolymerisationonclaymineralsurfacesas well as themechanism behind the observedenhanced iron oxide formation on bacterial

polymers. Our results highlight the strength ofDFS as a tool of investigating the determiningmechanisms behind mineral-organicinteractions.

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UsingLA-ICPMStoinvestigateseasonalityinCodotolithmicrochemistry

KristianNielsen1,SimonHansen2,TonnyThomsen2andKarinHüssy11TechnicalUniversityofDenmark,NationalInstituteofAquaticResources,2GeologicalSurveyofDenmarkandGreenland,DepartmentofPetrologyandEconomicGeology

Fishagesaretraditionallydeterminedbyvisuallyinspecting the ring structures in fish ear stones(otoliths).Theseagesareimportantinfishstockmanagement, e.g. when assessing fishingpressure, growth patterns or stock conditions.FortheeasternBalticcodthemethodsofvisualagedeterminationhasalwaysbeenproblematic,and in recent years this has worsened, causingproblems for the stock management. In thisproject we aim to develop an alternative agedetermination method using the chemicalcomposition of otoliths. We have analysed 132otoliths using LA-ICPMS line transects whichprovideachronologicalrecordofthefish’sentirelife fromhatch to catch. The elements analysedwereMg,P,Ca,Mn,Cu,Zn,SrandBa,whicharethe most abundant elements in otoliths. Theotoliths are recaptures from a mark-recaptureexperiment, where cod were tagged with anexternaltagandaninternalchemicalmarkerbyinjecting SrCl2, which incorporates into theotolithduringgrowth.DuringLA-ICPMSanalysis,theSrmarkerwasdetectedbyscreeningwitha3µm laser spot size, whereas the analyses wereperformedusingabeamsizeof40µmat5µm/sprogressing rates.TheSrmarker acts as a timestamp that allows evaluation of the LA-ICPMSelemental analysis in time. The aim is toinvestigateifsomeoftheanalyzedelementsvaryonaseasonalbasis,andhowwellthiscanbeusedfor age determination. The presentation will

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includemethoddetailsandpreliminaryresultsofthison-goingproject.

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Manganesespeciationanddistributioninforaminiferalcalciteundervaryingenvironmentalconditions

NadineQuintanaKrupinski1,SamWebb2,PerPersson1,Marit-SolveigSeidenkrantz3,TakashiToyofuku4andHelenaFilipsson11LundUniversity,2StanfordSynchrotronRadiationLightsource,3AarhusUniversity,4JAMSTEC

Benthic foraminiferal Mn/Ca, though oftenreferred to as an indicator of authigeniccontamination,hasrecentlybeensuggestedasabottom water oxygen proxy. However, ourunderstandingofMn incorporation intobenthicforaminiferaisincomplete,androlesofpotentialcontaminant phases need to be clarified. ToevaluatewhetherMncan indicatepasthypoxia,weneedtounderstandwhere/howMnoccursinbenthic foraminifera: is it incorporated into thecalciteasaMn-bearingcarbonatespecies,andareother forms of Mn present? We also studyhow/whether changing environmentalconditions and vital processes may affect Mnspeciationanddistribution.

Weuse synchrotronmethods (X-rayabsorptionspectroscopy (XAS)) and micro-X-rayfluorescence (μXRF) mapping) to evaluate howMnisincorporatedintothebenthicforaminiferacalcitelattice(itsdistributionandspeciation).Wecomplement this with solution ICP-MS todetermine mean Mn/Ca values for pooledforaminifera from the same samples. We usefield-collected samples of living benthicforaminifera (to avoid diagenetic effects) fromtwo oxygen conditions to evaluate whetherdiffering environmental conditions affect Mndistributionandcoordination.

Spectral data (XAS) indicate that Mn in theforaminiferal tests occurs as a Mn-carbonate,whilesmallexternaldebriswithhighMninthese

uncleaned foraminiferagenerallyhasMn-oxide-type spectra (removable via cleaningmethods).μXRF maps show that in many species, Mn isfairly evenly distributed at low-moderateconcentration throughout the test, potentiallysuggesting stable oxygenation conditions.However, other species have specific high-Mnchambers, perhaps suggesting intervals ofgreater oxygen stress or a response toforaminiferal processes that alter themicroenvironment.

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13.3.InorganicGeochemistry

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MicroscopicviewofhydrogenmotioninClaymineralsfromneutronscattering

HeloisaBordallo11NielsBohrInstitute-UniversityofCopenhagen

Neutron science is the science of everyday life,providingamicroscopicviewofthematerialswerelyonformodernlife.Neutrons,similarlytoX-rays, penetratematter. However, unlike X-rays,neutrons interact with matter in a differentmanner, thus allowing the identification ofelements with very low molecular weight,including hydrogen. For this reason, neutronspectroscopy brings unique information abouthydrogenmobilityandcancontributeforbetterunderstanding the mechanisms that governprocessesinclaydominatedenvironments.

In this talk I will discuss on this promisingapproach by presenting a couple of specificexamples of quasi-elastic neutron scatteringexperiments. The first is related to theinvestigation of how the transportmechanisms(of water or ions) are affected by an appliedelectricfield.Toshedlightintothisquestion,wehave focused specifically on the dynamics ofwaterinclaysthroughinvestigatingtheoriginofchanges observed inwater resistanceunder in-situelectricfieldstimuli.Thesecondfocusonin-situmeasurementsperformedduringcontrolledexposuretowatervapourandhowthedynamicsof adsorbedwater changeovera large rangeofunsaturated conditions.Using this approachwewere able to confirm that true materialequilibriumatintermediatehydrationstatesisatime dependent phenomenon. The overallknowledgeacquiredusingneutronspectroscopyopensnewpossibilities in themitigationof soilcontamination and geo-environmentalengineering, where the role played by watercontrolsthesystemproperties.

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Turbostraticdisorder:LessonslearnedfromFe-bearingLayeredDoubleHydroxides.

KnudDideriksen1,LauraVoigt2,MarcoMangayayam1,CasevanGenuchten3,CathrineFrandsen4,KristenM.Ø.Jensen1,S.L.S.Stipp1andDominiqueJ.Tobler11Nano-ScienceCenter,DepartmentofChemistry,UniversityofCopenhagen,Denmark,2DepartmentofChemistry,TechnicalUniversityofDenmark,Denmark,3Dept.ofEarthSciences-Geochemistry,UtrechtUniversity,Utrecht3508TA,TheNetherlands,4DepartmentofPhysics,TechnicalUniversityofDenmark,Denmark

Turbostraticdisorderexistsinorderedmaterialswithhighlyanisotropicbondstrength(e.g.,clays)andaffectstheirproperties(e.g.,stabilityandionexchange). It arises when sheets of stronglybonded atoms, stacked along the direction ofweaker bonding, are displaced so that atomicalignment across sheets is lost.Layered doublehydroxides (LDH) are composed of MeII-MeIIIhydroxide sheets separated by interlayers withwater and weakly held anions. To probe shortrange order (1-40 Å) in synthetic LDHs in thesulphate green rust (FeIII) - nikischerite (AlIII)series, we performed pair distribution function(PDF) analysis of high energy X-ray scatteringdata. Results show that structural coherencealong the c axis decreases with increasing Alcontent,althoughBraggpeaksareclearforbasalplanes.ThePDFforsyntheticnikischeriteisbestmatched by the calculated pattern for coherentscattering domains composed of a single metalhydroxide sheet. Parallel to the decrease in thestructural coherence between layers, thecoherencewithinlayersalsodecreasesmarkedlyto~6 nm for synthetic nikischerite. Thus, thismaterial does not simply have unaligned, butotherwisestructurallydevelopedsheets.Instead,crystals are mosaic with coherent scatteringdomains that decrease in all directions. In fact,theaspectratioof the largegreenrustsulphatecrystals is comparable to that of the smallcoherent scattering domains in syntheticnikischerite. Given that the structure of

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disordered material is very complicated tocharacterise with traditional techniques, wespeculate to what degree silicate clay mineralshave mosaic crystals rather than onlyturbostraticdisorder.

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CaCO3scaling:NucleationandgrowthinhibitionofaragonitebyMgSO4

MiaRohdeNielsen1,JuanDiegoRodriguez-Blanco2,KarinaSand1andSusanStipp11Nano-ScienceCenter,DepartmentofChemistry,UniversityofCopenhagen,Denmark,2DepartmentofGeology,TrinityCollegeDublin,Dublin,Ireland

Mg2+andSO42-areabundant inseawaterand inhydrothermal fluids and are hence naturallypresentwherecalciumcarbonatemineralsform.Bothionsareknowntoinfluencenucleationandgrowth of CaCO3 polymorphs but reports ofaragonitegrowthinhibitionbyMg2+(±SO42-)arecontradictory. We used UV-vis spectroscopy toexplore the influence of Mg2+ and SO42- onnucleationandgrowthratesofcrystallineCaCO3phases and we examined the solids usingscanningelectronmicroscopy(SEM)andpowderX-ray diffraction (PXRD). SO42- promotedformation of vaterite, extended the inductiontime for nucleation and decreased growth rate.Mg2+(±SO42-)promotedformationofaragoniteinpreference to calcite. Aragonite nucleation andgrowth was inhibited by Mg2+ alone and incombination with SO42-. Mg2+ clearly prolongedinduction time and inhibited aragonite growthproportional toMg2+ concentration. The resultssuggest an environmentally friendly method toinhibitaragonitescaleformation,forexampleindesalinationplants.

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14.Hydrocarbongeologyandenergy14.1. Geothermal energy andCO2storage

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AssessingEuropeangeologicalCO2storagecapacity

KarenL.Anthonsen1andNielsE.Poulsen11GeologicalSurveyofDenmarkandGreenland

Deployment of large scale CCS in Europe isdepending on knowledge about location andstorage capacity of the most attractive storageareasandthusareliableCO2storageatlasisakeytoolforplanningfutureCCSoperations.

Since thebeginningof 1990ties, several studieshave attempted to map and estimate theEuropean storage capacity for CO2. Among themostprominentaretheJouleIIproject(Hollowayet al. 1996), the GESTCO project from 2004(Christensen & Holloway, 2004), the CASTORproject (2006), the EU GeoCapacity project(Vangkilde-Pedersen et al. 2009) and the CO2StoPproject(Poulsenetal.2013).

Theseprojectsmoreorlessbuildononeanother,but there are differences between the projectswith respect to number of countries included,screening parameters, classification of storagesites and assessment methodology. It isimportanttorecognisetheevolutionofEuropeanCO2 assessments and the challenges related tothe methodology (static or probabilistic) formapping and estimating storage capacities inEurope.

ApartfromtheEuropeanEUco-fundedprojects,NorwayhaspublishedanatlasfortheNorwegiancontinental shelf (Halland et al. 2014) and theNORDICCS project made an assessment for theNordic countries (Anthonsen et al. 2013) andreleasedajointNordicCO2storageweb-atlasin2015. Both United Kingdom and Spain havepreparedanationalCO2storageatlas.

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SeismicinterpretationofasloppingoffshorepotentialCO2aquifer;theGassumFormationinSkagerrakbetweenNorwayandDenmark

UlrikGregersen1,IrfanBaig2,AnjaSundal2,LarsHenrikNielsen1,MetteOlivarius1andRikkeWeibel11GEUS,2UniversityofOslo

The first phase of the project “Optimized CO2storage in sloping aquifers – CO2Upslope” isseismic stratigraphic interpretation of thesiliciclastic Upper Triassic–Lower JurassicGassum Formation in Skagerrak betweenNorwayandDenmark.ThewellsFelicia-1,J-1and13/1-U-1 provide seismic-well ties for selectedlinesfromeight2Dseismicsurveysconstitutingthe database. The work resulted in a detailedinterpretation of the top and base of theformation and three sequence stratigraphichorizonswithintheaquifer(SB5,TS9andTS10).Theformationismostlylessthan100mthickinthe study area, with its thickest parts locatedin/neartheFelicia-1well(230m).Theformationthinstowardseastandnorthandshallowstothenorthwhere it is truncated inplaces.The threeinternal horizons approach the base of theformation towards north and only TS10continuesintothenorthernmostpartofthestudyareawhereittiesnearthebaseofthe13/1-U-1well.Someminortrough-shapedseismicfeatureswithin the formation may indicate channelincision. The formation is succeeded bymudstones of the Fjerritslev Formation dividedby two internal horizons. Fourteen assignedfaultsandadditionalminorfaultsareinterpreted.Most faults are normal faults trending SW–NEand someareassociatedwith ridges/structuresformed by regional tectonic events. Most faultsslightlyoffsettheTopGassumhorizonandpartsof theFjerritslevmudstones.Succeedingphasesof the project involve establishment of a 3Dgeologicalmodelformingthebasisfornumerical

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modelling of CO2 injection, movement andtrapping.

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Anumericalinvestigationofcombinedheatstorageandextractionindeepgeothermalreservoirs

MartonMajor1,SørenErbsPoulsen2andNielsBalling11AarhusUniversity,Denmark,2VIAUniversityCollege,CampusHorsens,Denmark

Heat storage capabilities of deep sedimentarygeothermal reservoirs are evaluated throughnumerical model simulations.We combinestorage with heat extraction in a doublet wellsystem when storage phases are restricted tosummer months. The effects of stored volumeand annual repetition on energy recovery areinvestigated.Recovery factors are evaluated forseveraldifferentmodel setupsandwe find thatstoring90°Cwaterat2500mdepthiscapableofreproducing, on average, 67% of the storedenergy. In addition, ambient reservoirtemperatureof75°Cisslightlyelevatedleadingto increased efficiency. Additional simulationsconcerningpressurebuildupinthereservoirarecarriedouttoshowthatsafetylevelsmaynotbereached.ReservoircharacteristicsareinspiredbyDanish geothermal conditions, but results areassumed to have more general validity. Thus,deep sedimentary reservoirs of suitableproperties are found to be viable options forstoringaccessenergyforhighdemandperiods.

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ShallowsubsurfacethermalstructureforonshoreDenmark

IngeliseMøller1,NielsBalling2andClausDitlefsen11GeologicalSurveyofDanmarkandGreenland,Denmark,2DepartmentofGeoscience,AarhusUniversity,Denmark

Information of shallow subsurface geothermalconditionsis importantfornumberapplicationsincluding exploitation of shallow geothermalenergy, heat storage and cooling as well as ofgeneralgeoscience interest.Availablemeasuredtemperatures and thermal conductivitiescovering Danish onshore areas to a depth ofabout 300 m have been compiled andanalysed.Temperature data from about 50boreholes, 100-300 m deep and thermalconductivitiesmeasuredonsamplescollectedat31 well-characterized outcrops and on corematerial from 20 boreholes are included.Temperature gradients and thermalconductivitiesweregroupedaccordingtodetailsoflithologyoverwhichtheyweremeasured.

Significantthermalvariationsareobserved.Atadepthof100m,temperaturesvarybetween7.5and 12 °C and at 200m, between 9 and 15 °C.Characteristic temperature gradients are in arangeof1-4°C/100m.FollowingFourier’slawof heat conduction (heat flow = thermalconductivity x temperature gradient) acorrelation is observed between temperaturegradientsandthermalconductivitiesofdifferentlithologies, and a regional estimate ofcharacteristic shallow heat flow in Denmark isobtained. Quartz-rich sand deposits (highthermal conductivity) show low temperaturegradients, chalk and limestone intermediategradients and almost pure clay (low thermalconductivity) high gradients. Mean thermalconductivities range between 0.6 and 6W/mK.An estimated regional heat flow of about 37mW/m2 is in good agreement with local,classically determined heat-flow values fromshallow borehole data. Due to long-termpalaeoclimatic effect, this value is significantlybelowdeepbackgroundheatflow.

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Understandingnature'ssecretsandusingthenewknowledgetosolvesociety'schallenges:insightsforCO2sequestration

S.L.SvaneStipp1andandtheMembersoftheNanoGeoScienceResearchSection11Nano-ScienceCenter,DepartmentofChemistry,UniversityofCopenhagen

Theelectronicsrevolutionhasgivenustoolsthatcan"see"atmolecularscale,providingwholenewinsightintothephysicalandchemicalprocessesthatcontroltheinterfacebetweennaturalsolidsand fluids (anything that flows, water, oil, CO2,gases).Byunderstandinghownatureworks,wefind clues to solve some of the challenges thatsocietyfaces.AnimportantissueistoreducetheCO2 available in the atmosphere and oceans byconverting it to mineral form, where it will bestable for millennia. By understanding theprocesses that take place at the surfaces ofminerals,wecantailorundergroundgasstoragefacilities to bemore effective andwe can buildmodels to predict their safety. What we havelearnedaboutCO2injectionintothebasalticrocksof Iceland has also inspired investigationswithmineral fibre insulation and the design ofnanoparticles for in situ remediation ofcontaminated groundwater. Our work is veryfundamentalandalsoveryapplied.Wecombineexperimentwiththeory, inthelab,thefieldandatsynchrotronradiationfacilities.

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Regionalevaluationofstructuralcollapseinsandstonereservoirsandimpactonreservoirquality,acasestudyfromtheEntradaSandstone,Utah,USA

NikolineBromander1,SigridØstmodaCosta1,ElinSkurtveit2,JamesEvans3,IvarMidtkandal1,AlvarBraathen1,ValentinZuchuat1andAnjaSundal11UniversityofOslo,Norway,2NorgesGeotekniskeInstitutt(NGI),Norway,3Dept.ofGeology,UtahStateUniversity,Logan,Utah,USA

In this study we examine exhumed paleo-reservoirsshowingevidenceofpastCO2-chargedfluid accumulation to better understandprocesses related to geological sequestration ofCO2 in subsurface siliciclastic reservoirs. Fielddata was collected from the wet aeolian dunesystemintheJurassicEntradaSandstoneinUtah,USA, and in particular the reservoircharacteristics of the light-coloured fluvial andaeolian dune interlayers have been evaluated.Bleaching in red rocks is interpreted to havedeveloped in response to reduction and/ordissolution of iron oxides as CO2-charged fluidsfromunderlyingreservoirsescapedthroughthesedimentary succession. Some light-coloured,highlyporous layers containextensiveamountsof deformationbands,whichmaybe associatedwithstructuralcollapse.

