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Abstracts / Quaternary International 279-280 (2012) 121–232 155
record a dramatic slowing of aggradation at 6 cal kyr BP when sea levelstabilized during 6–4 cal kyr BP (the Holocene sea-level highstand). As sealevel fell to the present level during 4–0 cal kyr BP, the river mouth pro-graded rapidly toward the Gulf of Bac Bo (Gulf of Tonkin) and the riverchannels extended seaward. In the West Floodplain, lateral accretionovertook vertical accretion to generate the present longitudinal profile.During this period, human settlements spread across the delta plain,lagging around 2 kyr behind the shoreline migration.
THE GREENLAND ICE SHEET AND THE CLIMATE – A REVIEW
Svend Funder. Centre of GeoGenetics, Natural History Museum, Uni,DenmarkE-mail address: [email protected]
During LGM the margins of the Greenland ice sheet around the wholeperimeter stood on the shelf – but where? The first estimates had to bebased on evidence from land such as weathering limits on coastalmountains, major moraine belts, and altitudes of marine limits. Still theestimates ranged from inner to outer shelf, often under the assumptionthat the ice margin could not stop mid-shelf, and if it reached the shelfedge in one area, this should apply to the whole perimeter. Modelling,mainly on the basis of palaeoclimatic data, have presented a similardisparity between maximum and minimum estimates, assessing theGreenland ice sheet's contribution to Holocene sea level rise - i.e. thedifference in ice volume between LGM and now - to between 0.3 and 2.6m. Recent years have given spectacular new insight into shelf-ice distri-bution and behaviour - especially by detailed seismic surveys on the shelfand cosmogenic isotope surface exposure dating on coastal mountains.Combining old and new evidence we present a new model on the icedistribution during LGM. The model is, as far as possible, based on tangibleevidence and implies that different sectors of the ice sheet respondeddifferently to climate change during and after LGM, and that coverage ofthe shelf may have been variable from one sector to another. Will themargin respond with similar complexity to global warming?
CULTURAL AND ENVIRONMENTAL LANDSCAPE TRANSFORMATIONDURING THE NEOLITHIC IN NORTHERN GERMANY AND SOUTHERNSCANDINAVIA
Martin Furholt. Christian-Albrechts-University, GermanyE-mail address: [email protected]
From a cultural perspective the shaping of landscapes during the southernScandinavian and northern German Neolithic shows two distinct phases ofhigh activity. The first one dates from 3600 to 3200 BC and is characterisedby the widespread construction of thousands of megalithic graves. Thesecond phase dates from 2900 to 2600 BC, archaeologically defined bySingle Grave barrows. Interestingly, these are mainly found in areas devoidof megalithic graves, i.e. hitherto ‘empty’ spaces in the landscape. The oldmegalithic centres seem to miss these new cultural developments, as ifcultural innovation was taking place in the former peripheries.Is this cultural pattern mirrored in terms of human impact on the envi-ronment? Are the cultural developments connected to changes ineconomic activity? A comparison of proxies from available pollen analysesfrom the region and the distribution of monuments, settlements andmaterial culture productionwill be carried out to assess this relationship inits spatial and temporal variability.
THE ‘SHREWS’ CRISIS EVENT’ (EARLY PLEISTOCENE) IN SPAIN:A BIOGEOGRAPHICAL AND BIOSTRATIGRAPHICAL APPRAISAL
Marc Furió. Institut Català de Paleontologia, SpainE-mail address: [email protected]
Only four different genera of shrews (family Soricidae) live currently inEurope. However, the situation was different in the past, with a muchhigher diversity during the Pliocene than nowadays. This period in Europerepresents the ‘golden age’ of shrews, having recorded up to 14 differentgenera. This was probably because the climatic stability of the Pliocene
enhanced the speciation processes resulting in the creation of severalecological niches that do not exist anymore. The Pliocene assemblagesin continental Europe combined genera which only have present-dayclose relatives in south-western Asia, North America or Africa, togetherwith some without close extant representation, and othersdmoresuccessfuldwhich are currently widely spread.On the other hand, by the Middle Pleistocene the European assemblagesof shrews were very similar to the modern ones, with only one moregenus than nowadays. That means that there was a drastic reduction ofthe diversity of the Soricidae in Europe during the Early Pleistocene. Thisfact was noticed in Central and Eastern Europe by J. Reumer in 1985, wholater coined the name ‘shrews’ crisis event’. A recent inspection of thisinterval in the Spanish fossil record has reassessed this observation, withlocalities younger than 2.5 Ma showing progressively a lower diversity ofshrews than the older ones. The exceptional placement of the IberianPeninsuladat intermediate global latitude and but being the south-westernmost area of continental Europedprovides new clues to under-stand the extinction of most of these genera in terms of both time andspace.
EROSION AND FILLING OF A GLACIALLY OVERDEEPENED TROUGH INTHE NORTHERN ALPINE FORELAND OF SWITZERLAND SINCE THE MIS 8
Heinz Furrer. Palaeontological Institute and Museum, University, SwitzerlandE-mail address: [email protected]
Geological and geophysical studies in the Wehntal (20 km NW of Zurich)reveal the existence of a glacially overdeepened trough cut into molassebedrock and filled with up to 180 m of Quaternary sediments. A 93.6 mlong sediment core was drilled down to bedrock and represents one ofthe few records in the northern Alpine Foreland providing insights intotiming of erosion and infilling history of glacially overdeepened struc-tures. Based on multi-proxy data and luminescence dating, the sedimentsuccession is interpreted from bottom to top as: in-situ molasse bedrock,overlain by diamictic till deposited during Marine Isotope Stage (MIS) 8.It is suggested that this extensive ice advance caused substantial erosionof probably older infill and of bedrock. The till merges into laminated,fine-grained proglacial lake sediments, which accumulated also duringMIS 8, proximal to a calving glacier-front as confirmed by the presence ofnumerous dropstones. The overlaying lake sediments are similar to theformer unit, but the absence of dropstones indicates a more distal lakefacies during MIS 7. The continuous succession is then interrupted bya hiatus that covers almost the complete MIS 6, which is believed torepresent a major glaciation of the Alps. Although a striking drop incarbonate content and shear strength, as well as an increase in grain sizecan be noticed in the overlying sequence, no obvious erosional featuresare visible. The overlying unit documents a gradual infilling of thepalaeolake and onset of biological productivity due to climate warmingduring early MIS 5, culminating in the accumulation of peat during lateMIS 5e. During early MIS 3, the peat was flooded, producing silty sedi-ments characterized by relative high organic carbon contents. Thereafter,the palaeolake was filled, resulting in the accumulation of the fossil-richpeat deposited w45 ka ago, which was finally covered with local alluvialsilts and sands.
LOW-STAND LAKES AND GARBLED GASTROPODS: THE PROBLEMS OFINTERPRETING THE ENIGMATIC DEGLACIAL AND POSTGLACIALENVIRONMENTS OF THE CELTIC SEA SHELF
Mark F.A. Furze. MacEwan University, CanadaE-mail address: [email protected]
Recent work on the last glaciation of the British Isles has lead to animproved understanding of the nature and timing of the retreat of theBritish-Irish Ice sheet (BIIS) from its southern maximum (Isles of Scilly).However, offshore records from the Celtic Deep Basin (CDB) within theBIIS limit remain enigmatic. Cores show a shell-rich upward finingsequence of Holocene marine sand above an erosional contact cut inlaminated muds with infrequent lonestones. Molluscs, in situ forami-nifera, and marine diatoms are absent from the basal muds, but rare
