THE GEOLOGY OF THE EAST ALBANY–FRASER OROGEN — A FIELD GUIDE

7/25/2019 THE GEOLOGY OF THE EAST ALBANY–FRASER OROGEN — A FIELD GUIDE

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RECORD 2011/23

THE GEOLOGY OF THE EAST ALBANY

OROGEN — A FIELD GUIDE

Government of Western AustraliaDepartment of Mines and Petroleum



Government of Western Australia

Department of Mines and Petroleum

Record 2011/23

THE GEOLOGY OF THE EAST ALBANY–FROROGEN — A FIELD GUIDE



MINISTER FOR MINES AND PETROLEUMHon. Norman Moore MLC

DIRECTOR GENERAL, DEPARTMENT OF MINES AND PETROLEUMRichard Sellers

EXECUTIVE DIRECTOR, GEOLOGICAL SURVEY OF WESTERN AUSTRALIARick Rogerson



Contents

Preface .............................................................................................................................................................The Albany–Fraser project: scope, collaborative work, and progress ......................................................

The geology of the east Albany–Fraser Orogen — a field guide: part 1

Tectonic setting of the Albany–Fraser Orogen ....................................... ....................................... ...................

Eastern Goldfields Superterrane — subdivisions and geology ....................................... .........................

Structural history of the Eastern Goldfields Superterrane ................................................................Isotopic constraints of the Eastern Goldfields Superterrane ..................................... .........................

Gold mineralization in the Eastern Goldfields Superterrane ............................................................Eucla basement ........................................................................................................................................

Tectonic subdivisions of the Albany–Fraser Orogen ................................................. ......................................

Northern Foreland ....................................................................................................................................

Munglinup Gneiss .............................................................................................................................Barren Basin — Cycle 1 sediments ..........................................................................................................

Stirling Range Formation ..................................................................................................................

Mount Barren Group .........................................................................................................................

Woodline Formation..........................................................................................................................

Unnamed metasedimentary units ......................................................................................................Fly Dam Formation ...........................................................................................................................



Stop 8. Fraser Fault Zone .......................................................................................................................5

Directions to Stop 9 ........................................................................................................................5

Stop 9. The Eddy Suite ..........................................................................................................................5

Directions to Stop 10 ......................................................................................................................5Stop 10. Granitic gneisses — Eddy Suite? ............................................................................................5

Directions to Kalgoorlie ..................................................................................................................5Excursion 2: Tropicana in a regional context ..................................... ....................................... ........................... 6

Directions to Tropicana ...................................................................................................................6

Geological overview .....................................................................................................................................6

Tropicana Gold Project ..........................................................................................................................6

Tropicana joint venture ownership ...................................... ........................................ .................... 6Discovery and project history .........................................................................................................6

Project geology ...............................................................................................................................6

Host rocks .......................................................................................................................................6

Stratigraphic architecture ................................................................................................................6Mineral deposit architecture ...........................................................................................................6

Mineralization .................................................................................................................................7

Day 1 .............................................................................................................................................................7

Stop 1. Havana South ............................................................................................................................7Stop 2. Hat Trick Hill .............................................................................................................................7

Locality 2.1. Hat Trick Hill ............................................................................................................7

Locality 2.2. Hat Trick ridge ..........................................................................................................7Locality 2.3. Hat Trick ridge ..........................................................................................................7

Day 2 .............................................................................................................................................................7

Directions to Stop 3 ........................................................................................................................7

Stop 3. Mafic to ultramafic rocks — Archean greenstone?...................................................... ..............7Directions to Stop 4 ........................................................................................................................7

Stop 4. Bobbie Point Metasyenogranite ..................................... ....................................... ..................... 7

Di ti t St 5 7



21. Initial-Hf evolution plot comparing the Biranup Zone to the Northern Foreland and

Archean fragment ..................................................................................................................................

22. The 1800–1550 Ma hafnium evolution of the Biranup Zone .................................... .............................

23. Initial-Hf evolution plot comparing the Fraser Zone and Recherche Supersuite to theBiranup Zone .........................................................................................................................................

24. Probability density diagram of Lu–Hf model ages: Fraser and Biranup Zones, andRecherche Supersuite ...........................................................................................................................

25. Schematic tectonic evolution diagram for the Biranup Zone .................................... .............................

26. Route and stops for Excursion 1 ........................................ ....................................... .............................

27. Route and stops for Excursion 1, superimposed on the pre-Mesozoic interpreted bedrock geology ....

28. Route and stops for Excursion 1, superimposed on a gravity data................................................ .........29. Route and stops for Excursion 1, superimposed on reduced-to-pole aeromagnetic data .......................

30. Photographs of the Munglinup Gneiss (Excursion 1, Stop 1) ................................... .............................

31. Photographs of Biranup Zone migmatite and Archean metasyenogranite (Excursion 1,

Stops 2 and 4). ........................................................................................................................................32. Compilation of pseudosections from semipelites from Gnamma Hill and Mount Malcolm .................

33. Tera–Wasserberg concordia plots and U–Pb ages of monazite analyses from Gnamma Hill

and Mount Malcolm ..............................................................................................................................

34. Photographs of the Fraser Range Metamorphics and Newman Shear Zone (Excursion 1,Stops 6 and 7). ........................................................................................................................................

35. Aeromagnetic image, showing strong to mylonitic fabric in the Fraser Zone .................................... ...

36. Photographs of the Fraser Fault Zone (Excursion 1, Stop 8) .................................... .............................37. Photographs of the Eddy Suite (Excursion 1, Stop 9). ....................................... ....................................

38. Photographs of the Eddy Suite (Excursion 1, Stop 10) ...................................... ....................................

39. Route and stops for Excursion 2 ........................................ ....................................... .............................

40. Route and stops for Excursion 2, superimposed on the pre-Mesozoic interpreted bedrockgeology ..................................................................................................................................................

41. Route and stops for Excursion 2, superimposed on gravity data .................................... .......................

42 R t d t f E i 2 i d ti d t



Spaggiari et al.



GSWA Record 2011/23 The geology of the east Albany–Fraser O

The geology of the east Albany–Fraser Orogen — a field

by

CV Spaggiari, CL Kirkland, MJ Pawley, RH Smithies, MTD Wingate, MG DoTG Blenkinsop2, C Clark 3, CW Oorschot3, LJ Fox1, and J Savage1

PrefaceThe Albany–Fraser Orogen lies along the southern and

southeastern margins of the West Australian Craton (WAC;Fig. 1). The orogen is dominated by Paleoproterozoic and

constraints, and limits the number of ovisited during the excursions. For thesguide includes extra details and illus

outcrops that lack good track access.Thi fi ld id i t d i t t



Spaggiari et al.

Gawler

Musgrave

L a c h l a n

O r o g

e n

Albany Fraser

PatersonOrogen

WestAustralian

Craton CP

Cambrian and younger orogens:

Ross–Delamerian, Lachlan, Thomson, and New England Orogens

Neoproterozoic to Cambrian Orogens:

Pinjarra Orogen

East African Orogen

Paleo-to Mesoproterozoic provincesin Australo–Antartica:

Albany–Fraser–Wilkes Orogen

Mawson Craton

Possible extensions ofthe Mawson Craton

2 0 S

3 0 S

1 4 0

E

1 3 0 E

1 2 0 E

1000 k

D e l a

m e r i a n

O

r o g e n

T h o m s o n

O r o g

e n

Proterozoic basins

Proterozoic orogens,undifferentiated

Archean cratonsPilbara

Yilgarn

North Australian

Craton

South Australian

Craton

Australian elements:

CCr

M–F–W

Arunta Orogen

Capricorn Orogen




due to the vast area that the orogen covers (Figs 1 and 2),and the minimal bedrock outcrop available in mostregions. The project commenced in 2006 with the releaseof the South Yilgarn aeromagnetic dataset, focusing on

the central part of the orogen (Geological Survey ofWestern Australia, 2007; Spaggiari et al., 2009). Theproject has since expanded to the eastern part of theorogen and includes the collection and interpretationof new geophysical datasets, collection and analysisof major- and trace-element geochemistry, and a moreextensive geochronology/isotopic analysis (U–Pb,Lu– Hf, and Sm–Nd) program funded in part throughthe Exploration Incentive Scheme (EIS). The Co-fundedDrilling Exploration Program of the EIS is also providingvaluable drillcore for sampling, and information fromthe various companies involved. In the past two years,GSWA has worked in collaboration with research staff atthe Department of Applied Geology, Curtin University,on understanding metamorphic P–T conditions and thetiming of metamorphism using monazite geochronology.

Two honours theses from this collabcompleted (Oorschot, 2011; Adams, 2

The project has focused on th

Paleoproterozoic areas adjacent to tmargin in the eastern part of the Albawith the aim being to gain an undcharacter of that margin and its relmineralization. We are also currently mwhich includes looking at the Mesoprotas we do so, the Proterozoic rocks beobscured beneath the Eucla and Bigand 3). The aim in this eastern regiointerpreted bedrock geology map of th

the Eucla Basin, utilizing drillcore and help define both the nature of that basemof the orogen. Through EIS funding, anco-funded drilling, several stratigraphito test interpretations and constrain the



Spaggiari et al.

The geology of the east Albany–Fraser Orogen — a field guid

This section outlines the tectonic setting and currentnomenclature for the Albany–Fraser Orogen, and definesand briefly describes its major tectonic units, lithologicalunits, and events. A geological history of the orogen andinterpreted tectonic models are also presented. Unlessstated otherwise, all geochronological dates reported inthis field guide are U–Pb age determinations from zircon

grains dated by ion microprobe (SHRIMP), and are quotedwith 95% confidence intervals. Published GeochronologyRecords for dated samples are referenced normally;uncited results should be considered as ‘in preparation’.

Tectonic setting of theAlbany–Fraser Orogen

The Albany–Fraser Orogen lies along the southern and

Supersuites (formerly the RecherchEsperance Granite), and three major baet al., 2009). The Kepa Kurl Booya Prodivided into the fault-bound tectonic unitZone (formerly the Biranup Complex), (formerly the Fraser Complex), and the (formerly the Nornalup Complex) (Fig.

1990a, 1995b; Spaggiari et al., 2009). described below in ‘Tectonic subdivisionFraser Orogen’.

The main tectonic events recognizedAlbany–Fraser Orogen (Fig. 4) are thePaleoproterozoic Biranup Orogeny, whic. 1680 Ma Zanthus Event (Kirkland et the Mesoproterozoic Albany–Fraser Otook place in two stages: 1345–1260 M

1215–1140 Ma (Stage II) (Clark et al., 200Cl k 2004 ) St I h b i t t




2

2

Co-funded d

Other

Loongana

Haig

Eucla DrillingProject

C u n d

e e l e

e F a u l t

F r a s e

r F a u l t

N e w m a n

S h

e a r

Z o n e

Sh e a r Z

o n

e

Trans–Australian Railway

E y r e H w y

A L B

A N Y – F R A S E R O

R O G E N

EUCLABASEMENT

MundrabillaShearZone

R o d

o n a

S h e a r

o Z

n e

N e w

m a n

S h e a r

Z o n e

1415 to 1407 Ma

114

1598 ±

Y I L G A R N

C R A T O N

FraserRangeNorth

Hannah1293 ± 18 Ma (inherited);1170 ± 4 Ma (metamorphic)

The Serpent

BurkinBig Red

MADURAPROVINCE

FP

NSD

1326 ± 6 Ma (magmatism);c. 1185 Ma (metamorphism)1167 ± 2 Ma (granite)

1478 ± 4 Ma (metamorphic)

Z o n e



Spaggiari et al.

Kurnalpi Terranes, which also have similar age patternsto the Youanmi and Burtville Terranes, suggests theincorporation of older crustal components into the rocksof the younger terranes.

Five main granite types have been recognized in theEastern Goldfields Superterrane (Champion and Sheraton,1997), with most felsic magmatism occurring betweenc. 2720 and 2630 Ma (older granites are scattered acrossthe superterrane). Although there is overlap in their ages,the magmatism responsible for the different granite types‘peaked’ at different times.

generally restricted to the Kurnalpi Terrane, and havea magmatic age peak between 2720 and 2680 Ma.

magmatic age peak between 2720 and 2680 Ma, andlesser volumes until <2655 Ma.

in age from 2675 to <2655 Ma, and are generally

This sequence of deformation events hato tectonic switching at a convergent bouet al., 2010). According to Blewett et al. deformation event, which occurred aft

produced locally developed, minor verticavariable extension vectors attributed to the

A major feature of the Eastern Goldfieldsthe development of north-northwesterly and faults. A deep-crustal seismic travcentral part of the Eastern Goldfields Supeet al., 2004) showed that the terrane-bounand Hootanui Fault systems, and the YZone, are large-scale, east-dipping, listri

extend to the base of the crust. Such strulong and complex histories. For examplShear Zone preserves three phases oincluding dextral strike-slip shearing itight to isoclinal folding and layer-parshearing in the greenstones adjacent twhich is demonstrably contemporaneous wdeformation; and sinistral strike-slip hangingwall to the east (Pawley et al., 200

age of the syn-kinematic Point Salvationlocated in the footwall of the shear zone, th




endowment, with structurally controlled mineralizationoccurring throughout most of its deformation history,and with some deposits recording multiple gold events(Blewett et al., 2010 and references therein). Only minor

gold deposition occurred during D1 (c. 2720 Ma andc. 2670 Ma) and D2 (c. 2665 Ma; e.g. the TarmoolaDeposit), but it is from D3 onwards that the volume of goldmineralization increased significantly. The developmentof the D3 extensional shear zones between c. 2665 andc. 2655 Ma provided crustal-scale conduits for the transferof mantle-derived magmas, fluids, and metals, and sitesfor gold deposition (e.g. Sons of Gwalia at Leonora).Several gold deposits, such as New Holland near Agnew,formed during D4a (c. 2655 Ma) reverse dip-slip faulting,

but it was the change in shortening direction during D4b (2655–2650 Ma) that led to the formation of the largestgold deposits (e.g. Kalgoorlie, Sunrise Dam, St Ives,Kanowna Belle, and Lawlers). Blewett et al. (2010)proposed that rotation of the stress axes at 2655– 2650 Maled to sinistral shearing and the development of a newnetwork of contractional and dilational jogs, whichwere favourable sites for fluid flow and traps for golddeposition. D5 (2650–2635 Ma) transtension resulted in

northerly trending, dextral shearing and development ofassociated brittle structures which host mineralization at

on the western margin of the Yilgarn Csignificant rotation drag of the westeAlbany–Fraser Orogen during the la(Beeson et al., 1995; Fitzsimons, 200

been correlated with other late-stage faFraser Orogen, such as the north-norsinistral mylonite zones that cut Biwest of Esperance, and c. 1140 Ma Esgranites nearby (Bodorkos and Clark,

Exploration drilling in the Maduintersected ultramafic, metagabbroicrocks at the Loongana prospect southvariably to strongly magnetic metagab

prospect; and heterogeneous gneissilayered quartz–chlorite–garnet schisbanded-iron formation (BIF), and aBurkin prospect (Fig. 3). Medium-grthe Loongana prospect yielded a dateinterpreted as the age of igneous crygranitic protolith that either intrudes,the mafic protolith in the same secLNGD0002, depth interval 363.52 –

178070, Nelson, 2005a). Pinkish-whigrained, unfoliated biotite microtona



Spaggiari et al.

Biranup

Zone

Fraser

Zone

Nor

Z

Northern

Foreland

ecnivorPayooBlruKapeKnotarCnragliY

Albany–Fraser Orogen

1200

1300

1400

1500

Age

(Ma)1100

BurnsideGranite

AlbanyGranite

STAGE II

STAGE I

Pelite

? ?? ?

? ?

? ?MetamorphicsFraser Range

CYCLE 2SEDIMENTS

? ?

1450

1350

1250

1150

CYGnowangerup–

Fraser dykes




to migmatization. Three analyses of zircon cores fromGSWA 182485 yielded dates of 2408–2293 Ma, possiblyreflecting the ages of sedimentary detritus in the protolith,if the gneiss is interpreted as a metasedimentary rock. Four

analyses of zircon cores from the same sample yieldeda weighted mean date of 1538 ± 17 Ma, which couldrepresent a maximum age of deposition.

East of the Mundrabilla Shear Zone, within the ForrestProvince, the Alliance Petroleum Eucla No. 1 welllies over a distinctly ovoid geophysical feature withhigh magnetic intensity, interpreted as a late graniticintrusion (Fig. 3). It forms part of a set of northeasterlytrending nested plutons with moderate to strong magnetic

signatures. Small rock chips and mineral fragments fromthe base of the well (from 215–222 m; GSWA 194773) areinterpreted to be derived from a granitic rock, and containoscillatory zoned zircon grains that yielded a date of1140 ± 8 Ma, interpreted as the magmatic crystallizationage of the inferred granite protolith (Kirkland et al.,2011j). A single analysis on an unzoned zircon crystalyielded a date of 1598 ± 14 Ma, interpreted as either theage of an inherited component within the granite, or theage of zircon incorporated from another rock unit (e.g.a sedimentary rock) within the drillhole. The magnetic

that indicate that much of it was oriYilgarn Craton (Spaggiari et al., 2002011k). The Munglinup Gneiss is intergrade, more strongly reworked compon

Foreland, bound by major faults.Reworking of the Yilgarn Craton in thevaried from moderate- to high-strain dunder amphibolite- to granulite-facconditions (Munglinup Gneiss and the Mount Barren Group), to low- to modersemi-brittle, greenschist to amphibolite et al., 1988; Myers, 1995a; Jones, 20in conditions generally reflects lowe

and lower metamorphic grade with ifrom the orogen (i.e. northwards), oof shallower crustal levels of the Nora section of the Pallinup River, west the central Albany–Fraser Orogen, Bdescribed an increase in deformation ito south, with progressive overprintinnorth-northwesterly trending ArchMesoproterozoic, Albany–Fraser Orogsouthwesterly trending dextral shear

foliations. The northern limit of the i d fi d b h f di



Spaggiari et al.