The working hypothesis is that observedreservoir collapse structures (deformationbands) in specific layers is a regional featurerelatedtosedimentaryfacies.Deformationbanddistributions and orientations are used todocumentreservoircollapse.Deformationbandsoccur in different structural settings; clustersconnected to faults cutting the stratigraphy,single deformation bands exclusively in fluvialand aeolian dune interlayers dying out in theover/underlaying facies forming small scalefaultsinthereservoir,aswellasinmajormeter-scale circular collapse structures. Deformationbands were present in some specific layersthroughoutthefieldarea,withfrequenciesfrom0 to 18 permeter and the degree of structural

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collapse increased towards zones of highdeformation,e.g.faults.Preliminaryresultsshowthat collapse structures are regional featuresexclusivelyoccurringintwotypesoffacies,withthe degree of collapse locally determined bystructuralparameters.

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MassestimationofCO2trappingintheSmeaheiareservoir

TatianaSacco1,AnjaSundal2andHelgeHellevang31UiO-UniversityofOslo,Masterstudent,2UiO-UniversityofOslo,PostdoctoralFellow-SectionofGeologyandGeophysics,3UiO-UniversityofOslo,AssociateProfessor-SectionofPhysicalGeographyandHydrology

CO2 storage in saline aquifers is an importantmeasure to reduce anthropogenic greenhousegas emissions. The Smeaheia reservoir (locatedeastof theTroll field,50kmoffshore)hasbeenproposed by Gassnova and Statoil as a suitableCO2sequestrationsiteduetolowleakageriskandlargestoragecapacity.Theaimofthisworkistodetermineandquantifythetemporaldistributionof CO2 in i) mineral phase; ii) dissolved in theformationwater; and iii) freephase for specificlayers and facies in the Smeaheia reservoircandidate.

The reservoir interval (1.2 to 1.6 km depth)comprisesdepositsfromMiddletoUpperJurassicages; named Sognefjord, Fensfjord andKrossfjordformations.Theseareheterogeneousshallow marine and deltaic sandstones. TheDraupne Formation consists of marinemudstones and serves as a sealing unit.TheHeather Formation comprises silty-claystoneswithlowpermeability,interfingeringwithsandyunits.

In addition to the porosity and permeabilitydistribution, the geochemical trappingpotentialforCO2 inSmeaheia is considered in this study.The low salinity (TDS~5.6g/l) providesdissolution potential for CO2, and favormineraldissolution. High porosity (~30%) and

permeability(~500to1500mD)causespreadingof a CO2 plume. Smaller grains yield largerreactivesurfaces,acceleratingthedissolutionofframework minerals (e.g. chlorite, feldspars,pyrite), and thus reactivity is facies dependent.Relatively low temperature (~50 ºC) andpressures(120-160bar)inSmeaheiawillaffectmineraldissolutionkineticsandthepotentialforsubsequent CO2 trapping through carbonateprecipitation(e.g.siderite,ankerite).

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GeologicalconstraintsontheimmobilizationpotentialforCO2intheUpperTriassic–LowerJurassicGassumFormation(Skagerrak,Norway)

AnjaSundal1,HelgeHellevang1,MetteOlivarius2,RohaldinMiri1,LarsHenrikNielsen2,UlrikGregersen2,OddAndersen3,HalvorMøll-Nilsen3,RikkeWeibel2andPerAagaard11UniversityofOslo,2GEUS,3Sintef

IntheCLIMIT-funded“CO2-Upslope”project,themain objective is to improve reservoircharacterization schemes tooptimizegeologicalstorage of CO2. Coupledmodelling is applied toestimate trapping efficiency and migrationdistancesinordertoensuresafestorageinopen-boundary, sloping aquifer type reservoirs. TheGassumFormationcomprisesfluvialtomarginalmarine sandy and muddy deposits. TheprospectivereservoirislocatedinSkagerraknearindustrial, onshore CO2 emission sources. Ourestimates of the reaction potential for CO2 inthesesub-arkosicsandstonesindicatesignificantcapacity for immobilization of injected gas intofluid and solid phases. The salinity of theformationwaterishigh,andthusthedissolutionpotential is limited (~0.65mol/kg),butmaybecatalyzed by solid carbonate precipitation -driving further dissolution of CO2. PHREEQ-Csimulations in a reservoir setting with 20 %porosity show dissolution of oligoclase andchlorite, providing cations and facilitatingprecipitation of magnesite, siderite and calcite,

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trapping more than 5 mol/l carbon after 1000years. Petrography and geochronology resultsindicate immature sand with relatively highcontents of reactive phases (i.e. feldspar, rockfragments) in the upper part of the GassumFormation, which dominates on the Norwegianshelf, caused by a shift in provenance areatowards the south during the later phases ofdeposition. Ongoing research activities in “CO2-Upslope” will further improve thesedimentological, structural and diageneticmodel as basis for reservoir simulations.Ultimately,acompletestorageschemetailoredtothe Gassum Formation and representative ofmigrationassistedCO2storageinslopingaquiferswillbeprovided.

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15.Marinegeology15.1.Tectonic,geodynamic,oceanographic,andcryosphericevolutionoftheArcticOceanfromMesozoictopresentday

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TheOpeningoftheArctic-AtlanticGateway:Tectonic,OceanographicandClimaticDynamics–StatusoftheIODPInitiative

WolframGeissler1andJochenKnies21AlfredWegenerInstituteHelmholtzCentreforPolarandMarineResearch,27568Bremerhaven,Germany,2GeologicalSurveyofNorway,7491Trondheim,Norway/CAGE,UniversityofTromsø,9037Tromsø,Norway

Themodernpolarcryospherereflectsanextremeclimate state with profound temperaturegradientstowardshigh-latitudes.Itdevelopedinassociation with step-wise Cenozoic cooling,beginning with ephemeral glaciations and theappearanceofseaiceinthelatemiddleEocene.Thepolaroceangatewaysplayedapivotalroleinchangingthepolarandglobalclimate,alongwithdeclininggreenhousegaslevels.TheArcticOceanwas an isolated basin until the early Miocenewhenriftingandsubsequentsea-floorspreadingstarted between Greenland and Svalbard,initiatingtheopeningoftheFramStrait/Arctic-AtlanticGateway(AAG).Althoughthisgatewayisknown to be important in Earth’s past andmodernclimate,littleisknownaboutitsCenozoicdevelopment. The opening history and AAG’sconsecutivewideninganddeepeningmusthavehad a strong impact on circulation and watermassexchangebetweentheArcticandtheNorthAtlantic Oceans. To study the AAG’s completehistory, ocean drilling sites in the Boreas BasinandalongtheEastGreenlandcontinentalmarginare proposed. These sites will provideunprecedented sedimentary records that willunveil the history of shallow-water exchange

betweentheArcticandtheNorthAtlanticOceans,andthedevelopmentoftheAAGtoadeep-waterconnectionanditsinfluenceontheglobalclimatesystem.

Getting a continuous record of the Cenozoicsedimentary succession that recorded theevolutionoftheArctic-NorthAtlantichorizontaland vertical motions, and land and waterconnectionswill alsohelpbetterunderstandingthe post-breakup evolution of the NE Atlanticconjugate margins and associated sedimentarybasins.

ORAL

DepositionalhistoryofthewesternAmundsenBasin,ArcticOcean

JohnR.Hopper1,CarlosCastro2,PaulKnutz1andThomasFunck11GeologicalSurveyofDenmarkandGreenland,2NielsBohrInstitute

Seismic reflection data collected in thewesternAmundsenBasinshowauniformandcontinuouscover of sediments over oceanic basement. Aninterpretationofseismicfaciesunitsshowsthatthe depositional history of the basin reflectschanging tectonic, climatic, and oceanographicconditions throughout the Cenozoic. The earlyhistory of the basin shows a tectonicallyinfluencedrestrictedbasin thatgaveway in theearly to mid-Miocene to a bottom currentdominatedenvironmentindicatedbyabuildupofcontouritedeposits. It issuggestedthatthis isaresponsetotheopeningoftheFramStraitandtheestablishment of geostrophic bottom currentsthat flowed from the Laptev Sea towardsGreenland. These deposits are overlain by aseismic facies unit characterized by buriedchannels and erosional features. These includeprominentbasinwardleveesystemsthatsuggesta channelmorphologymaintained by overbankdeposition of muddy sediments carried bysuspensioncurrentsperiodicallyspillingoverthechannel pathway. These deposits indicate a

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changetoamuchhigherenergyenvironmentthatisproposedtobearesponsetobrineformationassociated with the onset of perennial sea icecover in the Arctic Ocean. This interpretationimplies that the development of significant seacoverresultsinasignificantchangeintheenergyenvironmentoftheoceanthatisreflectedinthedepositional and erosional patterns observed.Thelackofsimilarhighenergyerosionalfeaturesand the presence of contourite depositsthroughoutmostoftheMiocenemayindicatetheArcticOceanwasrelativelyice-freeuntiltheverylatestMiocene.

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ArcticClimatePerturbationsduringtheEarlyTriassicBioticCrisis

JochenKnies11GeologicalSurveyofNorway

Fractured and kaolinite weathered basementrockshavebeendiscovered invariouswellsoffthe Norwegian coast and inferences on timing,source to sink relationships, andenvironmentalimplications have been widely discussed. Thereason for the kaolitinization has often beenrelatedto intensivechemicalweatheringduringlateTriassictoearlyJurassictimes.Chronologicalcontrol has primarily been inferred from theoverlying late Jurassic/early Cretaceousmarinetransgression and poorly constrained K-Ardatings from weathered basement onshore aswell as climate conditions favourable forkaoliniteformation.

Inthisstudy, Ipresentevidencethatthedeeplyweathered basement off the mid-Norwegiancoast represent a complete paleosol profileformed ca 250 million years ago. The timingcorroborateswiththeEarlyTriassicbioticcrisisand suggest a causal relationship betweenintense chemical weathering, high atmosphericCO2 concentration, extreme ocean warming,delayedbioticrecovery,increasedriverinefluxofnutrientsandwidespreadanoxia/euxinia in thehigh northern latitudes during a time of rapidglobalclimateperturbations.

ORAL

GreenlandIceSheetevolutionanddynamicsseenfromtheperspectiveofalargeglacialfansystem,northeastBaffinBay

PaulCKnutz1,AndrewMWNewton2,JohnRHopper1,MadsHuuse3,UlrikGregersen1,EmmaSheldon1andKarenDybkær11GeologicalSurveyofDenmarkandGreenland,ØsterVoldGade10,1350Copenhagen,Denmark,2SchoolofEarthandEnvironmentalSciences,UniversityofManchester,M139PL,UK,3CryosphereResearchatManchester(CRAM),UniversityofManchester,M139PL,UK

The Greenland Ice Sheet (GrIS) is a majorfreshwaterreservoirandakeycomponentoftheglobal climate system sounderstanding its pastdynamic behaviour is crucial for underpinningclimatemodelpredictions.Thelong-termhistoryof the GrIS ismainly deduced from deep oceandrilling sites while relatively little informationexistsfromitsdynamicglacialmargins.Herewepresent mapping results, based on a dense 2Dreflection-seismicgridtiedtoindustrywelldata,which illuminates the stratigraphy and spatialevolutionoftheMelvilleBugt-Upernaviktrough-mouth fansystem.The fandepocentres, formedby sediments eroded and transported by thenorthern GrIS, are constructed by sequentiallyorganized prograding depositional units,boundedbyglacialerosionsurfaces thatextendinto steeply dipping clinoforms on the outermargin. South of the main trough, the erosionsurfaces are commonly onlapped by laterallycontinuous strata attributed to sea-leveltransgressions.Thestudyrevealselevenphasesof ice stream advance over the northwestGreenlandcontinentalmarginsincetheonsetofshelf-basedglaciationataround2.8Ma.TheGrISadvance phases were interrupted by glacialretreats and sea-level rises that appear tocorrelate with super-interglacial periodsidentifiedintheSiberianArcticregion.Moreover,achangein ice flowconfigurationfromuniformglacial advances to distinct trough-based

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drainage points to a major change in GrISdynamicsthroughtheMid-Pleistocenetransition.

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OntheoriginofthemarginalplateausnorthofSvalbardandGreenland

YngveKristoffersen1,YoshihideOhta2,JohnK.Hall3andGeirB.Larsen41UniversityofBergen/NansenEnvironmentalandRemoteSensingCentre,2(retired)NorwegianPolarInsititute,3(retired)Geol.SurveyofIsrael,4Lundin-Norway

The marginal plateaus north of Svalbard andGreenlandareconjugatefeatureswithrespecttothe Gakkel Ridge and likely to share a geologichistory.

Dredge hauls from three sites on the YermakPlateau have recovered an abundance ofmetasediments and gneisses with strongaffinities to known lithologies from northwestSpitsbergen.Theresultssupporttheearlierideaoftheplateaubeingacontinentaloutlierexceptforitsnortheasternmosttip.TheoutlierriftedoffthemarginnorthofSvalbardandmovedwiththeGreenland plate which implies significantPaleogenedextralshearmotionclosetothecoastof Spitsbergen. Past coast-parallel shear issupported by observed seismic velocityanomalies in the crust characteristic ofcontinentaltransformboundaries.

AseismicreflectiontransectacrossMorrisJesupRise show an eastern flat-topped spur ofundeformedwest-dipping layers and awesterndome-structure cored by deformed sediments,possiblyanimbricatestackofthrustsheets.Highamplitude rough seismic reflections interpretedas lava flowsarepresentatdepth in the40kmwidedepressionbetweenthesetwostructures.

The shared geologic history of the marginalplateausinvolveYermakPlateauriftingoffnorthof SvalbardatChron24and theeasternMorrisJesupSpurriftingofftheYermakPlateauataboutChron 15. The Morris Jesup Spur is likely to

represent the pre-Cenozoic continental slopenorthofSvalbard.

ORAL

LateCenozoicpaleoenvironmentanderosionestimatesforthenortheasternSvalbard/northernBarentsSeacontinentalmargin,NorwegianArctic

AmandoLasabuda1,WolframGeissler2,JanSverreLaberg3,Stig-MortenKnutsen4,TomArneRydningen3andKaiBerglar51ResearchCentreforArcticPetroleumExploration(ARCEx),IG,UniversityofTromsø,Norway,2Alfred-Wegener-InstitutHelmholtz-ZentrumfürPolar-undMeeresforschung(AWI),Bremerhaven,Germany,3DepartmentofGeosciences,UniversityofTromsø–theArcticUniversityofNorway,Tromsø,Norway,4NorwegianPetroleumDirectorate(NPD),Harstad,Norway,5FederalInstituteforGeosciencesandNaturalResources(BGR),Hannover,Germany

The upper Cenozoic sedimentary succession ofthenortheasternSvalbard/northernBarentsSeacontinentalmarginisanalyzedusingavailable2Dseismic data. The primary focus is to betterunderstand the glacial paleoenvironments andsedimentaryprocessesaswellastoestimatetheglacial erosion of the inferred source areas.Seismic faciesanalysisshows threemain facies;paralleltoobliqueparallel,contorted,andchaoticseismicpatterns.Theseobservationssuggestaninterplay between contour current and glacial-related mass-wasting processes. The seismicmapping showsabundant contouritedepositionsincetheMiocene,interpretedtoberelatedtotheestablishment of an ocean circulation systemfollowingtheopeningoftheFramStrait,similartopresentconditions.Theglacigenicdebritesandits associated mass-transport deposits areinterpretedtocharacterizetheareainfrontofthetroughs. This is likely related to extensiveglaciations in the Plio-Pleistocene duringwhichicesheetsrepeatedlyadvancedtotheshelfbreakduring the full-glacial conditions. The intertrough-mouthfanareasappeartobedominatedbycontouriticdepositscharacterizedbyaseries

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of sediment waves and sheeted drifts. In thestudied margin, there is an increasing trend ofmass-wastingprocesseseastwards,whilealong-slope processes dominate to the west. Isopachmapsoftheglacialstratawillbepresentedalongwiththeerosionestimatesusingamass-balanceapproach. Major sediment source areas will bediscussedinrelationtothelateCenozoichistoryofthisstudiedmargin.Thiscontributionwillbeusefultobetterunderstandthedynamicsofupliftand erosion events in the greater Barents Seaarea.

ORAL

EnigmaticcratersandgiantgasflaresinthecentralBarentsSea

FrancisChantelNixon1,ShyamChand1andTerjeThorsnes11Norgesgeologiskeundersøkelse

Recent analyses of high-resolution multibeamswath bathymetry and water column datacollectedfromthecentralBarentsSearesultedinover 300 new observations of active gas flaresemanating from southeast Storbanken (~100-200 m below modern sea level; mbsl).Seabedfluid escape features, including pockmarks,craters, andmounds (tentatively interpreted asgashydratepingos;GHPs)werealsomappedinthis area. Interestingly, mapped fluid escapefeaturesdonotcoincidewiththelocationsoftheactivegasflares,whichisincontrasttohundredsofsimilarcraters,GHPs,andco-locatedgasflares~300kmsouthwest,atdepthsof310-370mbsl(Andreassenetal.,2017).TheGHPsandcratersobservedonsoutheastStorbankenoccuroutsideofthemethanehydratestabilitylimit,indicatingthat the gas hydrates underlying the GHPsconstituteamixofmethaneandheaviernaturalgases, which remain stable at shallower waterdepths and/or warmer temperatures.Thecraters,mostofwhichareimmediatelyadjacentto the GHPs, indicate that methane hydrates(≥99.9% methane) were formerly present, butbecame unstable and dissociated from theseabed,likelybetween~12-15kaBPfollowing

deglaciation.Depending on future warming ofbottom waters in the Barents Sea, the gashydrates underlying the GHPs on southeasternStorbankencoulddissociaterapidly,formingnewcratersandsending largequantitiesofmethaneto the sea surface and atmosphere.Such eventshave important implications for both seabedgeohazard mapping and for climate changemodels,whichmusttakeintoaccountallsourcesandsinksofmethane,apowerfulgreenhousegas.

