report 59: geology and mineralization of the ......copper–gold volcanogenic massive sulfides,...

DEPARTMENT OF MINERALS AND ENERGY

GEOLOGICAL SURVEY OF WESTERN AUSTRALIA

REPORT59

GEOLOGY AND MINERALIZATIONOF THE PALAEOPROTEROZOICBRYAH AND PADBURY BASINS

WESTERN AUSTRALIA

by F Pirajno S A Occhipinti and C P Swager

GOVERNMENT OFWESTERN AUSTRALIA

REPORT 59

GEOLOGY AND MINERALIZATIONOF THE PALAEOPROTEROZOICBRYAH AND PADBURY BASINSWESTERN AUSTRALIA

byF Pirajno S A Occhipinti and C P Swager


Perth 2000

MINISTER FOR MINESThe Hon Norman Moore MLC

DIRECTOR GENERALL C Ranford

DIRECTOR GEOLOGICAL SURVEY OF WESTERN AUSTRALIADavid Blight

Copy editor D P Reddy

REFERENCEThe recommended reference for this publication isPIRAJNO F OCCHIPINTI S A and SWAGER C P 2000 Geology and mineralization of the Palaeoproterozoic Bryah and Padbury

Basins Western Australia Western Australia Geological Survey Report 59 52p

National Library of AustraliaCataloguing-in-publication entry

Pirajno Franco 1939ndashGeology and mineralization of the Palaeoproterozoic Bryah and Padbury Basins Western Australia

BibliographyISBN 0 7309 6653 4

1 Geology Structural mdash Western Australia mdash Bryah Basin2 Geology Structural mdash Western Australia mdash Padbury Basin3 Mines and mineral resources mdash Western Australia mdash Bryah Basin4 Mines and mineral resources mdash Western Australia mdash Padbury Basin5 Bryah Region (WA)6 Padbury Region (WA)I Swager C PII Occhipinti S A (Sandra Anne)III Geological Survey of Western AustraliaIV Title (Series Report (Geological Survey of Western Australia) 59)

5531099413

ISSN 0508ndash4741

Grid references in this publication refer to the Australian Geodetic Datum (AGD84)

Printed by Optima Press Perth Western Australia

Copies available fromInformation CentreDepartment of Minerals and Energy100 Plain StreetEAST PERTH WESTERN AUSTRALIA 6004Telephone (08) 9222 3459 Facsimile (08) 9222 3444wwwdmewagovau

Cover photographFerruginous shale of the Millidie Creek Formation with a well-developed pencil cleavage 25 km northwest of Fraser Well(BRYAH AMG 651660)

iii

Contents

Abstract 1Introduction 1Regional tectonic setting 3Geology stratigraphy and geochronology 4

Peak Hill Schist and Marymia Inlier 5Bryah Group 6

Karalundi Formation 6Narracoota Formation 7

Peridotitic and high-Mg basalt association 7Intrusive rocks and layered intrusions 7Mafic and ultramafic schist 8Metabasaltic hyaloclastite 9Felsic schist 9Volcaniclastic rocks 10Carbonated and silicified metavolcanic rocks 11Jasperoidal chert 11Geochemistry of the Narracoota Formation 11

Ravelstone Formation 16Horseshoe Formation 16

Padbury Group 17Labouchere Formation 18Wilthorpe Formation 19

Beatty Park and Heines Members 19Robinson Range Formation 20Millidie Creek Formation 20Unassigned units of the Padbury Group 21

Structure 21D1 structures 23D2 structures 23D3 structures and their relationship to D2 structures 25D4 structures 25

Metamorphism 25Structural synthesis 27Mineralization 32

Gold deposits 33Peak Hill Jubilee and Mount Pleasant deposits 39Harmony deposit 41Labouchere Nathans and Fortnum deposits 41Wembley deposit 42Wilgeena deposit 43Durack St Crispin and Heines Find prospects 43Ruby Well group 43Mikhaburra deposit 43Wilthorpe deposit 43Cashman deposit 44

Volcanogenic copperndashgold deposits 44Supergene manganese deposits 44Iron ore 45Talc 45Discussion 45

Tectonic model and conclusions 46Acknowledgements 48References 49

Appendix

Gazetteer of localities 52

Plate

Interpreted geology of the Palaeoproterozoic Bryah and Padbury Basins

iv

Figures

1 Stratigraphy of the former lsquoGlengarry Basinrsquo 22 Simplified geology of the Bryah Padbury and Yerrida Basins 43 Rotated orthoclase porphyroblast Peak Hill Schist 54 Partially recrystallized mylonite Peak Hill Schist 55 Peak Hill Schist mylonite from the Hangingwall Sequence 56 Outcrop of quartz mylonite Peak Hill Schist 67 Peak Hill Schist (Crispin Mylonite) illustrating a typical mylonitic fabric 68 Maficndashultramafic volcanic rocks of the Narracoota Formation (Dimble Belt) 89 Basaltic hyaloclastite Narracoota Formation 9

10 Mafic volcaniclastic rock Narracoota Formation 1011 Volcanic breccia intersected in diamond drillhole BD1 1012 Total alkali versus silica diagram for rocks the Narracoota Formation 1313 Total alkali versus silica diagram defining limits of alkaline and subalkaline basalts of the

Narracoota Formation 1414 Geochemical characteristics of the Narracoota Formation rocks 1415 Geochemical discriminant plots for Narracoota Formation 1516 TiO2 versus FeOMgO plot for maficndashultramafic rocks of the Narracoota Formation 1617 Schematic stratigraphy of the Horseshoe Formation 1718 Major regional structures in the Bryah and Padbury Groups 2219 Simplified geological map of the Bryah and Padbury Groups 2420 Selected hypothetical cross sections through the Bryah and Padbury Groups 2721 Model of the structural development of the BryahndashPadbury Group succession 2922 New model of the structural development of the BryahndashPadbury Group succession 3123 New model for the structural development of the BryahndashPadbury Group succession

and the Peak Hill Schist 3224 Schematic north-northwest to south-southeast cross section from the Bangemall Basin

into the Yarlarweelor gneiss complex and then into the Bryah and Padbury Basins 3325 Distribution of mineral deposits and occurrences in the BryahndashPadbury and Yerrida Basins 3626 Distribution of mineral deposits and occurrences in the Bryah Group within the BRYAH

1100 000 map sheet 3827 Albite porphyroblasts in mylonitic schist at Mount Pleasant 3928 The Mine Sequence schist 4029 Schematic geological map of the Fiveways Main and Mini opencuts Peak Hill deposit 4030 Peak Hill Mini opencut showing the ore-bearing mylonitic schist graphitic schist and

Marker quartzite unit 4031 Diagrammatic cross section of the Harmony ore zones 4132 The west wall opencut showing the contact between biotitendashsericitendashquartz schist and

deformed Despair Granite 4433 Sketch illustrating a conceptual model for the origin of precious and base metal

deposits in the BryahndashPadbury and Yerrida Basins 4534 Schematic illustration showing the preferred model of the tectonic evolution of the Bryah and

Padbury Basins within the context of the Capricorn Orogen 46

Tables

1 Stratigraphy of the Bryah and Padbury Groups 32 Representative chemical analyses of the Narracoota Formation 123 Magnesium numbers for the Narracoota and Killara Formations 134 Selected geochemical parameters for the Narracoota Formation 135 Sequence of deformation events in the Bryah and Padbury Basins 236 Mineral paragenesis of the Bryah Group and relationships between diagnostic metamorphic

minerals of the Bryah Group and deformation fabrics 287 Gold production and remaining resources in the Bryah and Padbury Groups 348 Mineral production and remaining resources in the Bryah and Padbury Groups 359 Mineral deposits and occurrences in the Bryah and Padbury Basins 36

Digital dataset (in pocket)

Whole-rock geochemical analyses of Narracoota Formation rocks (narracootacsv)

MIGSDAF
File Attachment
narracootacsv
MIGSDAF
Note
Click on paperclip icon to open attached files - Acrobat 5 (full) or Adobe Reader 6 (and later versions) required To request copies of digital data please visit 1313httpwwwdoirwagovaugswacontact

1

GSWA Report 59 Geology and mineralization of the Palaeoproterozoic Bryah and Padbury Basins WA

Geology and mineralization of thePalaeoproterozoic Bryah and Padbury

Basins Western Australia

by

F Pirajno S A Occhipinti and C P Swager

AbstractThe Palaeoproterozoic Bryah and Padbury Basins are part of the Capricorn Orogen a collision zonebetween the Archaean Pilbara and Yilgarn Cratons The Bryah Basin contains a succession of maficand ultramafic rocks of mid-oceanic ridge basalt to oceanic plateau affinity overlain by clastic andchemical sedimentary rocks The Bryah Basin was formed during back-arc sea-floor spreading andrifting on the northern margin of the Yilgarn Craton The Padbury Basin contains a succession ofclastic and chemical sedimentary rocks and was formed on top of the Bryah Basin as a forelandstructure resulting from either the c 1800 Ma oblique collision of the Pilbara and Yilgarn Cratons(Capricorn Orogeny) or the c 2000 Ma collision of the Glenburgh terrane and the Yilgarn Craton(Glenburgh Orogeny)

Important mineral deposits are contained in both basins and include mesothermal orogenic goldcopperndashgold volcanogenic massive sulfides manganese and iron ore The origin of the goldmineralization is related to metamorphism and deformation linked to the Capricorn Orogeny at c 18 GaThe formation of other deposits is related to pre-orogenic syngenetic processes

KEYWORDS Bryah Basin Padbury Basin Palaeoproterozoic stratigraphy geochemistry maficrocks ultramafic rocks mineralization mesothermal deposits gold

IntroductionIn early 1994 the Geological Survey of Western Australia(GSWA) commenced fieldwork to reassess the geologyand mineralization of the Palaeoproterozoic GlengarryBasin as part of a program of new mapping initiativesThe Glengarry Basin as defined by Gee and Grey (1993)constitutes the western part of the greater Palaeo-proterozoic Nabberu Province which in the east includesthe Earaheedy Basin (Bunting et al 1977 Hall andGoode 1978 Gee 1990)