Orogeny (Myers et al., 1996). The Munglinup Gneiss isnow interpreted as a reworked part of the Yilgarn Cratonbased on similarities in lithologies, protolith ages (Fig. 5;Spaggiari et al., 2009), and Lu–Hf data (Kirkland et

al., 2011k). It represents the southernmost exposures ofthe craton within elongate, craton-parallel, fault-boundpackages of predominantly granitic gneiss. West ofRavensthorpe, in the central Albany–Fraser Orogen, theMunglinup Gneiss is part of the Northern Domain ofBeeson et al. (1988), where it is bounded by the linked,south-dipping Boxwood Hill and Yungunup Pool Thruststo the north, and the south-dipping Millers Point Thrustand Bremer Fault to the south (Geological Survey ofWestern Australia, 2007). The thrusts are high-strain zones

that locally contain leucosomes, and are interpreted asoblique thrust faults with a component of dextral strike-slip movement (Beeson et al., 1988). South of the MountBarren Group, the northern margin of the MunglinupGneiss is bounded by the Jerdacuttup Fault (Fig. 2), whichlinks with the Bremer Fault to the west. These faults areinterpreted to form the northern edge of a separate, easternfault-bound package of Munglinup Gneiss, with the MountBarren Group contained within a separate thrust packagebetween the two fault-bound slices of Munglinup Gneiss(cf. figs 2 and 15, Spaggiari et al., 2009).

The oldest granitic phases recognized inGneiss are a migmatitic granitic gneiss frwest of Quagi Beach (Stop 1 on Fi184334), and a medium- to dark-grey, s

monzogranitic gneiss with well-developelayering (GSWA 184120) outcropping alRiver, west of Bremer Bay, in the centraOrogen (Spaggiari et al., 2009). The miggneiss yielded an upper intercept date ofinterpreted as the magmatic crystallizagranitic protolith (GSWA 184334, KirklanThe monzogranitic gneiss from the Pallinan interpreted igneous crystallization date(GSWA 184120, Bodorkos and Wingate,

The most abundant phase in the Munglileucocratic, banded, tonalitic to monzoThe gneissic fabric appears to be intrudeporphyritic monzodiorite, and both grandate at least two episodes of folding (S2009). Zircons from the two phases, obsPoint, about 70 km west of Quagi BeacAlbany–Fraser Orogen, give igneous crysthat are within uncertainty of each otherfor the leucocratic tonalitic gneiss (G




NF

CBZ

ES

EBZ

NBZ

FZRS

AF

mmmdin

Biran

Stag

Stag

1000

1500

2000

2500

Age(Ma)

NW SErelative distance along NW–SE traverse

Major faults

Terrane boun

Geological bS l it

North AustralianCraton

O in e

a)

b)



Spaggiari et al.

b) c)

34°0

a) 121°30'

F3

F2

F2

F3F2

F3 F3

F3

R D

I S E

L A N D

E A S H

R Z O N E

BIRANUP

ZONE

MUNGLINUPGNEISS

C O R A

U M P S

H E R A Z

E O N

H E Y W

D – C H

O O E Y N

E F A U

L T Z O

N E

10 km

Excursion route

Excursion stop

Fold axial trace

1

Aeromagnetic trend line

1




Wingate, 2008b). Migmatitic gneiss from west of QuagiBeach (GSWA 184334, Kirkland et al., 2011b) yielded adate of 1184 ± 6 Ma from two analyses of zircon rims,indicative of high-grade metamorphism at this time.

The Munglinup Gneiss has been affected by at least threephases of folding, and is locally sheared and boudinaged(Spaggiari et al., 2009). Megascale structures are well-defined in aeromagnetic imagery, particularly as foldinterference patterns, due to the presence of magnetitein the metamorphic fabrics (Fig. 6a). The fold patternscorrespond to mesoscale structures in outcrop, whereearly hook folds (F1) of gneissic banding in leucocratictonalitic gneiss are refolded into approximately north-

trending, open to tight folds (F2; Fig. 6b). These arerefolded by easterly to northeasterly trending tightfolds, which are parallel to the dominant trend of theorogen (F3; Fig. 6c). The F2 and F3 folds are interpretedto correlate with the megascale refolded folds visiblein the aeromagnetic imagery (Fig. 6a). These folds arecut by shears that locally contain leucosomes, whichindicates that this last phase of deformation took placeat high temperatures, probably at the upper amphiboliteto granulite facies (Fig. 6c,d). In outcrop, dextral shears

trend predominantly in an easterly direction, whereasi i l h d d i l h h B h

Formation, Mount Barren Group, and W(Woodline Sub-basin; Plate 1; Fig. 2). the Yilgarn Craton, and are interpreteremnants of a much larger basin syst

the Barren Basin — that evolved aloreaches of, the Yilgarn Craton margPaleoproterozoic (Fig. 4; Thom et al.,et al., 2008; Spaggiari et al., 2009). Isof quartzite and metaconglomerate, semipelitic rocks in the northeastern aFraser Orogen are interpreted to be basin system. The higher grade pelirocks of the Fly Dam Formation in thebelow) are interpreted to be somewh

distal components of the Barren Basipart of a separate, still younger, Messystem (Fig. 4). Together, the metaof the Barren Basin are interpreted series of related or linked basins forduring, the Biranup Orogeny. TheyCycle 1 sediments, to reflect the firbasin formation preserved in the Alba(Fig. 4). These Cycle 1 sediments

relate to active-margin, rift-, or backsubstantially modified the Yilgarn Cra



Spaggiari et al.

Mount Barren Group

The Mount Barren Group is exposed in the centralAlbany–Fraser Orogen, and consists of lower-greenschist to upper-amphibolite facies, Paleoproterozoicmetasedimentary rocks, which overlie the southern edge ofthe Yilgarn Craton along a strike length of about 120 km,extending from Bremer Bay to east of Ravensthorpe(Fig. 2; Plate 1; Thom et al., 1977, 1984b; Witt, 1997). Thegroup is divided into the Steere Formation, the KundipQuartzite, and the Kybulup Schist (Thom and Chin, 1984;Thom et al., 1984a).

The Steere Formation is the lowermost unit of this

group, and consists of a thin basal conglomerate withclasts of quartzite, chert, BIF, and felsic volcanic rocks,overlain by several metres of pebbly sandstone and 4 mof dolomitic limestone (Thom et al., 1977, 1984a; Witt,1997). At its type locality in the Western Steere River, theSteere Formation non-conformably overlies the ArcheanManyutup Tonalite of the Yilgarn Craton (Thom et al.,1977, 1984a).

The Kundip Quartzite consists predominantly of thickly

bedded pure quartzite, which is interbedded with mica-and magnetite bearing q art ite and m dstone and minor

between the Kundip Quartzite and the KThis phosphatic unit is thinly bedded alternating medium- to coarse-grainedcarbonaceous shale, enriched in phosp

Authigenic xenotime overgrowths on zfrom the phosphatic unit yielded four aof 1693 ± 4, 1645 ± 3, 1578 ± 10, and(Vallini et al., 2002, 2005). The datievidence of Stage I or II metamorphiswas interpreted as a shielded, low-strain its low permeability and porosity (ValliBased on detailed petrography and geochet al. (2005) deduced a paragenetic sequewhich provided a framework for the geoc

1693 ± 4 Ma date was interpreted to date of unconsolidated sediments, and therefthe depositional age of the unit. The onsepossible change to anaerobic conditions,to have commenced prior to c. 1654 Ma. Tage components of 1578 ± 10 and 1481interpreted to reflect periods of hydrothgrowth post-dating quartz cementation, further burial. Detrital zircon studies

Barren Group are consistent with this xyielding a maximum depositional age




siltstone tens of metres thick (Hall et al., 2008). Minorunits consist of pebble and cobble conglomerates, andmatrix- to clast-supported chert breccias. These rocksare folded into open, upright, northeasterly trendingfolds, and contain a weak to moderately developed,axial-planar spaced cleavage (Hall et al., 2008). Twodominant sets of paleocurrent directions were recorded,indicating both southeasterly and southwesterly directedflow. These paleocurrent readings have been interpretedeither as transverse and axial components in a foreland-basin setting, or as fluvial to deltaic and barrier islandsedimentary processes interacting with longshore currents(Hall et al., 2008). The depositional setting is interpretedas changing from a distal fluvial environment to a marine-

dominated setting (Hall et al., 2008).

The Woodline Formation has a maximum depositional ageof 1737 ± 28 Ma, permitting a similar depositional timeas the Mount Barren Group (Fig. 4; Hall et al., 2008).However, detrital zircon age spectra from the WoodlineFormation were interpreted as most similar to spectrafrom the upper section of the Earaheedy Group on thenortheastern margin of the Yilgarn Craton (Hall et al.,2008). Although there are significant differences between

the age components of the Woodline Formation and MountB G (H ll t l 2008 d f th i )

a quartz-rich, micaceous matrix, anrich laminated metasiltstone beds thdenoted UC on Fig. 4). Above this is a interbedded with metagritstone an

Bedding in the metaconglomerate dipcut by a weak to moderate foliation thaat a shallower angle. This indicates tha(direction to next antiform) is to the locality is in the overturned limb of plunging antiform. Preliminary geoc(GSWA 182416) indicate a maximage of 1752 ± 19 Ma (1), and olddates of 2835–1794 Ma, includincomponents at c. 2635 Ma and 1807

that the metaconglomerate, and bquartzites and metasandstones describof the same sedimentary cycle (CyclPaleoproterozoic metasedimentary roBasin (Stirling Range Formation, Moand Woodline Formation) (cf. Bunting

Along Ponton Creek, north of the Railway, is a psammitic gneiss tha

evidence of anatexis such as thin leintruded by coarse pegmatite. Howev



Spaggiari et al.

a) b)

c) d)




Within the eastern Nornalup Zone, preliminarygeochronology of drillcore samples of migmatitic gneissfrom the Big Red prospect (Fig. 3) (Hole BRDDH1,GSWA 182473 and 182475) yielded a large range of

predominantly Archean detrital ages, and a maximumdepositional age of 1729 ± 27 Ma (1). These migmatitesare tentatively interpreted as Barren Basin Cycle 1sediments, implying that some sediments from thisbasin system were deposited a substantial distance fromthe craton margin. Nonetheless, this interpretation isconsistent both with the presence of Paleoproterozoicbasement in the Nornalup Zone (see ‘Nornalup Zone’section), and the interpretation of the MesoproterozoicFraser Zone as possibly developing in a rift setting within

Archean to Paleoproterozoic crust (see ‘Fraser Zone’section). The preliminary geochronology shows that themigmatitic gneisses from Big Red were metamorphosedunder high-temperature conditions at 1193 ± 5 and1176 ± 10 Ma, and were intruded by Esperance Supersuitegranite at 1167 ± 2 Ma, during Stage II of the Albany–Fraser Orogeny (Fig. 4).

Fly Dam Formation

horizons are layered on the centialternating quartzofeldspathic and mrich material, and also contain abunda0.5 – 2 cm in diameter (Fig. 7d). mostly migmatitic, and contain bothleucosomes, and leucosomes paraaxial-planar foliation. These leucosocontinuous and probably belong to aThe leucosomes are also locally boudinfoliation. Diatexitic textures occur loca

Petrographically, the semipelitic rocksdefined by biotite (dominantly), hoK-feldspar, and quartz. This foliat

abundant garnets that are inclusioresorbed. Inclusions are mostly K-include epidote or zoisite, quartz, andbands comprise a mixture of K-feldperthite, and quartz. These minerallobate grain margins, and there is somrecovery in smaller quartz grains. Thecontains a fine- to medium-grained mK-feldspar (dominant), plagioclase, microcline. These all have ragged gra

also show some evidence of recrystalld tl h l bl ti t t



Spaggiari et al.

Beachcomber 1

Coonana / Jones

Fly Dam

31°00'

123°30'

c. 2680

c. 1680 Mac. 1683 Ma

1689 ± 6 Ma1666 ± 12 Ma

1667 ± 11 Ma

1683 ± 8 Ma

BIRANUPZONE

NORTHERNFORELAND

YILGARNCRATON

PontonCreek




Given the predominance of sandstone and mudstoneprotoliths, the metasedimentary rocks of the Fly DamFormation could be interpreted as turbidites, possiblyrepresenting the youngest known, more distal, and deeperwater component of the Barren Basin Cycle 1 sediments,deposited during the late stages of the PaleoproterozoicBiranup Orogeny. Alternatively, they could be muchyounger, Mesoproterozoic sediments, and therefore partof Cycle 2 (see ‘Arid Basin — Cycle 2 sediments’ section;Fig. 4). It is interesting to note that their provenanceappears to be dominated by Paleoproterozoic BiranupOrogeny aged components, suggesting derivation fromrelated volcanic sources, and/or the relatively rapidexhumation and exposure of the basement.

Kepa Kurl Booya Province

Myers (1990a) divided the Albany–Fraser Orogen intotwo major tectonic units: an inboard, intensely deformedcomponent named the Biranup Complex, and an outboardcomponent named the Nornalup Complex. In Myers’ earlydefinition, the Biranup Complex contained what were latercalled the Munglinup, Dalyup, and Coramup Gneisses(Myers, 1995b), as well as the Fraser Complex (Myers,

interlayered with reworked rocks of twithin the Northern Foreland (Figs 9et al., 2009).

The Biranup Zone is dominated by i

orthogneiss, metagabbro, and pararanging from c. 1800 to 1625 Ma (Flack of evidence for a Paleoproterotectonothermal event in the southern to the suggestion that the Biranup Zterrane accreted onto the Yilgarn CraStage I of the Albany–Fraser Orogeny1995; Clark et al., 2000; Spaggiari et arecent work has shown that the Biran

likely to have formed autochthonouslyCraton margin (Kirkland et al., 2011a). Zone, the presence of fragments ofwith ages typical of Yilgarn Craton grinterpretation (Plate 1; Fig. 5). These the ‘S-bend’ area around, and to the soAndrew, and possibly include rocks aSplinter prospect (Figs 9 and 10; see Ex3, and 4). This interpretation is furLu–Hf data from granitic rocks in the

‘Lu–Hf isotopes’ section), which indic



Spaggiari et al.

2684 ± 11 Ma

1668 ± 7 Ma

1297 ± 8 Ma

1695 ± 16 Ma

1658 ± 26 Ma

Zone B

123°00'122°30'

3 2 ° 3 0 '

N O R

T H E R N F O R E L A N D

BIRANUPZONE

FRASERZONE

Cave Rock

2

3




2684 ± 11 Ma

1668 ± 7 Ma

1297 ± 8 Ma

1695 ± 16 Ma

1658 ± 26 Ma

Zone B

123°00'122°30'

3 2 ° 3 0 '

N O R

T H E R N F O R E L A N D

BIRANUPZONE

FRASERZONE

Cave Rock

2

3



Spaggiari et al.

As described above, the Biranup Zone also containsmetasedimentary rocks, most of which are migmatiticparagneisses (see ‘Barren Basin — Cycle 1 sediments’section).

Eddy Suite

The Eddy Suite, which ranges from megacrysticmetamonzogranite and equigranular metasyenograniticgneiss, to rapakivi-textured metagranodiorite andmetagabbronoritic rocks, occurs in the eastern BiranupZone, and is well exposed west of Harris Lake (Fig. 8;see Excursion 1, Stop 9). These rocks have been dated atc. 1660 Ma, and represent the dominantly younger, more

juvenile, component of Biranup Zone magmatic rocks(Kirkland et al., 2011a,k). The metagranodiorite containsovoid K-feldspars up to 3 cm long, with a millimetre-wide mantle of more calcic feldspar, and rounded quartzphenocrysts up to 6 mm in diameter, within a medium-grained groundmass. These textures are typical of manyProterozoic A-type rapakivi granites (Rämö, 2005). Themetagabbronorite is fine to medium grained, and formsirregular enclaves within the metagranodiorite. These

enclaves have lobate, commonly gradational, boundarieswith the metagranodiorite suggesting that the two

pressures of about 6.5 – 8 kbars (Figs 41973; Myers, 1985; Clark et al., 1999;Pisarevsky, 2008; Spaggiari et al., 2009; OMetagranitic rocks range from metammetasyenogranite. The metasedimentaroccur along the northwestern side of the Fare typically intercalated with layers of or amphibolite (Fig. 12b) that were prodykes, sills, or sheets related to the intrusions. Whereas pelitic and semipeliticthe metasedimentary component in the the Fraser Zone (e.g. Gnamma Hill and Msee Excursion 1, Stop 5), the northern exthe Fraser Zone contains metasedimentary

calc-silicate affinities, and may represent marls, or volcaniclastic protoliths. In these rocks contain layers packed with ucoloured, euhedral garnets up to 1 cm,sugary matrix dominated by quartz and le(Fig. 12c). There are also variable amosome epidote or zoisite, minor hornblenamounts of magnetite.