POSTER

AnautomatedcryogenicmagnetometerattheGeologicalSurveyofNorwayfornaturalremanentmagnetizationandrockmagnetism:AcasestudyofNorth-EastAtlanticcontinentalmarginsediments

MartinKlug1,KarlFabian2,JochenKnies2andSimoneSauer31GeologicalSurveyofNorway,Trondheim,Norway,2GeologicalSurveyofNorway,Trondheim,Norway;CAGE-UiTTheArcticUniversityofNorway,Tromsø,3CAGE-CentreforArcticGasHydrate,EnvironmentandClimate;UiTTheArcticUniversityofNorway

A new, automatically operating cryogenicmagnetometersystemattheGeologicalSurveyofNorway is used to acquire natural remanentmagnetization (NRM) and rock magneticparametersfromtwolocations,WestBarentsSea(~71.6°N,16.2°E) and Vestnesa Ridge, NWSvalbard(~79.0°N,6.9°E).Themagnetometerlabsetup comprises an automated robot samplefeeding, dynamic measurement operation andmonitoring, and customised output-to-databasedata handling. The setup is designed todynamically enable a variety of parallelmeasurementswithseveralcoupleddevices(e.g.balance, MS2B) to effectively use dead-time inbetween the otherwise time-consumingmeasurementswith thecryogenmagnetometer.Web-basedaccessallowsremotequalitycontroland interaction 24/7 and enables high samplethroughput.

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Inthestudiedcoresthemagneticpropertiesarecombined with geophysical, geochemicalmeasurements and optical imaging, bothradiographic and colour images, from high-resolution core-logging. The multidisciplinaryapproach enables determination andinterpretation of content and formation of themagnetic fraction, and its development duringdiagenetic processes. Besides palaeomagneticage determination the results offer theopportunity to study sediment transformationprocesses that have implications for the burialand degradation of organic matter. The resultsalso help to understand long and short-termvariability of sediment accumulation. Chemicalsediment stability is directly linked toenvironmentalandclimatevariabilityinthepolarmarineenvironmentduringtherecentpast.

POSTER

ThegeneralseafloormorphologyoftheNEGreenlandshelf-InsightsfromnewmarineshallowseismicandcoredatacollectedduringtheNorthGreen2017expedition

LasseNygaardEriksen1,KatrineJuulAndresen1,ToveNielsen2,ChristofPearce1,TineLanderRasmussen3,HansRøy4andMarit-SolveigSeidenkrantz11DepartmentofGeoscience–SeisLabandCentreforPastClimateStudies,AarhusUniversity,2Departmentofgeophysics,GeologicalSurveyofDenmarkandGreenland,3DepartmentofGeosciences,UiT,TheArcticUniversityofNorway,4DepartmentofBioscience-CenterforGeomicrobiology,AarhusUniversity

We present preliminary observations fromseismicdatasupportedbymarinesedimentcoresfromtheNEGreenlandshelfbetween80°Nand74°N.Thedatawereacquired innearly ice-freeconditions and consist of~2200 km of shallowseismic subbottom profiler data as well assedimentcoresfrom15differentsites.Thedatawere acquired during the NorthGreen2017expeditioninSeptember2017,andrepresentan

areathathasbeenrarelyaccessedduetomostlyperennialsea-icecoverpriorto2017.

The data cover a wide range of differentgeological provinces across the NE Greenlandshelf, but can roughly be subdivided into deeptroughs (formed by glacial erosion) andbasementhighs,whichalsoappeartobeaffectedbyglaciers. Innearlyallareas,athincover(1-3m) of most likely Holocene mud drapes thevarying structures. Sedimentary basins (withestimatedmud/claythicknessuptoca.15-20m)were only encountered in a few places on theshelf,primarilylinkedtoglacieroutlettroughs.

Varyingseafloormorphologiescanberecognizedsuch as blocky and faulted seafloor, ruggedseafloor possibly related to slope failures,potential iceberg plough-marks, basementoutcrops and flat seafloor related to minorsedimentary basins. Similarly, the reflectionsbelow the seafloor showvarying characteristicssuch as parallel high-amplitude continuousreflections and low-amplitude discontinuouschaotic reflections indicative of changingsubsurface.

POSTER

ActivefaultsystemsandsubmarinelandslidesalongtheEasternSakhalinslope,theOkhotskSea

D.D.Rukavishnikova1,K.A.Dozorova1andB.V.Baranov11ShirshovInstituteofOceanology,RussianAcademyofSciences,Moscow,Russia

Continuous sub-bottom profiling and detailedbathymetrymapsobtainedduring internationalprojectsin1998-2015hasfirstrevealedareasofactive tectonics and associated submarinelandslideswithin central and northern areas ofSakhalin Island slope, the Okhotsk Sea. Activefaults form two local systems within limitedareas.WithinthenorthernareathefaultsystemcontainsNEandNWstrikingnormalandstrike-slip faults. In this area tectonic deformationcaused displacement and destruction of a

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sediment blockwith approximate volumeof 16km3. NW striking normal faults form steepinstabletectonicscarpsupto120mhigh.Seismicsurvey reveals mass transport deposits withestimatedtotalvolumeof3km3atthebaseofthelargest scarp Within the central slope segmentthe active fault system contains NE and NSstriking normal and strike-slip faults. VerticaldisplacementsalongtheNEnormalfaultsresultin subsidence of sediments and form closeddepressions with steep walls. Failure of one ofsuchsteepwallsformedalandslidewithvolumeofabout4km3.Thepresenteddatashowthattheactive tectonics creates favorable conditions forlandslidesgenerationinthestudyarea.

15.2.Paleo-landscapeanalysisbasedonhigh-resolutionmarinedata

ORAL

Theimpactofaburiedshearmarginmoraineandthermokarstlandscapesonice-streamdynamicsoftheSWBarentsSearevealedbyhigh-resolution3Dseismicdata

BenjaminBellwald1,SverrePlanke1,NinaLebedova-Ivanova1,EmiliaDariaPiasecka2,MohamedAliMatar3,KarinAndreassen2andReidunMyklebust41VolcanicBasinPetroleumResearch(VBPR),2UiTTheArcticUniversityofNorway,3NordicGeo-Consult,4TGS

Meter-scale glacial landforms and layers, notresolvable by conventional seismic data,comprise new information about glacierdynamicsand fluid flow,whicharevaluable forthe development of offshore infrastructure andgeohazardassessments.Thegoalofthisstudyisto characterize the paleo-landscape of the SWBarentsSeaonameter-scale, tocorrelate thesestructures with the sub-surface geology and tostudytheirimplicationsonice-streamdynamics.The database consists of c. 200 km2 of high-resolutionP-Cable3Dseismicdataand37gravitycores in the SW Barents Sea. The grids of thepickedseabedandUpperRegionalUnconformity(URU)horizons,whichdefinethetopandbaseofthe Quaternary sediment sequence, arecompared with interpretations obtained fromconventional 3D seismic and multibeamechosounderdata.SeabedimagesinterpretedinP-Cable 3D seismic data show an increasedresolution and sharpness compared to surfacesderived from multibeam echosounder andconventinal3Dseismicdata.Hill-holepairsandrhombohedral ridges atURU are interpreted asgeological structures formed by subglacialthermokarsticprocesses,indicatingthepresenceofpermafrost.Reflectionswithintheintraglacialsedimentpackagearenotvisibleinconventional

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seismicdata,andincludeashearmarginmoraine,masstranportdepositsandsoftbeds.Thisstudyshows that high-resolution seismic data can beused to identify geological structures inmultibeam echosounder quality of both theseabed and the shallow sub-surface. Identifiedthermokarst landscapes, a submarine braidedriverandashearmarginmorainehaveledtothedevelopmentofarevisedice-streammodeloftheSWBarentsSea.

ORAL

GeologicalsettingofAnholtLoch(SiteM0060)IODPExpedition347

JørnB.Jensen1,OleBennike2,KatrineJ.Andresen3andOleRønø31DepartmentofMarineGeology,GeologicalSurveyofDenmarkandGreenland(GEUS),2DepartmentofMarineGeology,GeologicalSurveyofDenmarkandGreenland(GEUS).,3DeparmentofGeoscience,AarhusUniversity

IODPExpedition347SiteM0060issituatedinthesouthernKattegatatawaterdepthof34m.Thebackgroundselectionofthecoringpositionwasarathercoarsegridofseismiclines,thatindicatesanerosionalvalleysoutheastofAnholtIslandinthe Kattegat Sea. The valley was originallyinterpretedasinfilledbyasequencefromMIS6,MIS5e,andMIS3(Lykke-Andersenetal.1993).Later boomer profiles and shallow cores show,that theyoungerpartsof the infill is lateglacialand Holocene age (MIS 2–MIS 1; Jensen et al.2002).

In2013theIODPprogramcoreM0060reachedatotal depth of 232.5m of which 0 to 9 mbsf isMarine Holocene and the range 9 to 82 mbsfcoversthemostrecentdeglaciation14–18kaBPi.e.(Bokhari2015).Ongreaterdepthsalternatingsandyandsiltysequencesarerecorded,whilethelowermost84mconsistsofdiamict.

Parallel to Expedition 347 a local Danish –SwedishprojectDAN-IODP-SEIScarriedoutHighResolution2Dseismics(Nørmarketal.2014)andinspring2017a3Dhighresolutionsurveywas

carried out in connection with the GeocenterDenmarkprojectSEDI-TRAPS.

CorrelationofthecoringresultsandtheseismicdatashowthattheAnholtLockis linkedcloselyto the structural development of the TornquistZonestrike-slipfaultsystemandsynsedimentaryLate- and Postglacial depositional patternsdocumentthatreactivationhastakenplace.

ORAL

Postglacialpaleo-landscapeevolutionofAalborgBay-LæsøRende,northwesternKattegat–resultsofaregionalaggregaterawmaterialmappingcampaign

NielsNørgaard-Pedersen1,JørgenO.Leth1,OleBennike1andSteenLomholt11GeologicalSurveyofDenmarkandGreenland

In 2016 a regional shallow seismic mappingcampaignforaggregaterawmaterialstookplacein an 1800 km2 area in Aalborg Bay innorthwesternKattegat.Themainpurposeofthestudy, performed for theDanishEnvironmentalAgency,wastoassessthedistributionandqualityof aggregatematerial aswell asmonitoring thehabitatconditionsinthearea.MappingofbasisoftheHolocene deposits in the area, representingthelowstandperiodatabout12.000-10.000yrs.BP,revealsanetworkofvalley/channelsystemswhich appear to be connected to the majordrainage systems connected to inletsof easternJutland.Rapidlyincreasingrelativesealevelfromabout 10.000-7.000 yrs. BP enhanced marinetransportofverylargevolumesofsandymaterialfrom the northwestern Kattegat in to thenorthernpartof thestudyarea.Elongatedsandbars tens of kilometers long formed in LæsøRende.Inthemid-Holoceneatabout5000-4000yrs.BPrelativesealevelculminatedatabout4-5mabovepresentsealevel.Duetothecontinuedisostatic uplift of the northern part of Kattegatrelative sea level fell after c. 4000 yrs BP. Thelargesandbarand interveningchannelsystemswere selectively eroded and large amounts of

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sandy material were transported southward tothe central deeper part of Aalborg Bay. Thedevelopmentofageologicalmodelencompassingthepresentdistributionofspecificstratigraphicunits and the relatedpaleo-landscape evolutionin relation to sea level changes, is an importantprerequisite for predicting aggregate rawmaterialdistributionandqualityvariability.

ORAL

GlaciotectonicthrustcomplexoffshoreHolmsland,theDanishNorthSea-NewResults.

BernhardNovak1andHenriqueDuarte21Independent,2GeosurveysEd

Geologicalstructuresandseismicstratigraphyofa large-scale glaciotectonic thrust complex hasbeeninvestigatedinanarea5kmoffshorealongthecoastlineofftheHolmslandDunesarea,westDenmark.Adensegridofseismicdatacombinedwithsurfacesamplesandboreholesinformationhavebeenanalyzedina6by15kmarea.Thebaseof the Quaternary (D,b) constitutes anunconformity interface to Neogene. A smoothseismichorizon(D,d)thatoutlinerampsandflatsconstitutes a decollement surface beneath thethrust complex. New analysis (and data) yieldevidencesthatthebaseQuaternaryunconformityis unaffected by the deformation and that nearhorizontalparallelseismicfaciesonlapsD,b.TheseismicunitD,0betweenthehorizonsD,bandD,dshows medium to high amplitude parallel(onlap), mound, channel, oblique and chaoticseismic facies. This 0 to 30meter thick seismicunit is interpreted to represent glaciolacustrinelaminated sediments (parallel facies) depositedover a proglacial outwash plain environment.AnalysisofthrustblockdipvariationsaboveD,0suggestsacorrelationtothethicknessofunitD,0and the thrust style. In areaswhere the unit isabsentafold/domedeformationstyleatthebaseof the complex is accompanied by steep thruststyleandmaximumspacebetweenthrustridgesabovethefolds.OurmodelsuggeststhatunitD,0function as a hydro conductive agent beneath

tens of meters of glaciolacustrine deposit.Variations in the appearance of unit D,0 andlithological variations in the lacustrine depositsresultsinvariationsinthruststyle.

POSTER

Paleo-rivervalleysneartheDoggerBankintheDanishandGermansectorsoftheNorthSea–anundiscoveredtributarysystemtothePaleoElbeValley

TrineAndreasen1,KatrineJuulAndresen1,DanielA.Hepp2andHannoKeil31SeisLabAarhus,DepartmentofGeoscience,AarhusUniversity,Høegh-GuldbergsGade2,8000AarhusC,2CentreforMarineEnvironmentalSciences,MARUM,Bremen,3FacultyofGeosciences,UniversityofBremen

Thisstudypresentsanewsystemofpaleo-rivervalleyssoutheastof theDoggerBankwhichhasbeen mapped using high-resolution subbottomprofilerdataandsedimentcoresacquiredduringa RV Heincke expedition to the German andDanishsectorsoftheNorthSeainMay2016.

Thepaleo-riversystemcoversanareaofapprox.200km2andisfoundbelowathinsuccessionofmarinesediments,whichindicatesthattheriversystemformedpriortothemarinetransgression8000yearsago.Theriversystemischaracterisedbyacentral,5kmwideandupto6mdeepNE-SW striking valley that intersects six older andsmallerNW-SEstrikingchannels.

The course of the wider central valley roughlyfollows the contours of the submerged DoggerBankandthe infillof thevalley ischaracterisedby well-defined subparallel and continuousreflections.This suggesta steady infillingof thevalley, which may have occurred within anestuary environment prior to the marinetransgression.

The six older and smaller channels havehighersinuosity and followsa courseperpendicular totheDoggerBank.Thesechannelsareinterpretedto constitute an oldermeandering river system

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dewatering the Doggerland and terminating inthePaleo-ElbeValleyeastofthestudyarea.

The six oldermeandering rivers can be readilylinked to other similar systemsmapped furthersoutheast (Hepp et al., 2017) and there isgenerally a very good agreement of our newfindings with the existing theories on thedevelopmentof theDoggerland landscape sincetheWeichselianlowstand.

POSTER

LateglacialtoHolocenegeologicaldevelopmentofthewesternLimfjord–reconstructionofadynamicpaleolandscape

KatrineJuulAndresen1,AndersDahlin2,KasperU.Kjeldsen3,HansRøy3andMarit-SolveigSeidenkrantz41SeisLabAarhus,DepartmentofGeoscience,AarhusUniversity,Høegh-GuldbergsGade2,8000AarhusC,2SeisLabAarhus,DepartmentofGeoscience,AarhusUniversity,3CentreforGeomicrobiology,DepartmentofBioscience,AarhusUniversity,4CentreforPastClimateStudies,DepartmentofGeoscience,AarhusUniversity

The western Limfjord in northern Denmarkcompriseswiderwater-areassuchasLøgstørandThistedBrednings,narrowstraits, small islandsand some larger islands with spectacularlandscapessuchasMorsandFur.TheQuaternarydevelopment of the fjord has been highlygoverned by surface processes related tochanging ice-covers which has carved-out thefjord, deformed the Cenozoic successionincluding the Eocene Mo-clay by thrusting andfolding,andgeneratedsea-levelfluctuationsduetoice-meltingandisostaticglacialrebound.Atthesametime,deepgeologicalsubsurfaceprocessessuch as rising salt diapirs, tectonic faulting andfluid migration have also controlled theformationofthelandscape.

In this study, we present a detailed subsurfaceinvestigation of Visby Bredning in the westernLimfjord based on high-resolution seismic dataand sediment cores acquired during the

WesternLimfjord-expedition in May 2017. Ourpreliminary results show that the Quaternarypaleolandscapefromtheseismicdataasexpectedis very dynamic, andmost likely have recordedthehistoryfromanice-coveredtoshallow-waterenvironment.The seismicdata typically showadistinct transition from high-amplitude chaoticreflections interpreted as Weichselian till, tolower amplitude, semi-parallel, continuousreflections interpreted as the Holocenesuccession.Afewplaces,weobserveathirdunitinbetweentheglacialandHoloceneunits,whichwe tentatively suggest could represent lateglacial deposits. Sediment descriptions and agedatingfromtwogravitycoresinVisbyBredningare included to address the Holocenedevelopment in more detail and unravel thechanginginfluenceoffresh,brackishandmarinewatersinVisbyBredning.