The new mapping initiative resulted in the reappraisalof the geology tectonic evolution and mineralizationof the Glengarry Basin which is now recognized toconsist of three main geotectonic units the BryahPadbury and Yerrida Basins As a result the volcano-sedimentary rocks of the former lsquoGlengarry Grouprsquo arenow divided into the Bryah and Yerrida Groups (Fig 1 andTable 1) characterized not only by different lithologiesbut also by different regional structures metamorphismand mineral deposit types Some formations previouslyassigned to the lsquoGlengarry Grouprsquo have been reassigned

to the Padbury Group (Martin 1992) In additionthere is evidence to suggest that the economicallyimportant lsquoPeak Hill Metamorphic Suitersquo previouslyconsidered to be part of the lsquoGlengarry Grouprsquo (Gee1987) constitutes a separate unit the Peak Hill Schistderived from a protolith of probable Archaean ageConsequently the previous nomenclature (lsquoGlengarryGrouprsquo and lsquoGlengarry Basinrsquo) is no longer used Detailsof the old and new stratigraphy are presented in Figure 1and Table 1 and discussed in later sections The revisedstratigraphy of the former lsquoGlengarry Basinrsquo is presentedin Occhipinti et al (1997) Details of the stratigraphy andstructure of the lower Padbury Group are presented inMartin (1998)

The Bryah and Padbury Basins lie within the ROBINSON

RANGE and PEAK HILL 1250 000 sheets (MacLeod 1970Elias and Williams 1980 Gee 1987) and the north-western and northeastern corners of the BELELE andGLENGARRY 1250 000 sheets (Elias 1982 Elias et al

Capitalized names refer to standard 1100 000 map sheets unless otherwisespecified

2

Pirajno et al

1982) The Bryah and Padbury Groups (Fig 2) make upthe western part of the former lsquoGlengarry Basinrsquo andare now interpreted to have developed in rift and forelandbasins respectively (Martin 1994 Pirajno 1996 Pirajnoet al 1996 Pirajno et al 1998b) The Yerrida Group(Fig 2) makes up the eastern part of the former lsquoGlengarryBasinrsquo and includes two subgroups the Windplainand Mooloogool Subgroups (Fig 2 Table 1) whichdeveloped in sag and rift basins respectively (Pirajno et al1995ab 1996) The geology and mineralization ofthe Yerrida Basin are described in a separate Report(Pirajno and Adamides 2000) The Bryah Group isin faulted contact with the Yarlarweelor gneiss complexthe Marymia Inlier of the Archaean Yilgarn Cratonand the Palaeoproterozoic Yerrida Group The contactbetween the Bryah and the Yerrida Groups is along anortheasterly trending high-angle reverse fault (the GoodinFault)

Based on structural and metamorphic criteria the areaoccupied by the Bryah and Padbury Groups and thePeak Hill Schist can be regarded as a single domainIn this Report where appropriate this domain is referred

to as the BryahndashPadbury Basin The geology newstratigraphy geochronological constraints structureand metamorphism of the Bryah and Padbury Groups arediscussed The geochemistry of the volcanic componentof the Bryah Group and mineral deposits of the Bryahand Padbury Basins are also summarized A tectonicoverview and proposed model for the geodynamicevolution of the Bryah and Padbury Basins withinthe framework of the Capricorn Orogen conclude thereport

Work in the BryahndashPadbury area involved 125 000-scale mapping to produce 1100 000-scale geologicalmaps Geological mapping was carried out using125 000-scale colour aerial photography (availablefrom the Western Australian Department of LandAdministration) aeromagnetic images (400 m line-spacedcollected by GSWA in 1994) and Landsat TM imagesResults of geological mapping were integrated withpetrographic geochemical and geochronology studiesDuring this work a total of 1450 rock samples werecollected of which 776 were thin-sectioned and 136geochemically analysed In addition logging of diamond

Figure 1 Stratigraphy of the former lsquoGlengarry Basinrsquo

Gee (1987)P

AD

BU

RY

BA

SIN

GR

OU

PG

LEN

GA

RR

Y B

AS

ING

RO

UP

Millidie Creek Formation

Robinson Range Formation

Wilthorpe Formation

Labouchere Formation

Horseshoe Formation

Narracoota Volcanics

Karalundi Formation

Doolgunna Formation

Johnson Cairn Shale

Thaduna Greywacke

Juderina Formation

Maraloou Formation

Crispin Conglomerate

Finlayson Sandstone

Peak Hill Metamorphics

GLE

NG

AR

RY

BA

SIN

GR

OU

P

Maraloou Formation

Thaduna Greywacke


Doolgunna Formation

Johnson Cairn Shale

Juderina Formation(Finlayson SandstoneMember)

YE

RR

IDA

BA

SIN

GR

OU

P

Win

dpla

in S

ubgr

oup

Moo

loog

ool S

ubgr

oup

Peak Hill Schist

BR

YA

H B

AS

ING

RO

UP

PA

DB

UR

Y B

AS

ING

RO

UP

TE

CT

ON

IC C

ON

TA

CT


Wilthorpe Formation


Horseshoe Formation

Karalundi Formation

Ravelstone Formation

Narracoota FormationMaraloou Formation

Killarra Formation(Bartle Member)

Doolgunna Formation

Thaduna Formation

Juderina Formation

170100

Gee and Grey (1993) Occhipinti et al (1997) Pirajno et al (1998b this study)

Robinson RangeFormation

Unconformity

Unconformity

Johnson CairnFormation

NOTE New or redefined units (Occhipinti et al 1997)

(Finlayson and BubbleWell Members)

ARCHAEAN BASEMENT

FMP409a

3


drillcore (1100 m) and several visits to prospects andoperating mines considerably enhanced our knowledge ofthe geology of the area Most of the mapped areas werealso included in a regional regolith geochemical samplingprogram covering the PEAK HILL ROBINSON RANGE andGLENGARRY 1250 000 sheets (Subramanya et al 1995Bradley et al 1997 Crawford et al 1996)

Interim accounts of the structural and stratigraphicrelations of the BryahndashPadbury and Yerrida Basins havebeen reported by Pirajno et al (1995ab 1996) andOcchipinti et al (1997) Pirajno (1996) and Pirajno et al(1995a 1998b) discussed possible models for the tectonicevolution of the BryahndashPadbury and Yerrida Basins Thestructure and metamorphism of the BryahndashPadbury Basinhave been described by Occhipinti et al (1998abc)whereas details of mineral potential production andore deposit geology can be found in Pirajno andOcchipinti (1995) and Pirajno and Preston (1998)Published 1100 000 geological maps and accompanyingExplanatory Notes that wholly or partly cover the BryahndashPadbury Basin comprise BRYAH (Pirajno and Occhipinti1998) GLENGARRY (Pirajno et al 1998a) MILGUN (Swagerand Myers 1999) PADBURY (Occhipinti et al 1998a)DOOLGUNNA (Adamides 1998) and MARYMIA (Bagas1998) The southern portion of the JAMINDI 1100 000 mapsheet containing rocks of the Bryah Group was alsomapped The layout of these map sheets in relation to theBryahndashPadbury Basin and adjacent tectonic units is shownin Figure 2 The geology of the Bryah and Padbury Basinsis presented in Plate 1

Regional tectonic settingThe Bryah and Padbury Basins are situated along thenorthern margin of the Archaean Yilgarn Craton and arepart of the Capricorn Orogen (Fig 2 inset of Plate 1)The Capricorn Orogen also includes the Ashburton Basin

and the Gascoyne Complex and can be traced for morethan 1000 km with northwesterly to westerly trendsforming a broad belt of deformed low-grade volcano-sedimentary high-grade metamorphic and granitoidrocks

The Capricorn Orogeny resulted from the collisionbetween the Pilbara and Yilgarn Cratons at c 1800 Maand involved the closure of an intervening oceanformation of a back-arc basin and the possible accretionof microcontinental fragments (Myers 1993 Myers et al1996 Tyler et al 1998) Prior to the Capricorn Orogenythe c 2000 Ma Glenburgh Orogeny (Occhipinti et al1999) resulted in the accretion of the Glenburgh terraneonto the Yilgarn Craton The convergence between thePilbara and Yilgarn Cratons was essentially oblique andresulted in the development of easterly trending strike-slipmovements which included regional sinistral faults TheCapricorn Orogeny also affected other tectonic units suchas the Archaean Narryer Terrane Marymia Inlier SylvaniaInlier and parts of the Hamersley Basin (Tyler andThorne 1990 Myers et al 1996 Tyler et al 1998)

The Palaeoproterozoic volcano-sedimentary andsedimentary successions of the Bryah and Padbury Basinsare unconformable on the northern margin of the YilgarnCraton whereas to the north they are either unconform-ably overlain by or in faulted contact with rocksof the Bangemall Basin and the Archaean graniticrocks of the Marymia Inlier The Marymia Inlier iseconomically important because it hosts a number of golddeposits including the Peak Hill deposit (AMG 672190E7163150N) on the southwestern tip of the inlier (seeMineralization)

Localities are specified by the Australian Map Grid (AMG) system AMGcoordinates (eastings and northings) of localities discussed in the text arelisted in Appendix 1

Table 1 Stratigraphy of the Bryah and Padbury Groups

Group Age Formation Rock type(Ma)

Padbury Group Millidie Creek sericitic siltstone chloritic siltstone banded iron-formation(peripheral foreland basin) dolomitic arenite

Robinson Range ferruginous shale banded iron-formation

ltc 2000 Wilthorpe quartz-pebble conglomerate(Beatty Park and (siltstonendashwacke and polymictic conglomerate respectively)Heines Members)

Labouchere turbidite sequence (quartz wacke siltstone)

unconformable contact mdash tectonized in many places

Bryah Group (rift basin) Horseshoe banded iron-formation wacke shale

ltc 2000 Ravelstone quartzndashlithic wacke

Narracoota maficndashultramafic volcanic rocks and intercalated sedimentary rocks

Karalundi conglomerate quartz wacke

faulted contact

Yerrida Group (sag and rift basin) c 2174

SOURCE Modified after Pirajno et al (1996)

4

Pirajno et al

Geology stratigraphy andgeochronology

The BryahndashPadbury Basin contains the Bryah andPadbury Groups and the Peak Hill Schist The stratigraphyfor the Bryah and Padbury Groups is summarized in

Figure 1 and Table 1 where a comparison with previousGSWA work is also provided The Peak Hill Schist is aseparate tectono-stratigraphic unit that is discussed herewith the Marymia Inlier as basement to the Bryah GroupDetailed descriptions of the various formations and theircontact relationships are presented in Occhipinti et al(1997) Martin (1998) Adamides (1998) Pirajno and