The Fraser Range Metamorphics are typi

by a well-developed, northeasterly tre




BIRANUPZONE

c.1295 Ma

1298 ± 5 Ma

1287 ± 14 Ma1466 ± 17 Ma

Phills

Brookman

American

Horseshoe

Heraclitus

Theofrastus

Similkameen

Yardilla East

Fraser Range 1

YardillaSouth

123°00'

32°00'

Fantasia

NORTHERN

FORELAND



Spaggiari et al.

a) b)

c) d)




which is also interpreted as an igneous crystallizationage (Clark et al., 1999). The age is within uncertaintyof the Verde Austral sample; however, the intrusion isinterpreted as post-D1 and pre-D2 (Clark et al., 1999).Metasyenogranite from near Symons Hill yielded asimilar crystallization age of 1298 ± 5 Ma (Kirkland et al.,2010b). Monzogranitic gneiss from the Fantasia dimensionstone quarry (Fig. 11) yielded a date of 1287 ± 14 Ma,interpreted as a minimum age for igneous crystallization(GSWA 177909, Wingate and Bodorkos, 2007a). Thesedates show that the ages of mafic and felsic intrusions areindistinguishable throughout the Fraser Zone (Fig. 14).

Early metamorphism in the Fraser Zone, at 1304 ± 7 Ma,

is recorded by zircon rims developed within quartzmetasandstone, which is interlayered with amphiboliteand pyroxene granulite, and which has a maximumdepositional age of 1466 ± 17 Ma (GSWA 177910,Wingate and Bodorkos, 2007b). Other maximumdepositional and metamorphic ages are presented inPart 2, Excursion 1, Stop 5. All isotopic results from theFraser Zone indicate a short time interval for both maficand felsic igneous crystallization, predominantly between1305 and 1290 Ma, and essentially coeval granulite-facies

metamorphism (Figs 5 and 14) The close correspondence

is curious, considering the extent of hmetamorphism within the adjacent Bother units (Fig. 5). However, analysefrom sheared leucosomes within pelfrom Gnamma Hill (see Excursionprovided a younger age of 1236 ± 2either as evidence of a younger metaas the influence of hydrothermal fluidsTherefore, it is possible that the juxtapoZone against the Biranup Zone alonZone occurred, at least in part, during

Although several interpretations for tof the Fraser Zone rocks have been pu

enigmatic to some degree. Initially, boand metamafic components of the interpreted as an exhumed block of lo1975). However, after detailed mappingthe Fraser Zone were interpreted as parmafic intrusion, with the granitic androcks representing basement sliversformer Biranup Complex (Myers, analysis of trace-element data, it was armagmas were derived from a subduct

and that the ‘Fraser Complex’ repres



Spaggiari et al.

to the presence of Paleoproterozoic basement rocks inthe Nornalup Zone (see ‘Nornalup Zone’ below), and theBiranup-like Lu–Hf isotopic signature of the Fraser Zoneigneous rocks (see ‘Lu–Hf isotopes’ section).

Nornalup Zone

The Nornalup Zone is the southern- and easternmostunit of the Albany–Fraser Orogen (Fig. 2; Myers,1990a, 1995b). This zone is dominated and intruded bythe voluminous Recherche and Esperance Supersuites,which mask much of the original basement. In the easternAlbany–Fraser Orogen, the Nornalup Zone is separatedfrom the Biranup and Fraser Zones by the NewmanShear Zone and Boonderoo Fault, and from the MaduraProvince by the Rodona Shear Zone (Plate 1; Fig. 3).Supracrustal rocks in the Nornalup Zone comprise theMesoproterozoic Malcolm Metamorphics (previouslythe Malcolm Gneiss) and paragneissic rocks that occur inthe Albany region of the western Albany–Fraser Orogen.These supracrustal rocks belong to the Arid Basin, and arepart of the Cycle 2 sedimentary sequence (see ‘Arid Basin— Cycle 2 sediments’ section). Younger cover rocks are

Cycle 3 sediments which form part of the Ragged Basin

the Gwynne Creek Gneiss, and metasedof the Fraser Range Metamorphics (Figtheir close association with Fraser Zone mthe Fraser Range Metamorphics are coverZone’ section.

The Malcolm Metamorphics are dominatemetasedimentary rocks, including mafschist and minor calc-silicate rocks that ahad volcanic precursors (Plate 1; Fig. 1Malcolm Gneiss was reported to inclugranitic gneiss (Myers, 1995b), but recent has not found any evidence of this. The mrocks consist dominantly of muscovite–b

and quartzite, with subordinate garnet–bipelitic rocks that are locally migmatitic (Crecently dated samples of migmatitic seyielded maximum depositional ages ofand 1456 ± 21 Ma (Adams, 2011, 2012).these rocks are substantially younger thapublished maximum depositional age of(GSWA 112128, Nelson, 1995a), and alsuggestions of the presence of c. 1450 Min this area (Myers, 1995b) may reflect de

intrusive material Sample GSWA 11212




a)

CS134a

b)

Figure 15. a) Folded calc-silicate (green) rocks interlayered with mafic amphibolite (black); Malcolm MMalcolm (MGA 570579E 6260226N); b) semipelitic gneiss with layer-parallel leucosome; GwyGwynne Creek (MGA 688969E 6743276N)

and 2) It outcrops along the far northeastern edge of theF Z d l h h d i d b i i d al 1995) mark two major magmatic evi h S I d II f h Alb



Spaggiari et al.

which are similar to rocks of the adjacent Fraser Zone.Migmatitic gneiss (hole BRDDH2, GSWA 182476),interpreted as a probable metagranitic rock, yielded amagmatic crystallization age of 1326 ± 6 Ma, consistentwith the age of early Recherche Supersuite intrusions.

The same sample also yielded a date of 1187 ± 9 Ma,interpreted as Stage II high-temperature metamorphism.Mafic granulite (hole BRDDH2, GSWA 182477) yieldeda date of 1188 ± 4 Ma, also interpreted as the age of high-temperature metamorphism.

Recherche Supersuite meta-igneous rocks are also presentin the southeastern parts of the Biranup Zone, and oneoccurrence is exposed within the Munglinup Gneiss ofthe Northern Foreland. This suggests a spatial connectionbetween the Northern Foreland and the Kepa Kurl BooyaProvince, and between the Biranup and Nornalup Zones,during Stage I of the Albany–Fraser Orogeny. However,the Northern Foreland spatial connection is rather tenuous,being based solely on one example of biotite granodioriticgneiss from near Bald Rock, which has an igneouscrystallization age of 1299 ± 14 Ma (see ‘MunglinupGneiss’).

In the southeastern Biranup Zone, biotite monzograniticgneiss from Mount Burdett hornblende biotite

although the supersuite appears to be min the Nornalup Zone. Preliminary geocmonzogranite at Mount Ridley (GSWA 1yielded a magmatic crystallization age ofAlthough the monzogranite appears

outcrop, aeromagnetic imagery indicatesare deformed, and that the central, moreof the granitic body defines a strain shastrongly deformed gneissic rocks of theA similar granitic body, also interpreted Esperance Supersuite, occurs to the soutsuggesting that the magmatism thatEsperance Supersuite was not confined to Stage II, but extended from at least c. 1200

Ragged Basin — Cycle 3sediments

In the eastern Albany–Fraser Orogen, theFormation was not deposited until after Sand is therefore interpreted as a cover unKepa Kurl Booya Province, here termed C

of the Ragged Basin (Figs 2 and 4) Ali hi h M d P i h S li b




S t a r t

E s

p e r a n c e

6 2 5 0 0 0 0 m N 6 3 0 0 0 0 0 m N

1 2 2 ° 0 0 '

1 2 8 8 ± 1 2 M a

1 2 9 9 ± 1 8 M a

1 2 8 3 ± 1 3 M a

1 1

3 8 ± 3 8 M a

1 3 2 2 ± 1 1 M a

1 6 8 8 ± 1 2 M a

1 1 9 6

± 1 1 M a

C

o r u m u p H i l l

M o u

n t B u r d e t t

M o u n t R i d l e y

O b s e r v a t o r y P o

i n t

UP E

B I R A N U P Z O N E

I n c l u d e s i n t r u s i o n s o f

R e c h e

r c h e a n d E s p e r a n c e

S u p e r s u i t e s

N O R N A L U P

Z O N E

I n c l u d e s i n t r u s

i o n s o f

R e c h e r c h e a n d E

s p e r a n c e

S u p e r s u i t e s



Spaggiari et al.

granitic gneiss, and a two-pyroxene metagabbro that isundeformed in its core but deformed and amphibolitic atits margins (Clark, 1999). Outcrops of migmatitic peliticgneiss contain mesosomes of biotite–sillimanite–garnet–cordierite–feldspar–quartz(–spinel), and leucosomes that

are K-feldspar-rich with localized garnet(–cordierite).These gneisses record granulite-facies metamorphicconditions of approximately 800°C and >5 kbar (Clark,1999; Clark et al., 2000). The depositional age of theSalisbury Gneiss is unknown, although a lack of evidencefor Stage I metamorphism suggests deposition afterthis event, and therefore that the unit is distinct fromthe Malcolm Metamorphics (Clark, 1999). Migmatiticleucosome derived from partial melting of the pelitic

gneiss yielded dates of 1214 ± 8 (18 core analyses) and1182 ± 13 Ma (six rim analyses; Clark et al., 2000). Theolder date is interpreted as the age of crystallization ofthe leucosome, whereas the younger date is interpretedto reflect zircon growth during decompression from peakmetamorphic conditions (Clark et al., 2000).

In the Malcolm Metamorphics, a late-stage pegmatiteyielded a SHRIMP U–Pb monazite age of 1165 ± 5 Ma.This was interpreted as the age of crystallization of the

pegmatite the age of shearing related to thrusting of the

older than an IDTIMS baddeleyite age ofrom the Binneringie Dyke (French et precise SHRIMP baddeleyite and zircoand 2407 Ma from the Jimberlana Noriteunpublished data). Dykes belonging to the

Dyke Suite crosscut Archean structuresCraton, but are in turn cut by structures foMesoproterozoic Albany–Fraser Orogeny

The Gnowangerup–Fraser Dyke Suitlargest of the five mafic dyke suites, exthe southern and southeastern parts Craton, and forming part of the c. 12Moorn Large Igneous Province (WingaIt includes northeasterly trending dykes fAlbany–Fraser Orogen and southeastern informally named the Fraser dykes, whicontinuous with those in the central Albanand southern Yilgarn Craton. Most dykthe Gnowangerup–Fraser Dyke Suite arstrongly magnetic. Their trend changes feast-northeasterly in the west, to northeast — parallel to the craton margin. Iimages, the dykes are visible as mult

with the two dominant trends overlapp




The Nindibillup Dyke Suite comprises mafic (dolerite)dykes with an east-southeasterly trend (Spaggiari et al.,2009). These dykes vary from strongly magnetic andextensive — some up to hundreds of kilometres long— to moderately or nonmagnetic varieties that are less

extensively developed. The dykes of this suite clearlycrosscut major structures of the Albany–Fraser Orogen,and post-date Stage II (1215–1140 Ma) of the Albany–Fraser Orogeny. Preliminary geochronology, based ona sample from one of the largest (over 400 km long),strongly magnetic dykes of this suite, has yielded a dateof c. 750 Ma, although additional geochronology will berequired to confirm this age.

The Beenong Dyke Suite comprises a set of northwesterlytrending dykes (Spaggiari et al., 2009), which are mostlymoderately magnetic and tend to be relatively short inlength, especially in comparison to dykes of the NindibillupDyke Suite. Their age is presently unknown, although theyclearly crosscut structures in the Albany–Fraser Orogen.Their composition is also unknown. Although these dykeshave the same trend as the c. 1210 Ma Boyagin dykes,which are part of the Marnda Moorn Large IgneousProvince in the western Yilgarn Craton (Wingate et al.,

2005) they are probably younger as they crosscut Stage II

scale, layer-parallel leucosomes (Fignorthwesterly trending isoclinal folds planar foliation. The axial planes weby a second generation of leucosomessampled for dating by chiselling out the

along the axial plane (Fig. 7h). The datwo generations of leucosomes are withianother. The structural observations indiinjection occurred during a period southwesterly directed shortening (prthe age of which is constrained by the zfrom these samples. The characteristic of the gneisses in the Ponton Creek with the trends in aeromagnetic data w

slice that contains the gneisses (Fig. preserves evidence of both the shortemigmatization that accompanied it; i.e.The northwesterly trending fabric isnortheasterly trending fabric of the Frasebounds the Mesoproterozoic Fraser Zon

The Albany–Fraser Orogeny is dtectonic events: Stage I (1345–1260(1215– 1140 Ma) (Clark et al., 2000; B

2004a) Stage I of the orogeny is wide



Spaggiari et al.

geochronological data, age-constrained ‘suites’ may berecognized both chemically and geographically. Thesedata not only help us to understand the petrogenesis ofthe specific magmatic units, but can form a powerfulmapping tool and provide critical information on the

geodynamic evolution of the orogen itself. Although ourgeochemical database is not extensive enough for rigorousinterpretation, the data currently available confirm thata larger and geographically more extensive dataset willgreatly contribute to the understanding of the evolution ofthe Albany–Fraser Orogen.

Granitic rocks of the Biranup and

Fraser ZonesBased on the geochemistry of a limited number ofsamples, granitic rocks from specific tectonic regionsand of particular ages appear to form relatively distinctgroups, permitting, as yet very cautious, petrogeneticinterpretations. For example, the 1700–1650 Ma granitesof the eastern Biranup Zone are sodium-poor calc-alkaline rocks (Fig. 17a). Their major and trace-element

compositions and their continuous range of silica values

The most primitive gabbros are low- to metholeiites (Fig. 18a,b; green dots) withpatterns showing small to moderately nanomalies (not shown), which is consistearc, oceanic-arc, or fore-arc setting — o

with minor crustal contamination. The qurock between the gabbro sheets is cdiverse, but can essentially be subdiend-members: one with high thorium, ytterbium concentrations (Fig. 18c–e; redmargin, and field with yellow shade), fractionation of a mafic magma (possiitself); and the other with low lanthanumconcentrations, and high La/Yb ratios

dots, and field with blue shade), perhapstemperature partial melting of dry quamaterial. Interestingly, gabbros that showfor mingling or hybridization, or that weclose to lithological contacts (Fig. 18c–e; trends consistent with mixing between pmagmas and both felsic end-member cothree-component mixing). This type of mto be typical of a deep crustal ‘hot-zone’repeated gabbro intrusion eventually

temperatures above the solidus of both




1

2

3

4

5

6

60 65 70 75 80

NaO

2

SiO2 SiO2

a) b)

0.6

0.7

0.8

0.9

1.0

1.1

60 65 70

Fe*

Ferroan granites

800

1000

1200

8

10c) d)



Spaggiari et al.

0

1

2

3

40 4045 50 5055 60

KO

2

Medium-K

0

1

2

3

4

5

6

FeO*/MgO

Tholeiitic

Calc-a

15

20

50

60

70

SiO2 SiO2

a) b)

c) d)




(Kinny and Maas, 2003). To use this information toconstrain the time of extraction of the hafnium from themantle (crustal residence time) an assumption on the Lu/ Hf ratio of the precursor hafnium reservoir is required (i.e.the material in which the hafnium resided prior to being

incorporated into the zircon). Based on this assumption(e.g. a Lu/Hf ratio of typical crust is 0.015), the time atwhich hafnium retained in the zircon was extracted fromthe mantle can be estimated (e.g. Griffin et al., 2002).

Sm–Nd model ages (TDM) of 2930–2920 Ma obtainedfrom the rocks of the Munglingup Gneiss in the NorthernForeland (Fig. 2; see above) are similar to those fromfelsic units within the Eastern Goldfields Superterrane(Nelson et al., 1995). Hafnium analyses from theNorthern Foreland define a relatively restricted rangeof initial-hafnium values, indicating extraction from themantle at about 3.4 Ga (Fig. 19). The Eastern GoldfieldsSuperterrane yields hafnium model ages of 4.2 – 2.9 Ga.The model ages from the Northern Foreland are broadlysimilar to those from the Eastern Goldfields Superterraneand support the interpretation that the Munglingup Gneissis a component of the craton that was intruded by graniticrocks during Stage I, and metamorphosed to granulite

facies during Stage II of the Albany Fraser Orogeny

Domain of the Youanmi Terrane. Howbetween the crustal sources of the cYilgarn Craton is implied by the ovradiogenic values in the Youanmi Terevolved analyses in the Eastern Goldfi

This overlap is consistent with an aufor the Eastern Goldfields Superterrathe margin of the Youanmi Terrane), layered crustal architecture for the crat

Hafnium values for the Northern Fothe area of overlap between the valuGoldfield Superterrane and Youanmi A non-parametric statistical test (Koltest; Fasano and Franceschini, 1987

components in zircon between the inditerranes of the Yilgarn Craton and the reveals a weak correlation between theSuperterrane hafnium components, between the Northern Foreland and Yoother regions (Fig. 20; Table 1). The does not imply a total absence of coevaevents across this region, but indicates events in specific areas, or more likdifferent magma sources (e.g. a juvt th ith diff t l d t l



Spaggiari et al.