POSTER

TheYoungSoundfjordsystem,NEGreenland–InsightsfromnewmarineshallowseismicandcoredatacollectedduringtheNorthGreen2017expedition

LasseNygaardEriksen1,KatrineJuulAndresen1,ToveNielsen2,ChristofPearce1,TineLanderRasmussen3,SofiaRibeiro2,SørenRysgaard4,HansRøy5andMarit-SolveigSeidenkrantz11DepartmentofGeoscience–SeisLabandCentreforPastClimateStudies,AarhusUniversity,2Departmentofgeophysics,GeologicalSurveyofDenmarkandGreenland,3DepartmentofGeosciences,UiT,TheArcticUniversityofNorway,4DepartmentofBioscience-ArcticResearchCentre,AarhusUniversity,5DepartmentofBioscience-CenterforGeomicrobiology,AarhusUniversity

TheYoungSound fjordsystem inNEGreenlandgenerallyconsistsofanouter,up to7kmwide,shallowwater(<200m)partandaninnernarrow(2kmwide)anddeeperwater(300-400m)partknown as the Young Sound Deep. The fjordsystem have been extensively surveyed formarine,terrestrialandmeteorologicaldatasince1994(Bendtsen2014etal.),but theunderlying

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seafloor and the subsurface sediments have toour knowledge only beenmapped superficially.In this study, we present preliminaryobservations from seismic mapping andsediment coring within the Young Sound. Thedata that consist of 400 km of shallow seismicsubbottom-profilerdataandfoursedimentcoreswere acquired during the NorthGreen2017expeditioninSeptember2017andrepresentthefirst detailed marine seismic study of thegeologicaldevelopmentofthefjordsystem.

Weshowthat thecentralbasin inYoungSoundDeepisfilledwithafairlythicksedimentpackage(at least 40-50 m where thickest). There wasfurthermore a clear distinction in both theseafloormorphologyandthesubsurfacegeologyfromtheinnerpartofthefjordtowardstheouterpart of the fjord, which is most likely a directrepresentationofthesimilarmarkedchangesintopography at the fjord sides. Thus, ourobservations from the high-resolution shallow-seismicdatasuggestthatwecantrackfirst-ordererosion and depositional processes within thefjordbackintime.

POSTER

DeepgeologyatVejleFjord–PaleogenestructuralcontrolofaQuaternaryfjordsystem

JakobRoued1,Marit-SolveigSeidenkrantz1,LarsOleBoldreel2andKatrineJuulAndresen11SeisLabAarhusandCentreforPastClimateStudies,DepartmentofGeoscience,AarhusUniversity,2DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen

VejleFjordinDenmarkisbelievedtohaveformedasatunnelvalleyinitiallycarved-outduringtheElsterian glaciation and later reused andexpanded during succeeding glaciations andinter-glaciations. Folds and thrust faults in thepresent-day coast-profiles of the fjord bearevidenceofglacialdeformationwhileoutcropsofPaleogeneandNeogenesedimentshaveaidedthereconstruction of the paleolandscape. It hashowever not been investigated in detail, how

deeper geological structures could havecontrolled and effected the configuration of thepre-VejleFjordlandscapeandinturnthefocusoftheQuaternaryglacialprocesses.

Inthisstudy,weinterpretnewlyacquiredhigh-resolution 2D seismic data and sediment coresfrom Vejle Fjord with the aim of mapping andinvestigating the deeper geological structuresandtheirpotentialinfluenceontheformationofthe fjord. Our seismic data show a number offaults,which in thesouthernpartofVejleFjordoffsetEocenesedimentspresentlyattheseafloor.Thefaultscanbefolloweddowntoca.70mbelowthe seafloor, with a few faults continuing evendeeper.Threehypothesesfortheformationofthefaultsaresuggested:Quaternaryglacial tectonicdeformation, slope failure deformation, andpolygonalfaulting.Whichofthehypothesesthatare applicable have a great importance for theunderstanding of the early origin of Vejle Fjordandforfjordformationinsedimentarybasinsingeneral. To understand the faults, ourinterpretationisfocusedonconstrainingtheir3Dgeometriesandinturntheirtiming,activityandcontrollingfactors.

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15.3.TheQuaternarygeologyoftheNorthSeaBasin[co-organizedwithQuaternaryGeology]

ORAL

TheQuaternaryStratigraphyintheNorwegianSectoroftheCentralNorthSea–ASiteSurveyPerspective

BjörnBohling11Fugro

Quaternary deposits of the North Sea are ofparticular interest for geohazard and sitecharacterisation studies ensuring the saveemplacement of offshore installations (IOGP2013 & 2015). A coherent (litho-)stratigraphicframework is required in order to perform areliable interpretation of geophysical andgeotechnical site survey data and in order toensurethecomparabilityofresults.

The British sector of the North Sea has beensystematicallymappedby theBritishGeologicalSurvey. Reports and maps presenting seabedsedimentsandtheQuaternarygeologyhavebeenpublished (e.g. Johnson et al. 1993, Gatliff et al.1994). Such systematic mapping has not beenundertaken in the Norwegian sector of thesouthern and central North Sea. Therefore, theinterpretation of site survey data in theNorwegian sector is often based on theextrapolationof theBritishstratigraphicmodel,leading to a considerable degree of uncertaintyandinconsistency.Recentresearchhasimprovedthe understanding of Quaternary deposits (e.g.Buckley 2014, Ottesen et al. 2014). However,many studies focus on the early Quaternarysequence or make use of conventional 3Dexploration seismic data that have a relativelylowresolutionanddonot imagethecomplexityofmiddleandlateQuaternarydeposits.

This presentation will highlight issues andchallengesregardingtheQuaternarystratigraphyinthecentralNorthSeaasseenfromasitesurvey

perspective. Examples of high-resolution datawillbeshownfromsitesurveysintheNorwegiansector and in areas crossing the UK-Norwayborder.

ORAL

TheNorwegianStrandflat-anoffshoreperspective

HelgeLøseth11StatoilASA,R&DTrondheim

Thestrandflatisthepicturesqueworld-heritagetopographic low-land, islandand soundson thecoast of Norway. The age and processes offorming the strandflat have been debated sincefirst described by Hans Reusch in 1900. Theobjectiveofthisworkissetconstrainstotheageand formation processes of the strandflat bylinking it to the offshore geological evolution.Seismic andwell data are used to interpret theCenozoicgeologicalevolutionofthemarginwhilethe strandflat is studied through literature andfieldobservations.

Thenon-paralleltiltsofthestrandflatrelativetooffshore Cenozoic surfaces show that thestrandflatwasformedduringtheQuaternary.

Thestrandflatiswidest,upto50km,onthemidNorwegiancoast.Thecombinedeffectofglacialerosion(volume-vicemostimportant)andwaveerosionformedthestrandflat.Waveerosioncutleveled platforms into the glacial-segmentedcoast. This occurred most efficiently duringglacial periods when the coast was ice-freesimultaneouslyasthelandwasdepressedunderthe weight of the inland ice. During repeatedglacialandintra-glacialeventstheplatformgrewwider and deeper simultaneously as the coastgradually rose and tilted westward underisostatic adjustments formonshoreerosionandoffshoredeposition.OutsideMøreandTromsthestrandflatisisostaticlyforcedbelowthesealevelundertheweightofthetwoglacialdepocenters,the North Sea Fan and the Bjørnøya Fan. Theabsence of the strandflats in Finnmark and SE

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NorwayIexplainbyoffshoreglacialerosionandnoflexuraldown-bendingofthecoast.

ORAL

ThegeologicalhistoryoftheNorthSeaBasinduringtheQuaternary

DagOttesen1,ChristineBatchelor2,JulianDowdeswell2andHelgeLøseth31GeologicalSurveyofNorway,2ScottPolarResearchInstitute,UniversityofCambridge,3StatoilASA

The Quaternary sediments of the central andnorthernNorthSeahavebeenmappedbasedona large 2D and 3D seismic database. TheQuaternary North Sea basin is a N-S-trendingbasin,100-200kmwideandupto1000mdeep.Theinfillpatternofthebasinisoutlinedandthedepositional setting has been studied based onburiedsurfacesin3Dseismiccubes.Thecentralbasin is filled in by a thick, deltaic sequencedeposited from the E-SE,whereas the northernbasinisfilledinbyprogradingglacigenicdebrisflowsdepositedfromtheeast.

Ontopofthesedimentsmappedinthenorthernbasin,westoftheNorwegianChannel,anupperregional unconformity (URU) is present. Thisunconformityisdefinedbyashiftfromwestward(below) to eastward (above) dipping reflectors,recording a major change in sedimentation(beforeandaftertheonsetoftheformationoftheNorwegian Channel). The age of the URU isuncertain, but a timing of around 0.8 millionyears is suggested. Parts of the sedimentarysequence have been linked to the seismicstratigraphy on the Dutch shelf, which is datedbased on palaeo-magnetic and biostratigraphicdata(KuhlmannandWong,2008).

ORAL

ThetunnelvalleysofthecentralandnorthernNorthSea(56°N–62°N):Distribution,CharacteristicsandGenerations

DagOttesen1,MargaretStewart2andMarcoBrønner11GeologicalSurveyofNorway,2BritishGeologicalSurvey

Tunnel valleys are km-scale linear landformsformed subglacially beneath large ice sheets. Inthe British andNorwegian sectors of theNorthSea, offshore tunnel valleys are associatedwithmultipleQuaternaryglaciations.Inthisstudy,weuse 2D and 3D seismic reflection data, andmagnetic data, to map more than a thousandburiedtunnelvalleysinthecentralandnorthernNorth Sea. The tunnel valleys are generallypresentfromtheseabedtodepthsofaround400metres,inastudyareaof180000km2from56°Nto around62°N.Buried tunnel valleys arewell-imagedinseismicreflectiondata,particularlyinhorizontal timeslices in 3D seismic data. Inmagneticdata,thetunnelvalleysappearassmallscalemagneticlows,likelyduetotheirinfillbeinglesscompactedandpotentiallymoreporousthanthesurroundings.

Thisworkprovides themostextensivestudyoftunnel valleys in the region to date, withmorethan 20% of the study area containing buriedtunnelvalleys,andalso finds the longest tunnelvalley recorded worldwide, with largemeandering tunnel valleys extending for morethan160km.Wealsofindtunnelvalleysfurthernorth than previously reported, as well as anumber of isolated tunnel valleys extendingtowards and into the Norwegian Channel. Asreported by other studies in the region, theapparentlyextensivenetworksofburiedvalleysare found to be comprised of cross-cuttinggenerations.Infourstudyareas,wefindbetween3and6generations,andrelatethemtopotentialicesheetconfigurations.

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QuaternarydepositionalenvironmentsandglacialhistoryoftheNorthSeaconstrainedbyaminostratigraphy

BenedictReinardy1,HansPetterSejrup2andBeritHjelstuen21StockholmUniversity,2UniversityofBergen

Theaminostratigraphyofupto1000mofglacialandinterglacialsedimentsintheNorthSeaBasinis compiled from multiple boreholes sites anddated using strontium isotope (Sr) analysis toprovide a chronological framework extendingthroughouttheQuaternary.Thenewrelativeandabsolute chronology also ties to regionalseismostratigraphy. Increasing sedimentdeposition rate during the Early Pleistocenereflects glacier ice advancing to the Norwegiancoast.Theearliestevidenceofgroundediceintheinvestigatedareacomesfrommegascaleglaciallineations formed during the Mid PleistoceneTransition. At least one episode of diminishedcoarse clasts and increased foraminiferaldiversity during theMid Pleistocene suggests aprogression from ice proximal to warmer,possiblyinterglacialconditions.Furthermore,thestratigraphically deepest generation of tunnelvalleys may have formed during the MidPleistocene.Aminoacidratiosindicatethatahighshear strength till containing chalk claststransported from thewest and/or south of thestudyareawaslikelydepositedduringMIS6.TheLate Pleistocene stratigraphy is dominated byglacimarine sediments and tills that arechronologicallywellconstrainedwithaminoaciddata.Asandlayerrecoveredatcoretopinpartofthestudyareaisinterpretedtocorrespondtothedrainageofanice-dammedlakeinthesouthernNorth Sea during the last deglaciation (MIS2).This study shows that much of the Quaternaryage sediments within the northern North Seawere deposited relatively rapidly during shortperiods of time probably leaving significanthiatuseswithinthestratigraphicrecord.

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Near-shoreseafloordepressionsintheWesternLimfjord,Denmark–potentialgeohazards?

AndersDahlin1,KatrineJuulAndresen1,KasperU.Kjeldsen2,HansRøy2andMarit-SolveigSeidenkrantz31SeisLabAarhus,DepartmentofGeoscience,AarhusUniversity,2CentreforGeomicrobiology,DepartmentofBioscience,AarhusUniversity,3CentreforPastClimateStudies,DepartmentofGeoscience,AarhusUniversity

Pockmarks which are circular to semi-circularseafloordepressionsformedduetofluidventing,is awell-known geological phenomenon that inseveral cases have proven to representgeohazards particular in relation to safety andcost implications for the integrity of seafloorconstructionsandpipelines.During theventing,fine-grained sediment is removed from theventing site leading to an excavation of theseafloor.

In this study, we present preliminaryobservations of 7 large-scale seafloordepressionsintheshallowwaters(<20m)ofthewesternLimfjord,Denmark.Thedepressionsaretentatively interpreted as pockmarks and havebeenmappedusinganewmultibeamandhigh-resolution2Dseismicsubbottomprofilersurveyand sediment cores acquired during theWesternLimfjord research expedition in May2017. The depressions are characterized by acomplex circular to elongated map viewmorphology, a width of 40-500 m, and typicaldepthsofca.3mwithverysteepsides(11°)andflattoruggedbottommorphologies.Intotal,thedepressionscoveranareaofroughly425.000m2and can be associated with the removal of ca.850.000m3of sediment,whichmayhave takenplace through violent fluid expulsions or slowseepage.

If the depressions are indeed pockmarks theywould represent a rare case of near-shorepockmarkswhich is very important to study inorder to constrain their formation, timing,duration and present-day activity and tounderstand their potential geohazard risk;

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particularlywhethersimilarstructuresmayforminthefuture.

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MorphologyofthesoutheastSkagerrak(Denmark)fromanewgeophysicaldataset

MatthewOwen1,ZyadAl-Hamdani1,JørnJensen1,JørgenLeth1,KatrineAndresen2andLasseEriksen21DepartmentofMarineGeology,GeologicalSurveyofDenmarkandGreenland,2DeparmentofGeoscience,AarhusUniversity

As part of the Danish marine habitat mappingprogramme an extensive geophysical datasetincludingmultibeambathymetry,sidescansonarand Innomar sub-bottom profiler has beenacquiredintheDanishSkagerrak.Approximately2200linekmofdatawereacquiredinanareaofapproximately 2600 km2, extending betweenSkagenintheeastandHirtshalsinthewestandfrom4mwaterto190minthedeeperSkagerraksome50kmnorthoftheDanishcoast.Thisnewdataset allows the first detailed morphologicalanalysis of this area and the first major studysincethemid-1990s.Anumberofmorphologicalfeatures are noted that both confirm previousobservationsandprovidenewinsights.Indeeperwater these include: outcropping strata in thewest, where the Jutland current erodes theseabed; sub-parallel wavy Innomar reflectorsindicatingcontouritedeposition;grooveserodedinto Holocene sequences, showing bottomcurrent pathways; a variety of depressionmorphologies coupled with a strong gas frontindicating gas release and pockmark formation.Where the gas is absent the Innomar signalprovides evidence of vertical chimneys andimagesreflectorspreviouslyassociatedwithlatePleistoceneice-proximalglacimarinedeposition:below a Holocene sequence tens of metres inthickness. Inshallowerwatersa largevarietyofbedforms, fromripplesto4mhighsandwaves,arepresentgivingstrongevidenceoftheacross-shelf sediment transport. These observations

havesignificantimplicationsforseabedhabitats,the carbon and sulphur cycle, as well as theregion’s glacial history, palaeoclimate andoceanography.

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BuriedValleysintheDanishCentralGraben

LasseKrogsgaardPrins1,KatrineJuulAndresen1andOleRønøClausen11SeisLabAarhus,DepartmentofGeoscience,AarhusUniversity

The Danish Central Graben has been subject toextensive seismic surveying (both 2D and 3D)duringthepastfourdecades.The3Dseismicdatahasmainlybeenusedforoilandgasexploration,butinthelastdecade,thesedatasetshaveprovenvery useful for investigating the Quaternarysediments and especially erosional channels.Geotechnical data such as CPTu logs havefurthermore proven very successful indetermining sediment types and byincorporatinggeotechnicaldatawecanoptimizeourgeologicalmodelsandcreateageotechnicalstratigraphy.Inthisstudy,wehaveutilizedboth3D and 2D high-resolution seismic data setstogether with geotechnical borehole data tointerpret theQuaternary landscapeevolution inthe Danish North Sea. The emphasis is on themorphology, infill and relative age of buriedQuaternaryvalleys.Wedescribe thedifferencesbetweentheseismicexpressionsofburiedrivervalleys and tunnel valleys.The present studycombines extensive mapping of these channelsfrom 3D seismic data with detailed seismicanalyses of high-resolution 2D seismic sitesurveysinordertovalidatethemappingfrom3Dtime-slice analyses. This gives us a betterunderstandingofthesedimentdistributioninthedifferent channels and their relative age. ThisstudyispartoftheDHRTC(DanishHydrocarbonResearchandTechnologyCentre)-fundedproject“SeismicAcousticMethods:Atoolforrefiningthe3Dgeotechnicalmodelsinamaturehydrocarbonproducingarea” inwhich thegoal is tocreatea

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geotechnicalstratigraphyfortheDanishCentralGraben.

15.4.Opensession

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EMODnetSeabedHabitat,anambitiousprojectformappingbenthichabitatsinEuropeanwaters.TheDanishcontribution.

ZyadAl-Hamdani1,NickyWitt1andMatthewOwen1GEUS

EMODnet (The European Marine ObservationandDataNetwork)isfundedbyDG-MAREandinits third phase is composed of eight thematic“Portals”aimingatproducingamulti-resolutionseabed digital map for the whole Europeanwaters that include bathymetry, geology,chemistry, biology, physics, human activities,seabedhabitatmappingand the recentlyaddedDataIngestionPortal.