Figure 2 Simplified geology of the Bryah Padbury and Yerrida Basins showing 1100 000 map sheet boundariesInset shows the position of the basins in relation to the Capricorn Orogen

MARYMIAINLIER

GOODININLIER

Goodin

Fault

Fault

Killara

Narracoota

30 km

PILBARACRATON

CAPRICORN OROGEN

CRATONYILGARN

FMP375

117deg

30

118deg

30

26deg00

25deg00

Murchison

FaultMorris

Earaheedy Group

Padbury Group

Yerrida Group

Archaean granitendashgreenstonebasement

Bangemall Group

Bryah Group

Proterozoic granites

Fault

Moorarie Padbury

MilgunMarquis

FaultCooinbar

NarryerTerrane

Murchison

Terrane

Kerba Fault

119deg

30

Gabanintha Yanganoo

MooloogoolGlengarry

Bryah Doolgunna

Jamindi Three Rivers

010300

BRYAH-PADBURY

BASINS

PROTEROZOIC

5


Occhipinti (1998) Pirajno et al (1998b) Occhipinti et al(1998c) and Swager and Myers (1999)

In this section the geology field relations stratigraphyand geochronological constraints of the Peak Hill SchistMarymia Inlier and the formations that make up the Bryahand Padbury Groups are discussed

Peak Hill Schist and MarymiaInlierThe Peak Hill Schist (formerly called the lsquoPeak HillMetamorphic Suitersquo Gee 1987) is exposed in the lsquoPeakHill Domersquo or anticline and constitutes a tectonic unitrepresenting the southwestern tip of the Marymia Inlier(Fig 2 Thornett 1995) The Peak Hill Schist iscontinuous with the Marymia Inlier and Thornett (1995)suggested that the lsquoPeak Hill Domersquo represents thedeformed southwestern end of the Marymia Inlier Fieldobservations and petrographic and aeromagnetic datasupport this view The boundary between the Peak HillSchist and granitic rocks of the Marymia Inlier is a zoneof intense deformation and metamorphism characterizedby tectonic interleaving and duplexing Towards thenortheast the intensity of the Capricorn Orogenydeformation in the Marymia Inlier granites decreases toareas where they are undeformed The contacts betweenthe Peak Hill Schist and rocks of the Bryah Group arefaulted (probably thrusted) and tectonically interleaved inplaces

Rocks of the Peak Hill Schist include phyllonitequartzndashmuscovite schist calc-silicate schist sericite(ndashquartz) schist and quartzndashmuscovitendashbiotitendashchloriteschist locally with rotated alkali feldspar porphyroblasts(Fig 3) and minor metabasite These units have beenvariously deformed and contain a range of mylonitictextures The mylonitic fabric of these rocks is revealedby SndashC surfaces and lines of lsquomica fishrsquo (Lister and Snoke1984) in a dominantly and variably recrystallized quartz-rich matrix (Figs 4 and 5) A few discrete mylonitic units

Figure 3 Orthoclase porphyroblast with curved inclusiontrails in quartzndashmuscovite schist of the Peak HillSchist crossed polars

Figure 4 Partially recrystallized mylonite (Crispin Mylonite)from the Peak Hill Schist This sample is from amylonitic quartzndashbiotitendashalbite schist from the MineSequence in which the biotite defines C planesThe S planes were obliterated by recrystallizationto a blastomylonite crossed polars

Figure 5 Peak Hill Schist mylonite The C surfaces havesurvived recrystallization and now form thin micatrails crossed polars

form arcuate zones interpreted as early possibly thrustfault zones (see Structure) One of these units is the PeakHill Mylonite (Pirajno and Occhipinti 1998) which is arefolded quartz blastomylonite and quartz mylonite lenswithin quartzndashmuscovite schist The Peak Hill Mylonite(Figs 6 and 7) is an important unit because it is spatiallyassociated with gold mineralization (Peak Hill and MountPleasant deposits) Other less conspicuous quartzmylonite lenses are common within the Peak Hill Schistand were previously mapped as cherts or banded cherts(Windh 1992) Another important unit is the CrispinMylonite (Pirajno and Occhipinti 1998) which lies in thesouthern part of the Peak Hill Schist between sericiteschist and quartzndashmuscovite schist The Crispin Mylonitereferred to by Gee (1987) as the lsquoCrispin Conglomeratersquois characterized by square to rounded quartz arenite clastsup to 60 cm long in a sericite-rich matrix On the basisof field and petrographic observations it is concluded

6

Pirajno et al

here that this unit is not a conglomerate but a mylonite(Pirajno and Occhipinti 1998) Mylonites that resembleconglomerates (pseudo- or tectonic conglomerates) havebeen reported by Peters (1993) and Raymond (1984ab)

The Marymia Inlier (Windh 1992 lsquoMarymia Domersquoof Gee 1987) represents a fragment of northeasterlytrending Archaean granitendashgreenstone basement Rocksof the Marymia Inlier are mainly granitic but also includesmall enclaves of calc-silicate rock orthoamphibolite andminor metamorphosed banded iron-formation (BIF) ThePeak Hill Schist is also tentatively placed within theMarymia Inlier The granitic rocks are locally stronglyfoliated to gneiss or display strong cataclastic fabricsGranitic rocks include both fine-grained (aplitic) andcoarse-grained porphyritic phases Some outcropspreviously mapped as granite by Gee (1987) have beenincluded in the Peak Hill Schist The granitic rocks of theMarymia Inlier are monzogranite in the east and showincreasing cataclastic deformation towards the southwest(Pirajno and Occhipinti 1998 Bagas 1998)

Bryah GroupThe Bryah Group is divided into four formations theKaralundi Narracoota Ravelstone and HorseshoeFormations (Figs 1 and 2 Table 1) The basal unit of theBryah Group is the Karalundi Formation which is infaulted contact with the Doolgunna Formation of theYerrida Group along the Goodin Fault The KaralundiFormation predominantly consists of quartz conglomeratequartz arenite lithic wacke and shale The NarracootaFormation (parts of which were previously known aslsquoNarracoota Volcanicsrsquo Gee and Grey 1993) is thedominant lithology in the Bryah Basin and consists oftholeiitic extrusive and intrusive rocks and subordinateultramafic units intercalated with minor jasperoidal chertunits and clastic sedimentary rocks The NarracootaFormation is disconformably overlain by and locallyinterfingers with the Ravelstone Formation TheRavelstone Formation comprises a succession of lithic andquartz wacke shale and siltstone that was deposited byturbidity currents This formation is in turn conformablyoverlain by the Horseshoe Formation comprising quartzwacke manganiferous shale and banded iron-formation

The age of the Bryah Group is poorly constrainedbetween c 2000 and 1800 Ma Detrital zircons ofuncertain provenance in the Ravelstone Formation (upperBryah Group) provide a maximum age of 2014 plusmn 22 Ma(Nelson 1997) The Bryah Group must be older than theunconformably overlying Mount Leake Formation (outlierof the Earaheedy Group) which has a UndashPb (detritalzircon) maximum age of 1785 plusmn 11 Ma (Nelson 1997)The PbndashPb isochron ages obtained from pyrite from themesothermal Mikhaburra gold deposit (174 Ga Pirajnoand Occhipinti 1998) and from inferred syngenetic pyritefrom the Narracoota Formation (1920 plusmn 35 Ma Windh1992) probably represent mineralizing events in the BryahBasin rather than the depositional age of the BryahGroup

Karalundi Formation

The Karalundi Formation forms the base of the BryahGroup outcropping in a northeasterly trending belt alongthe southeastern margin of the Bryah Basin (Plate 1)Rocks of the Karalundi Formation are estimated to reacha thickness of approximately 2500 m In the southeastalong the Great Northern Highway Karalundi Formationrocks are in faulted contact with the Doolgunna Formation(Yerrida Group) On the southeastern side of the Peak HillSchist and in faulted contact with it the KaralundiFormation outcrops 35 km east of the Wilgeena mine Inthe south the Karalundi Formation is intercalated withmafic volcaniclastic rocks of the Narracoota Formation

The Karalundi Formation is characterized by immatureclastic (mainly quartzndashlithic wacke and conglomerate)units containing angular quartz and lithic fragments setin a sericitendashclay-rich matrix Other rock types includesiltstone calcareous siltstone cross-bedded areniteferruginous arenite litharenite minor dolomite andpurple green and black shale The Karalundi Formationalso contains pods of hematitic jasperoidal chert (see

Figure 6 Outcrop of quartz mylonite Peak Hill Schist Notethe flaggy nature of this rock and its steep dip

Figure 7 Peak Hill Schist (Crispin Mylonite) illustrating atypical mylonitic fabric and SndashC planes (C planesare horizontal S planes trend from upper right tolower left between the C planes) crossed polars

7


below) which were interpreted by Gee (1979 1987) asfumarolic pipes

On DOOLGUNNA quartz arenite and conglomerate unitsare present within a dominantly hematitic shaly successionthat was interpreted by Adamides (1998) as a deep-waterlateral facies of the Bryah rift succession This successionalso contains olistoliths (exotic blocks) whose origin isnot clear Adamides (1998) suggested that they might havebeen derived from units of the Juderina Formation as aresult of inversion of the adjacent Yerrida Basin and upliftof the Goodin Inlier

Narracoota Formation

Rocks of the Narracoota Formation constitute a majorlithotype of the Bryah Group They form the bulk of thegroup with a thickness estimated at about 6 km (Pirajnoand Occhipinti 1998) and extend for more than 180 kmeast to west across the Bryah Basin The NarracootaFormation conformably overlies and locally interfingerswith the Karalundi Formation and also interfingers withand is in disconformable contact with the base of theoverlying Ravelstone Formation Contacts between theNarracoota Formation and Padbury Group are tectonic Inthe north regional structural relationships suggest that theNarracoota Formation is also in tectonic contact with theHorseshoe Formation Gravity modelling indicates that theNarracoota Formation forms the floor of the central partsof the Bryah Basin (Pirajno and Occhipinti 1998)