0 7

0.8

0.9

1.0

y in

itial

0.2820

0.2825

0.2830

DM

KalgoorlieTerrane

KurnalpiTerrane

YamarnaTerrane a

BurtvilleTerrane

YouanmiTerrane

Kalgoorlie Terrane - 1.000 0.012 0.683 0.000

Kurnalpi Terrane 1.000 - 0.033 0.465 0.000

Yamarna Terrane a 0.012 0.033 - 0.060 0.000

Burtville Terrane 0.683 0.465 0.060 - 0.000

Youanmi Terrane 0.000 0.000 0.000 0.000 -

Northern Foreland 0.000 0.002 0.000 0.000 0.000

NOTES: (a) indicates a low number of analyses and therefore uncertain significance.

Table 1. Table of K–S P-values used to test the hypothesis that the hafnium isotope model-age distributioare identical between samples from individual Yilgarn Craton terranes and the Northern Forelanof greater than 0.05 indicates a 95% confidence that the model-age components are similar. A c50 Ma uncertainty is assumed for each model age. The samples highlighted in bold have a statisticHf isotopic signature in their zircon components (at the 95% confidence level).




176

177

Hf/

Hf

initial

CLK30 22.08.11Age (Ma)

Central Biranup ZoneEastern Biranup Zone

Northeastern Biranup ZoneSoutheastern Biranup Zone

Fraser Zone

Gwynne Creek GneissFly Dam Formation

0.2810

0.2812

0.2814

0.2816

0.2818

0.2820

0.2822

0.2824

1000 1100 1200 1300 1400 1500 1600 1700 1800

CHUR

DM

Recherche Supersuite0

10

20

30

40

50

2

4

6

8

10

12

Number

Number

Central Biranup Zone

Eastern Biranup Zone

Northeastern Biranup Zone

Southeastern Biranup Zone

RechercheSupersuite

Fraser Zoneintrusives

Fraser Zone

metasediment

60

Figure 23. Initial-hafnium evolution plot for magmatic zirconsfrom the Fraser Zone and Recherche Supersuitecompared to the Biranup Zone (no results formetamorphic or hydrothermal zircons are included).Reworking of Biranup Zone crust can accountfor the most evolved Fraser Zone and RechercheSupersuite hafnium compositions. Detrital zirconsfrom metasedimentary rocks in the Fraser Zone

indicate additional juvenile input into the orogen



Spaggiari et al.

(Fig. 23). This juvenile signature indicates new crustgeneration prior to Stage I. Although speculative, thevariation through time towards more evolved values inthe Fraser Zone granites could imply oceanic subductionprior to crustal thickening, and melt interaction with a

larger volume of unradiogenic crustal material. This inturn could imply that active margin processes associatedwith the Fraser Zone could be extended back in time fromc. 1345 Ma (the beginning of Stage I) to at least 1400 Ma,although more data are needed to constrain this. Giventhat the Biranup Zone may have developed in a back-arc setting during the late Paleoproterozoic (Kirklandet al., 2011a), this may suggest a nearly continuousactive margin along the southern West Australian

Craton (in present coordinates) during most of the latePaleoproterozoic to Mesoproterozoic.

Tectonic modelsBased on current geochronological constraints, the tectonicevolution of the Albany–Fraser Orogen encompasses aninterval from at least 1800 Ma, through to 1140 Ma (Fig. 5).One of the difficulties in constraining tectonic models is thef h h f h d h dj i i

composed of exotic crust, with possiblethe Gawler Craton (Myers et al., 1996) Province of the southern Arunta Orogeal., 2009). These suggestions were also the interpretation that the southern an

Yilgarn Craton margin was passive atHall et al., 2008). However, more recentautochthonous models of the formationZone by modification of the Yilgarn Cractive-margin processes (Kirkland et al., connections to the Yilgarn Craton wrecognized in GSWA mapping and Rb–Sr(Bunting et al., 1976), in limited U–Pb(Black et al., 1992), and in limited S(Nelson et al., 1995).

The presence of Archean crustal fragmenlike ages, the extensive formation of relabasins (Barren Basin), hafnium and neodsignatures that indicate Yilgarn-like sPaleoproterozoic magmas, and a progrof juvenile material into Archean unraare all indicative of a continental-rift ssetting. This setting could have been pasystem, although the distance (to the sou

di t ) t f bd ti

GS / f O




subduction retreat

c) c. 1680 Ma

b) c. 1690 Ma back-arc basin

Yilgarn

Yilgarn

Biranup intrusions withY ilgarn fragment

Cycle 1 sediments

Cycle 1 sediments: volcaniclastics

asthenosphere

asthenosphere

Biranup intrusions

Deformation — Zanthus Event Biranup Zone intrusions

Cycle 1 sediments

p r o t o - C u n d e e l e e

F a u l t

seamounts?

a) c. 1710 Ma

194737

194731

194709

S i i t l



Spaggiari et al.

at 2634 ± 29 Ma, and interpreted to be part of anotherArchean fragment (Plate 1; Fig. 9; GSWA 179644,Wingate and Bodorkos, 2007c). Granitic rocks withc. 2680 Ma ages are widely recognized within the YilgarnCraton, including the high-Ca granites within the Eastern

Goldfields Superterrane (Cassidy et al., 2006; Championand Cassidy, 2007), the Southern Cross Domain of theYouanmi Terrane (e.g. GSWA 168963, Nelson, 2001), andwithin the Northern Foreland of the Albany–Fraser Orogen(Spaggiari et al., 2009).

East of Tropicana, the presence of rapakivi feldspar-bearing metasyenogranite with a magmatic crystallizationage of 1627 ± 4 Ma (GSWA 194736, Kirkland et al.,2010h) suggests back-arc extension may have continued

until about that time. After this, there is no record ofany tectonic activity within the present bounds of theAlbany–Fraser Orogen (west of the Rodona Shear Zone)until the commencement of the Albany–Fraser Orogenyat c. 1345 Ma (Fig. 4). However, in the adjacent MaduraProvince, the migmatization of gneissic rocks fromthe Burkin prospect, dated at 1478 ± 4 Ma (see ‘Euclabasement’ section; Fig. 3), indicates tectonic activityat that time, and the presence of pre- 1478 ± 4 Macrust beneath the Eucla Basin. Furthermore, there are

ti f j il t f ti b t 1450

Fraser Dyke Suite, emplaced at c. 1210 al., 2000, 2005), and the Esperance Suand 5). Stage II tectonic activity has beeintracratonic reactivation during the assembsupercontinent (Clark et al., 2000; Fitzsim

Stage I (1345–1260 Ma)

Stage I marks the time when the Nortand Biranup, Fraser, and Nornalup Zosynchronous tectonothermal or magmatic In previous models, this was taken as the the timing of the amalgamation of the variof the Kepa Kurl Booya Province, and of th

the Yilgarn Craton margin, in part via nothrusting (Myers et al., 1996; Clark et al., and Clark, 2004b; Spaggiari et al., 2009). with these models included a poor undespatial relationships between the differenover time, particularly for the early parts oand the question of whether to place thadjacent to the West Australian CratonMawson and South Australian Craton, or e

P i l lli i th ht t h

GSWA Record 2011/23 The geology of the east Albany Fraser O




which is most voluminous in the Nornalup Zone, mostlikely encompasses the same event, with Fraser Zonemagmas representing a shorter pulse. Within the BiranupZone, occurrences of Recherche Supersuite granites areconcentrated in, or possibly restricted to, the southeastern

exposed part (Plate 1; Fig. 16), suggesting that Stage Imagmatism was focused along the Mesoproterozoicsouthern and southeastern margins of the West AustralianCraton (present coordinates), but some distance from theYilgarn Craton component; i.e. within the outer parts ofthe Biranup Zone, as well as within the Nornalup Zone.

This scenario is seemingly at odds with models of cratoncollision during Stage I, although if the rift settingoccurred within a back-arc environment (as for the

Biranup Orogeny), the collision (or suture zone) mayhave been much farther outboard. Any model of collisionwith the combined Mawson and South Australian Cratonmust also account for the presence of the Madura, Forrest,Waigen, and Coompana Provinces (Figs 1 and 3), whichare poorly understood (see ‘Eucla basement’ section).In the scenario outlined above, the c. 1410 Ma rocksof the Madura Province could be interpreted as partof a magmatic arc. A dynamic back-arc setting for theFraser Zone would be consistent with the rapid burial of

i t i ll j il C l 2 di t f ll d l t

approximately 75 m.y. at high temperato granulite facies), on a major scaStage II could represent the effects(cf. Barquero-Molina, 2010), althougthe suture zone may have been a su

away from the margin of the West AIn either case, the structure of the obeen significantly modified during Staevent that appears mostly responsible northwest-vergent fold and thrust archthroughout most of the orogen.

The commencement of Stage II wastemperature metamorphism of the Sthe eastern Nornalup Zone and the so

Zone between c. 1225 and c. 1215 2000; Spaggiari et al., 2009). Metac. 1225 Ma, recorded in the southeasterButty Head), suggest that Stage II mayslightly earlier than previously propo(2000). This was followed by the widespof the c. 1210 Ma Gnowangerup–F(Clark et al., 2000; Wingate et al., 200geochronological data (Fig. 5), it is temperature metamorphism and asso

id d d i St II H

Spaggiari et al



Spaggiari et al.

The geology of the east Albany–Fraser Orogen — a field guid

Excursion 1: highlights of thegeology of the east Albany–

Fraser OrogenThis four-day excursion starts in Esperance and finishesin Kalgoorlie, covering a total distance of about 1040 km.

The geological sites in this excursion have been chosenbecause of their relative ease of access, quality of outcrop,and coverage of tectonic units, with the aim of providingan overview of the current work on the geology of theeast Albany–Fraser Orogen. To achieve this, large drivingdistances are necessary.

A general view of the excursion route is shown inFigures 26–29. Access to stops is via highways, shireroads, and four-wheel drive (4WD) tracks over a

bi i f l d l l d l d

exposed section of the Munglinup Gneissby major faults. The Munglinup Gneiss isto granulite-facies, reworked componenCraton, and forms part of the Northern‘Munglinup Gneiss’ section; SpaggiarSoutheast of the exposure, structures withiGneiss are cut by the Red Island Shearand 16). The Red Island Shear Zone —

small rocky island, visible from the coasthat the shear zone passes through — is ithe present-day expression of the boundNorthern Foreland and the Biranup Zone oBooya Province (Geological Survey of W2007).

The Munglinup Gneiss comprises agranulite-facies granitic gneiss interlayeof metamorphosed mafic rocks, and wit

h (j ili ) hib li i hi





Stop 8

End

Fig. 8

Fig. 11

121°

3 1 °

2 °

123°122°

Spaggiari et al



Spaggiari et al.

J E R D

A C U T T U P

F A U L T

124°30'123°00'121°30'

3 1 ° 3 0 '

3 3 ° 0 0 '

Fold

GEO

Fold

Trans–

End

Kalgoorlie

2

34

5

67

8

9,10





J E R D

A C U T T U P

F A U L T

124°30'123°00'121°30'

3 1 ° 3 0 '

3 3 ° 0 0 '

T

End

Kalgoorlie

2

34

5

67

8

9,10

Spaggiari et al.



Spaggiari et al.

J E R D

A C U T

T U P

F A U L T

124°30'123°00'121°30'

3 1 ° 3 0 '

3 3 ° 0 0 '

F

MAG

F

Trans–A

End

Kalgoorlie

2

34

5

67

8

9,10




g gy y

a) b)

c) d)

Spaggiari et al.



p gg

contains about 60% mesoperthite, 30% quartz,4.5% hornblende, 2.5% plagioclase, 2% clay–limonitealtered ?pyroxene, and 1% biotite, magnetite, titanite,and apatite. Subparallel grains and lenses of hornblende,altered ?pyroxene, opaque oxide grains, and titanite

up to 2 mm long together define a weak foliation,with individual grains up to 7 mm long. Some quartzand mesoperthite grains are also elongate parallel tothe foliation and are up to 4 mm long. The quartz andplagioclase grains are anhedral, with some plagioclaseintergrown with mesoperthite, and some as discrete grains.Most titanite has been altered to leucoxene.

Directions to Stop 4:

Continue driving 9 km along the Mount Andrew Track to Mount Andrew (MGA 493910E 6385287N). From here,walk west for approximately 700 m to the outcrop area ofStop 4 (MGA 493278E 6385090N).

Stop 4. Mount Andrew — Archeanfragment

Day 3

Continue northwest on the Mount An13.9 km from the Telegraph Track interseas you enter Southern Hills Station. Dri

left. Drive 1.9 km, bear right. Drive 1straight ahead (slight left) to follow fencelto reach the intersection with the FraseTurn right. Drive 4 km to Gnamma Hill.

Stop 5. Gnamma Hill — Frase

Metamorphics

The purpose of this stop is to exam

metasedimentary rocks within thewhich has been subject to detailed megeochronological investigation (Oorscho194714, Kirkland et al., 2011h; GSWA 1et al., 2011i). The field descriptions of largely based on Oorschot (2011).

Lithologies




a) b)

c) d)

Spaggiari et al.



Thermobarometry

Gnamma Hill semipelitic gneisses contain a peakmetamorphic assemblage consisting of quartz–garnet–sillimanite–ilmenite–K-feldspar–liquid–biotite.Petrological and phase-equilibria modelling of these rocks

constrain peak metamorphic conditions to 800–850°Cand 8–9 kbar (Fig. 32; Oorschot, 2011). The presence ofquartz, sillimanite, opaque minerals, and minor K-feldsparand biotite preserved in garnet, plus the absence ofprograde cordierite or kyanite, together indicate a progradepath along a geotherm of approximately 1250°C / GPa.Post-peak isobaric cooling at approximately 9 kbar haspreviously been documented by Clark et al. (1999).

metamorphosed at a high temperature, rerim growth at 1292 ± 5 Ma (GSWA 19et al., 2011h). This date is within unc1285 ± 7 Ma age determined for the cleucosomes within the same psammitic

194715, Kirkland et al., 2011i).Monazite from the granulite-facies semiGnamma Hill was dated in thin section by(SHRIMP) and yielded ages of 1285–12Oorschot, 2011). This age range was intemetamorphism, although not necessarily metamorphism. No difference was obsmonazite from different mineralogical sample (e.g. included in garnet, versus

Large monazites from a sample of leucoage of 1274 ± 9 Ma, interpreted as the agcrystallization (Oorschot, 2011). Analyrims from the same crystals providedof 1234 ± 17 Ma, interpreted as evidenmetamorphic, or fluid-related, event (see a

The difference between slightly older ages fduring metamorphism and slightly youcrystallization ages is consistent with k y

a n i t e

s i l l i m

a n i t e

7 5 0 ° C / G P a

post 1260 Maisobaric cooling

10

9

8




11401180

13401380

1300

1340

0.068

0.072

0.076

0.080

0.084

0.088

0.092

0.096

0.100

207

206

P

b/

Pb

4.0 4.2 4.4 4.6 4.8 5.0 5.2238 206

U/ Pb4.3 4.5

23

0.076

0.078

0.080

0.082

0.084

0.086

4.1

207

206

P

b/

Pb

1160

1200

1360

1400

0.075

0.077

0.079

0.081

0.083

0.085

0.087

0.089

3.9 4.1 4.3 4.5 4.7 4.9 5.1

207

206

P

b/

Pb

238 206U/ Pb

1200

1240

1280

1320

1360

in garnetin matrix

rims

FR10-011 FR10-007

Age(Ma)

FR10-007FR10-011

1274 ± 9 Ma1279 ± 19 Ma 1234 ± 17 Ma 1285 ± 16 Ma

Spaggiari et al.



a) b)

c) d)




Stop 7. Newman Rocks — NewmanShear Zone

The purpose of this stop is to observe mylonite and high-strain zones related to the formation of the Newman

Shear Zone, and to examine both Paleoproterozoic andMesoproterozoic metagranitic rocks within the shear zone.The Newman Shear Zone is a major structure that marksthe boundary between the Fraser and Nornalup Zones, andin this region is defined by a prominent demagnetizationzone that is at least 70 km long in aeromagnetic data(Figs 10, 11, and 29). The Newman Shear Zone is alsodefined by a distinct change in gravity data, from a high(dense) signature related to Fraser Zone rocks to the west,to a moderate (less dense) signature related to Recherche

Supersuite and Nornalup Zone rocks to the east (Figs 11and 28).