The aim of the Seabed Habitat is to produce abroadscale seabedhabitatmapof allEuropeanwaters. A cost effective method to obtain fullspatial coverage seabed habitat maps usesenvironmental layers such as sediment types,bathymetry,photicdepthetc.,asproxytomodeltheseabedhabitatwasadopted.

In the Phase I seabed habitat maps wereproduced with 1km resolution, in Phase II theresolution was increased to 250m and in thecurrent Phase III the aim is to produce 100mresolution broad-scale habitat maps for allEuropeanwaters.Additionally,individualhabitatmaps from national surveys and point datasetsfrom national monitoring programs will becollatedandstandardised(INSPIRE),alsohabitatdistribution models. The final habitat map isconverted into EUNIS classification as thecommonclassifierforEuropeanwatershabitats.

To achieve thismember states need to provideavailableinformationgatheredthroughmappingendeavoursandpointsampling.

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DenmarkhascontributedinallEMODnetPhases.We present the latest habitat mapping projectperformedbyGEUS/OrbiconintheNorthSea.

ORAL

WhendidtheDanish/German/Swedishstraitsform?

OleBennike1,JørnBoJensen1andNielsNørgaard-Pedersen11GEUS

The timing of the formation of theDanish/German/Swedish straits and the firstmarine influence in the Baltic Basin has beenmuchdebated.HerewepresentnewradiocarbonagesfromsedimentcoresretrievedfromDanishwaters.Mostagesarebasedonshellsofmarinemolluscs, which means that the ages areuncertainbecausewedonotknowthereservoirage in the past. We use a reservoir age of 400years, which is based on dating of museumspecimens collected before testing of nuclearbombsstarter. It is clear from theages that theGreatBelt(Storebælt)wasinundatedbeforetheSound (Øresund). The oldest ages from thenorthern part of Great Belt are about 8700 cal.yearsBP.FromthecentralpartoftheGreatBelttheoldestagesareabout8100cal.yearsBPandin the south-western Baltic Basin ages variesfrom 7200 to 7600 cal. years BP. Sedimentsdeposited prior to the occurrence of marinemolluscs contain brackish-water ostracodes(Cyprideis torosa and Cytheromorpha fuscata);the sediments are usually laminated and non-bioturbated.Thebrackish-waterphasemayhavelasted500to1000years.

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EMODnetGeology–agatewaytomarinedatainEurope

JørgenO.Leth1,BjarniPjetursson1,MatthewJ.Owen1andZyadAl-Hamdani11GEUS

Rapidaccesstoreliableandaccurateinformationis vital in addressing threats to the marineenvironment, for developing policies andlegislation to protect vulnerable marine areasand in understanding trends and forecastingfuture changes such as the effects of climatechange.Theaccesstoaneffectivepan-Europeanmarine data infrastructure will also enableeffective and efficient marine spatial planningand legislation for environment, fisheries,transportanddefence.

The European Marine Observation and DataNetwork (EMODnet) is a network ofmore than160 organisations assembling marine data,productsandmetadata tomake the fragmentedresources more available to public and privateusers relying on quality-assured, standardisedand harmonised marine data, which areinteroperableandfreeofrestrictionsonuse.Allmarine data users including marine industries,decision-making bodies, scientific research andthe public in general, benefit from the overallphilosophy of the EMODnet data infrastructure“collect once and use many times”. GEUS hasbeen involved in EMODnet-Geology since thestartin2009.EMODnet-Geologyhassuccessfullycompiled harmonised offshore data across theEuropean seas including: sea-floor geology,seabed substrates, rates of coastline migration,geological events and probabilities andmineralresources. The products are available via theEMODnet Geology Portal. In its third phase(2017-2020),theexistingdataproductsisfurtherdeveloped with higher resolution (1:100.000)includingmorethematicthemessuchas,seabedgeomorphologyandQuaternaryandsubmergedlandscapes.Newservicesarebeingbuilt,sousersnowcaninvestigateandsearchforboreholedataand seismic survey data using interactivemapsandtools.

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16.Geomorphology16.1.RemoteSensing-Digitalmapping,remotesensingand3dmodelsinEarthScience

ORAL

The2017eruptionofErta‘Alevolcano,Ethiopia:acasestudyinmonitoringremotevolcanoeswithsatellites.

TalfanBarnie1,AshleyDavies2,GezahegnYirgu3,MooreChris4,SimonCarn5,DavidPieri2,CliveOppenheimer6,JulietBiggs7,TimWright4andAndyHooper41NordicVolcanologicalCenter,InstituteofEarthSciences,Reykjavik,Iceland,2JetPropulsionLaboratory-CaliforniaInstituteofTechnology,Pasadena,USA,3SchoolofEarthSciences,AddisAbabaUniversity,AddisAbaba,Ethiopia,4SchoolofEarthandEnvironment,UniversityofLeeds,Leeds,LS29JT,UK,5DepartmentofGeologicalandMiningEngineeringandSciences,MichiganTech,USA,6DepartmentofGeography,UniversityofCambridge,DowningPlace,Cambridge,CB23EN,UK,7SchoolofEarthSciences,UniversityofBristol,WillsMemorialBuilding,QueensRoad,Bristol,UK

Most volcanoes on Earth are not monitored bylocal sensor networks, but we can potentiallytrack all subaerial eruptions using spacebornesensors. Here we investigate the prolongedfissureeruptionofErta‘AlevolcanoinnorthernAfar,Ethiopia,whichbeganinJanuary2017.Weare unaware of any local installations ofmonitoring equipment despite the longevity oftheeruptionandthegeodynamicsignificanceofthevolcano,whichliesonanaxialvolcanicrangeof the Red Sea rift system. The volcano is ofparticularimportance,asoverthepast15yearsor so the behaviour of the lava lake(s) in thesummitcalderahaveapparentlytrackedorevenheraldedvolcanicandtectonicactivitywitnessedacrossthebroaderAfar-RedSearegionsincetheearly2000s.Usingasuiteofroutinely-,manually-andautomatically-commissionedsatellite image

acquisitions, we have been able to follow theeruption with high-temporal resolution. Inparticular,wehavebeenabletoreconstructtimeseries of gas and lava emissions, and grounddeformation.Wehavealsobeenabletodocumentvariation in activity at the lava lake itself,monitoring lava level and tracking individualoverflows on time scales of tens of minutes.Integratingobservationsofboththelavalakeandvent, which represent two windows into themagmatic system, provides an unusualopportunity to contains the behaviour of amagmaticsystemduringaneruption.

ORAL

A10-yearseriesofsurfacekinematicsofperiglacialsortedcirclesfromSfMclose-rangephotogrammetry

IvarBerthling1,LucGirod2,AndreasKääb2andRadmilPopovic11DepartmentofGeography,NorwegianUniversityofScienceandTechnology,2DepartmentofGeosciences,UniversityofOslo

Sorted circles are one type of periglacialpatterned ground, created by large-scalecryoturbationduetofreezingandthawingoftheactive layer. It is one of the most conspicuoustypes of patterns created by geomorphicprocessesontheearthsurface,andwidelyusedasanexampleofemergenceincomplexsystems.

Since2007wehaveattemptedtodocumentthespatial pattern of displacements going on insorted circles at 79°N on Kvadehuksletta, Ny-Ålesund, Svalbard using Structure-from-Motion(SfM) photogrammetry and feature-tracking.Published results (Kääb et al. 2014) show theapplicability of thismethod in terms of gaininghigh-resolution information on vertical andhorizontaldisplacementswithinthesortedcirclesystem. This presentation will document adecade of displacements within these sorted

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circles, but also comment on challenges andpossiblesolutionsfor long-termSfMmonitoringofsortedcircles.

During 2007 and 2010 campaigns,we acquiredtheimagesfromaportableladder.In2015,2016and 2017, images were shot from a cameraattachedtoalongpoleviaawificonnectiontothecamera. The design was set up to yield atheoretical resolution of the digital elevationmodelofaround1mm.

ORAL

Combinedvisualisationof3DoutcropandrelatedgeoscientificdatausingLIME

SimonJ.Buckley,KariRingdal,BoweiTong,BenjaminDolva,NicoleNaumann,TobiasH.Kurz

UniResearchCIPR,N-5020Bergen,Norway

Digital representation of the earth’s surfacetopography, using techniques such as digitalphotogrammetry, laser scanning and publiclyavailable digital elevation models, is nowcommonplace ingeologyandotherareasof thegeosciences.Highresolutionandaccuratesurfacemodelsaidquantitativemapping, interpretationandanalysis,actingasaframeworkforcompilingproject data. In addition to 3D modelling,complementary imaging techniques (e.g.multispectral, hyperspectral and thermalimaging) add colour and spectral informationthat can be used for interpretation of patterns,texture, object material properties anddistributions. Integrated 2D–3D analysis canprovide powerful synergy when applied toproblemsingeoscience.Furthermore,compiling3D spatial datasets with supplementary spatialandnon-spatialinformationinasinglegraphicalenvironment aids interpretation andcommunication of study data to students,collaboratorsandotherstakeholders.

Despite the current easeof acquiringdigital 3Dmodels, the increasing access to publiclyavailable data, and the wealth of disparate

ancillaryinformationsources,softwaretoolsforadvanced co-visualisation, interpretation anddata sharing are non-standard and rely oncustomsolutions fordifferentapplications.Asameansofaddressingthisimbalance,thecurrentcontribution presents LIME, a lightweight, highperformance software package for viewing andinteracting with 3D models and related spatialand non-spatial data sources. The softwarefocuses on the novel integration of a variety ofgeospatial and field data, such as 3D models,georeferenced images and maps, logs,interpretationpanels,andhyperspectralimages.Inaddition,measurementandinterpretationcanbecarriedoutbydigitisinginthe3Dscene.Akeycomponent is the generation of high qualityvisualproducts,suchasbyprojectingimageand3D data onto photorealisticmodels to generatenovel overlay layers. These features areexemplified through case studies inhyperspectral imaging, geophysical dataintegrationanddigitaloutcropmapping.

ORAL

Crystal-scalemagneticanomaliesrevealedbyscanningmagneticmicroscopy

NathanChurch1andSuzanneMcEnroe11NTNU,Trondheim,Norway

Scanningmagneticmicroscopy(SMM)mapsthemagnetic field generated by petrologic thinsectionsorpolishedrocksurfacesatthesub-mmscale, creating the possibility to resolve thecontribution of individual grains and mineralphases to bulkmagnetic signal. The instrumentdevelopedatNTNUhasthecapabilitytomeasureboth remanence properties and, uniquely, themagneticresponseinafieldofknownmagnitudeand direction. A series of case studies arepresented to examine the capabilities of themicroscope and to describe applications to thestudy of crustal magnetism. The use of well-characterizedsamplesallowssignalsinmagneticscans to be attributed to grains of known

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composition, including the discrimination ofsignal associated with discrete oxides andassemblagesofexsolvedoxidesinsilicates,whichcan be observed to have differing directions ofmagnetisation. The ability of this instrument toimage in fieldsmimicking those experienced inthe crust allows the observation of the inducedmagneticresponse,bothqualitativelyintheformof changes in magnetization direction, andquantitatively by varying experimentalconditions.ThiscapabilitygivesSMMtheabilitytomapbothremanent responseandgenerateamap of susceptibility, and provides a powerfulnew tool for the examination of bulk magneticresponseintheEarth’scrust.

ORAL

3DmodellingandvisualisingofresourcedepositsinNorwaywithUAVtechnologyand3DMOVE

IainHenderson1,MorganGanerød1,EspenTorgersen1andTomHeldal11GeologicalSurveyofNorway

ThisstudycombinesdetailedterrainmodelsandorthophotosofresourcedepositsinNorwaywithgeologicalinformationunderground.Theterrainmodels are constructed using photogrammetryfrom a DJI Phantom4 drone and Litchi MissionHub software. Individual flight plans areuploaded to the autonomously flying droneleading to better model construction andmoreefficient use of drone battery time. Point clouddata is uploaded to the Agisoft PhotoscanProfessional software, where the 3D meshrepresenting the ground surface is created andcontrol points are added. The resultantgeoreferencedmeshisexportedto3DMOVEandintegrated with underground geological data,producingafullyintegratedterrain-geological3Dmodel. We have constructed several, widelydifferent models: the Høgtuva Be-deposit iNordland, theKleivanslatemineinOppdal,andthe marble deposit at Fauske in collaborationwithNorwegianRoseAS.Anumberof valuableproductshavebeeendeveloped:Fulldigital3D-

models, volume calculations and mappedvolumes,contourmaps(depthtolayer/volume)andvolumethickness.Theseproductscontributetoabetterunderstandingofthegeology,amoreeffective running of the deposits and, not least,areattractiveproductsforfinancialcontributorsanddecisionmakers.Thisprojectisregardedasadevelopmentprojectwherewehavecreatedtheworkflow required from initial drone flightplanning,drone flying,pointcloudmanagementtomodelintegrationin3DMOVE.ThisprojectisaninitiativeoftheMineralResourcesDivisionattheGeologicalSurveyofNorwayincollaborationwithseveralNorwegianMiningcompaniesandispartlyfinancedbyMineralklyngenNorge.

ORAL

ASPECTspectralimagingCubeSatforplanetarystudies

TomasKohout1,AnttiNäsilä2,TuomasTikka3,MikaelGranvik4,AnttiKestilä5,AnttiPenttilä4,JanneKuhno3,KarriMuinonen4,KaiViherkanto2,EsaKallio5andJaanPraks51DepartmentofPhysics,UniversityofHelsinki/InstituteofGeology,TheCzechAcademyofSciences,2VTTTechnicalResearchCentreofFinland,3ReaktorSpaceLabLtd,Finland,4DepartmentofPhysics,UniversityofHelsinki,5DepartmentofElectronicsandNanoengineering,AaltoUniversity,Finland

ASPECT(AsteroidSpectralImagingMission)isa3U(30x10x10cm)CubeSatconceptdesignedfordeepspaceexplorationofsmallSolarSystembodies.ThepayloadofASPECTisaminiaturizedvisible - near infrared (500-2500 nm) spectralimager.TheprimaryscientifictaskofASPECTisorbitalhighresolutioncompositionalmappingofthe target surfacewith ameter resolution. Theobtained compositional maps can be used tostudyspaceweatheringandimpactprocesses,aswell as in evaluation of areas for subsequentsamplingorin-spaceresourceutilization(ISRU).ASPECTisproposedtobepartofEuropeanHERAmission to asteroid Didymos or Japanese MMXmissiontomartianmoonPhobos.

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ORAL

EnvironmentalmappingandmonitoringofIcelandbyremotesensing(EMMIRS)

GroB.M.Pedersen1,OlgaK.Vilmundardóttir2,FadiKizel3,NicolaFalco4,JoaquinM.C.Belart1,FriðþórS.Sigurmundsson5,GudrunGisladóttir5andJónAtliBenediktsson31InstituteofEarthSciences,UniversityofIceland,Sturlugata7,101Reykjavík,Iceland,2InstituteofLifeandEnvironmentalsciences,UniversityofIceland,3FacultyofElectricalandComputerEngineering,UniversityofIceland,4LawrenceBerkeleyNationalLaboratory,CA,USA,52InstituteofLifeandEnvironmentalsciences,UniversityofIceland

Iceland is exposed to rapid landscape changescaused by natural processes and man-madeactivities, which impact and challenge thecountry. Fast and reliable mapping andmonitoringtechniquesareneededonabigspatialscale. However, currently there is lack ofoperational advanced information processingtechniques, which are needed for end-users toincorporate remote sensing (RS) data frommultipledatasources.Hence,thefullpotentialofthe recent RS data explosion is not being fullyexploited.

The project Environmental Mapping andMonitoring of Iceland by Remote Sensing(EMMIRS) bridges the gap between advancedinformationprocessingcapabilitiesandend-usermapping of the Icelandic environment. This isdone by a multidisciplinary assessment of theHeklaarea,whichencompassmanyoftherapid

natural and man-made landscape changes thatIcelandisexposedto.

Anopen-accessbenchmarkrepositoryprovidinghigh-resolution LIDAR topography andhyperspectral data for land-cover and landformclassificationisunderconstruction.Furthermore,amulti-temporalarchivestretchingbackto1945allowsadecadalevaluationoflandscapechangesby the development of automated changedetectiontechniques.

The development of pattern recognition andmachine learning-based approaches to imageclassificationandchangedetection isoneof themain tasks of the EMMIRS project, aiming toextractandcomputeearthobservationvariablesas automatically as possible. Ground referencedata collected through a field campaignwill beusedtovalidatetheimplementedmethods,whichoutputs are then inferred with geological andvegetation models.Here, preliminary results ofan automatic land-cover classification based onhyperspectralimageanalysisarereported.

POSTER

SafeguardinglongrecordsofgeomorphologicalmeasurementsusingStructure-from-Motionfromground-basedimages

IvarBerthling1,BernardHallet2andRadmilPopovic11DepartmentofGeography,NorwegianUniversityofScienceandTechnology,2EarthandSpaceSciencesDepartment,UniversityofWashington

Modelling of the Earth System response toclimate change benefits from recordsdocumenting sub-system response acrossclimaticperturbations.FormanyoftheprocessesthattodayareincorporatedwithinanESM,wedonot have this advantage. One example iscryoturbation, the overturning of soil inpermafrost areas, suggested highly relevant forthe carbon budget. The process itself leaves noproxy records, except a mixture of soil organiccarbon of variable age beneath the ground

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surface, so recorded values of soil surfacedisplacements through time is needed for thispurpose.

During the 1980’ies, before the onset ofaccelerated climate warming in the Arctic,Bernard Hallet initiated measurements on thestone circles on Kvadehuksletta, Svalbard. Thestone circles are a remarkable example of theeffects of large-scale cryoturbation. Althoughthese measurements are not continuous, theinstallations are partly still in place. Theywerere-measured in 2010, 2015, 2016 and again inSeptember 2017. The purpose of thispresentation is to document our work onsafeguarding the remains of these installations,and to transform the methodology usingStructure-from-Motion from ground-basedimages, to enable continuing thesemeasurements into the future. Our goal is todocument how ground surfacemovements andcryoturbation have responded to the amplifiedeffectsofglobalwarmingathighlatitudes,andtounderstandthisresponse.