Rocks of the Narracoota Formation are affected bysea-floor metasomatism and regional prograde andretrograde metamorphism (see Structure) On the basisof field observations texture geochemistry and petrologyrocks of the Narracoota Formation can be subdivided intometamorphosed peridotitic and high-Mg metabasaltbasaltic hyaloclastite pyroclastic rocks intrusive rocksand mafic and ultramafic schist Collectively thesesubdivisions are referred to as metabasites Mafic andultramafic schists are characterized by a pervasiveschistosity but the distinction between mafic andultramafic is subtle and most clearly demonstrated usinggeochemistry In the area 2 km northeast of the Ravelstonemanganese opencuts a texture described by Hynes andGee (1986) as polygonal jointing has been observed in themetabasalt and appears to be a well-developed pencilcleavage High-Mg basalts are associated with peridotiticunits Intrusive rocks cover a range of types frompyroxenite to gabbroic rocks and dykes Metabasaltichyaloclastites are lava flows that interacted with seawaterand have a distinct spilitic character Volcaniclastic rocksincluding vent breccias are commonly present in bothbasaltic hyaloclastite and mafic schist

Typically the metabasite rocks of the NarracootaFormation contain no or very few feldspar phenocrystsOther authors have suggested that the presence ofmedium-grained embayed quartz crystals indicates theproximity of felsic volcanic rocks (Hill and Cranney1990 Windh 1992) Felsic volcanic rocks are associatedwith the upper part of the Narracoota Formation at andaround the Horseshoe Lights copperndashgold mine onJAMINDI 29 km east of the Fortnum mine on MILGUN

Fine-grained grey to black metamorphosed shale andslate are present in places as lenses of interflowsedimentary rocks within the volcanic succession Wheremore deformed and metamorphosed these slates are finelylaminated biotitendashchlorite schists South of the RobinsonRange small lenses of sedimentary rock (lithic wacke andshale) are intercalated with the volcanic rocks of theNarracoota Formation In places pods and lenses ofjasperoidal chert are associated with the volcanic rocks

Peridotitic and high-Mg basalt association

Massive layered high-Mg basaltic rocks (possibly lavaflows shown on Plate 1 as Anu) are preserved inprominent hills between Top Dimble Well and DespairBore on MILGUN Hynes and Gee (1986) described thissequence as komatiitic basalt with up to 20 MgOUnequivocal pillow structures as mentioned by Hynes andGee (1986) were not observed The rocks are meta-morphosed but their protoliths include olivine cumulate(peridotite) high-Mg basalt with plumose and harrisitictextures and medium-grained basalt Layering is mainlydefined by massive olivine cumulate layers up to 20 mthick and plumose-textured basalt layers up to 5 m thickLocally large sheaves of skeletal amphibole (afterpyroxene) are arranged at approximately right angles tothe layering and resemble harrisitic textures (Fig 8a) Thehigh-Mg basalt units are characterized by well-developedlsquospinifexrsquo-like textures with acicular tremolitendashactinoliteafter pyroxene and up to 30 interstitial plagioclase(replaced by epidote or zoisite) The high-Mg basalt isinterlayered with medium-grained basalt of similarmineralogy and composition with 8ndash9 MgO Thewhole-rock geochemistry of these rocks is discussed inGeochemistry of the Narracoota Formation

Peridotite units commonly consist of 70ndash80 fine- tomedium-grained olivine replaced by tremolite(ndashtalc)skeletal amphiboles after pyroxene and 20ndash30 fine-grained matrix of plumose-textured amphibole High-Mgbasalt contains up to 30 locally glomeroporphyriticolivine (now tremolite) lesser amounts of acicularpyroxene in a 60ndash70 amphibole plumose-texturedmatrix and 15 MgO One particular example contains35 olivine (only partly altered to talc) skeletal(lsquoswallow-tailrsquo) fresh orthopyroxene and lesser amountsof acicular skeletal amphibole prisms possibly afterclinopyroxene (Fig 8b)

Intrusive rocks and layered intrusions

A metadolerite sheeted dyke complex (shown as And onPlate 1) outcrops north of the Robinson Syncline Theserocks are associated with deformed pillow metabasalt andtend to be internally undeformed but commonly formelongate bodies subparallel to the S2 foliation Theycontain diopside amphibole epidote and minor olivine

Lenses of cumulate-textured units represented bypyroxenite or peridotite and gabbroic rocks are locallyintercalated with the mafic and ultramafic schist Alensoidal outcrop of metapyroxenite is present nearDurack Well Gabbroic rocks are common betweenTrillbar Homestead and Friday Pool on MOORARIE

8

Pirajno et al

(Occhipinti and Myers 1999) These rocks have beenmetamorphosed and folded but are largely undeformedinternally The gabbroic rocks are surrounded by higherstrain zones consisting of tremolitendashactinolite schist

The Trillbar Complex (shown as Ant on Plate 1) is a30 km long by 25 km wide layered maficndashultramaficintrusion in the westernmost part of the Bryah Basin Thecomplex consists of rhythmically layered mafic andultramafic rocks with the layering oriented at a low angleto the regional foliation (Occhipinti and Myers 1999)Rock types include rhythmically layered gabbromelanogabbro leucogabbro pyroxenite and peridotiteThese rocks are metamorphosed to greenschist facies butthe original igneous textures are locally well preservedThe Trillbar Complex rocks contain assemblages ofserpentinendashtremolitendashtalc tremolitendashtalcndashmagnetitetremolitendashactinolite and actinolitendashfeldspar Cumulaterocks include olivinendashpyroxene pseudomorphed bytremolite and sphene West of the Trillbar Homestead arelayers of metamorphosed pyroxenite and peridotite inwhich the original mineral phases are totally replaced by

tremolite talc magnetite and chlorite The TrillbarComplex is interpreted here as representing a remnant ofLayer 3 (layered gabbroic rocks) of an oceanic crustsuccession (Burke et al 1981) If this is correct thenprogressively lower levels of the Narracoota Formation areexposed from east to west and this is supported by thewidespread occurrence of volcaniclastic units in thecentral and eastern parts of the Bryah Basin

Mafic and ultramafic schist

Maficndashultramafic schist consists of actinolite(ndashchloritendashclinozoisite) schist and chlorite schist (shown as Anu andAn on Plate 1) In the south-central part of BRYAH schistoutcrops form an arcuate band (possibly an antiformstructure Gee 1987) south of and following the trendsof the Robinson Syncline and the southern limbs of theFraser Synclinorium (see Structure) North of thesestructures sparse outcrops of mafic schist are present justsouth and north of the Peak Hill Schist Within the schistare pods of less deformed or internally undeformedmetabasites in which pillow structures are locally wellpreserved Overall this large band forms a majoranastomosing sheared domain (Pirajno et al 1995b) Thedominant schistosity strikes approximately easterly orwest-northwesterly and dips steeply to the north andsouth A number of quartz veins within this shear domainalso strike easterly Maficndashultramafic schist was formedas a result of deformation and metasomatism of metabasiterocks along D2 shear zones (see Structure) In most casesall original volcanic textures are obliterated although inplaces round or elongate chlorite aggregates areinterpreted as original amygdales or fine pyroclasts

To the northwest on MILGUN the mafic volcanicschist occurrences are in faulted or sheared contactwith rocks of the Labouchere Wilthorpe and RobinsonRange Formations Hill and Cranney (1990) documenteda sequence of ultramafic to mafic schists with orwithout jasperoidal chert lenses overlain by fragmentalvolcaniclastic rocks fine-grained siltstone and felsic(intermediate and dacitic) crystal tuffs These are in turnoverlain by the Ravelstone and Horseshoe Formations

Mineral constituents of the mafic schist are actinolitechlorite and clinozoisite with minor calcite pumpellyitesericite titanite quartz and relict albite Ultramafic schisthas a simpler and commonly almost monomineralicmineralogy consisting of actinolitendashtremolite withretrogressed patches of pale-green chlorite In zones ofmore intense deformation chlorite- or epidote-dominatedassemblages are present (chlorite schist and epidositerespectively) These minerals developed due to strongmagnesium and calcium metasomatism probably duringcirculation of H2OndashCO2 fluids (Pirajno et al 1995b) Fluidinfiltration caused the breakdown of tremolite andclinozoisite to produce chlorite calcite and silica Thesilica thus liberated was then channelled through shearzones resulting in silicification and quartz veins (Pirajnoet al 1995b) An example of this can be seen in abreakaway 13 km east of the Wembley gold mine wheremafic schist and deformed pillow lavas display chloritealteration and pervasive silicification near and along awest-northwesterly trending shear zone In high-strain

Figure 8 Maficndashultramafic volcanic rocks of the NarracootaFormation (Dimble Belt) a) Komatiitic pyroxenitewith skeletal amphibole prisms after a quench-textured pyroxene matrix b) Peridotite with olivinepartly altered to talc around the edges and pyroxenein a fine-grained tremolite matrix both in planepolarized light

9


zones a new fabric is defined by the alignment ofamphibole prisms elongate epidote and quartz Theseschists are commonly characterized by well-developedlsquopencil cleavagersquo as a result of two intersecting planarfabrics

Metabasite rocks commonly show relict igneoustextures of prismatic plagioclase and interstitial amphiboleand more abundant unoriented prisms or acicular grainsof fine- to medium-grained amphibole Massive sheaf-liketextures of acicular amphibole are interpreted as primaryigneous textures A few plagioclase phenocrysts (3ndash5 mm)are preserved The amphibole is colourless to pale-greenpleochroic actinolite (or actinolitendashtremolite) plagioclaseis albite and commonly pseudomorphed by clinozoisitendashepidote or sericitized in zones of alteration Minorconstituents include chlorite quartz and sphenendashleucoxene with local zones of massive epidote(ndashcarbonate)

A schistose metabasite 5 to 8 km northeast of the PeakHill opencut contains actinolite arfvedsonite calcitediopside epidote and quartz The alignment of actinoliteand arfvedsonite defines the S2 schistosity and thereforeboth these minerals were formed during prendashsyn-D2 (seeStructure) The presence of the arfvedsonite (sodicamphibole) suggests either an original sodium-rich rockor later sodic metasomatism during or prior to D2

Metabasaltic hyaloclastite

Metabasaltic hyaloclastites form a prominent outcrop areapartly covered by ferricrete and colluvium south of theMurchison River These rocks are separated from themafic and ultramafic schist by the Murchison Fault(Plate 1) and probably represent a substantial thicknessof mafic lavas and hypabyssal material Hynes and Gee(1986) and Gee (1987) estimated a total thickness rangingfrom 4 to 6 km On the northern part of the GLENGARRY