Approximately 36 km southwest of Newman Rocks, nearthe southwesternmost part of the demagnetization zoneand in the hinge of the large-scale S-fold described above(Excursion 1, Stop 2), coarse-grained monzograniticgneiss with a strong gneissic fabric has yielded apreliminary date of 1297 ± 8 Ma, interpreted as the age

L–S tectonite fabric (Fig. 34f) has yiedate of 1763 ± 11 Ma, interpreted as thcrystallization of the granite (GSW516435E 6447139N). This indicatePaleoproterozoic granitic rocks on t

the Fraser Zone, probably related to gBiranup Zone. Metasyenogranite of dated in the northeastern Biranup ZTropicana at McKay Creek (see ‘Biraor Excursion 2, Stop 3). The metagranGSWA 194784 is different from themegacrystic metagranite seen here at that it does not contain large K-feldspa

Retrace the route back to Fraser Range S

Day 4


From Fraser Range Caravan Park, d Eyre Highway and turn right (east). Dturnoff for the Symons Hill Track (on t

Spaggiari et al.



8

910

BIRANUPZONE

E D

D Y

S U I T E

Fly DamFormation

F r a

s e r F

a u l t

Z o n e

FRASERZONE

F

F

F

3 1 ° 3 0 '

123°30'123°00'

c. 1650 Ma

1670 ± 7 Ma

1660 ± 6 Ma

1665 ± 7 Ma

1665 ± 6 Ma

1668 ± 11 Ma

1671± 6 Ma

1617 ± 26 Ma

1640 ± 12 Ma

1666 ± 11 Ma

1677 ± 5 Ma

2656 ± 17 Ma

2684 ± 31 Ma




a)

b)


Retrace the track 6.1 km to the inteSymons Hill track, and turn left (norththis track for approximately 30 km; atrack on the left (MGA 551220E 65221

to the next track intersection and conti Drive 2.1 km to Stop 9 (MGA 546153along the northwestern edge of the saview of the different lithologies herit is worth walking over the northeapproximately 700 by 400 m wide risalt lake.

Stop 9. The Eddy SuiteThis locality has excellent exposures to the c. 1665 Ma Eddy Suite (part of a sequence of mingled and mixed memetagabbronorite and their inferred hymetagranodiorite contains rounded qup to 6 mm wide, and ovoid rapakito 3 cm long with a mantle of morwithin a medium-grained groundma

Spaggiari et al.



garnet-rich segments and layers are interpreted to beintruded remnants of the semipelitic schist exposed at thesouthwestern end of the salt lake.

Metagranodiorite from this locality yielded a dateof 1665 ± 6 Ma, interpreted as the age of magmaticcrystallization (GSWA 194720, Kirkland et al., 2010j).The sample contains ovoid rapakivi feldspars, tabulareuhedral feldspars, and rounded quartz phenocrysts, allwithin a fine- to medium-grained groundmass. Visuallyestimated, the sample’s mineralogy includes about 35%plagioclase, 30% quartz, 25% microcline, 6–8% biotite,1–2% garnet, and 1–2% hornblende–epidote; accessoryminerals include apatite and zircon. The rapakivi textureis defined by grains up to 15 mm long and 10 mm wide,

with cores of microcline (up to 10 by 6 mm) rimmed byaggregates of quartz and inequigranular, coarse-grainedplagioclase. Discrete euhedral plagioclase grains arealso present in this sample, and contain small inclusionsand interstitial patches of microcline and quartz. Someplagioclase grains contain needles of epidote and minorsericitized cores. Aggregates of biotite(–hornblende)are developed within some plagioclase-rich rims onK-feldspar grains, but can also form discrete clots. Garnet,epidote, and hornblende are associated with the biotite

Semipelitic, garnet–micaceous schist inmetagranodiorite, exposed at the souththe salt lake (MGA 546046E 6534694N),moderately north-northeasterly plungingwith metagabbronorite in the core. T

inclined with a southeast-dipping axial folds a strong foliation (S1). A mineral lineon the S1 plane has the same orientataxis. The southeastern limb of the fold inortheasterly trending shear zone contaiand boudinaged rocks. A mineral lineatstrain zone plunges 62° towards 005. A cuts the fold parallel to the hinge. In sschist contains rounded porphyroclastsimilar to those in the rapakivi me

(Fig. 37c). The rounded K-feldspar porinterpreted to have been derived from passociated with intrusions of Eddy Suitsubsequently dispersed throughout the schstrain deformation. Late granitic to pegmthe foliation and folding, both here and elocality.

A sample collected from the sheared se(GSWA 194722, Kirkland et al., 2010c) yi




a) b)

c) d)

Spaggiari et al.



a) b)

c) d)




decametre-scale folds with moderately southeast-dippingaxial planes. Within the hinges are small-scale tight foldswith a similar trend, which fold both the gneissic fabricand thin leucosome layers. The tighter angle of these foldssuggests they may represent an earlier phase of co-axial

folding. The gneissic fabric is cut by pegmatitic veins5–10 cm wide.

Along strike to the northeast at this locality (Stop 10;MGA 545986E 6535986N), are two phases of graniticgneiss with a well-developed gneissic foliation that dipsconsistently and moderately to the southeast (Fig. 38b).As at the locality described above, thin leucosome veinsare tightly folded with this foliation (Fig. 38c). Locally,however, the folded leucosomes have an axial-planar

foliation that is parallel to the main foliation. Younger,coarser leucosome veins are slightly discordant to thegneissic foliation (Fig. 38b) or crosscut it at high angles(Fig. 38d). Apart from the late, high-angle leucosomeveins, the sequence suggests the possibility of continuedleucosome formation before and after folding, with theinjection of new (low angle) leucosome following folding.Coarse, late pegmatite also crosscuts the gneissic fabricand folding, as do quartz veins.

most of the quartz and feldspar grains long. Some of the plagioclase grains disseminated fine-grained epidote.

The other granitic phase at this localitysyenogranitic gneiss with sparse and leucosomes, both of which are gneissic foliation, and are folded wyielded a date of 1668 ± 11 Ma, inteof magmatic crystallization of the sye194724, Kirkland et al., 2010l). The about 45% microcline, 36% quartz,5–6% biotite, <1% hornblende, and oxide grains, titanite, apatite, and ziare less than 2 mm long, with a fo

dark yellow-brown biotite and very hornblende. Rare plagioclase containsand fine-grained muscovite of secondatitanite grains are largely altered to leu

Directions to Kalgoorlie:

Continue another 10.2 km along the snorthwest, to an intersection with aand turn right (to the east). Drive 2.1

Spaggiari et al.



Excursion 2: Tropicana in aregional context

This four-day excursion starts and finishes at Tropicana,covering a total distance of about 300 km, not includingdriving times and distances from Kalgoorlie. Thegeological stops described in this excursion have beenchosen based on their relative ease of access, quality ofoutcrop, coverage of the various tectonic units, and toprovide an understanding of our current interpretations ofthe geology of the Tropicana region.

A general view of the excursion route is shown inFigures 39–42. All access is via 4WD tracks situated on

crown land or DEC-managed lands (i.e. Plumridge LakesNature Reserve). Some tracks are located within an activeexploration and mining area (Tropicana Joint Venture,or JV), and access via drilling tracks requires an escortby staff from the Tropicana Gold Project. Although thisguide provides location details for use by anyone wishingto independently follow the excursion route, it must benoted that restrictions apply to DEC-managed lands.Please contact the relevant authorities before proceeding,especially as track conditions are subject to change,

Please note that substantive new infrasTropicana JV is currently in developmenreplacement of the existing access trackexploration camp, and the provision of thand communications requirements for a m Access to the Tropicana mine site, airfi access roads requires prior written appGeneral Manager, Tropicana Mine.

Geological overview

The Tropicana region covers the noexposures of the Albany–Fraser Orogen and 40). It comprises rocks of the Nor

Biranup Zone, and Gwynne Creek GneCycle 2 sediments). In this region, Nornalup Zones are entirely under the coBasin. Outcrop is sparse throughout mucincluding around the Tropicana Deposilarge areas with no outcrop at all.

The Carboniferous to Permian Paterlocally overlies this part of the orogenunconformable contacts, mostly preserve




Sto

St

See enlargements:Figs 4

Sto

Stop 1

121°

2 9 °

3 0 °

124°123°122°

Spaggiari et al.



C U N D E E L E

E

F A U L T

125°00'124°30'124°00'

29°00'

1

Neale

Havana

Swizzler

CrouchingTiger

Atlantis

Pleiades

Hercules

Kamikaze

Hat Trick

Muirfield

Boston Shaker

Rusty Nail

Voodoo Child

Black Dragon

ScreamingLizard

Excurs

PreMines

Indu

Excurs

Fold a

Aerom

Mafic

Fault

GEO

Fold; a

4

Tropicana

7 8910

65

4

3

1

2

Y A M A R N A

S H E A R Z O N E




C U N D E E L E E

F A U L T

125°00'124°30'124°00'

29°00'

Neale

Havana

Swizzler

CrouchingTiger

Atlantis

Pleiades

Hercules

Kamikaze

HatTrick

Muirfield

Boston Shaker

Rusty Nail

Voodoo Child

Black Dragon

ScreamingLizard

E

M

E

A

F

F

4

Tropicana

F

M

7 8910

65

4

3

1

2

Spaggiari et al.

125°00'124°30'124°00'



C U

N D E E L E E

F A U L T

125°00'124°30'124°00'

29°00'

1

Neale

Havana

Swizzler

CrouchingTiger

Atlantis

Pleiades

Hercules

Kamikaze

HatTrick

Muirfield

Boston Shaker

Rusty Nail

Voodoo Child

Black Dragon

ScreamingLizard

Excurs

PreMines

Indu

Excurs

Aerom

Fault

MAGNET

Fold; a

4

Tropicana

Fold a

Mafic

7 8910

65

4

3

1

2




a)

CS154

b)

Figure 43. a) Strongly altered metagranite, sampled approximately 7 km north of Tropicana, which yielded anage (GSWA 182435, see text for details); b) mafic to ultramafic rocks intruded by the same metaat the same locality.

Spaggiari et al.



CS162 12.06.12

PERTH

400 km

KALGOORLIE

TropicanaGold Project

W.A.

100 km

Tropicana JVgranted tenure

Tropicana JVapplications

Miscellaneous licencefor water exploration

Kalgoorlie–Boulder

Pinjin

Sunrise Dam

Laverton

Tropicana Gold Mine

TGMtenements

Figure 44. Tropicana Gold Project: location, tenements, andaccess routes. Figure courtesy of AngloGoldAshanti; abbreviations used: JV = joint venture;

ShakerShear

BostShea(BSS

JiggerShear Zone

TRO

145 000

144 000


th t th t th t d ill d fi t A D illi i ti i i th S i l



that the stronger northern zone was not drilled first. Aswith the initial RC program at Tropicana, the first RCresults received were disappointing, despite the strongbiotite–pyrite alteration noted in most of the holes. Laterresults from the northern zone indicated that Havanahad the potential to be both larger and higher grade thanTropicana. Better results from this program included 26 m@ 2.0 g/t, 11 m @ 3.1 g/t, 21 m @ 4.0 g/t, 32 m @ 2.5 g/t,30 m @ 4.4 g/t, 41 m @ 3.7 g/t, and 18 m @ 6.0 g/t.Furthermore, several sections at Havana showed twomineralized zones, whereas only one zone was identifiedat Tropicana. The project now moved rapidly into aphase of resource delineation drilling. A project scopingstudy completed in April 2007 indicated the potential fora viable project and led to the commencement of pre-

feasibility studies in mid 2007. Approval to commencethe bankable feasibility study (BFS) was obtained in 2009.

During the fourth quarter of 2009, a program of sixholes was drilled to test for potential extensions alongthe northern margin of the Tropicana zone. Detailed3D modelling of the geology, combined with structuralanalysis of drillcore, suggested that the mineralizationmay have been offset along a major bounding shear,now known as the Boston Shaker Shear Zone (Fig. 45).

Drilling is continuing in the Swizzlerproposed Tropicana and Havana pits) anA pre-feasibility study is being carrieand underground mining options for mineralization, and this is anticipated toMineral Resource. The project remains its first gold in the December quarter o

Project geology

The Tropicana Deposit has a knoof about 5 km, and defines a nomineralized corridor approximately 1all grid references are relative to true otherwise; the Tropicana local grid n

east of true north). The deposit commineralized zones — from north to Shaker, Tropicana, Havana, and Ha(Fig. 45). The deposit as a whole is locextensive mineralized system, which 10 km along strike.

Neither the immediate metamorphmineralized zones are exposed at the presence of widespread Recent to

Spaggiari et al.

Table 2 Tropicana GoldProject: mineral resourceestimates 31 December2010 versus30 June2011 Tablecourt



31 December 2010 30 June 201

Mineral resource Classification Tonnes

(millions) Grade (g/t

Au) Ounces

(millions) Tonnes

(millions) Grade (g/

Au)

Open pit Measured 25.8 2.18 1.80 28.4 2.15

Indicated 28.8 2.04 1.89 43.9 1.89

Inferred 16.6 1.81 0.96 1.0 3.06

Total — open pit 71.2 2.03 4.65 73.3 2.01

Underground Measured 0.00 0.00 0.00 0.00 0.00

Indicated 0.00 0.00 0.00 0.00 0.00

Inferred 5.3 3.65 0.63 5.3 3.65

Underground — Havana Deeps 5.3 3.65 0.63 5.3 3.65

Total Tropicana Measured 25.8 2.18 1.80 28.4 2.15

Indicated 28.8 2.04 1.89 43.9 1.89

Inferred 21.9 2.26 1.59 6.3 3.56

Project Total 76.5 2.15 5.28 78.6 2.12

Table 2. Tropicana Gold Project: mineral resource estimates, 31 December 2010 versus 30 June 2011. Table courtAshanti.

Table 3. Tropicana JV: ore reserve estimates, 30 November 2010 versus 30 June 2011. Table cour


The metamorphic rock associations and mineralized zones The mineralized zones are principa



The metamorphic rock associations and mineralized zonesare cut by younger, syn- to post-peak metamorphic maficintrusions. The dolerite intrusions display the effectsof greenschist-facies metamorphism and range fromnonfoliated to schistose. Mafic dykes with crystallineinteriors and thin (1–2 cm) chilled or weakly sheared

margins are ascribed to the c. 1210 Ma Gnowangerup–Fraser Dyke Suite, providing a minimum age formineralization.

Stratigraphic architecture

The immediate host rocks to the mineral deposit haveundergone polyphase deformation resulting in a complexarrangement of lithofacies and significant thickening of

the package. Nevertheless, the distribution of lithofaciesassociations remains predictable at the deposit scale, andserves as a useful guide for planning drilling and proposedmining operations. The garnet gneiss facies associationdominates the immediate hangingwall of the mineralizedzones, forming a structurally thickened stratigraphicinterval up to 200 m thick at Havana (Figs 46 and 47).

Chert and former ferruginous chert units (metasedimentaryfacies association), are interleaved with the garnet

The mineralized zones are principarocks of the quartzofeldspathic gnefacies associations. This stratigraphicto herein as the ‘favourable horizon’) along the strike length of the deposhorizon is underlain by a mixed stra

comprising rocks of the quartzofegarnet gneiss, granulite, and amphibThe top of the footwall package is mappearance of garnet gneiss, amphibGold mineralization, generally of lin both the footwall and hangingwpackages as thin (typically <3 m) leof the metasedimentary facies, gquartzofeldspathic gneiss associations.thin intercepts up to 10 g/t gold hahowever, the continuity of these zoncurrent drillhole spacing (typically 25–

Mineral deposit architecture

Together, the Boston Shaker, TropicHavana South zones define a northeast-tcorridor approximately 1.2 km wide bybeen tested to a vertical depth of up t

Spaggiari et al.

W



Ore zone

Saprolite

Pebblysandstone

Basalt dyke

Garnet gneiss

Amphibolite

Metamorphosedferruginous chert

Pegmatite

T

F a v o u r a b l e

h o r i z

o n

F o o t w

a l l

W

CS165

300

Biotite chlorite dominantschist

–

Quartzofeldspathicgneiss

200

100

RL


47900 48000 48100 48200 48300



CS166

Section line

T P A 0

1 3 1

T P A 0

1 3 2

T P A 0

1 3 3

T P R C

0 1 9

T P D 0

0 9

T P A 0

1 3 4

T P R C

0 5 7

T P D 0

1 0

T P D 0

1 8

T P R C

0 2 0

4 m

@ 1 . 0 1

g / t

5 m

@ 1 . 3 1

g / t

6 m

@ 2 . 6 5

g / t

2 4 m

@ 2 . 7 9

g / t

i n c . 8

m @ 1 . 7 4

g / t

a n d

1 0 m

@ 4 . 1

g / t

4 4 m

@ 1 . 4

g / t

i n c . 1 5

m @

2 . 8

g / t

2 m @ 1

5 . 0 g / t

1 9 m @

4 . 7 g / t

1 7 m @

1 . 4 g / t

3 2 m @

1 . 5 5

g / t

i n c . 8 m @ 1

. 1 6 g / t

a n d 1 8

m @ 2 . 0

6 g / t

1 6 m @

1 . 1 g

/ t

1 5 m @

1 . 0 g / t

3 0 m @ 2 . 3 1

g / t

i n c . 1 5

m @ 3 . 4 9

g / t 2 9 m @

4 . 3 7

g / t

i

1 9 m @

6 2

2 4

Transported

BOCO

> 0.5 g/t Au

Significant intercepts

300RL

200

100

47900 48000 48100 48200 48300

Figure 48. Simplified cross section,Tropicana zone (local grid 143500N). Figure courtesy of AngloGold A

Spaggiari et al.

a generally east-plunging line. Higher-grade lodes in the grade threshold, K-feldspar rich gneiss



a generally east plunging line. Higher grade lodes in theHavana South and Boston Shaker structural domains arelaterally discontinuous and many are displaced on shears,making interpretation of the RC drillholes difficult.