POSTER

UAVtopographicsurveyofamigratingdune–pitfallsandfirstresults(Sylt,southernNorthSea)

BenjaminEberhardt1andSebastianLindhorst11UniversityofHamburg,InstituteforGeology,Bundesstr.55,20146Hamburg,Germany

High resolution topographic information isinstrumental in analyzing sand transportprocesses on active coastal dunes. Unmannedaerialvehicles(UAV)greatlyfacilitatetheon-sitecollection of aerial images and structure-from-motion (SfM) algorithms allow producingdetailed topographic models from UAV-basedphotogrammetric surveys. First results from aSfM case study from an active (but partlyvegetated)migratingdune(duneheightupto30m) are presented including survey design,georeferencing issues and applied dataprocessingsteps.Aimofthisstudyistotesttheapplicability of UAV-based topographic surveys

to quantify sand transport volume along theslipfaceofthedune.Themodelcomprises2500images with a resulting ground-samplingdistanceof1.67cm/pixeloveranareaof550x530 m. Special attention is given to theidentification of artifacts caused by the lessstructured,uniformsandareas.

POSTER

UAVphotogrammetrytomonitorstabilityofrockclimbingsites

AxelHellman1,MarkD.Johnson1andAnneHormes21DepartmentofEarthSciences,UniversityofGothenburg,2InstituteofGeology,TheArcticUniversityofNorway,Tromsø

Monitoringofsteeprockfacesanddocumentingtheirgeostructuralcharactertoevaluatestabilityisadifficulttaskfromthebottomofasteeprockface.Unmannedaerialvehicle(UAV)sensorsandtechnologyhaveseenarapiddevelopmentoverthelastfiveyears.Theycanenablesurveyingandmonitoring of rock-slope failures and detachedblocks in areas previously inaccessible andhazardous(Boccalietal.,2017).Forthisproject,we study two frequently visited rock-climbingcrags in Sweden and Austria, both withdocumented rock-fall activity. In Sweden, arecentrock-falldestroyedawell-knownclimbingroute in Fjällbo, Gothenburg. In Austria,Engelswand is a very popular climbing crag inÖtztal, where we counted 70 climbers on oneSaturday,withreoccurringsmallerrock-fallsandoccasionallylargerblocksoccurringinthespringduringthemeltingperiod.

Our study explores the accuracy of UAVphotogrammetry for the analysis of rock-fallhazards.InAustria,wetestedaroughacquisitionworkflow deploying handhold GPS points asground control points together with aerialimageryandtelemetrydata.Weaimtocomparetheaccuracyofthisquickmethodwiththemoreresource and cost-inefficientmethod of using a

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differential GPS and triangulation points toacquireahighprecisionofgroundcontrolpoints.

The UAV imagery is processed in differentsoftware packages for compilation andcomparison of accuracy. 3D models, digitalterrain models (DTMs) and point clouds areproducedandwillbeusedforkinematicanalysis.Preliminary 3D model results suggest that therough workflow provide accurate and detailedoutputs.

POSTER

ClassificationofblockfieldsinNorwayusingMachineLearning

MadsNedergaardPaulsen1andDavidLundbekEgholm21Aarhusuniversitet,2AarhusUniversitet

TheoriginofScandinavia’sextensiveblockfieldshasbeenasubjectofdebateforsometime.Onehypothesissuggests that theblock fieldsmainlyformed by pre-Quaternary warm-climatechemicalweathering(Paascheetal2006),whileanother hypothesis uses Late-Cenozoic cold-climate physical weathering mechanisms toexplain the block fields through long-termperiglaciallandscapeevolution(Goodfellowetal.2014, Egholm et al. 2015). Several field studieshavemappedtheextentofselectedblockfieldsinScandinavia, but the full distribution of blockfieldshasnotyetbeenstudied.

In this master-degree study, we aim to useMachine Learning to map the distribution ofblock fields in Scandinavia. The vast amount ofpublicavailableLIDARdataprovidesuswiththeopportunitytostudydistributionsof landforms,e.g. along climatic gradients set by latitude orelevation. However, the shear data volume andtheneedforconsistentobjectivemappingcallforautomatic classification methods based ontopographic features such as elevation, surfaceslope,curvature,androughness.Wediscusstheapplicability of selected Machine Learningalgorithms, such as k-means clustering, SVM,boosting gradient and Neural Networks, we

evaluate pros and cons of the differentalgorithms.

16.2.Holocenecoastalmorpho-sedimentarysystems:Archives,processesandforcingmechanisms

ORAL

Didcuspateforelandformationtriggerlarge-scalebarriercoastretreat?

MikkelFruergaard1,LasseSander2,JérômeGoslin1,ThorbjørnJoestAndersen1,PeterJohannessen3,LarsHenrikNielsen4andMortenPejrup11DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,2Alfred-Wegener-Institute,3GeologicalSurveyofDenmarkandGreenland,4GeologicalSurveyofDenmarkandGreenland(GEUS)

Thestratigraphicevolutionofbarriersystemsiscontrolledbytheratiobetweenrateofsea-levelrise and rate of sediment supply from externalsources. Because of increasing coastal erosionand flood risk caused by the global rising sealevel,many studiesonbarrier systemevolutionarefocusedonunderstandingtheimpactsofsea-levelchangesdespitechangesinsedimentsupplyare equally important controlling coastalevolution. In this study we investigate howchangesinsedimentsupplyinfluencedthelarge-scalecoastalevolutionoftheDanishWaddenSeabarriercoast.Thiscoast iswave-dominatedandangular wave approach generates a largesouthward-directed littoral drift. The Wadden

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SeaisboundedtowardsthenorthbythecuspateforelandofBlåvandsHukandtheshallowmarineshoal of Ulven. Based on detailedsedimentological and chronologicalinvestigations of ~60 km barrier coast wepresent several stratigraphic evidences that thecoast experienced region-wide flooding andcoastal erosion between 4500 and 1400 yearsago. New chronological data suggest thatcoinciding with the flooding and erosion,sedimentaccumulationandaccretiontookplaceintheareadirectlynorthoftheDanishWaddenSea.WesuggestthattheretreatofthecoastwasrelatedtotheconstructionofcuspateforelandofBlåvands Huk that largely trapped the littoraldriftfromthenorth,preventingthesandreachingthe Wadden Sea coast and thus shifted thedepositional locusnorthward from theWaddenSea. The study indicates how sediment supplyand large-scale morphology of the coast cancontrolcoastalevolution.

ORAL

High-resolutionHolocenewindinessandstorminessovertheNorthSea:insightsfromFilsølake,WesternDenmark.

JérômeGoslin1,LarsB.Clemmensen1,MikkelFruergaard1andLasseSander21InstituteforGeosciencesandNaturalResourcesManagement-UniversityOfCopenhagen,2AlfredWegenerInstitute-Sylt

Possessing long and accurate archives of paststorm events is one key towards a betterunderstanding of the atmospheric patternsdriving these latter and of how coastal systemsreacted in the past to changing forcingmechanisms. During the last decade, severalHolocene storminess chronologies have beenbasedonaeolianinfluxeswithincoastallakesandmires (e.g. Björck and Clemmensen, 2004; DeJong et al., 2006; Nielsen et al.; 2016; Orme etal.,2016).

This study presents a high-resolution (pluri-annual)historyofHolocenepastwindinessand

storminess over the North Sea reconstructedfrom a coastal lake of Western Denmark. Pastaeolianactivityandstorminessarereconstructedusing aeolian sand inputs preservedwithin theorganic-richlakesediments.

Ourdatademonstratehigh-frequencyvariationsofaeoliansandinfluxbetweenca.5000and2200yrs B.P. that we believe adequately reflect thechanges in past wind-climate and storminess.Impressivelycyclicpluridecadal-scale“breathingpatterns” in storminess activity are observedbetweenca.5000and4300yearsB.P.Amassivesandinvasionisthenobservedaround4300yrsB.P., inaccordancewith the firstperiodofdunebuilding obsreved along the west coasts ofDenmark (Clemmensen et al., 2001; 2009) andsimultaneousltoaperiodofclimatedeteriorationwidely recognized elsewhere in Europe andglobally. The signal then progressively slowlyfades-out, most probably reflecting coastalprogradationanddunefixation.

These resultswill allowus to discuss potentialinternal and external climate forcingmechanisms, as well as to question theinterdependencies between aeolian activity,sedimentarydynamicsandrelativesea-level.

ORAL

DetaileddynamicdevelopmentandsedimentaryarchitectureofaHolocenetoRecentmicro-tidalbarrier-island,DanishWaddenSea.

PeterNielsJohannessen1,MikkelFruergaard2,LarsHenrikNielsen1,LarsNielsen2,IngeliseMøller1,ThorbjørnJoestAndersen2,StefanPiasecki1andMortenPejrup21GeologicalSurveyofDenmarkandGreenland(GEUS),2DepartmentofGeosciencesandNaturalResourceManagement

TheRømøbarrier-islandis14kmlong,4kmwideand theHolocene deposits c. 15m thick. It is averysand-richsystemasitreceivescoastaldrift

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sandfromnorthandsouthalongtheshoreface.Itis separated fromthemainlandbya8kmwidelagoon. Average tidal range is around 1.8 m.During strong westerly storms, the water levelincreases considerably, up to 5 m above meansea-level.

Thebarrier-islandformationstarted forc.8000yearsagoandisstillactive,whichallowsdetailedstudies on recent sedimentary processes.Stackinggeometriesofdifferentsandunitshavebeen unraveled based on: Seven c. 25 m longsedimentcores,35kmgroundpenetratingradar(GPR) reflection profiles, and dating of 70 coresamplesusingopticallystimulatedluminescence(OSL) providing a unique stratigraphicframework.

Due to the detailed knowledge of thestratigraphic framework, depositionalenvironmentsandpreciseages,adetailedpalaeo-geographic reconstruction of theRømøbarrier-island has been carried out. The barrier-islandinitiatedasa short andnarrow island.The first5000 years the barrier island sand aggradedbecause sedimentation kept pace with therelative sea-level rise. The last 3000 years thebarrier-islandprogradedseawards,astherateofrelative sea level rise decreased. Thisaggradational-progradational development hasresultedinathickandbroadreservoirsandbody.

Thisstudyshowsthatifthereisasurplusofsand,abarrier islandcanaggradeandevenprogradeduring a sea-level rise, creating thick barrier-islanddeposits.

ORAL

Wasthe4thlargestDanishLake(Mossø)oncemuchlarger?

SørenM.Kristiansen1,NielsEmilSøe1,AartKroon2,AndersVestChristiansen1andBentVadOdgaard11DepartmentofGeoscience,AarhusUniversity,Denmark,2UniversityofCopenhagen,DepartmentofGeosciencesandNaturalResourceManagement,Denmark

Waterlevelsoffreshwaterlakescanlowerduringthe course of an interglacial and sedimentationcan infill basins. Besides, wave actions developspit systems in larger lakes by longshoresediment transport that may cuts of smallerbasins. Here, we show combined effects of spitdevelopment, wave actions, antecedenttopography and lake level changes on theHolocenedevelopmentofthepresent-dayDanishlake, Mossø. A variety of methods were used:coring, intensive profile digging and remotesensing, geophysical mapping by seismicreflection and electromagnetic induction, anddating by radiocarbon and optically stimulatedluminescence.WefindthatMossøhasundergonewater level changes of perhaps 6 m and shoreerosion has varied accordingly. The sedimentsupplyforspitformationdependedofthevigoroferosion, onwinddirection and strength andonbuildingupof theplatform in frontof thespits.Strong spit activity was identified during threeperiods: c. 10 ka, 4.2 ka and 2.5-2.0 ka. Thelocation of spit formation was determined bychanges in lake level and also local bathymetryand sediment transport patterns. Two spitsconnectedandwerereinforcedbyabeachbarrierby2.5ka,todayconstitutingtheeasternshorelineof present-day Lake Mossø. The data suggestspresenceofanearlyHolocene largepalaeo-lakeMossøwith a 25 km east-west extent from thepresent-day lakes Skanderborg Sø to SaltenLangsø.Confirmationofthispaleo-lakerequiresmore investigations, as later erosions at thethresholds that connectsMossø to the adjacentlakes,andtoriverGudenå,remainsuncertain.

ORAL

Theoccurrenceandformationofwash-overdepositsalongtheshoresoftheinnerDanishWaters

AartKroon1,LarsClemmensen1andVernerB.Ernstsen11DepartmentofGeosciencesandNaturalResourceManagementUniversityofCopenhagen,Denmark

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Wash-over deposits occur along many beachesfringingtheinnerDanishWaters.TheyareoftenlocatedontheHolocenebarrierislandsandspitsand they are important accumulative featureswitharelativelyhighpreservationpotential.Thebarrier islands and spits are formed byalongshore driven wave-induced currents andthey partly get their sediments from adjacenteroding glacial cliffs. Wash-over fans are oftenpresentatthelandwardsideofthebarrierorspitcrestandtheyareformedduringstormsunderacombination of high water levels and onshoredirected high waves. The high water levels arehowever not always caused by wind set-upduring storms in the inner Danish waters. Thejointprobabilityofwaterlevelsandwavesshowsthat under 30% of the high water levels havelarge waves. This means that the frequency ofoccurrence of wash-over fan events is far lessthanextremewaterlevelstatisticswouldsuggest.Inthepresentpaper,wewilladdressthespatialoccurrenceofdifferenttypesofrecentwash-overfans ineastDenmarkusingsatellite imagesandlidarobservations.Wewillalsoshowthedrivingforcesbehindwash-overfanformationandshowthe frequency of occurrence of these drivingforces.

ORAL

Polargravelbeach-ridgesystems–sedimentaryarchitectureanduseasclimatearchive(SouthShetlandIslands,Antarctica)

SebastianLindhorst11UniversityofHamburg,InstituteforGeology,Bundesstr.55,20146Hamburg,Germany

The sedimentary architecture of polar gravel-beach ridges is presented and it is shown thatridge internal geometries reflect past wave-climateconditions.

Ground-penetrating radar (GPR) data obtainedalong the coasts of King George Island (SouthShetland Islands, Western Antarctic Peninsula)show that beach ridges unconformably overlie

seaward-dipping strata of the strand plain.Whereas strand-plain progradation isinterpreted to result from swash sedimentationatthebeachfaceunderenduringcalmconditions,ridgeconstructionreflectsenhancedwaveactionat the beach due to elevated storminess orreduced nearshore sea ice. The internalsedimentary architecture of individual beachridges is interpreted to reflectmaximumwave-runup height during the time of ridgeconstruction. Ridges at sheltered parts of thecoast exhibit either seaward-dipping beds,interpreted to result from swash deposition, oranaggradationalstackingpatternbeingtheresultofwaveovertopping.Atexposedbeaches,largerridgesdevelopcomposedofseaward-aswellaslandward-dipping beds. Development ofindividual beach ridges is seen to result frommultiplestormsratherthansingleevents.

The number of individual ridges which arepreservedfromagiventimeintervalvariesalongthe coast depending on the morphodynamicsetting: Sheltered coasts are characterized bynumeroussmallridges,whereasfewerbutlargerridgesdeveloponexposedbeaches.

Data show that even ridges at higher elevationcan be subject to later reactivation andreworking. This questions sea-levelreconstructionsbasedsolelyonmorphologyanddating of polar beach ridges and advise carefulinvestigation of the stratigraphic architecturepriortosamplingfordatingpurposes.

POSTER

StratigraphyandsedimentaryarchitectureofpolderfillsalongtheNorthFrisianWaddenSea(southernNorthSea)–potentialarchivesofsea-levelandclimatevariability(projectSEASTORM)

AmalieCordua1,SebastianLindhorst1andChristianBetzler11UniversityofHamburg,InstituteforGeology,Bundesstr.55,20146Hamburg,Germany

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During thepastmillenniumtheNorthSeacoastwasalteredbysea-levelandclimatefluctuationsas well as by the onset of human landreclamation.Polders,areasembankedalong thecoast during the last millennium, bear uniquesedimentaryarchivesofcoastalevolutionduringdifferenttimeintervals.Thesearchivesaresofarunread.

AsafirstresultoftheongoingprojectSEASTORM,stratigraphy and sedimentary architecture ofselected polders on the German Eiderstedtpeninsulaarepresented.Thepeninsulahasbeenshaped by land reclamation since the 10thcentury,andsincethe12thcenturythehistoryofpolder embankment is documented. Thesedimentary successions were investigated onthebasisofasedimentologicaldataset(grainsize,XRF, core description, X-radiographic images,and radiocarbon ages); depositional geometrieswere imaged by means of ground-penetratingradar. A LIDAR-based high-resolution digitalterrain model allows for geomorphologicalinvestigations.

The sedimentary succession preserved in thepolders documents the complex geologicalevolutionoftheareacomprisingmultiplephasesof salt-marsh growth, re-flooding and erosion.Correlation of sedimentary successions indifferentpoldersaimsonovercominglocal-scaleeffects to reconstruct changes in sea level andclimateoscillations.