1100 000 sheet the metabasalts are intercalated withsedimentary rocks of the Karalundi Formation (Pirajnoet al 1998a) These metabasaltic rocks are interpreted ashyaloclastites mdash a term that denotes fragmentation dueto quenching (Fig 9) of lavas flowing in water or eruptingunder an ice sheet This results in non-explosive fracturingand disintegration of the quenched lavas (McPhie et al1993 Fischer and Schmincke 1984)

The metabasaltic hyaloclastites are undeformeddominantly of mafic composition and have a spiliticcharacter Spilites are basaltic rocks that become alteredthrough metasomatic exchange with seawater therebyincreasing their sodium content The hyaloclastites havenormative albite from 13 to 23 wt and Na2O contentsof up to 6 wt

The metabasaltic hyaloclastites are commonly aphyricand composed mainly of acicular crystals of actinolitearranged in sheaves together with epidote minorcarbonate prehnite quartz and titanite in a fine-grainedgroundmass of albite microlites chlorite and epidoteCoarse-grained equivalents (clinopyroxene and plagioclaselaths) display ophitic to subophitic textures North of theMikhaburra (Holdens Find) gold deposit a small shaft has

Figure 9 Basaltic hyaloclastite of the Narracoota Formationshowing cuneiform devitrified shards now replacedby silica and sericite plane polarized light

exposed a vesicular rock containing serpentinized olivinecrystals set in a very fine grained altered matrix ofactinolite probably replacing pyroxenes

These metabasalts are commonly unfoliated andmassive with a characteristic brecciated or jigsaw-fittexture outlined by epidote carbonate prehnite and quartzveining along cooling joints In places these cooling jointsmay form pseudo-pillow structures and may be mistakenfor pillow lavas (Hynes and Gee 1986) Microscalejigsaw-fit textures are also seen

Felsic schist

Felsic schists which host sulfide mineralization (seeMineralization) at the Horseshoe Lights copperndashgolddeposit are present in the northern part of the BryahBasin Stratigraphically the felsic schist are at the top ofmafic metavolcanic rocks of the Narracoota Formation andoverlain by rocks of the Ravelstone Formation (seebelow) which contain chert lenses and layers close to thiscontact The felsic rocks are offset by a northeasterlytrending fault near the mine area and extend for about75 km in a southeasterly direction where they are offsetagain by a northeasterly trending fault However they donot reappear on the other side of the fault where the maficmetavolcanic rocks are in contact with the clasticsedimentary rocks of the Ravelstone Formation

Felsic schist includes quartzndashsericite schist sericiteschist and chlorite schist all showing varying degrees ofdeformation and development of mylonite Examinationof drillcore from the Horseshoe Lights mine revealedstructures reminiscent of felsic volcaniclastic rocks suchas collapsed pumice fragments Quartzndashsericite andsericite schist are composed of quartz and feldsparporphyroclasts partially replaced by quartz and sericitecarbonate or chlorite and wrapped around by granoblasticaggregates of quartz and sericite these aggregates aretraversed by anastomosing bands of sericite Tourmalineis present in places In one example sericite schistcontains elliptical opaque fragments suggestive ofcollapsed pumice Chlorite schist is composed of chlorite

10

Pirajno et al

and granular quartz with the chlorite forming distinctmonomineralic laminae X-ray diffraction analyses ofaltered schist indicate the presence of quartz kaolinpyrite hematite goethite and dioctahedral sodianmuscovite or potassian paragonite

Based on petrographic and core examinations thefelsic schist precursor rocks may have been quartzndashfeldspar porphyry and felsic volcaniclastic rocks

Volcaniclastic rocks

Mafic volcaniclastic rocks have well-preserved eutaxiticor fragmental textures despite intensive foliation (Fig 10)In the Fortnum mine area mafic fragmental rocks andfine-grained mafic volcaniclastic rocks are spatiallyassociated with jasperoidal chert pods The fragmentalrocks are strongly schistose with flattened and stretched

fragments of chlorite schist quartzndashchlorite schist withplagioclase phenocrysts quartzndashfeldsparndashamphibole rock(metabasalt) medium-grained plagioclase grains andmore rarely quartz crystals in a fine-grained matrix Finelylayered mafic schists consist of an amphibolendashplagioclasematrix with scattered prismatic to ovoid plagioclasephenocrysts and quartz lsquoeyesrsquo Amphibole accessorybiotite and sericite lenses have a strong preferredorientation suggesting that recrystallization in these fine-grained rocks has destroyed any volcaniclastic texture

Volcanic breccia is present in at least three localitiesThe most important of these is 5 km north of the oldCashman mine in the southern part of BRYAH (seeMineralization) Outcrops of volcanic breccia are alsopresent at the Cashman mine and 3 km west of the PeakHill ndash Fortnum road junction The nature of these angularclast-supported poorly sorted blocks of mafic volcanicmaterial suggest that they are vent breccias Volcanicbreccia was intersected throughout 455 m of core indrillhole BD1 (BRYAH AMG 380380) drilled by NorthExploration Ltd in 1993 (McDonald 1994) This coreintersection is briefly described below

Drillhole BD1 was drilled to a depth of 520 m at aninclination of 70deg towards the south and intersected claysand gravels to a depth of 65 m followed by weatheredmafic volcanic breccias to 96 m Below this depth to theend of the hole at 520 m spectacular fresh proximal vent-facies material consisting of angular blocks and clasts ofbasaltic lava tuff and chert were intersected (Fig 11)Crude bedding is present locally as are thin layers oflaminated or cross-laminated cherty material The holebottomed in cross-laminated chert which is interpreted aspyroclastic surge and tuff deposits The basaltic rocksinclude fine-grained vesicular basalt and feldspar-phyricand augite-phyric basalts The porphyritic varieties arecharacterized by a microlite-rich feldspar matrixclinopyroxene granules interstitial glass and chlorite andopaque minerals (titanite or rutile) The feldspar

Figure 10 Mafic volcaniclastic rock of the NarracootaFormation showing relict glass shard (in centre)plane polarized light

Figure 11 Volcanic breccia of the Narracoota Formation intersected in diamond drillhole BD1 Clasts arepredominantly of basaltic rocks the matrix exhibits albitic alteration Width of the core trays is 040 m

11


phenocrysts are selectively altered to sericite whereas theaugite phenocrysts are fresh and exhibit distinct zoningVesicles are infilled (from rim to core) by albite epidotechlorite and calcite Minor sulfide specks mainlychalcopyrite may be present in the vesicular basalt Tuffscharacterized by fluidization (due to degassing) andeutaxitic textures consist of glass shards and crystal andlithic fragments set in a devitrified and variably alteredglassy matrix Alteration phases are mainly chloritecalcite quartz and albite Chalcopyrite blebs are presentin places Hydraulic fracturing and veins of calciteprehnite quartz and chlorite are abundant One sectionbetween 200 and 360 m is characterized by albiticalteration (sodium metasomatism) which imparts a pinkto reddish colouration to veinlets and patches where thealbite is present

The fragmental mafic volcanic rocks in drillhole BD1are interpreted to represent a proximal vent-facies volcanicbreccia This vent-facies material coincides withprominent magnetic and Bouguer gravity anomalies(Pirajno et al 1995a) The magnetic anomaly which isrelated to the presence of magnetite in pyroxene basalthas a well-defined northeasterly trending elliptical shapeand could conceivably indicate the remnants of a majorvolcanic edifice Magnetic modelling suggests thepresence of two tabular bodies dipping 25deg to the north(Bui Dung 1999 pers comm) The gravity anomaly isat the centre of a large regional gravity high whichunderlies most of the area occupied by the NarracootaFormation (Pirajno and Occhipinti 1998)

Carbonated and silicified metavolcanic rocks

Carbonated and silicified maficndashultramafic rocksinterpreted as part of the Narracoota Formation outcropin the Horseshoe anticlinal block (Plate 1) These rocksare compositionally heterogeneous and both underlie andare intercalated with rocks of the Horseshoe FormationThis suggests that the interleaving is tectonic becauseelsewhere in the Bryah Group the Horseshoe Formationis not observed to be in direct contact with the NarracootaFormation (Occhipinti et al 1999)

Jasperoidal chert

Jasperoidal chert pods are present locally within theNarracoota Formation (Gee 1987 Hill and Cranney1990 Pirajno and Occhipinti 1998) but are commonlytoo small to be represented individually on geologicalmaps One of the largest pods outcrops 15 km due southof Ruby Duffer Well in the southern part of BRYAH Windh(1992) investigated the chert pods in some detailgeochemically discriminated them on the basis of theirNiCr ratios and distinguished jasperoidal syngeneticexhalative chert silicified volcanic or sedimentary rockssilicified shear zone rocks and surface silicificationSeveral of these chert pods such as those in theNarracoota Formation south of the Peak Hill Schist innorthern BRYAH are quartz mylonites mdash probably Windhrsquos(1992) silicified shear zone rocks A few may be chemicalprecipitates deposited by hot springs whereas others mayrepresent silicified fault zones

The cherty material is reddish to grey colouredmassive to banded and extensively veined by quartzThe chert consists of very fine grained recrystallizedquartz with equant to elongate polygonalndashgranoblastictextures locally with a crystallographic preferredorientation Minute opaque minerals locally includingmagnetite or pyrite define trails parallel to the quartzfoliation In the Yarlarweelor opencut (Fortnum mine)pebbles of these cherts in overlying mafic fragmentalrocks suggest that the cherts formed as exhalative horizonsrelated to volcanism Alternatively the jasperoids mayrepresent iron-rich silicification along major shear zonesIn the Yarlarweelor opencut the chert pods host epigeneticgold mineralization in and around quartz(ndashpyrite) veinsystems (Hill and Cranney 1990)

Geochemistry of the Narracoota Formation

Major trace and rare earth element (REE) whole-rockanalyses of samples of metabasite rocks of the NarracootaFormation collected during this study are included in thedigital dataset in the back pocket These data were usedto characterize the geochemistry of the volcanic rocks ofthe Narracoota Formation in an attempt to better definethe rock types and gain an insight into the nature of theparent magma(s) and tectonic setting Representativeanalyses of Narracoota Formation rocks are presented inTable 2

The Narracoota metabasite rocks are commonly oftholeiitic composition with mixed mid-ocean ridge basalt(MORB) ndash oceanic island and continental geochemicalsignatures They span the range from high-Mg basalt tokomatiite and peridotitic komatiite or peridotite (possiblysubvolcanic cumulates) Common characteristics includehigh MgO high Ni and Cr moderate to low REEabundances and nearly flat chondrite-normalized REEpatterns with weak Eu anomalies possibly reflectingdepleted asthenospheric mantle sources (Pirajno and Davy1996 Pirajno et al 1996 Pirajno and Occhipinti 1998Occhipinti et al 1998ac) There are subtle chemicaldifferences between the hyaloclastites and maficndashultramafic schists (Tables 3 and 4 see below)