In sections parallel to the plunge direction, higher-grade

(about 3 g/t gold) lodes are enveloped by lower-gradeshells and are oriented at a slightly steeper angle than themodelled approximately 0.3 g/t gold envelope (Fig. 50). Insections orthogonal to the plunge direction, approximately3 g/t gold lodes comprise steeper bounding domains andflatter linking segments, the intersection of which definesthe principal lineation (Fig. 51). The resultant geometryis interpreted as a linked shear system that manifests indrillcore as discontinuous biotite–sericite–pyrite shearsdeveloped on the millimetre to centimetre scale, andare characterized by asymmetric S–C fabrics and sigmaporphyroclasts.

Mineralization

Two mineralization styles are identifiable in the TropicanaDeposit, based on sulfide mineral occurrence and host rocktype. They are:

grade threshold, K feldspar rich gneissfacies contain a higher proportion of gold within the quartzofeldspathic gneiss assocSulfides within the ore zones are domi(2–8%; grain size <0.2 mm), with acceschalcopyrite, electrum, and telluride min

minerals including, but not limited to, spand bornite. Free gold occurs mostly (typically 10–30 µm) inclusions within commonly along biotite–sericite fractureminerals. Visible gold has been obserdrillcore from the Boston Shaker zone, quartz veins are notably absent. The penveloped by a disseminated pyrrhotite(–is locally more strongly developed in t

particularly at Havana. Within the minerapyrrhotite inclusions in pyrite suggest variable, oxidation states.

Mineralized zones are enclosed within aalteration envelope. The alteration envemineralogical zonation, with central biotcalcite(–siderite) zones passing outward thbiotite > chlorite(–calcite) zones, into sebiotite–calcite) zones at the margins (Fig.


outward from controlling thrusts into a rheologically and and gold mineralization formed from



3 g/t

SW (local)

TFRC100 TF

w g g ychemically receptive K-feldspar rich gneissic package.Permeability created during brittle fragmentation wasaccompanied by synchronous partitioning of strain intopervasively biotite–sericite–pyrite-altered dissolution- andshear-planes that envelop more competent lithons. Sulfide

gsilica-undersaturated fluids bufferedat variable oxidation. In combinatiassemblages, the occurrence of chalcopelement concentrations in pyrite suggesexceeding 350˚C.

Spaggiari et al.



Ore zone

Saprolite

Pebblysandstone

Basalt dyke

Garnet gneiss

Metamorphosedferruginous chert (ANC)

Quartzofeldspathic gneiss (ANF)

Transp

BOC

H a n g i n

g w a l l

F a v o u r a b l e

h o r i z o n

F o o t w a l l

W

300

200

100

RL

F ld hib l t / bi tit i (ANFA)


Day 1 A prominent hill 2.6 km northeast



Day 1

Stop 1. Havana South

This stop (MGA 6 49300E 67 60100N) is located within an

active exploration and mining area. Access is via drillingtracks and requires an escort by staff from the TropicanaGold Project.

Use of hammers and removal of samples at this localityis strictly prohibited, as the exposures are located within the bounds of a registered archeological site.

Rubbly outcrop on a low ridgeline southeast of the HavanaSouth orebody marks the position of a major shear zone

(Crouching Tiger Shear Zone) that can be traced forseveral kilometres in RC and diamond drilling. Domainsof sericite and chlorite schist 5–10 m wide locally containlithons of lower-strain rock showing greater preservation ofearlier deformation fabrics. Within schistose domains, thefoliation dips moderately to the east-southeast, with an S–Cintersection lineation plunging approximately 30° towards110–130. S–C fabric relationships are contradictory, asboth dextral and sinistral kinematics are identifiable,altho gh de tral kinematics are more ab ndant

pDeposit provides a rare opportunitybasement rocks within this sand-coTrick Hill lies at the southern end of a that has been mapped in detail (Fox, 2section of the guide summarizes the d

described by Fox (2010).

The geology of the Hat Trick Hill areBIF, amphibolite, granulite, and feldipping BIF units cap many of thcoincide with hinge regions of open,and synforms. Banding within the BIFparallel to original stratification, but modified by metamorphism, isoclpegmatite intrusion. Evidence of early the BIF is recorded by asymmetricalfolds (F1). In some locations, F1 folds aan axial planar cleavage (S1) that is sub(bedding; S0) along the limbs, and dbetween cherty and carbonate-rich baF1 folds plunge to the north and south the hinge surfaces dip approximately strong mineral elongation lineation (Lthe banding plane parallel to the F1 fo

Spaggiari et al.

INDEX MAP 655000 mE 6



MAIN MAP

INDEX MAP 655000 mE

THE SOUTH

T-JUNCTION

Quartz vein

Monzonite/gabbro — inferred

Monzonite/gabbro, aeromagnetic inference

Banded iron-formation locally ±hematite / magnetite

Granite, locally ± pyroxene, migmatite

Granite, locally ± pyroxene, migmatite — inferred

Pegmatite

Dacite

Monzonite/gabbro

2 km

6


sheared contacts. L1 dominantly plunges to the southeast, actinolitic amphibole, minor quartz, ti



and small-scale F1 folds display a well-developed axialplanar cleavage. F2 folds and a weak stretching lineationdefined by aligned magnetite plunge gently to the south.Combined, the minor fold vergence and reverse faultseparation of the BIF units are inconsistent with refolding

of a large-scale F1 fold around northeast-trending F2 folds.

Locality 2.3. Hat Trick ridge

This locality (MGA 6 55900E 67 66900N) is accessible fromthe Tropicana exploration camp via active explorationtracks within the Tropicana Gold Project mining leases.

Lying at the northern end of Hat Trick ridge is an outcroparea of high structural complexity. Strings of BIF areinterleaved with schist that locally contains lithons ofgranitic gneiss. Banding (bedding) within the BIF dipsboth to the west and to the east, marking the position ofa northeast-oriented fold with a hinge surface dippingapproximately 50° towards 110. Folds are ascribed toF3 on the basis of rotation of L1 around the northeast-trending axes. Gentle, upright F4 folds are evident on themetre scale, and cause widespread warping of the outcroppattern at this locality and throughout the Hat Trick area.

oxide grains. The pyroxenes (dominaand lesser orthopyroxene) are partlrimmed by amphibole and chlorite,also relict hornblende overgrown by pamphiboles are acicular and range from

to blue-green, to blue, with the latter insodic composition. Large cracks in thwith chlorite and locally, epidote. Tovergrown with epidote and zoisite, avein is present. This rock may have beup to granulite facies, and subsequenamphibolite–greenschist facies.

A second sample of metagabbro (Gcomposed mostly of plagioclase andclinopyroxene but possibly minor orpyroxene is overgrown by blue-greeamphibole, although minor relict hpresent. The plagioclase is overgrowminor zoisite, and there is also minooxide grains, quartz, apatite, and posA foliation is defined by amphibole metagabbro may have been metamorphfacies (based on the presence of ?orth

Spaggiari et al.

Granite, locally ±i i



Figure 55. Detailed geological map of the Hat Trick Hill area, showing banded iron-formation (in yellow), granitic gneiss (in purple), and the main F2 fold

6766300 mN

655500 mE

25 m

655600 mE

CS160 03.07.12

Bedding, inclined

F1

F2

F3

ShearThrust

F syncline2

F anticline2

Banded iron-formation ±hematite / magnetite

ypyroxene, migmatiteGranite, locally ± pyrox-ene, migmatite inferred—


a) b)



Cs172

Figure 56. a) Quartz veins in Bobbie Point Metasyenogranite; Excursion 2, Stop 4, Bobbie Point; b) PaleoPoint Metasyenogranite (GSWA 194737).

Spaggiari et al.

latter indicating younging to the southeast (Fig. 57b,c).B ddi f th ti t t h lf t

basin formation along the margin of thed i ifti i t d d i th B



Bedding ranges from the centimetre to half-metrescale, and its orientation varies from vertical to steeplysoutheast-dipping. The metasedimentary rocks contain aweak, low angle cleavage dipping steeply to the northwest.The facing direction, bedding cleavage relationships, and

intersection all indicate a northeasterly plunging anticlinewith its hinge to the northwest; i.e. this ridge is in theeastern limb of an upright anticline.

Across strike to the east is sparse rubbly outcrop ofstrongly foliated phyllitic schist. At the easternmost partof this section, just below a small rise of laterite, is astrongly deformed quartzite with a northeasterly trending,vertical foliation that contains a mineral lineation plunging37° towards 028. This coincides with a minor shear zone

interpreted in the aeromagnetic data (Plate 2; Fig. 42),which is parallel to the major northeasterly trending shearzones that occur in the vicinity of gold mineralization tothe northeast (e.g. Hercules Prospect).

Preliminary geochronology of a quartzite sample (GSWA182405) from this locality has yielded a maximumdepositional age of 1990 ± 15 Ma, based on a weightedmean date from two analyses from a single zircon. A

i i f h i f

during rifting, prior to and during the B(see ‘Barren Basin — Cycle 1 sedimQuartzite mapped to the west at LindsGraaff and Bunting, 1977), adjacent toFault (Plate 2), is inferred to be anot

Barren Basin Cycle 1 sediments. A pos1760–1750 Ma detrital maxima, whichthese sediments, are the c. 1760 Ma gthe Biranup Zone. This indicates mixingdetritus from the Yilgarn Craton (i.e. fromwith Biranup Zone granitic rocks (potentsources, or from the opposite direction, o

Although this field guide does not inclumetaconglomerate locality southeast o

(there is no track to it), it is includedcomparison to the metasedimentary at Stop 6. The pebbles in the metacosubangular to subrounded, and range fromlong) and closely packed (clast-supp(0.5 – 2 cm long) and more sparse (maThey are commonly black and white anhave magnetic susceptibility measuring uunits. There are distinctive iron-rich la


a) b)



c) d)

Spaggiari et al.

long, occur mostly within the micaceous lamellae, whereasrare patches rich in microcrystalline tourmaline occur in

parallel to the axial plane of the fold. dense finely layered strongly foliated roc



rare patches rich in microcrystalline tourmaline occur inquartz-rich lenses.

Camp off the track nearby.

Day 3


Retrace the tracks past Bobbie Point to Rason Lake Road,and then southwards through to the intersection with theTropicana Camp Road. Continue straight ahead for 2 kmon Rason Lake Road, avoiding the right turn (the main

road to the Tropicana airstrip). You are now on the trackthat leads to Plumridge Lakes Nature Reserve. Continue for 7.3 km to the turnoff to Pleiades Lakes (MGA 6 68821E67 58867N). Note that both the turnoff and first 5–6 km oftrack can be quite washed out. Continue following thetrack for 22.2 km, to Stop 7 (MGA 6 83549E 67 70104N).

Stop 7. Pleiades Lakes —Paleoproterozoic metagranites

dense, finely layered, strongly foliated roc10 m long by 4 m wide is surroundedfelsic dykes, and by a weathered paveme(Fig. 58a). The lens is in the shape of a stplunging S-fold, and contains earlier, sma

folds with an axial-planar foliation.

The metasyenogranitic dykes are nonmathe dark lens has magnetic susceptibilityfrom 2000–6000 x 10-5, and locally e8000 x 10-5 SI units, indicating a high maThis suggests that the lens is likely metamorphosed iron-formation. A samplerich rock (GSWA 182407) has a magnetic1200–2000 x 10-5 SI units, with the varia

in part to the layering. The sample contaproportions of magnetite, metamorphic and quartz, about 10% plagioclase, anbiotite. Iron-rich clots and schleiren are metagranites west of Pleiades Lakes (sStops 6 and 7). If this lens is a raft metamorphosed iron-formation, then it these sediments locally affected the commetagranites.


yielded moderate to high magnetic susceptibility readingsthat range from 200 1800 x 10-5 SI units indicating the

secondary muscovite and sericite, inamphibolite-facies metamorphism



that range from 200–1800 x 10 SI units, indicating thepresence of magnetite in these clots.

The K-feldspar megacrystic metagranite yielded apreliminary date of 1689 ± 9 Ma, interpreted as the

magmatic crystallization age (GSWA 182428; Fig. 58c).Two analyses yielded preliminary dates of 1800 and1784 Ma, interpreted as the ages of inherited components.The date of 1689 ± 9 Ma indicates that the megacrysticmetagranite is distinctly older than the metasyenograniticdyke dated at Stop 7, which is consistent with the fieldrelationships seen here (Fig. 58b). To the south of thislocality, at Stop 9, is a similar K-feldspar megacrysticmetagranite, although with a more syenograniticcomposition, which yielded a preliminary date of

1694 ± 7 Ma (GSWA 182411). These dates, and the olderdates from Bobbie Point (c. 1710 Ma; Excursion 2, Stop 4)and MacKay Creek (c. 1760 Ma; Excursion 2, Stop 5),show that granitic magmatism of dominantly alkalinecomposition affected this region from at least c. 1760 Mathrough to c. 1670 Ma, although the c. 1760 Ma granitesmay represent an earlier, separate event. Most of thesegranitic magmas also show evidence for the presence of aco-magmatic mafic phase.

amphibolite-facies metamorphism biotite–garnet) may have been foltemperature modification.

To the west, near the track (MGA 68

is an area of scattered outcrop of a mmingled with the K-feldspar megac(Fig. 58d). This has produced a hybridquartz and K-feldspar phenocrysts, r3–10 mm in size, within a fine-grainedThe mafic intrusive has an igneous be originally of noritic compositionPLUMRIDGE 1:250 000 sheet (van de G1977). It is slightly magnetic, at 1units. Just east of the track, the hybr

subvertical, high-strain fabric trending nlineation plunging 52° towards 154.

Two samples of this hybrid rock and 182409) have quartz and K-felranging from 3–10 mm within a finIn thin section, GSWA 182408 has defined by interlocking plagioclaserelict clinopyroxene overgrown by

Spaggiari et al.

a) b)



c) d)


Day 4 Stop 10. Mylonite and ultrazones




Drive cross-country, approximately 300 m to the south(MGA 6 84379E 67 69891N).

Stop 9. Pleiades Lakes —Paleoproterozoic metagranite

The purpose of this stop is to view small whalebacks andboulders of metasyenogranite, one of which was sampledfor geochronology. The metasyenogranite is pink togrey, coarse grained, and seriate textured to porphyritic.

It contains tabular feldspars up to 2 cm long, within acoarse-grained, seriate groundmass of feldspar, quartz,and biotite. Quartz phenocrysts are typically mauve incolour, and biotite occurs in clots up to 4 mm in diameterthat also locally contain magnetite. These clots sometimesform millimetre- to centimetre-scale, wispy, irregularschlieren that are strongly magnetic (Fig. 59a). Themetasyenogranite also contains strongly magnetic maficpods that appear to have disaggregated and dispersed asmafic clots throughout the rock The metasyenogranite

zones

This stop is in an area of good ouseveral ridges. At this locality, K-femetagranite is interlayered (or mingled

The metagabbro is fine grained (averagand although foliated, has a relict ignmoderately magnetic, up to about 20Metagabbro sample GSWA 18242 complagioclase and minor perthite, withovergrown by complex mixtures ogreen amphibole, epidote, opaque oxiand ?chlorite. Some of the opaqueby amphibole. As metagranite sampwas cut perpendicular to the lineationthe mylonitic fabric. The porphyrK-feldspar, microcline, or perthite, acoarse muscovite within the fabric. Tfine grained, and consists of feldspaabundant, tiny, aligned biotite flakessection was cut, the feldspar and quarecrystallized with recovery textures.

The K-feldspar megacrystic metagran

Spaggiari et al.

a) b)



c) d)


thereby constraining the timing of brittle deformation inthis rock to between 1270 and 1193 Ma (Kirkland et al.,

a)



( ,2011a).

The geochronology indicates that deposition of theGwynne Creek Gneiss took place after the Biranup

Orogeny, and that a substantial component of the detrituswas sourced from rocks of the Biranup Zone. Thisinterpretation is consistent with other Cycle 2 sediments,such as those in the Fraser Range. Mafic sills or dykesand localized intrusions of ultramafic rocks throughoutthe metasedimentary succession are probably relatedto the c. 1300 Ma Fraser Zone intrusions. Interpretedmetamorphic dates of 1297 ± 7 Ma and 1270 ± 11 Maindicate minimum depositional ages, and most likelydate high-temperature metamorphism and leucosome

formation in the Gwynne Creek Gneiss during Stage Iof the Albany–Fraser Orogeny. The younger date of1193 ± 26 Ma indicates that these rocks were also affectedduring Stage II, possibly after a period of uplift and brittledeformation. These interpretations are consistent with fieldrelationships, as described below.

The approximately 16 km long, north–south sectionof Gwynne Creek and adjoining areas provide good

b)

Spaggiari et al.