POSTER

ChronologyandlateHoloceneevolutionofCaletadelosLoros,NEPatagonia,Argentina

LasseSander1,MortenPejrup2,AndrewSeanMurray3,GerardoM.E.Perillo4,LuísAriélRaniolo4andMikkelFruergaard21Alfred-Wegener-Institute,List/Sylt,Germany,2UniversityofCopenhagen,Copenhagen,Denmark,3NordicLaboratoryforLuminescenceDating,UniversityofAarhus,Denma,4InstitutoArgentinodeOceanografia,BahíaBlanca,Argentina

CaletadelosLorosisacoupledbeachridgeandtidallagoonsystemlocatedonthenorthernshoreof San Matías Gulf, Patagonia, Argentina. Thestudyisbasedonremotelysenseddata,sedimentcores and a comprehensive dataset of agesdetermined using optically stimulatedluminescence(OSL).Wepresentobservationsonthe geomorphology, sedimentology andchronology of the field site and proposeinferencesonthedriversbehinditslateHoloceneevolution. Caleta de los Loros is located in atopographical depression within a cliffedshoreline composed of friable sand and gravelstones. The oldestmarine deposits of Holoceneage formed in the inner part of the depressionaround2300 yr ago. Between1000 and500 yrago,anupto4kmwidestrandplainformedintheexposed southern part of the system. The tidallagoon subsequently experienced a period ofincreasedsedimentationbetween500and100yrago. The system is hence much younger thansimilar coastal environments in Patagonia andshows no apparent relation to changes in therates ofmid- to late Holocene sea level change(Schellmann&Radtke,2010).However,stagesinthe morphosedimentary evolution of Caleta delosLorosareconcurrentwithproposedchangesin humidity and wind regime for northernPatagonia as well as with changes in humanoccupation and subsistence strategy (Favier-Dubois and Kokot, 2011; Marcos et al., 2012).CaletadelosLorospresentsanewexampleofthepotential importance of sensible environmentalchanges for the rapid and non-lineardevelopmentofcoastalsystems.

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16.3.LidarinGeomorphology

ORAL

Mappingmorphologyandvegetationinshallowwaterusingtopobathymetriclidar

MikkelS.Andersen1,ZyadAl-Hamdani2,LauridsR.Larsen3,FrankSteinbacher4,RamonaBaran4,BjørnM.Torsvik5andVernerB.Ernstsen51NIRASA/S,Denmark&Dept.ofGeosciencesandNaturalResourceManagement,Uni.ofCopenhagen,DK,2GeologicalSurveyofDenmarkandGreenland(GEUS),Denmark,3NIRASA/S,4AirborneHydroMappingGmbH,Austria,5DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,Denmark

Thecoastalzoneisunderpressurefromhumanexploitationandclimatechange,whichleadstoaneedforsustainablecoastalzonemanagement–a challenge which requires high resolutionmappingandmonitoring.Historically, therehasbeen a gap of information in shallow water,however, the emerging technology of airbornetopobathymetric lidar has proven capable ofsimultaneously capturing topographic andbathymetricelevationinformation,resultinginaseamless coverage of the land-water transitionzone. The new technology also provides apotential for detailed identification andclassification of shallow water morphologicalunits and vegetation – which was previouslyimpossible tomap, or at best itwasmapped in

very lowdetail. The aimof the studywas to 1)develop a procedure for processingtopobathymetriclidardataandgeneratingDigitalElevation Models (DEMs) in coastal zones, 2)automaticallyclassifymorphologicalunits,and3)investigate the potential of mapping shallowwater vegetation. We show results from twolocationswith different environmental settings:the Knudedyb tidal inlet system in the DanishWadden Sea and Rødsand lagune in the innerDanishwaters.

ORAL

MorphologicmappingandmonitoringofsedimenttransportusinghighresolutiontopobathymetricLidarinmanifoldgeomorphicsettings:ExamplesfromIsarriverinMunichandWaddenSeainDenmark

RamonaBaran1,FrankSteinbacher1,WolfgangDobler1,MikkelS.Andersen2,LauridsR.Larsen2andVernerB.Ernstsen31AirborneHydroMappingGmbH,Innsbruck,Austria,2NIRAS,Allerød,Denmark,3DepartmentofGeosciencesandNaturalResourceManagement,UniversityofCopenhagen,Denmark

Fluvial and coastal/tidal environments arevaluable ecosystems under pressure due toglobalization and/or climate change. Theirdetailed mapping is required to manage rivercourses and coastal zones in a sustainableway.Traditionally, thetransitionzonesbetweenlandandwaterweredifficultorimpossibletomapandinvestigate in high spatial resolution due tochallenging environmental conditions. The newgeneration of airborne topobathymetric LiDARpotentially enables full-coverage and high-resolution mapping of land-water transitionzones.Repeatedsurveysprovidetheopportunityfor geomorphologic mapping, monitoring andquantifying fluvial and coastal sediment-

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transport. We first present results from tworepeatedtopobathymetricsurveysalongtheIsarriver inMunich, Germany, to quantify andmapriver-bed changes related to a large flood (June2013). We evaluated river-bed elevationdifferencesbetween thesurveybefore (October2011) and after (July 2013) the flood yieldingelevation differences of several decimeters tometersduetoerosionandsedimentationofbed-material. The detailed analysis provides newpossibilities to better manage inner-city riverstructures and support future planning onrestorationalongtheIsarriver.Inasecondstudy,we performed a topobathymetric LiDAR surveyintheKnudedybtidalinlet-systemintheDanishWaddenSea(April-May2014).Thisdatasetwasused for detailed geomorphic analysis on theintertidal drainage-network and bedforms, andwas further compared to a topographic LiDARsurvey (2011) to evaluate and quantifymorphodynamics, e.g. sediment-transportdirections. Our results demonstrate that highresolutiontopobathymetricLiDARisanefficient,widely applicable tool to monitor andmeasurefluvial and coastal sediment-transport andgeomorphicprocesses.

ORAL

ActiverockglaciersatsealevelinFinnmark,NorthernNorway?

KarianneLilleøren1,VetleAune1,BerndEtzelmüller1andTrondEiken11DepartmentofGeosciences,UniversityofOslo

Rockglaciersaregeomorphologicalexpressionsof permafrost presence. Their state of activityindicates occurrence of current or formerpermafrost.Aseriesofrockglaciersemergingatsea level have been identified inNordkinnhalvøya, Northern Norway, and haveearlier been classified as relict landforms(Lilleøren & Etzelmüller, 2011). However, arecently published permafrost model of theNordic countries (Gisnås et al., 2016) simulatespermafrost at similar elevations elsewhere inFinnmark,butmainlyinmiresaspalsas.

Wehavenowsurveyedoneoftheserockglaciers,situatedinIvarsfjord,byrepeateddroneimagery(2016-2017) and Terrestrial Laser Scanning(2017). Digital elevation models (DEMs) werecompiledfromaerialphotosfrom1975,1982and1992, and a network of miniature data loggerswas employed over the rock glacier surface toevaluate near surface temperatures. Two shortERT(ElectricalResistivityTomography)profileswereestablishedfromthetoptothefrontslopeoftherockglacier.

Our first results indicate both thermokarstdevelopment and front position advances since1975.Thisimpliesthattherockglacierisactive,but currently degrading. The ground surfacetemperature network indicates above 0˚Ctemperatures as an annualmean.We thereforebelieve that permafrost can be present even atcoastal sites in Finnmark in special settings,indicatingsporadic(palsas)tomorewide-spread(rock glaciers) permafrost, but in a state ofdegradationatpresent.

With large-scale permafrost thaw occurring intheArctic at present, this area could serve as atime-space substitute of High-Arctic landscapeslikeSvalbardorSiberiainachangingclimate.

ORAL

BetterVisualisationofAir-borneLaserScanningforgeomorphologicalandarchaeologicalinterpretation

ThomasLjungberg1,DavidStott2andSørenMunchKristiansen11InstitutforGeoscience,AarhusUniversitet.,2InstitutforGeoscience,AarhusUniversitet;ArkæologiskIT,MoesgaardMuseum.

Digital elevation models derived from high-precision Air-borne Laser Scanning (ALS orLiDAR) point clouds are becoming increasinglyavailable throughout theworld.Theseelevationmodelspresentsaveryvaluabletoolforlocatingand interpreting geomorphological as well asarchaeological features in the landscape. Theelevation models are, however, not always

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directly useable, because the variations inelevation in the models often are orders ofmagnitude larger than the features of interest,which makes these hard to see. It is thereforeusually necessary, and always advisable, toenhance (transform, improve, manipulate) thevisualappearanceoftheelevationmodel,sothatthefeaturesofinterestaremoreclearlyshown.Inthis paper,wediscuss theusefulness of severaladvanced visualisation techniques for locatingand interpreting a.o. fossil beach ridges, paleo-lake shorelines, sub-glacial meltwater courses,Iron Age Celtic field boundaries, and variousother geological and archaeological phenomenaunderDanishconditions.

POSTER

EcoMapProject:BalticSeaenvironmentalassessmentsbyinnovativeopto-acousticremotesensing,mapping,andmonitoring.

SigneSchilling1,ZyadAl-Hamdani2,VernerErnstsen1,JørnBoJensen2,AartKroon1andJensSchneidervonDeimling31IGN/KU,2GEUS,3UniversityofKiel

Remotesensingandclassificationoftheseafloorarerequiredtoobtainacomprehensiveviewonthemarineenvironment. It allows foranalysingspatio-temporaldynamics,monitoringofnaturalseabed variations, and evaluating possibleanthropogenic impacts, all being crucial inimplementing marine spatial planning forsustainable use of the sea that leads to theeconomicgrowthoftheregion.

The EcoMap project will develop a remotesensingcataloguedocumentingthefeasibilityoflatestopto-acousticmethodsforimprovedBalticSea habitat monitoring. This catalogue will bedevelopedincloseco-operationwithauthoritiesto meet their requirements and will allowstakeholders with different interests to quicklyjudge which remote sensing method is ideallysuitedforrespectivemonitoringtasksofspecifichabitats.EcoMapcommencedinSeptember2017

andwillcontinue for threeyears.Theproject ispart of the BONUS Programme, co-funded bynational research funding agencies of the threeproject partner countries Germany, Poland andDenmark..

16.4.OpensessioninGeomorphology

POSTER

LandslidesinnorthwestIran:acasestudyonthelandslidehazardzonationinBaleghluchaiwatershedinArdabilusingAHPFuzzymethod

KeristinehJananeh1andShahramRoostai11GeographyDepartment,UniversityofTabriz,Tabriz,Iran

Landslidesandslopeinstabilitiesareamongtheimportant natural hazards, which cause humanand financial casualties and loss of economicresources every year. The northwest of Iran isprone to theoccurrenceof landslidesdue to itsmainly mountainous topography, complexgeology, abundance of tectonic activities andearthquakesandvariableclimate.Thesehazardsmostly occur in natural slopes or thosemanipulated by human. This contributionincludes a case studyon the landslidepotentialzonation within the Baleghluchai watershed inNW Iran. First, the main factors including theslope and its direction, geology, soil, climate,distancefromtheroadandriverandlandusagewere determined. The method of currentinvestigation was Fuzzy AHP in the GISenvironment, based on which, after preparingdata layers using the above-mentionedparametersandgivingweightstothemintheGIS

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environment,thelandslidepotentialmap,aswellas classification was carried out by Fuzzy AHPmethod.

According to the final zonation map, thewatershed was divided into 5 classes. Resultsshowed that the largest part of the watershed(32.21%)haslowlandslidepotential,whileabout13.5% of it has very high potential. Areaswithvery high and high landslide potential (327.39km2area)aremainlylocatedinthenorthwestofthewatershed,withsomesmallareasdistributedinthesouthandeast,whileareaswithverylowandlowpotential(504.06km2)aremainlyfoundinthecentraltonorthwesternandsouthernpartsofthewatershed.

17.Education,preservationandoutreach17.1.Education,communication,preservationandGeoheritage

ORAL

GeologyDayinSweden,lessonsfrom17years

NellyAroka11GeologicalSurveyofSweden

GeologyDayisaSwedishnon-profitorganization.Our aim is to spark curiosity among the publicandtohighlightthebenefitsofbasicknowledgeof geology and earth sciences to society. Everyyearsince2001ourorganizersinvitethepublicto take part in a nationwide celebration ofgeologyinSeptember.Atthe17yearmarkweaskourselves;what havewe learned,what are ourchallenges andhowdowe continueworking topromoteearthsciencesthroughouttheyear?

ORAL

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Challangesinconveyinggeologytosociety.-ExamplesfromDanishlandscapestracedbyaNorwegiangeologist,inordertocreatecuriosityforgeologyandexplaingeologicalprocesses.

ThorbjørnKaland11UniversityofBergen

Thoughschoolsatalllevelsareteachinggeologyand science, we are facing frequent lacks ofknowledgeleadingtomisunderstandingofbasicgeology.

Teachers,journalists,bureaucratsandpoliticiansmayneedtoupgradeknowledgeingeology.

Geologistsneedtomeetthechallengeandsharetheirinterestsforearthscience.

Buthow?

The best way of making people search for theanswersofeverything’sgenesis, is to take themoutoftheirrooms,andrediscovernature.

ScandinavianandGermantouristsdrivethroughDenmark to see everything, - but geology. TheydisregardthemostbeautifuljewelsofDenmark.

Mostsiteshavegotageologicalstorytotell.

Howmaywemakethe localsocietyunderstandtheirlocallandscape?Newvisualtoolsmaybringbacktheicecapwithitsdrainandmovement.

How may social media tell more than anygeologist?

Trolltunga is a cliff in Western Norway, lyinglonelyfor10.000years.

Aftera few foreignhikersdropped into the siteandpostedtheirpictureonFacebook,Trolltunga=Norway.Yearlymorethan100.000hikerswalkthe9hourmountainwalk to take theirselfieatTrolltunga.

Thisstoryrevealssomeinterestingchallenges:

-Wheredowefind“Trolltungs”?

-Dowe reallywant to share themwith therestoftheworld?

-Howcanlocalcommunitybenefitthesite?

-Howmaywe plan formassive traffic in asustainableway?

The presentation will show examples fromDanish landscapes,withtheobjectivestocreatecuriosityforgeologyandgeologicalprocesses.

ORAL

Whatdoweactuallyteachstudentsinthefield?

RieHjørnegaardMalm11UniversityofOslo

Fieldwork has a central position in thegeosciencesandistypicallyanintegratedpartofthestudyprogramme,whereitisconsideredbymanyasacrucialpartofthelearningprocessandlinkedtotheprocessofbecomingaprofessionalgeoscientist (King, 2008; Raab & Frodeman,2002).Fieldwork issuggestedtobeaneffectivelearningarenatoteachthescientificmethodandreasoning(Mogk&Goodwin,2012).Educationalresearchshowsgreatopportunitiesforlearning,but how dowe knowwhat the students learn?Andhowdoesourteachinginthefieldaffectthestudents’opportunitiestolearn?

InthispieceofresearchIfollowstudentscloselyinthefieldandexplorehowandwhattheylearn.Byseeingteachingfromthestudents’perspectiveIamabletoshowindetailhowtheorganizationof teaching has an influence on the learningpotentialsforthestudents.

When the students are given the freedom toexplore and collect data on their own theyexperiencealearningsituationthatsimulatesanauthentic research situation. In this process itprovestobecrucialthatthestudentsareallowed

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tomakemistakesandaregivenenough time todiscuss their data collection. If we only showstudentshowtoworkinthefieldgreatlearningopportunitiesarelost.Ipresentresultsfrommyresearch on students working in the field inmainlandNorway,Svalbard,theOrkneyIslands,and the Spanish Pyrenees and discuss how wecanconstructteachinginthefieldthatpromoteslearning.

ORAL

GeneralizedbedrockmapofFinlandandrelatedmaterial

PerttuMikkola11GeologicalSurveyofFinland

In most countries the laymen’s typically havelimitedunderstandingofgeologicalconceptsandprocesses.Reasonsbehindthisaremultiple,butone recognised factor, at least inFinland, is thelack of suitable teachingmaterial that could beusedinelementaryandhighschools.Toanswerthis need Geological Survey of Finland (GTK)producedin2016ageneralised1:1000000scalebedrock map (Mikkola et al. 2016), which isbasedonthesamedatabaseasthe”professional”version compiled by Nironen et al. (2016). Thegeneralisation was done in association withgeography teachers to ensure that for exampleterminology used is understood by the targetgroup. Although themap is available as a printready pdf-file, the most important distributionchannel isanonlinemapservice. Inthisserviceusercanopenshortinformationboxesbyclickingonthemapobjects.Theseincludeforexampletheageoftheformation,itsdistributioninFinland,inwhatkindofenvironment itwasgeneratedandoneortwophotosofrepresentativeoutcropsorsamples.Readymadeslidepackagesonthelargergeological entities, e.g. the Archean in Finland,werealsodistributedtothegeographyteachers.

The idea in these was that individual teachercould use the one, or ones, containinginformation about the bedrock in his/her area.Theproducedmaterialisnaturallyhighlyusableinpopularisinggeology toanynon-professionaltargetgroup.

ORAL

RockFossilsonTour–Zoologicalnomenclatureatitscoolest!

JesperMilàn1,MatsE.Eriksson2,AchimG.Reisdorf3,EsbenHorn4andRuneFjord51GeomuseumFaxe,Denmark,2DepartmentofGeology,LundUniversity,Lund,Sweden,3UniversityofBasel,Switzerland,410TonsAPS,Denmark,5RuneFjordStudio,Denmark

Zoological nomenclature, the science of namingextantandextinctorganismscanseemlikeadullfield with little public appeal. However, a newtravelling exhibition “Rock Fossils on Tour”,dealing with just that theme, has managed toattract awide international audience and reachfar beyond the normal palaeontological circles,andstraightintotheheartofrockfans!

The exhibition portrays fossils that are namedafterrock,punk,pop,jazzandheavymetalstars,and features exclusive lifelike sculpturalreconstructions of the animals. In addition, themusicians who lent their names to science arepresentedalongsideamusinganecdotesfromthescientistsresponsibleforthisunusualetymology.Manyoftheitemshavebeensignedbytherockstars. The exhibition has gained extensiveattention in the media and news groupsworldwide, and has been verywell received byboth music and fossil fans in the six Europeanmuseumsithasvisitedsofar.

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Thisisthestoryofhowtheexhibitioncametobe,from a spontaneous capricious idea, its rise tosuccess,andtheplansforitsfutureexpansion.