Hynes and Gee (1986) and Pirajno and Davy (1996)reported on the petrochemistry and tectonic setting ofthe Narracoota Formation metabasite rocks Hynesand Gee (1986) concluded that they have fairlyuniform chemistry and are of MORB affinity although theoriginal mafic volcanic rocks may have been emplacedthrough the rifting of continental crust Pirajno and Davy(1996) proposed that the Narracoota Formation meta-volcanic rocks might have formed in a setting analogousto that of the present-day Gulf of California (Lonsdaleand Becker 1985) The origin of the NarracootaFormation metabasites is discussed in Tectonic model andconclusions

Classification based on chemistry

The total alkali ndash silica (TAS) and high-Mg plot(Le Maitre 1989) indicates that the bulk of the rocks ofthe Narracoota Formation range in composition fromkomatiitendashpicrite through basalt to basaltic andesite

12

Pirajno et al

Table 2 Representative chemical analyses of the Narracoota Formation

Rock _________________ Mafic schist _________________ _______ Hyaloclastite _______ _______ Ultramafic _______ ____ Trillbar __type schist ComplexSample 132788 132789 132790 133033 133050 112643 116485 104256 132791 139138 139139 135482 143538

Percent

SiO2 5424 4945 5277 463 4907 5187 5139 5011 4923 4723 4789 5137 4961TiO2 028 113 031 019 026 073 063 053 019 016 017 037 141Al2O3 1422 1172 1466 948 794 138 1512 1503 1043 765 867 1481 1391Fe2O3 248 345 184 661 635 224 296 278 146 396 201 232 561FeO 598 824 705 741 101 848 662 529 834 548 708 561 717MnO 017 019 018 025 198 02 016 014 018 012 015 016 022MgO 929 1243 1036 1517 778 1036 83 936 2063 2877 2678 869 656CaO 1106 1107 962 1451 2262 974 1144 1514 86 641 704 1068 1136Na2O 218 212 274 003 009 216 32 145 092 018 019 306 204K2O 007 008 046 001 284 036 01 011 002 003 001 006 022P2O5 003 013 002 003 007 007 006 005 001 001 001 003 011Total 10000 10001 10001 9999 10001 10001 9998 9999 10001 10000 10000 9716 9822

Mg 6687 6615 6795 6692 6736 6377 6142 6816 792 85 843 ndash ndash

Parts per million

Ag ndash ndash ndash ndash ndash 1 ndash 1 ndash ndash ndash ndash ndashAs 155 157 052 22551 13032 ndash ndash ndash ndash 832 ndash ndash ndashAu ndash ndash ndash ndash ndash 104 ndash ndash ndash ndash ndash ndash ndash

Ba 55 140 79 27 2 846 341 127 92 74 37 102 39 322Cd ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash

Co 55 86 58 223 51 ndash ndash ndash 99 113 111 ndash ndash

Cr 509 1 201 686 2 574 72 489 364 283 1 836 2 530 3 146 593 82Cu 168 124 63 327 20 108 101 39 55 9 11 59 172Ga 10 16 10 8 9 12 12 13 8 6 6 12 19Hf ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash 07 14Mo ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash 08 26Nb ndash 63 ndash ndash 52 ndash ndash ndash ndash ndash ndash 1 9Ni 203 548 241 1 274 91 258 143 164 866 1 531 1 230 124 98Pb ndash 2 ndash ndash 7 ndash ndash ndash ndash ndash ndash 1 4Pd ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndashPt ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndashRb 1 ndash 6 ndash 85 6 ndash 2 ndash 1 ndash 1 4Sb ndash ndash ndash ndash ndash 415 ndash 511 ndash ndash ndash ndash ndashSc 50 41 51 31 10 ndash ndash ndash 40 34 38 51 48Sr 64 149 64 54 100 163 82 188 23 23 7 61 279Ta ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndashTh ndash 104 ndash ndash 717 ndash ndash ndash ndash ndash ndash ndash ndashU ndash ndash ndash 064 13 ndash ndash ndash ndash ndash ndash 08 14V 196 277 202 138 78 250 249 217 144 115 143 235 362W ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndash ndashY 13 18 12 8 16 17 14 11 8 6 7 17 24Zn 65 94 68 45 50 85 73 55 62 51 45 61 91Zr 13 68 15 17 50 51 47 38 7 7 8 20 86

La 089 936 043 054 1819 36 35 35 093 017 056 2 6Ce 218 2264 129 084 4445 9 83 83 153 042 082 2 15Pr 037 29 02 02 418 12 11 13 02 009 019 0 2Nd 166 1193 108 102 1511 57 51 57 102 047 079 5 12Sm 08 328 065 056 306 15 14 15 065 03 034 ndash ndashEu 042 13 032 028 223 09 07 08 029 011 011 ndash ndashGd 166 409 141 085 305 23 17 2 129 065 071 ndash ndashTb 04 069 031 018 04 04 04 04 029 014 016 ndash ndashDy 268 408 233 12 202 27 24 24 214 108 116 ndash ndashHo 071 087 057 028 037 05 05 05 053 027 03 ndash ndashEr 222 231 173 094 115 18 15 16 162 083 091 ndash ndashTm 039 033 027 016 017 02 02 02 027 014 015 ndash ndashYb 229 196 182 115 125 15 14 15 166 086 09 ndash ndashLu ndash ndash ndash 019 02 02 02 02 ndash 013 014 ndash ndash

13


(Fig 12) A small number of samples plot in the boniniteand andesite fields All metabasites of the NarracootaFormation (ultramafic and mafic schists and basaltichyaloclastite) are of subalkaline tholeiitic affinity (Fig 13)They commonly have restricted silica contents rangingfrom 45 to 55 wt (Fig 12)

The metabasites are all quartz albite anorthitediopside hypersthene and magnetite normative Themafic schists are hypersthene normative with lowerMgO contents (lt15 wt) and magnesium numbers (Mgmdash defined as MgO(FeO + MgO)) ranging from 43 to 74(Table 3) Some mafic schists have no quartz and areolivine normative (5ndash6 and up to 20 in some maficschists) The ultramafic schist is hypersthene and olivinenormative with MgO contents ranging from 153 to227 wt and Mg ranging from 75 to 86 (Table 3) Themetabasaltic hyaloclastites are albite and clinopyroxenenormative and have MgO contents of lt10 wt and Mgof between 47 to 68 (Table 3)

Ultramafic schist mafic schist and metabasaltichyaloclastite can be distinguished in terms of their Cr Niand Ti abundances FeOMgO ratios (Tables 3 and 4Figs 14a and 14b) and chondrite-normalized REEpatterns The hyaloclastite rocks are depleted in Cr andNi and enriched in TiO2 relative to the maficndashultramaficrocks (Fig 14c)

The Jensen (1976) cationic plot is based on theproportion of Fe2++Fe3++Ti versus Al and Mg cationsrecalculated to 100 and is particularly useful fordiscriminating subalkaline and Mg-rich metamorphosedvolcanic rocks in which the alkali content may havebeen modified during deformation and metamorphism(Rollinson 1993) In the Jensen plot (Fig 15a) the

Narracoota Formation rocks span the range of compo-sitions from high-Mg tholeiite through to komatiite andperidotitic komatiite in a trend of increasing MgO

Chondrite-normalized rare-earth element diagramscommonly regarded as the most useful of the traceelement plots in the petrogenesis of igneous rocks areused to determine the possible nature and source of themelts Particularly important are the overall patterns fromlight to heavy rare earth elements (LREE to HREE) thenormalized abundance of Eu controlled by feldspar andthat of Ce controlled by seawater or hydrothermal fluidsFor the Narracoota Formation rocks chondrite-normalizedREE abundances (Figs 15b and 15c) are commonly low(lt1 to lt40 times chondrite) The mafic schist ischaracterized by a spread in LREE from depleted toenriched (Fig 15b) with individual patterns almostidentical to those of mid-ocean ridges (OrsquoNions et al1976 Schilling 1982) and the recent basaltic lavas ofIceland (Schilling et al 1982) More specifically theLREE-depleted patterns (western Bryah Basin) arestrikingly similar to those of the Lau Basin spreadingcentre in Fiji (Pearce et al 1995) whereas slightlydepleted to slightly enriched LREE patterns (eastern Bryah

Table 3 Magnesium numbers for the Narracoota and Killara Formations

Rock Formation Range of Mg Average Mg Standard deviationof Mg

Metabasaltic hyaloclastite Narracoota 4677 ndash 6816 5716 525Mafic schist Narracoota 4337 ndash 7409 5957 669Ultramafic schist Narracoota 7516 ndash 8560 8105 254Tholeiitic basalt Killara 3504 ndash 6603 5035 739

NOTE Mg Magnesium number defined as MgO(FeO +MgO)

Table 4 Selected geochemical parameters for the NarracootaFormation

Parameters Hyaloclastite Mafic schist Ultramafic(mean values) schist

(LaYb)N 144 1702 037TiO2 (wt) 086 068 019NiCr 043 039 042Al2O3TiO2 162 205 4668MgO (wt) 731 780 2119

35 45 55 650

1

2

3

4

foidite andesite

basalt

boninite

basalticandesite

MgOgt18 picrite

basanite

tephrite

MgOgt18 amp TiO lt1 komatiite

picrobasalt

FMP365 021199

22

2

2

2

2

MgOgt18 amp TiO gt1 meimechiteMgOgt8 amp TiO lt05

SiO (wt)

Na

O +

K O

(w

t)

Figure 12 Total alkali versus silica diagram (Le Maitre1989) for rocks of the Narracoota FormationNote that a small number of samples fall withinthe boninite field this however may be due tohydrothermal alteration