Some of this amphibole is quite blue and is probablyreibeckite. Another amphibole is pleochroic pale-green to

Beeson, J, Delour, CP and Harris, LB 1988

metamorphic traverse across the Albany Mo

A li P b i R h 40



p p p gvery bright emerald green, and is locally intergrown withfibrous amphibole. Some of the opaque oxide grains haverims of small garnets, and there are also sparse, small,euhedral garnets throughout the matrix. There appears to

be some relict pyroxene (orthopyroxene?), which is veryaltered and overgrown with fine amphibole and chlorite.These are set within a matrix of interlocking plagioclase,some of which may be anorthite (no albite twinning). Thesample also possibly includes rare titanite and accessoryapatite.

Semipelitic gneiss (GSWA 184399; sampled adjacent tothe track turnoff to this locality) is fine to medium grained,and has a strong to mylonitic foliation. It comprises about

10–15% biotite and 8–10% garnet, with the remaindercontaining K-feldspar, plagioclase, and quartz, withaccessory epidote, opaque oxide, and zircon. Biotite ispale to medium brown, and is aligned in the foliation.Garnet is clear, partly overgrown, and is locally wrappedby the foliation, or has pressure shadows. The quartz andfeldspars have mostly lobate or ragged grain boundaries,although some grains show recovery textures and 120°

junctions. The thin section also contains textures in the

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Craton, Western Australia. Part I. Kalgoorlie and Gindalbie Terranes:

Precambrian Research, v. 161, p. 135–153.

Love, GJ 1999, A study of wall-rock contamination in a tonalitic gneissfrom King Point, near Albany, Western Australia: Curtin University

of Technology, Perth, Western Australia, BSc Honours thesis

(unpublished).

Muhling, PC and Brakel, AT (compilers) 1985, Mount Barker – Albany,

Western Australia: Geological Survey of Western Australia, 1:250 000Geological Series Explanatory Notes, 21p.

Myers, JS 1985, The Fraser Complex: a major layered intrusion in

Western Australia, in Professional papers for 1983: Geological Surveyof Western Australia, Report 14, p. 57–66.

Myers, JS 1990a, Albany–Fraser Orogen, in Geology and mineralresources of Western Australia: Geological Survey of Western

Australia, Memoir 3, p. 255–263.

Myers, JS 1990b, Yilgarn Craton — mafic dyke swarms, in Geology and

mineral resources of Western Australia: Geological Survey of WesternAustralia, Memoir 3, p. 126–127.

Myers, JS 1995a, Geology of the Albany 1:1 000 000 sheet: Geological

S f A li 1 1 000 000 G l i l S i

Australia, 4p.

Nelson, DR 2005c, 178072: tonalitic gneiss, Hai

Record 598: Geological Survey of Western A

Nelson, DR, Myers, JS and Nutman, AP 1995, C

of the Middle Proterozoic Albany–Fraser OroAustralian Journal of Earth Sciences, v. 42, p

Nemchin, AA and Pidgeon, RT 1998, Precise con

baddeleyite U–Pb age for the Binneringie

Western Australia: Australian Journal of

p. 673–675.

Oorschot, CW 2011, P–T–t evolution of the Fras

Orogen, Western Australia: Geological Surv

Record 2011/18, 101p.

Pawley, MJ, Romano, SS, Hall, CE, Wyche, S an

The Yamarna shear zone: a new terrane boun

Yilgarn Craton?, in Geological Survey of W

Review 2007–08: Geological Survey of W

Western Australia, p. 27–33.

Pawley, MJ, Wingate, MTD, Kirkland, CL, Wych

SS and Doublier, MP in press, Adding piece

crustal growth and a new terrane in the no

Western Australia: Australian Journal of E

no. 5.

Spaggiari et al.

Thom, R, Chin, RJ and Hickman, AH (compilers) 1984a, Newdegate,

Western Australia: Geological Survey of Western Australia, 1:250 000

Geological Series Explanatory Notes 24p

Wetherley, S 1998, Tectonic evolution of the M

Albany–Fraser Province, Western Australia: Un

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Geological Series Explanatory Notes, 24p.

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Turek, A 1966, Rubidium–strontium isotopic studies in the Kalgoorlie–Norseman area, Western Australia: Australian National University,

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i d SA i k G l i l S




Logistics

These field excursions are designed on a safari-style, self-drive, self-cater basis; i.e. participants are responsible fortheir own transport (see notes below regarding vehiclesuitability), camping equipment, food, and water. Although

this guide provides location details and driving directions,which can be used by anyone wishing to independentlyfollow the excursion routes, it is also recommended thattravelers take topographic maps and a GPS for navigation.

The excursions involve several nights of camping. In mostof the camping areas, there are no facilities of any kindavailable. It is important that participants bring enoughfood and water to last the duration of each excursion,

Appendix

Field trip logistics

fitted or supplied with fire extinguisand all repair and recovery equipmentduring off-road driving, including trepair, and bog recovery equipment. fitted with long-range fuel tanks, careproperly store any portable fuel tanks (

drivers should be suitably certified or road (4WD) driving.

Convoy procedure

This section applies to all GSWA-ledcan involve large numbers (as many travelling for long distances. Norma

Spaggiari et al.

Excursion 1

Day 1:

Day 3:

AM: intersection of the Rason L



Day 1:

AM: corner of Farrell’s Road and South CoastHighway — 33°44′18.2″ S, 121°17′53.7″ E

PM: intersection of the Coolgardie–EsperanceHighway and Telegraph Track — 32°21′16.4″ S,121°45′34.0″ E

Day 2:

AM: Stop 2 — MGA 492094E 6395845N

PM: intersection of the Mount Andrew Trackand Telegraph Track — MGA 481033E 6411397N

Day 3:

AM: Stop 5, Gnamma Hill —MGA 471530E 6439471N

PM: Fraser Range Station —MGA 480565E 6456426N

Day 4:

AM: intersection of the Rason LTropicana Camp Road —MGA 663957E 6762255N

PM: Stop 8, Pleiades Lakes area

MGA 684468E 6770483N

Day 4:

AM: Stop 7, Pleiades Lakes areaMGA 683549E 6770104N

PM: Start of Plumridge Lakes — MGA 681534E 6753770N

Travel from Tropicana to Kalgoorlie:

AM(1): intersection of the TropiArgus Corner Road — MGA 629

PM(1): Argus Corner (about 5 hTropicana) — 30°10′05″ S, 123°

PM 2: Pinjin, left-hand turnoff oKurnalpi Road — MGA 472830


Camping

The excursion involves several nights of camping



The excursion involves several nights of camping.Participants are responsible for bringing their owncamping equipment, including swags, tents, and food.Potential hazards involved in collecting firewood and

around open fires are to be noted and appropriate caretaken. All rubbish is to be removed. All participants arerequested to exercise appropriate care and discretion withrespect to ablutions, and all waste is to be buried andtissues disposed of by burning (noting bushfire hazardsin doing so, particularly in high winds). Please be awareof the potential to become disoriented and detached fromthe camp whilst seeking privacy for ablutions. If you getlost, stay where you are and wait for your absence to benoticed. Always carry a box of matches or a lighter in case

you need to light a signal fire.

Other potential hazards involved with camping in theAlbany–Fraser region include snake bites, and scorpion,centipede, spider, and other insect bites or stings.

Note that wild camels represent a threat, and should neverbe approached.



This Record is published in digital format (PDF) and is available as a freedownload from the DMP website at<http://www.dmp.wa.gov.au/GSWApublications>.

Information CentreDepartment of Mines and Petroleum100 Plain StreetEAST PERTH WESTERN AUSTRALIA 6004Phone: (08) 9222 3459 Fax: (08) 9222 3444http://www dmp wa gov au/GSWApublications

Further details of geological products produced by theGeological Survey of Western Australia can be obtained by contacting:



PATERSON FORMATION: conglomerate(includingdiamictite),sandstone,andsiltstone;largelyglacigene

Albany–Fraser Orogeny StageII (1215–1140Ma)

Doleriteandgabbrodykes;east-northeast- tonortheast-trending;mostlyinterpretedfromaeromagneticdata;concealedwheredashed

ìÒBN-odìÒNB-odìÒNW-od

maficdykes;northwesterlytrending;interpretedfromaeromagneticdatamaficdykes;west-northwesterlytrending,variablymagnetic;someexceeding400km long;mostlyinterpretedfromaeromagneticdata

northwest-trendingmaficdykes;interpretedfromaeromagneticdata;concealedwhere dashed

BeenongDykeSui te:Nindibillup DykeSuite:Cosmo NewberyDykeSu ite:

ìEP-gìEP-gm

Graniticrock;undeformedtomoderatelydeformed

Monzogranite;undeformedtomoderatelydeformed;includesmagnetite-richvarieties

318–270Ma

1200–1140Ma

c.1210Ma

n g e r u p –

F r a s e r

y k e S u i t e

ìoìod

Maficintrusiverock

Doleritedyke,sill,orplug;fine- tomedium-graineddoleriteandgabbro;concealedwheredashed

E s p e r a n c e S u p e r s u i t e

C A R B

O N I F E R O U S –

P

E R M I A N

P A L E O Z O I C

P H

A N E R O Z O I C

P R O T E R O Z O I C –

P H A N E R O Z O I C

G U N

B A R R E L B A S I N

A L B A N Y – F R A S E R O R O G E N

ìo

ìEP-g

ìod

ìGF-od

ì ÒB N- o d ì ÒN B- od ìÒNW-od

ìEP-gm

æåpa-sepg

REDUCED-TO-POLE AEROMAGNETIC IMAGE

123° 124°

29°

30°

125°

GEOLOGICAL SURVEY OF WESTERN AUSTRALIA GEOPHYSICAL AND REMOTE SENSING IMAGERY AND REFERENCE FOR PLA



Albany–Fraser Orogeny StageI (1345–1260Ma)

Metagabbroicrocks;mayincludefelsicgranulite,metagraniticandìmogFR

ìxmog-mgnFR Metagabbroicandmetamaficrocks;mayincludemetagraniteand

GWYNNE CREEK GNEISS: psammiticgneisswithminorsemipeliticlayers;includesminormetagranitic,metamafic,andmeta-ultramaficrocks

ìmgBRìxmg-mogBR

ìxmgn-mogBR

Metagranite

Graniticgneissintrudedbycoarsepegmatite;undivided;mayincludeinterleavedFraserZonerocks

K-feldsparmegacrysticmetagraniteandmetasyenogranite,mingledwithmetagabbroicrocks;hybridrocks;

Quartziteandmetasandstone,interbeddedwithmetasiltstone;locallyinterbedded

Doleriteandgabbro;includescumulateandgranophyricdifferentiates;concealedwheredashed

ðxmgn-mwaAFON ðxmg-moAFON

ðxmin-mogAFON

Graniticgneiss;quartzofeldspathicgneiss,locallywithgarnet;amphibolite;metagranite;minor metabandediron-formation;mayinclude BiranupZone intrusions

Metagraniticandmetamaficrocks;ArcheangraniteandgreenstoneandProterozoicgraniticandmaficrocksdeformedand

Metabandediron-formation,metagabbro,andmetaleucogabbro;mayincludemetagraniteand BiranupZone intrusions

c.1305–1290Ma

metasedimentaryrocks,maficandfelsicgranulite

metasedimentaryrocks;undivided

withmetaconglomerateandpebblymetasandstone

MOUNT RAGGED FORMATION: psammiticschistandquartziteinterbeddedwiththinlayersofpeliticrocks

ìRE-mgìRE-mgm

Metagranite;heterogeneous;evengrainedorporphyritic;moderatelytostronglydeformed;mayincludeintrusionsof EsperanceSupersuite

Monzograniticgneiss;maycontainremnantsof BiranupZone rocks

1305–1290MaFRASER RANGE METAMORPHICS:sheetedandmostlystronglydeformedmetagabbro,

metagranite,andminormetasedimentaryrocks;includeshybridrocksandmaficandfelsicgranulite

1335–1290Ma

FRASER RANGE METAMORPHICS

ìFM-xmdn-mhn

ìFM-xmhn-mno

Sedimentarygneiss;psammitic,semipelitic,andlocallycalc-silicatelayers;

Sedimentarygneiss;interlayeredpsammitictopelitic,amphibolite-togranulite-faciesgneiss,commonlyinterlayered withbandsofamphibolite,or maficandfelsicgranulite

commonlyinterlayeredwithbandsofamphibolite,ormaficand felsicgranulite

ìgk-xmtn-moìmm-xmh-mws MALCOLMMETAMORPHICS:interbeddedpsammiticandpeliticschist;maficamphiboliticschist;minorcalc-silicaterocks;mayincludegraniticdykesandintrusions

Metagraniticandmetamaficrocks,undivided;mayincludemetasedimentaryrocks

Biranup Orogeny(1710–1620Ma)

ìxmgn-mdnBR Graniticandmetasedimentarygneissesdominant;includesintrusionsof Recherche and EsperanceSupersuites;mayincluderemnantsof Archeanrocksìxmgni-mhnBR Migmatitic,monzogranitictosyenograniticgneissesdominant;commonlygarnet-bearing;mayincluderemnantsofArcheanrocks

FLY DAMFORMATION: interbeddedpsammitictopeliticgneisswithleucosomes;c .1620Ma

1321–1150Ma

1330–1280Ma

1700–1620Ma

1480–1345Ma

c.1665MaMetagranodiorite,metadioriteandmetagabbro,graniticgneiss,lensesofmetasedimentaryrocks,

andpegmatite;mayincluderemnantsof other BiranupZoneunits

c .1708Ma

c.1760Ma

c.2410Ma

c.1750Ma WOODLINE FORMATION:quartzmetasandstone,quartzmetaconglomerate,

ðmgBR Metagraniticrocksdominant;mayincluderemnantsofArcheanrocks

Metagraniticandgneissicrocksdominant,locallywithmaficamphibolitelenses;mayincluderemnantsofArcheanrocks ðmgnBR ðmgniBR ðxmgss-mwaBR ðxmwa-mgssBR

Migmatitic,monzogranitictosyenograniticgraniticgneissesdominant;mostaregarnet-bearing;mayincluderemnantsof Archeanrocks

Foliatedmetagraniticrockswithlensesofmaficamphibolite;mayincluderemnantsof Archeanrocks

Maficamphibolitedominant;intrudedbyfoliatedmetagraniticrocks;mayincluderemnantsof Archeanrocks

2700–1650Ma

2800–1330Ma

Metamonzogranite;foliated ñmgmBR

ñmgrBR Metasyenogranite;mostlyhomogeneous;weaklytostronglyfoliated;localfolded maficamphibolitelenses;sparseleucosomes

2700–2630Ma

2710–1330Ma

metamorphosedduringthe Albany–Fraser Orogeny

ñxmu-mdAFON

ñxmb-muAFON

ñxmi-mdAFON

ñmbAFON

ñxmog-maeAFON ñmoAFON

Meta-ultramaficrocks,quartzite,metaconglomerate,andmetasandstone

Greenstones,undivided;mayincludeironformation

Metabandediron-formation,metachert,metasedimentaryrocks,andamphibolite

Metamaficvolcanicrocks,undivided

Metagabbroandmeta-ultramaficrocks;intrudedbymetagranite

Meta-igneousmaficintrusiverock,undivided

Biotitemetamonzogranite;mediumtocoarsegrained ñmgmY ñmgnY ñmgssY ñgY ñgmY

Graniticgneiss,locallymigmatitic;includeslocalmaficbandsand enclaves

Foliatedmetagranite,locallygneissic;mayincludeamphibolitelenses;includesdeeplyweatheredrockGraniticrock,undivided;metamorphosed

Monzogranite;commonbiotiteandrarelocalhornblende;minorgranodioriteandsyenogranite;fine tocoarsegrained;equigranular toporphyritic;

massivetoweaklyfoliated;metamorphosed

Gneiss;protolithunknown

Siliciclasticsedimentaryrock,undivided;includessandstone,siltstone,shale,and chert;metamorphosed

G n o w a n D y

mayincluderemnantsofArcheanrocks

W i d g i e m o o l t h a

D y k e S u i t e

graniticgneiss,heterogeneous,andminormetamaficrocks;Archeangraniteandgreenstoneand

Proterozoicgraniticandmaficrockdeformedandmetamorphosedduringthe Albany–Fraser Orogeny

MUNGLINUP GNEISS:

2900–2660Ma

c.2706Ma 1

2716–2638Ma 2

2679–2634Ma

R e c h e r c h e S u p e r s u i t e

P R O T E R O Z O

I C

A R C H E A N – P R O T E R O Z O I C

N E O A R C H E A N – P A L E O P R O T E R O Z O I C

M E S O P R O T E R O Z O I C

P A L E O P R O T E R O Z O I C –

M E S O P R O T E R O Z O I C

P A L E O P R O T E R O Z O I C

E d d y S u i t e

peliticlayersgarnet- andbiotite-rich

andmetasiltstone

R A G G E D B A S I N

A R I D B A S I N

B A R R E N B A S I N

F r a s e r a n d N o r n a l u p Z o n e s

M A D U R A P R O V I N C E

B i r a n u p Z o n e

B i r a n u p Z o n e

B i r a n

u p Z o n e

N o r t h e r n F o r e l a n d




ìmgBR

ñgY

ðmgBR

ìWI-o

ñgmY

ìRE-mg

ñsYKA

ñmgnY

ìrg-mh

ìwo-mt

ñmgmY

ìbt-mgr

ñmgssY

ñmgrBR

ìmogFR

ñmnYKA

ñmgmBR

ìfd-mhng

ñmoAFON ñmbAFON

ðmgnBR

ìRE-mgm

ðmgniBR

ìxmg-mwMD

ìgk-xmtn-mo

ìkc-xmgr-mgi

ñxmi-mdAFON

ìxmog-mgnFR

ìxmt-mtqAFOB

ñxmb-muAFON ñxmu-mdAFON

ðmu-xmgn-mo

ìEY-xmgg-mog

ìmm-xmh-mws

ìFM-xmhn-mnoìFM-xmdn-mhn

ìFM-xmog-mgn

ðxmg-moAFON

ìxmgn-mogBR

ðxmin-mogAFON

ñxmog-maeAFON

ðxmgn-mwaAFON

ìxmgni-mhnBRì xm g- mo gB R ì xm gn -m dn BR

ðxmgss-mwaBR ðxmwa-mgssBR

metasyenogranite;weaklyfoliatedto mylonitic;includesminormingledmaficrocksandBOBBIE POINT METASYENOGRANITE:minorbandediron-formationrafts