ORAL

KnowledgeExchangeforResourceManagementandInternationalTrust–Aleppocasestudy

RodneyStevens1,MohamedAlkridi1andMichaelKouro11DepartmentofEarthSciences,UniversityofGothenburg

The KERMIT project deals with research andcapacity-buildingtargetedattwo,relatedgroupswith academic backgrounds: 1) refugees inEuropeand2) localpopulations in the stressedregionsfromwhichpeoplearefleeing.Althoughthe long-term focus is aimed at raising thecompetence and capacity for sustainableresource management in stressed regions, therefugees with academic backgrounds involveboth new challenges and opportunities withrelated objectives. These refugees needcomplementarystudytoadapttheireducationalbackground to European conditions, and at thesame time they can provide valuable expertiseand knowledge of specific regions and generalconditions where resource conflicts andmanagementhaveincreasedmigration.Utilizingtheconnectionstothelocalacademiccommunityandtheexistinginfrastructure,projectactivitiesexplore the dual and complementary goals toincreasehumancapacity, therebystrengtheningthehope forpositive, short-termand long-termdevelopmentsforbothgroups.

Cooperative projects and educational activitieswithpartnerinstitutesinstressedregionsarethedistinctiveprofileof theKERMITproject.Theseactivitiesbuilduponourinternationalnetworksand the multidisciplinary research from thecooperativeprojects,utilizingearlierresultsandemphasizing the exchange activities forknowledge transfer in all directions. One on-going case studydealswithwater-managementstrategies for Aleppo, Syria, and considers theincreasedpollutionloadingonagriculturalareasalongtheriverduetocontinuedirrigationduringthewarwhilethewater-treatmentplanthasnotfunctioned.Inaddition,urbanpollutionsources,transportpathways,andrecipientsaremodeledusingsystemstructuralanalysisandrelativeriskrankingmethods.

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GIS-anappropriatetoolforundergraduatefieldmapping?

MortenAanvik1,SigmundSlang1,AmundBråtenRian1andMonikaOftedalVoll11UniversityofOslo

Geographic information systems, GIS, are keytools in the industry and geological surveys,increasing the efficiency of mapping and datacollection in the field. Though GIS usage iswidespread,thereislittlefocusonGISinthefieldpartsofthegeologyprogramattheUniversityofOslo.The focus lieson learningbasic fieldskillsand traditionalmappingmethods.Weareoftenmet with the argument that we need to hold abasic knowledge of traditional methods beforeadvancingtomorecomplexdigitalsystems.HerewereportuseofArcmapDesktoptodigitallymapan area in the inner Oslofjord as part of ourbachelorcapstonecourse.ToimplementArcMap

data files were created to record mappingobservations, together with DEM/DSM filesconstructedfromlaserdata.Computerfileswereinterpretedandanalysedduringfieldworktofindareas where more observations were needed.ThisresultedinahighlearningoutcomeinuseofArcMap. Comparing traditional mapping to GIS

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mapping highlights advantages of using digitaltools.Datacollection increasesgreatly inspeed,quantityandquality.Potentialdownsidesincludebattery life of devices and vulnerability toweather.Bothobjectionsareeasilymitigatedbyusingwaterproofcasesandpowerbanks.Digitalmapping greatly improved the quality andprecision of our map and geologicalunderstandingofthefieldarea.WeconcludethatGISisateachingaidthatshouldbeutilizedinfieldwork, having the potential to improve thegeologicalunderstandingofstudentsandpreparethemfortheworklife.

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SoapstonefromNuuk:Communicatingscientificandcommercialvalueofalocalresource

RebekkaKnudsen1,NynkeKeulen2,MajkenD.Poulsen3,KisserThorsøe4andMortenMeldgaardIlisimatusarfik,Nuuk,Greenland&NaturalHistoryMuseumofDenmark,CopenhagenUniversity,Denmark1GreenlandPerspective,NaturalHistoryMuseumofDenmark,CopenhagenUniversity,Denmark,2GeologicalSurveyofDenmarkandGreenland,NuukGreenland&CopenhagenDenmark,3GeologicalSurveyofDenmarkandGreenland,NuukGreenland&CopenhagenUniversity,Denmark,4GeologicalSurveyofDenmarkandGreenland,NuukGreenland

TheSoapstonefromNuukprojectbridgesthegapbetween scientists and people by anchoringresearchintosocietyandshowingitsrelevancetodaily life. Our goal is to inform the citizens oftowns and villages in Greenland about thepotentialforsmall-scaleminingofsoapstoneandto engage local community in using theopportunities soapstone holds; for small-scalemining,geo-tourismandlocalrockcollectorsandfor archaeological investigations. In order toengageabroadspectrumofthepopulationintheprojectwedecidedtoworkon3communicativelevels: i)Apractical level -wehostedan insitucitizen science workshop to teach theparticipants how to see the landscape and therock formations in the Nuuk area through the

geologists' and archaeologists' eyes; ii) Anengaging level - we hosted exhibitions and apublic event with the purpose of showingdifferent possibilities of making a living out ofsoapstoneaswellascommunicatingthismessagethroughthepress;iii)Ateachinglevel-wehavecommunicatedtheresultsoftheprojectthroughtalks,a filmandawebsiteabout theproject.Bymixing traditional scientific outreach withelementsofinvolvingcommunicationandafocuson direct relevance, we reached new types ofaudience.Byfocusingondirectrelevanceandbyinvolving several stakeholders representingauthorities (municipality level), business(business council and business support), art(museums and artists) and tourism (tourismorganisation and operators),we have created abetterunderstandingofhowtouseourresearchamonglocals.

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StevnsKlint,Denmark–UNESCOWorldHeritageSiteandhowtoconductgeologicalresearchatthesiteinthefuture.

JesperMilàn1andToveDamholt21GeomuseumFaxe/ØstsjællandsMuseum,Denmark,2VerdensarvStevns,StoreHeddinge,Denmark

TheUNESCOWorldHeritageSite,StevnsKlint,intheeasternDenmarkrepresentsthebestexposedCretaceous−Tertiary boundary section in theworld. The boundary clay layer is easilyrecognizablebeneathapronouncedtopographicoverhang, which separates the soft Cretaceouschalk from the overlying, harder Paleogenelimestone.Thismakestheboundarylayervisibleeven to the inexperiencedeye.Furthermore theexceptional complete marine fossil recordpresentatStevnsKlintmakesthesiteamongthebest localities worldwide for studying marinebioticturnoveracrosstheK-Pgboundary,andthediscoveryoftheiridiumanomalyintheboundaryclaylayerin1978madethesiteakeylocalityinthe scientific debate about an impact vs.volcanism related cause for theEndCretaceous

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extinction. The management of Stevns Klint asUNESCO World Heritage Site is developed inordertosecureprotectionofthesiteinamannerthat encompasses the opportunity for samplingforscientificpurposesandencouragescontinuedresearch activity. According to the agreedguidelinessamplingintheclifffaceforscientificpurposes may be permitted by the localgeologicalmuseum,ØstsjællandsMuseum.Whowill help, ensure that the sampling areconstructed in a manner that both ensures thescientificpurposeofthesampling,andminimizestheimpactontheprotectedcliffsite.

Østsjællands Museum invites all interestedresearchers to contact the museum to obtainpermits for sampling, and also to participate inthe effort to communicate the scientificimportanceofthesitetothegeneralpublic.

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GEARS: Geological heritage in innerScandinavia

TerjeMotrøen1,RolvDahl2andGunnelRansed31HøgskoleniInnlandet,2NorgesGeologiskUndersøkelse-NGU,3SveigesGeologiskeUndersøkelse-SGU

Thegoaloftheprojectistorecord,manageandcreate values based on the region's commongeological heritage. Achieved results will be acommon framework for geological surveying,registrationanddescriptionsofgeoresourcesinselected areas in Indere Scandinavia. Otherresults are the testing of new methods forinformation on geological heritage through theuse of new dissemination technology (VR / ARtechnology), obtaining material about thegeology of the region aimed at the public andresidents and organizing an internationalseminarongeologicalheritage.

Expectedeffectsareincreasedlocalandregionalawareness of the importance of geologicalheritageasa resource for tourismandbusinessdevelopment. Increased cooperation betweentourism and nature management, increasedawarenessandprideoflocallandscapes,aswell

assharedculturalandhistorical identity.Betterenvironmental management, better and newproductsforthetourismindustry,bettertouristexperiences, development of new tourist sitesandbettereducationintheregion.

In the interreg projectGEARS (2017-2019) ,areSGU project owners and NGU have projectmanagement. Inaddition,severalotherregionalinstitutions and companies from Norway andSwedenparticipateintheproject.

Interreg project Sweden and Norway (2017-2019): SGU is project owner, NGU is projectmanager In addition, several other regionalinstitutions and companies from Norway andSwedenparticipateintheproject.

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DetailedmappingofthepolydeformedGressholmenandRambergøyaislands,OsloRift-acapstonecourseprojectatOsloUniversity

MonikaOftedalVoll1,AmundRianBråten1,SigmundSlang1andMortenAanvik11UniversityofOslo

The small islands of Gressholmen andRambergøya, situated in the Inner Oslo FjordwithintheOsloRift,weremappedin1:5000scaleas part of the bachelor capstone course at OsloUniversity.Theislandscomprisemid-OrdoviciantoearliestSiluriansediments,recordingthelocalexpression of the global upper OrdovicianregressionandearlySilurian transgression.Therocks are dominated by shales, nodular shalesand limestone, locally fossilrich. IntheSilurian,thesequenceformedpartoftheCaledonianfoldand thrust belt. Repetition of layers and calcitefilled thrusts (locally with slickensides) arecommon, indicating top-to-southeastdisplacement. The islands themselves form alarge scale overturned southeast verginganticline with numerous parasitic folds ofdifferent orders. The compressional structures

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are overprinted by north-south trending sub-vertical extensional faults, commonlywith sub-vertical slickenlines. Dikes of differentcompositions,mainlystrikingnorth,arepresentontheislands.Boththefaultsandthedykesareparallel to the nearby eastern Oslo rift margin,and are consistent with east-west Permianextension associated with its formation. Thelimitedextentofthestudyareaandthecomplextectonic evolution of the islands make themhighly suited for undergraduate mappingprojects.Inparticular,successfulmappingoftheisland requires integration of the various sub-disciplines thatmake up the bachelor program,including sedimentology, paleontology,mineralogy-petrology and structural geology,within a tectonic framework. The mappingprojectprovidesanaturallaboratoryforrevising,testinganddevelopingfieldskillsinanauthenticcontext that prepares students for independentgeologicalworkintheirlatercareers.

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Field-basededucationinthehighArctic–howdigitaltoolscansupportactivelearninginGeology

KimSenger1,WesleyR.Farnsworth1,HanneH.Christiansen1,GrahamGilbert1,HoltHancock1,AndyHodson1,LenaHåkansson1,MariaJensen1,MalteJochmann1,MarkMulrooney1,RikoNoormets1,SnorreOlaussen1,AlexanderProkop1,AleksandraSmyrak-Sikora1andUNISgeologyadjunctstaff11UniversityCentreinSvalbard(UNIS),Dept.ofArcticGeology,N-9171Longyearbyen,Norway

The University Centre in Svalbard, UNIS, isNorway’s national high Arctic research andeducationhublocatedinLongyearbyen,Svalbardat 78°N. InArcticGeologyUNISoffersBSc,MScand Phd- level courses and semester packages(30ECTS)ingeologyandphysicalgeography.AllcoursesatUNISincludeasignificantfield-basedcomponent, and the natural environmentprovidesthe“lab”facilitiesforthecourses.Evenin this location Arctic field work can belogisticallydemanding.Similartoanyprogramingeology, it isbeneficial to increasethestudents’exposure to hands-on and realistic exercises, inorder toprepare themfor fieldwork. Increasedexposure also allows students to continuepracticing field skills after returning to theclassroom.

Weareactivepioneersofemergingtechnologiessuch as virtual outcrops and virtual reality asrelevanttoolstobeusedintheclassroom.Useoftabletsinthefieldprovidesaccesstodata,modelsand previous work (including classroom-basedpreparationexercises)duringthefieldwork,andallows for amore coherent learning experiencebetweenfield-andclassroomtime.Theaimofthedigitally supported learning environment is toincreasestudentlearningandincreasetheuseofformativefeedback.Inadditionitallowsustodohands-on, field relevant teaching year-round,includingduringthe4monthlongdarkseason.

Inthiscontributionweshareourexperiencesofusing these emerging technologies in a harshArctic environment in the framework of therecently revised BSc package offering at UNISusingactivelearning.

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18.Othertopics18.1.OtherSessions

ORAL

BeyondClassification–ManagingResourcesSustainably

SigurdHeiberg1,PerBlystad2,KerstinBrinnen3,CharlotteGriffiths4,TomHeldal5,JanneHokka6,ErikaIngvald7,KajLax7,HannuMakkonen6andHarikrishnanTulsidas41Petronavita.sandPetrad,2Petronavita.s.,3Svemin,4UNECE,5GeologicalSurveyofNorway,6GeologicalSurveyofFinland,7GeologicalSurveyofSweden

Successful resource management requiresrelevant information on the resource base,adequate framework conditions set byGovernments and society and enterprisingcapacity, also termed integrative dynamiccapabilities in the public, private and financialsectors.WebeginbyaddressinghowtheUnitedNationsFrameworkClassification forResources(UNFC)isbuilttohouseresourceinventoriesandthe guidance provided for applying this tominerals in Finland, Norway and Sweden. Theinformation is carried by the project, not thedeposit.Focusisonthequantitiesthattheprojectwill yield in the form of sales and non-salesproduction and how much will be left in thesubsoil. Inventories are constructed bycategorising separately the economic and socialconditions for development, their industrialstatus and the uncertainty with which thequantities are defined. The projects themselvescarryother importantmanagement informationsuch as time series of production, costs, labouretc. The classification is mapped (bridged) toother key classifications such as the CRIRSCOtemplate, the SPE PRMS and the new Russianclassification for oil and gas (RF2013). Thisfacilitates the reporting of a UNFC inventory intheseclassifications.

Beingaprojectbasedresourceclassification,theUNFChasbeenadaptednotjusttofossilenergyand mineral resources, but also to renewable

energy, including geothermal, and injectionprojectsforCO2storageandotherpurposes.

The presentation will open for a discussion onhowbest todevelopguidance for theuseof theUNFCintheNordicregionforthecommoditiesithasbeendevelopedfor.

POSTER

DETERMINATIONOFPALAEOPRODUCTIVITYUSINGCARBONQUALITYINANENDMEMBERMIXINGMODEL

JustinFadipe1andMaartenFelix11DepartmentofGeoscienceandPetroleum,NorwegianUniversityofScienceandTechnology

To improve our understanding of the globalcarbon cycle as well as the impact ofanthropogenic contributions to this cycle, it isimportant to understand the link betweenpalaeoproductivity and the amount of carbonthat is ultimately buried. There has beenmuchdebateregardingthefateoforganicmatter(OM)during its transition to the sea floor, and aboutthe quantification of OM remineralisation andpreservationwithinsubaqueoussediments.

Thisstudyappliesakineticmodelwiththeaimofquantifying thedecayof organicmatter in boththewatercolumnandduringtheearlystagesofsedimentation. Laboratory derived decay rateconstants for different constituents of organicmatter together with the duration required tosettle through the water column, were used toproduceaquantitativeestimateofcarbonfluxtothe sediment. The approach demonstrates itsvaliditywhen compared tomeasured trap datafrom literature. In addition, a comparisonbetween the modelled flux and empiricalequations showed similaroutputs forboth.Themodel results also compared well with (morelimited)measuredsedimentcolumndata.

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Estimating palaeoproductivity utilising theproposed kinetic model, necessitates thedistinctionoftherelativecontributionsofmarineand terrigenous sources to totalorganic carbon(TOC). Bulk geochemicalmeasurements of TOCand hydrogen index (HI) are used in an endmember mixing model, whereby the degradedmarine end member values are obtained byapplying the kinetic model. Application of thekinetic model to carbon quality providesreasonable estimations of degraded HI end-members.

POSTER

SurfacekinematicsofsortedcirclesusingStructurefromMotionphotogrammetryinJuvfonneandJuvasshøe

AndreaGaustad11Geografiskinstitutt,NTNU

Sortedcirclesareaformofperiglacialpatternedground that are recognized by characteristicgeometric shape. Sorted circles are believed tohaveanimportantfunctionasacarbonreservoirinhighlatitudes.

Thisresearchprojectislookingatsortedcirclesclose to Juvfonne and on Juvasshøe, Norway,using Structure from Motion photogrammetry(SfM).Theaimofthisstudyistounderstandthechanges of sorted circles during one meltingseasonattwodifferentlocations.Changesinthecircleswillbetracedbytrackingfeatures intheorthoimages.

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Frequency-magnitudeanalysisforlandslidesinSognogFjordane

HåvardMongstad1,GraziellaDevoli2andKarianneS.Lilleøren11DepartmentofGeosciences,UniversityofOslo/Norway,2HydrologyDepartment,NorwegianWaterResourcesandEnergyDirectorate,Oslo/Norway

ThecountyofSognogFjordaneinNorwayhasaclimate and topography which makes itvulnerable for debris avalanches, debris flowsand slush flows. The recently establishedlandslide forecasting service at NVE(www.varsom.no)isabletopredicttheirspatialand temporal occurrence. However, a betterunderstanding of these processes, their spatialdistribution, dimensions, mechanisms anddynamicsisneededtoimprovetheperformanceoftheservice,especiallyatlocalscale.

Themainobjectiveofthestudyistoinvestigateifthe landslide warning for the county can beimproved by considering the landslidemagnitude. The analysis implies mapping oflandslidesandananalysisofmeteorologicalandsedimentologicalconditionsofwhichtheeventswere triggered from. The analysis focus onlandslidesinsoil(debrisavalanches,debrisflows,slushflows) from2011andthroughout2017.Asample fromthe landslideeventswillbevisitedinfieldtoperformanalysisonlandslidevolume,thickness of deposit and some other landslideparameters.

Thestudywillalsoimplementananalysisoftheevents that had a corresponding landslidewarninglevelassociatedwithit.Avalidationwillthen be performed to compare the predictedoutcome with the resulting outcome of themeteorological event. This part of the masterthesis might clarify challenges the landslidewarningservicehastoday.Itmayalsoenlightenimprovementsor adjustments that isneeded toincreasethelandslidewarningserviceaccuracy.

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