14

Pirajno et al

Basin) are comparable to those of seamounts reflectinga more enriched source The nearly flat patterns havenegative Eu anomalies reflecting the primitive nature ofthe rocks presence of olivine clinopyroxene andorthopyroxene and fractionation of feldspar from themelt The patterns of the Iceland basalts that are nearlyidentical to those of the mafic schist of the Bryah Groupwere explained by Schilling et al (1982) as due toadvection of asthenospheric mantle at a mid-ocean ridgeConsidering field relations and petrological andgeochemical data it is conceivable that the NarracootaFormation metatholeiites may have had a similar originChondrite-normalized REE abundances for the meta-basaltic hyaloclastite are very low (9 to 14 timeschondrite) slightly LREE-enriched and with a distinctpositive Eu anomaly (Fig 15c) reflecting the addition ofalbite due to seawater metasomatism

The overall REE abundances and patterns of maficschist and hyaloclastite are strikingly similar to192 ndash 184 Ga mafic rocks of the Flin Flon belt in theTrans-Hudson Orogen in Canada (Lucas et al 1996)Some of the mafic rocks of the Flin Flon belt have beeninterpreted to belong to tectono-stratigraphic assemblagesof ocean floor and ocean island affinity Also the Flin Flonocean island tholeiites have REE patterns similar to

Figure 13 Total alkali versus silica diagram (Le Maitre 1989)defining limits of alkaline and subalkaline basaltsshowing the predominantly subalkaline nature ofthe Narracoota Formation

20

16

12

8

4

0

Na

O +

KO

(w

t)

22

857565554535

SiO (wt)2 11999FMP367

Hyaloclastite

Mafic schist

Ultramafic schist

Subalkaline

Alkaline

Figure 14 Geochemical characteristics of the NarracootaFormation a) TiO2 versus FeOMgO ratios notethe slight TiO2 enrichment of metabasaltichyaloclastite compared to maficndashultramafic schistb) Cr versus FeOMgO ratios note the Cr enrichmentof maficndashultramafic schist compared to meta-basaltic hyaloclastite c) TiO2ndashNindashCr triangular plotshowing Ni and Cr enrichment of maficndashultramaficschist compared to metabasaltic hyaloclastite

3

2

1

0

TiO

(wt

)2

1 2FeO MgO (wt)

Hyaloclastite

Mafic schist

Ultramafic schist

4000

3000

2000

1000

0

Cr

(ppm

)

1 2 3FeO MgO (wt)

Hyaloclastite

Mafic schist

Ultramafic schist

TiO 1002

Ni Cr91199FMP368a

Hyaloclastite

Mafic schist

Ultramafic schist

a)

b)

c)

15


Hawaiian tholeiites (Stern et al 1995) The inference fromthese comparisons is that submarine volcanoes may havebeen a component of the Narracoota Formation

Tectonic discriminant diagrams do not provide reliableinformation on the palaeotectonic environment withinwhich igneous rocks were emplaced (Duncan 1987 Wangand Glover 1992) Nevertheless if there is petrologicalevidence that the rocks have not undergone extensivecrystal fractionation and the overall geological context is

taken into account selected discriminant diagrams can beused to estimate palaeotectonic settings With the aboveconsiderations in mind and remembering that the rocksin question have a subalkaline chemistry the FeO(tot)ndashMgOndashAl2O3 plot of Pearce et al (1977) is deemedappropriate (Fig 15d) The FeO(tot)ndashMgOndashAl2O3 plot hasbeen used successfully in geologically well constrainedareas (Breitkopf and Maiden 1988) The FeO(tot)ndashMgOndashAl2O3 plot suggests that the Narracoota Formationvolcanic rocks were formed in tectonic environments of

a)

c)

b)

d)

MgO

TA

TDTR

CR CDCA

HFTBK

PKCB

HMT

Sam

ple

chon

drite

100

10

2La Pr Eu Tb Ho Tm Lu

Ce Nd Sm Gd Dy Er Yb

La Pr Eu Tb Ho Tm LuCe Nd Sm Gd Dy Er Yb

Sam

ple

chon

drite

100

10

1

6

FeO

MgO

221199

Al O32

FeO + TiO2

Al O32

FMP154


Metsabasltic hyaloclastite(tot)

Figure 15 Geochemical discriminant plots for Narracoota Formation rocks a) Jensen (1976) cationic plot showingrange of compositions from high-Mg tholeiite (HMT) through high-Fe tholeiite (HFT) basaltic komatiite(BK) peridotitic komatiite (PK) tholeiitic andesite (TA) tholeiitic dacite (TD) calc-alkaline basalt (CB)and calc-alkaline andesite (CA) b) Chondrite-normalized rare-earth element plot of mafic (HREE-enriched) and ultramafic (HREE-depleted) schist (normalizing factors after Sun 1982) c) Chondrite-normalized rare-earth element plot of metabasaltic hyaloclastite (normalizing factors after Sun 1982) d)Triangular discriminant plot (Pearce et al 1977) showing the tectonic environment of the NarracootaFormation Tectonic fields are as follows 1) spreading-centre island 2) orogenic 3) ocean ridge andfloor 4) ocean island and 5) continental

16

Pirajno et al

MORB ndash oceanic island to continental affinity (Fig 15d)This diagram however has limitations if the rocks havebeen subjected to ocean-floor metamorphism A moreuseful plot is the TiO2ndashFeO(tot)ndashMgO plot which was usedby Breitkopf and Maiden (1988) in their study of theNeoproterozoic Matchless Amphibolite Belt of theDamara Orogen in Namibia The TiO2ndash FeO(tot)ndashMgO plotsupports the gradation from MORB towards continentalflood basalt because the hyaloclastite rocks plot closer tothe continental field than do the mafic schist (Fig 16) Thisfeature together with other considerations such as Mgand geological and petrological constraints indicate thatthe hyaloclastite was erupted on a continental rift marginThis has important implications for the tectonic evolutionof the BryahndashPadbury Basin as explained in Tectonicmodel and conclusions


The Ravelstone Formation is poorly exposed in scatteredlow outcrops over a wide area in the northern and centralparts of the Bryah Basin Rocks of the RavelstoneFormation were previously considered by MacLeod(1970) and Gee (1979 1987) to belong to the lsquoThadunaGreywackersquo (now Thaduna Formation of the YerridaGroup) for which the type area is about 100 km to theeast-northeast on THADUNA (Pirajno and Adamides 1998)

The Ravelstone Formation comprises a succession oflithic and quartz wacke shale and siltstone that was

deposited from turbidity currents In the north theRavelstone Formation contains lenses of chert andis unconformably overlain by the MesoproterozoicBangemall Group West of the Peak Hill opencut thelower contact with the Narracoota Formation is dis-conformable whereas the upper contact with theHorseshoe Formation appears to be conformable In thecentral and northern parts of BRYAH the RavelstoneFormation although metamorphosed has no tectonitefabric On MILGUN (around Fortnum) however a well-developed foliation is present

Drillcore from the Harmony gold deposit shows thatthe contact between the base of the Ravelstone Formationand the top of the Narracoota Formation is interfingeredpossibly due to shearing The disconformable contactbetween the base of the Ravelstone Formation and the topof the Narracoota Formation is exposed in a river bedabout 1 km due east of the Fortnum ndash Peak Hill turn-offIn this area graded layers of immature subarkosicsandstone to siltstone contain fresh plagioclaseK-feldspar sericitized lithic fragments and angular quartzgrains in a matrix composed of sericite and biotite Inaddition the siltstone contains euhedral crystals oftourmaline Metamorphic brown biotite and muscovite areabundant and replace feldspars quartz and lithicfragments Lithic fragments include massive chlorite(ndashrutile) derived from mafic precursors chert hematitendashquartz shale as well as partly sericitized feldspar grainsQuartz grains include rounded to irregular shapes andbiotite is metamorphic in origin Quartz white micachlorite and variable amounts of carbonate are part of thefine-grained matrix Well-developed foliation wherepresent is defined by aligned sericite elongate quartzand to a lesser extent feldspar grains and by mica seamsNew muscovite flakes have grown along and across thefoliation

In the Fortnum mine area on MILGUN graded beddedlithic wacke and siltstone overlie the volcanic rocks of theNarracoota Formation The wacke contains medium tocoarse-grained crystals of feldspar (plagioclase minor K-feldspar) and quartz as well as fragments (fine metabasaltand chlorite) derived from mafic volcanic rocks Thefeldspar crystals which are strongly sericitized dominateover quartz The matrix consists of sericitendashchloritendashquartz with or without carbonate The reworked rocksinclude fragmental layers with fine metabasalt debris andgraded chloritic siltstone containing plagioclase laths Thederivation of the mafic component is easily explained butthe well-preserved feldspar crystals suggest nearbygranitic or felsic volcanic precursors

Horseshoe Formation

The Horseshoe Formation occupies areas west of thePeak Hill opencut and the northern parts of BRYAH

and MILGUN This formation includes finely laminatedferruginous (hematitic) shale and siltstone fine-grainedquartzndashfeldspar wacke with interleaved iron formation andchert graded quartz wacke manganiferous shalegarnetiferous biotitendashchlorite schist and garnetiferousiron-formation Relatively high manganese contents areinferred from the abundant manganese oxide staining in

CFB

MORB

20

18

15

13

10

08

05

03

000 1 2

TiO

2

FMP168 211099Ultramafic schist

Mafic schist

Hyaloclastite rocks

(tot)FeO MgO

Figure 16 TiO2 versus FeOMgO plot (Breitkopf and Maiden1988) for the Narracoota Formation showing themid-ocean ridge basalt (MORB) affinity of the maficand ultramafic schist and the transitional chemistryof the hyaloclastites towards continental floodbasalts (CFB)

17


weathered and lateritic rocks and lateritic manganese orehas been mined at the Horseshoe and Mount Padburymines The type area of the Horseshoe Formation is theHorseshoe Range (Occhipinti et al 1997) where athickness of approximately 1000 m was estimated by Gee(1979) The Horseshoe Formation overlies the NarracootaFormation however the contact is either conformable ortectonic Elsewhere on JAMINDI north of BRYAH theHorseshoe Formation overlies the Ravelstone Formationand the contact is gradational and conformable TheHorseshoe Formation underlies the Labouchere Formationof the Padbury Group The nature of this upper contactappears conformable however Martin (1994) suggestedthat there is a regional unconformity between these units

Structurally the Horseshoe Formation forms a broadsyncline with its axis trending approximately easterly Thesouthern limb of this syncline is in sheared contact withrocks of the Narracoota Formation In this area theHorseshoe Formation is complexly folded with axestrending 070deg parallel to the shear zone