MCKAY CREEK METASYENOGRANITE: metasyenogranite,mingledwithmetagabbro;localizedhybridsof metagranodioriteand

metadiorite;mayincludeintrusionsof BOBBIE POINT METASYENOGRANITE andremnantsofArcheanrocks

125°

123°122°

122°31°

32°

33° 33°

34° 34°

124°

0 200

Kilometres

SCALE 1:3000000

RADIOMETRICTERNARY IMAGE

124°

125°

125°

122°

29°

30°

31°

32°

123°

C u n d

e e l e e

F a u

l t

ìÒNW-od

ìod

ìÒNW-od

ìÒNW-od

ìod

ìod

ìod

ìod

ìod ìod

ìGF-od

ìÒNW-od

ìGF-od

ìod

ìod

ìGF-od

ìGF-odìÒNW-od

ìod

ìÒNW-od

ìGF-od

ìod

ìod

ìÒNW-od

ìod

AgY

ìbt-mgr

ðmgBR

Atp-xf-s

AmbYYA

AgY

Atp-xf-s

æåpa-sepg

æåpa-sepg

AmwYYA

AmgnY

AmbYYA

æåpa-sepg

Atp-xf-s

Atb-xs-c

AmbYYA

Atb-xs-c

æåpa-sepg

ìxmg-mogBR

Neale

Atlantis

Hercules

Muirfield

St Andrews

Carnoustie

PineValley

Purple Haze

PebbleBeachAu

Au

Au

Au

Au

Au

Au

Au

Au

R A S O N

LAK E

R O A D

124°0' 124°30' 125°0'620 660 700 740

INTEGEOLOGICAL SURVEY OF WESTERNAUST RALIA

PATERSON FORMATION:conglomerate (including diamictite),sandstone,andsiltstone;largelyglacigene

Northwest-trendingmafic dykes; interpreted from aeromagnetic data; concealed where dashed

Doleritedyke,sill,or plug;f ine- tomedium-graineddolerite andgabbro;concealedwheredashed

Graniticrocks;undeformed tomoderatelydeformed

Albany–Fraser OrogenyStage II(1215–1140Ma)

Doleriteandgabbrodykes;east-northeast- tonortheast-trending;mostly interpretedfromaeromagneticdata

Albany–Fraser OrogenyStage I(1345–1260Ma)

Metagranite;heterogeneous;even grainedorporphyritic;moderately tostronglydeformed;mayinclude intrusions of Esperance Supersuite

GWYNNE CREEK GNEISS:psammitic gneiss withminorsemipelitic layers;includes minor metagranitic,metamafic,and meta-ultramaficrocks

ìmgBRìxmg-mogBR

MetagraniteK-feldsparmegacrysticmetagranite andmetasyenogranite,mingledwith metagabbroicrocks;hybridrocks;

mayinclude remnants ofArchean rocks

1

CosmoNewbery

DykeSuite

Esperance

Supersuite

Gnowangerup–Fraser

DykeSuite

Recherche

Supersuite

CARBONIFEROUS–

PERMIAN

PALEOZOIC

PHANEROZOIC

Biranup Orogeny(1710–1620Ma)

MESOPROTEROZOIC

PROTEROZOIC

C

318–270 Ma

1200–1140Ma

c.1210Ma

1330–1280Ma

1480–1300Ma

1700–1620Ma

ìod

ìmgBR

ìEP-g

ìGF-od

ìRE-mg

ìÒNW-od

æåpa-sepg

ìgk-xmtn-mo

ìxmgn-mogBRìxmg-mogBR



F a u

l t

Y a m

a r n a

F r a s

e r F a

u l t

Z o n

e

C u n d

e e l e

e

C u n d e

e l e e

Cobbler Shear Zone

DonLinoShearZone

F a u

l t

S h e a r

Z o n e

F a u l t

C u n d e e l e e

F aul t

B o o n d

e r o o

F a u l t

B o o n d e r o o

ìGF-od

ìWI-o

ìod

ìÒNW-od

ìod

ìWI-o

ìÒNW-od ìÒNW-od

ìod

ìod

ìod

ìod

ìod

ìod

ìod

ìod

ìÒNW-od

ìod

ìGF-od

ìod

ìod

ìÒNW-od

ìod

ìGF-od

ìod

ìod

ìod

ìod

ìod

ìod

ìod

ìod

ìod

ìod

ìod

ìod

ìod

æåpa-sepg

ìxmg-mogBR

ìRE-mg

ìmogFR

ìxmgn-mogBR

ðxmgn-mwaAFON

ìgk-xmtn-mo

ðxmg-moAFON

ìxmog-mgnFR

ìEP-g

ìkc-xmgr-mgi

ìxmog-mgnFR

æåpa-sepg

ìmgBR

æåpa-sepg

ñxmog-maeAFON

æåpa-sepg

æåpa-sepg

ðxmin-mogAFON

æåpa-sepg

ñxmog-maeAFON

æåpa-sepg

ðxmin-mogAFON

æåpa-sepg

ìxmt-mtqAFOB

ìxmt-mtqAFOB

æåpa-sepg

æåpa-sepg

æåpa-sepg

ðxmin-mogAFON

æåpa-sepg

æåpa-sepg

ìxmt-mtqAFOB

æåpa-sepg

æåpa-sepg

ìxmt-mtqAFOB

ìxmg-mogBR

ìgk-xmtn-mo

ìxmgn-mogBR

Ninja

Havana

Airstrip

Swizzler

Pleiades

Kamikaze

AngelEye

BlackOak

Hat Trick

RustyNail

AngelsKiss

HavanaSouth

VoodooChild

BlackDragon

ChromiteCreek

CrouchingTiger

ScreamingLizard

Medusa –Peninsula

BostonShaker TropicanaGroup

Au

Au

Au

Au

Au

Au

Au

Au

Au

Au

Au

Au

Cr, Pt

Cr, Pt

Cr,P t

Cr, Ni,Cu, Au, Pt, Pd, HM

Au

Au

Au

Au

R A S O

N

L A K E

R O A D

124°0' 124°30' 125°0'

29°0'

29°0'

29°30'

29°30'

620000mE 660 700 740

6 7 2 0 0 0 0 m N

6720

6760

6760

6800

6800

ìxmgn-mogBR Graniticgneissintruded bycoarse pegmatite; undivided;may include interleavedFraser Zone rocks

BOBBIE POINT METASYENOGRANITE:metasyenogranite;weaklyfoliatedto mylonitic;includesminormingledmafic rocksand

MCKAY CREEK METASYENOGRANITE:metasyenogranite,mingledwithmetagabbro;localizedhybrids ofmetagranodioriteand

metadiorite;mayincludeintrusionsof BOBBIE POINT METASYENOGRANITE and remnants of Archean rocks

minor bandediron-formation rafts

Metagraniticrocks dominant;mayinclude remnants ofArcheanrocks

Dolerite and gabbro;includes cumulateand granophyricdifferentiates

ðxmg-moAFON

ðxmin-mogAFON

ðxmgn-mwaAFON

Metagraniticandmetamaficrocks;Archean graniteand greenstone andProterozoicgranitic andmafic rocks deformedand metamorp

Meta banded iron-formation,metagabbroandmetaleucogabbro;mayincludemetagranite and Biranup Zone intrusionsGraniticgneiss;quartzofeldspathicgneiss,locally withgarnet;amphibolite;metagranite;minor bandedmetairon-formation; mayinclu

Metagabbroandmeta-ultramaficrocks;intrudedby metagranite

ñmgnY ñgY

Graniticgneiss,locallymigmatitic;includeslocalmaficbandsand enclaves

Graniticrock,undivided;metamorphosed

TOBIN FORMATION:wacke,lithic sandstone,siltstone,abundantchert andbanded iron-formation,and minorfelsic volcaniclasticrocks

TOPPIN HILL FORMATION: felsic volcanic andvolcaniclastic rocks,withminorsiliciclasticsedimentary rocks; metamorphosed

Meta-igneous mafic rock; undivided

Metamaficvolcanic rock,undivided

c.

Widgiemooltha

DykeSuite

NEOARCHEAN–PALEOPROTEROZOIC

ARCHEAN–PROTEROZOIC

PALEOPROTEROZOIC

NEOARCHEAN

ARCHEAN

1708 Ma

1760 Ma

2700–1650 Ma

c. 2410 Ma

2800–1330 Ma

c. 2706 Ma1

2699–2682Ma23

ñgY ñmgnY

ñtp-xf-s

ìbt-mgr

ðmgBR

ñtb-xs-c

ñmbYYA

ñmwYYA

ìkc-xmgr-mgi

ðxmg-moAFON ðxmin-mogAFON

ñxmog-maeAFON

ðxmgn-mwaAFON

ìWI-o

SOUTHERN OCEAN

GSWARECORD2011/23 PLATE1

TAY

3032

ROE

3436

LORT

3131

HOPE

2932

PRICE

3833

NAMBI

3241

PINJIN

3437

DIMER

3937

YILMIA

3135

LEECH

4038

TRANS

4035

TOLGA

3934

HELMS

4039

BOYCE

3238

BAILEY

3540

RASON

3740

BINNJA

3940

DOVER

4032

HARMS

3533

MELITA

3139

TOPPIN

3640

WEEBO

3141

COWAN

3234

WILBAH

3040

MEINYA

3739

CULVER

3832

HOWICK

3430

YERILLA

3239

MINERIE

3240

ARNOLD

4040

DUNDAS

3232

JENKINS

3733

YABBOO

3438

BARDOC

3137

PONTON

3537

MULLINE

2938

NARNOO

3638

YARDINA

3334

MENZIES

3138

BOWDEN

3838

GWYNNE

3939

WILDARA

3041

CAIGUNA

3933

BALLARD

3039

CLAYPAN

3837

ERAYINIA

3435

ZANTHUS

3635

BURDETT

3331

RIVERINA

3038

NARETHA

3835

DOONGIN

4037

YARDILLA

3434

CARLISLE

3737

SCADDAN

3231

JARLEMAI

3639

LEONORA

3140

OLDFIELD

3030

McMILLAN

3441

MALCOLM

3630

YEOLAKE

3741

EDJUDINA

3338

BULDANIA

3333

KURNALPI

3336

SEEMORE

3936

CHARLINA

3532

COONANA

3535

MINIGWAL

3538

MERIVALE

3330

GODDARD

3736

BARTLETT

3839

CAVE HILL

3134

KANOWNA

3236

RAWLINNA

3935

GINDALBIE

3237

CAPE ARID

3529

LAVERTON

3340

MOOLYALL

2931

MONDRAIN

3329

BURTVILLE

3440

JOHNSTON

3033

KANANDAH

3836

EMU POINT

3734

ROCKHOLE

3932

SALISBURY

3629

KAKAROOK

3738

BEAUMONT

3431

ROUNDTOP

2933

MUNJEROO

2941

CAUSEWAY

3229

GAMBANCA

3732

LIGHTFOOT

3539

KITCHENER

3735

NORSEMAN

3233

MULGABBIE

3337

BURAMINYA

3531

PLUMRIDGE

3938

YANDALLAH

3636

BOORABBIN

2935

COWALINYA

3332

NOONDIANA

3634

CUNDEELEE

3536

DAVYHURST

3037

ESPERANCE

3230

DUNNSVILLE

3036

LAKE PERCY

2934

LAKE CAREY

3339

BALLADONIA

3633

RECHERCHE

3429

NORTHOVER

3031

KALGOORLIE

3136

CARDANUMBI

4033

MOUNT DEAN

3631

NEARANGING

2937

MOONYOORA

3637

SYMONS HILL

3534

WESTISLAND

2929

SANDY BIGHT

3530

MOUNT CELIA

3439

LAKE LEFROY

3235

WOOLGANGIE

3035

MARDARBILLA

3632

DOUBLE TANK

3834

COCKLEBIDDY

4034

STOKES INLET

3130

WATTLE CAMP

3731

INVESTIGATOR

3029

RAVENS-

THORPE

2930

EASTERN

GROUP

3730

MOUNT

MASON

2939

PEAK

CHARLES

3132

MOUNT

ALEXANDER

2940

S

DIAMOND

ROCK

3034

MORTON

CRAIG

3841

FRASER

RANGE

3433

SCHERK

RANGE

3840

DOROTHY

HILLS

3641

MOUNT

VARDEN

3341

MOUNT

WALTER

2936

MOUNT

ANDREW

3432

BRONZITE

RIDGE

3133

NEALE

JUNCTION

4041

MOUNT

BELCHES

3335

YELLOWTAIL

BORE

4036

DISAPPOINTED

HILL

3941

MULGABIDDY

CREEK

3541

BAILLY

SI 51-8

RASON

SH51-3

NEALE

SH 51-4

CULVER

SI 51-4

MENZIES

SH51-5

ZANTHUS

SH 51-15

NARETHA

SH 51-16

LEONORA

SH51-1

MALCOLM

SI 51-7

EDJUDINA

SH51-6

SEEMORE

SH 51-12

KURNALPI

SH 51-10

MINIGWAL

SH51-7

CAPE ARID

LAVERTON

SH51-2

NORSEMAN

SI 51-2

PLUMRIDGE

SH51-8

BOORABBIN

SH 51-13

CUNDEELEE

SH 51-11

ESPERANCE

SI 51-6

BALLADONIA

SI 51-3

KALGOORLIE

SH51-9

RAVENSTHORPE

SI 51-5

LAKEJOHNSTON

SI 51-1

WIDGIEMOOLTHA

SH51-14

MONDRAINISL ANDINVESTIGATOR ISLAND

1:250000maps showninbrown

Searchfor currentGSWAmapproducts online<http://www.dmp.wa.gov.au/GSWApublications>

1:100000mapsshown inblack

SHEET INDEX

* DMP datacanbe viewedinteractivelyviaGeoVIEW.WA<http://www.dm downloadedfromthe GSWADataandSoftwareCentre<http://www.d

Mineralsites*

Geology * 2011

JAN 2012

GeologicalSurveyofW

GeologicalSurveyofW

Theme Data Currency

DATADICTIONA

Therecommendedreferenceforthismapis:Spaggiari,CV andPawley,MJ2012,Interpretedpre-Mesozoicbedrock geology oftheTropicanaregion of

theeastAlbany–Fraser Orogen (1:250000), inThegeologyoftheeastAlbany–FraserOrogen—afieldguidecompiled by CVSpaggiari, CLKirkland,MJPawley,RHSmithies,MTDWingate,MG Doyle,TGBlenkinsop,

CClark,CWOorschot,LJFox, and JSavage:GeologicalSurveyofWesternAustralia,Record 2011/23,Plate2.

Cartography byAK Jones

GeologybyCV Spaggiariand CLKirkland 2008–11,and MJPawley2008 (Albany–Fraser); CMDoyleand S Jones2005,MJ Pawleyand SS Romano 2008(east Yilgarn)

Compiled byCV Spaggiari2009–11(Albany–Fraser) and MJPawley2010–11( east Yilgarn)

Edited byK Greenberg and SKMartin

GeochronologyfromGSWA data (published and inpreparation) andinterpretedfromexternalsources(listedbelow).

SomeGSWAgeochronologymaycomefromsamplesobtainedon adjoiningmapsheets.GSWAgeochronology

data areavailableonlineat<http://www.dmp.wa.gov.au/geochron>.

Geochronologyby:

(1) Cassidy,KF 2007,GA SampleID 98967050B:Geoscience Australia'sgeochronologydatabase,July2007datarelease.

(2) Sircombe,KN etal. 2007, GeoscienceAustralia,Record2007/1,p.169–174.

(3)Sircombe,KN etal.2007,GeoscienceAustralia,Record2007/1,p.175–180.

PublishedbytheGeologicalSurvey ofWesternAustralia

This map ispublishedin digitalformat(PDF)andis available onlineat<http://www.dmp.wa.gov.au/GSWApublications>.Copiesofthis map are availablefromtheInformationCentre,DepartmentofMinesandPetroleum,

100 Plain Street,East Perth, WA 6004.

Phone(08) 92223459

Website <http://www.dmp.wa.gov.au/gswa>

Fax(08) 9222 3444

Email [email protected]

Documents

THE GEOLOGY OF THE EAST ALBANY–FRASER OROGEN — A FIELD GUIDE