In the Horseshoe Range Gee (1987) recognized threeunits 1) a lowermost part consisting of regularly beddedwacke and shale similar to the underlying Ravelstonesuccession but finer grained more calcareous andcontaining less chlorite and more feldspar and quartzindicative of a granitic rather than mafic volcanicprovenance 2) a middle iron-formation member withseveral BIF (chertndashmagnetitendashstilpnomelane white chert)horizons intercalated with chloritic shale and 3) anupper unit of calcareous manganiferous shale andwacke The lowermost unit is exposed on MILGUN in thelow hills east of Fortnum airstrip where fine-grainedcarbonate-cemented wacke and shale contain dis-harmonic-folded white-chert lenses (2ndash12 cm thick) andless common discontinuous quartzndashmagnetite layers(2ndash3 cm) The quartz wacke component of the HorseshoeFormation contains quartz plagioclase microclinebiotite and muscovite all as detrital minerals Nearthe Peak Hill opencut the iron formation is made upof biotite amphibole chlorite quartz magnetite andgarnet This unusually high grade assemblage may berelated to the metamorphism of the Peak Hill Schist (seeMetamorphism)

About 1 km north of the Ravelstone manganesedeposits a reasonably good exposure of the HorseshoeFormation was examined in detail A stratigraphic columnfor this locality is shown in Figure 17 This is a foldedupward-coarsening package approximately 350 m thickwhich from base to top consists of quartzndashlithic wackewith banded chert interbeds displaying a well-developedaxial planar cleavage quartz wacke with iron formationand shale interbeds massive beds of coarse-grainedquartzndashlithic wacke intercalated with thin granular iron-formation amphibole- and garnet-bearing granular iron-formation layers and massive quartzndashlithic wackeintercalated with thin iron-formation bands The quartzndashlithic wacke contains chert clasts detrital subangularquartz fresh plagioclase crystals and biotite in a matrixof sericite green chlorite and iron oxide grains Bandedcherty material is composed of granular quartz aggregatesbrown biotite actinolite and very fine carbonate-richlaminae (this rock is best classified as a quartzndashbiotitendash

actinolite schist) The granular iron-formation consists ofgranular aggregates of quartz and iron oxides withinterstitial biotite and chlorite Syntectonic garnetporphyroblasts are replaced in part by quartz andcarbonate Massive lithic wacke consists of a packedaggregate of angular quartz feldspar and chert grains thematrix is volumetrically small and made up of biotitequartz and sericite Garnetiferous iron-formation has darklaminae of quartz granules with interstitial actinolitendashchlorite iron oxides and light-coloured microbands (1 cmthick) of quartz with actinolitendashchlorite iron oxides anddisseminated synndashlate-tectonic garnet porphyroblastsGarnet is also present as porphyroblasts growing acrossmicroband boundaries

Padbury GroupThe Padbury Group locally unconformably overliesthe Horseshoe Formation of the Bryah Group but inplaces is in faulted contact with the Bryah Group andYarlarweelor gneiss complex (Narryer Terrane Yilgarn

FMP156 020300

0

100

200

300

intercalated with thin BIF and shale interbeds

Garnetiferous BIF

Massive beds of coarse-grained lithic wackewith interbeds of garnetiferous BIF and

Banded iron-formation interbedded with massive

Banded chertQuartzndashlithic wacke with carbonate cement

wacke and soft granular iron-formation

(m)

granular iron-formation

Massive quartzndashlithic wacke layers

Micaceous wacke

Figure 17 Schematic stratigraphy of the HorseshoeFormation from an area of outcrops about 12 kmwest-northwest of the Peak Hill mine (after Pirajnoand Occhipinti 1998 width of column reflectsrelative resistance to weathering)

18

Pirajno et al

Craton Fig 2) Considerable onlap of the Padburysuccession onto the various formations of the Bryah Groupcan be inferred these contacts were faulted possibly inseveral stages during basin closure The age of thePadbury Group is poorly constrained Nelson (1997)reported a maximum age of c 20 Ga from the upper partof the Wilthorpe Formation and Windh (1992) inferred aminimum age of c 18 Ga from a leucogranite dyke

Martin (1994 1998) proposed a formal stratigraphy forthe lower Padbury Group based on detailed sediment-ological studies in the area covering the southeastern andcentral parts of MILGUN This formal stratigraphy replacedprevious stratigraphic divisions (Barnett 1975 Gee1979 1987 Windh 1992) and has since beenexpanded to include two distinct lithostratigraphic unitsas members within the Wilthorpe Formation the Heinesand Beatty Park Members (Occhipinti et al 1997) Martin(1994 1998) interpreted the Labouchere and WilthorpeFormations as an upward-coarsening deep-water turbiditecomplex overlain by shales and iron formation of theRobinson Range Formation The turbidites were derivedby erosion from the granitendashgneiss basement (YilgarnCraton) and by reworking of underlying sedimentary andmafic volcanic rocks in the Bryah Basin

The Padbury Group contains quartz wacke siltstoneconglomerate iron formations hematitic shale and minorclastic rocks and dolomite (Martin 1994 Occhipintiet al 1997) and is subdivided into four formationsLabouchere Wilthorpe Robinson Range and MillidieCreek Formations Martin (1994) interpreted the PadburyGroup to have been deposited in a retroarc foreland basinthat developed on top of the Bryah Group


The Labouchere Formation occupies areas in thenorthwestern part of the Bryah Basin where it isfaulted against the Yarlarweelor gneiss complex Martin(1994 1998) suggested that the Labouchere Formationunconformably overlies the Horseshoe Formation(Bryah Group) based on the regional geometry inthe Fortnum mine ndash Dandy Well area on MILGUN Theregional unconformity is inferred from the low-angletruncation of an iron-formation marker unit in theHorseshoe Formation against lowermost quartz areniteof the Labouchere Formation in the area south ofYarlarweelor Creek North of the Fortnum Fault ironformation within the Horseshoe Formation is nearlyparallel to bedding in the Labouchere FormationElsewhere in the region contacts between variousformations of the Bryah and Padbury Groupsare interpreted as unconformities (Windh 1992) oralternatively as faults or shear zones (Pirajno andOcchipinti 1998 Occhipinti et al 1998b) On BRYAH theLaboucherendashHorseshoe Formation contact is marked bya conglomeratic unit The Labouchere Formation isconformably overlain by and grades into the WilthorpeFormation (Martin 1994) although this contact waspreviously described as an unconformity (Gee 1979) Gee(1979) estimated the Labouchere Formation (including theWilthorpe Formation) to be 5000 m thick extending from

Mount Labouchere on MILGUN (type area Martin 1994)to the Horseshoe Range the southern continuation ofwhich is in northwestern BRYAH Martinrsquos (1994 1998)type section is a composite stratigraphy (up to 7000 mthick) based on four separate sections in southeasternMILGUN

The Labouchere Formation consists of quartz arenitemedium- to coarse-grained sericitic quartz wacke andsericitic siltstone minor conglomerate and banded iron-formation in an upward-coarsening succession Near theHorseshoe manganese mining area the LabouchereFormation consists of a thick succession of upward-finingcycles up to 700 m thick Each cycle consists ofconglomerate or a coarse lithicndashquartzndashsericite wacke unitat the base grading up through coarse- to fine-grainedquartzndashfeldsparndashlithic wacke and sericitic siltstone to iron-rich shale These cycles however become increasinglycoarser upwards so that there is regional upwardcoarsening The base of the topmost cycle begins with aquartz-pebble conglomerate Minor and thin bands of iron-formation are locally present as intercalations within thesedimentary units

Quartz arenite contains grain-supported well-roundedquartz in a sericitic matrix and is extensively silicified Aprominent quartz arenite marker forms the ridge includingMount Labouchere north of Fortnum mine on MILGUN andcan be traced for many tens of kilometres to the southeastwhere gradually more quartz wacke is interbedded withthe arenite A second quartz arenite marker approximatelyhalfway up the Labouchere Formation is present in thearea north of the Fortnum Fault In the same area an ironformation ndash chert layer is present about 250 m above thissecond quartz arenite Martin (1994) emphasized that thedeep-water environment of this iron formation indicatesa similar depositional environment for the clastic rocksQuartz wacke has a matrix-supported framework ofvariably rounded quartz grains minor lithic fragments andfeldspar in a sericitendashchlorite matrix whereas laminatedshale consists of sericitendashchlorite Wacke and siltstoneform numerous upward-fining cycles

Muscovitendashquartz schist or slate developed fromquartz wacke and siltstone in zones of high strain andhigher metamorphic grade adjacent to the Yarlarweelorgneiss complex Strongly foliated quartz wacke andmuscovitendashquartz schist occupy a 4 km-wide zone nearthe Labouchere mine on MILGUN Another belt of schistand slate is present between the Billara Fault and DespairGranite in southwestern MILGUN These strongly foliatedrocks can be traced northwards into recognizable thoughstrongly foliated pebbly quartz wacke The fine-grainedschist consists of elongate polygonalndashgranoblastic quartzwith spaced trails of aligned muscovite flakes Beddingndashcleavage relationships are found in less-deformed areaswhereas in high-strain zones differentiated layeringdeveloped from a pervasive crenulation cleavage

Sericite is abundant throughout most of the rocks ofthe Labouchere Formation The quartzndashsericite wacke iscomposed of subangular quartz grains embedded in asericitized matrix with occasional large muscovite lsquobooksrsquoand scattered small crystals of tourmaline and anatase

19


Quartzndashfeldsparndashlithic wacke is made up of subangularquartz grains polycrystalline quartz K-feldspar andplagioclase in a matrix of quartz sericite biotite andminor detrital zircons

Wilthorpe Formation

The Wilthorpe Formation (formerly lsquoWilthorpeConglomeratersquo Gee 1987) including the Beatty Park andHeines Members comprises quartz- and chert-pebbleconglomerate quartz wacke sericitic siltstone chloritendashquartz shale quartzndashsericitendashhematite schist dolomiticsandstone and finely laminated chert lenses TheWilthorpe Formation is conformably overlain by theRobinson Range Formation

Martin (1994) measured the type section of theWilthorpe Formation (about 1300 m thick) along theTalbot Divide In this area the characteristic quartz-pebbleconglomerate forms a prominent ridge to the east of hillsunderlain by the Robinson Range Formation In theFortnumndashLabouchere area on MILGUN the exact locationof the LaboucherendashWilthorpe Formation transitionalboundary is less well defined (Swager and Myers 1999)Along the western wall of the Nathans Deep Southopencut (labelled Nathan Deep on Plate 1) severalupward-fining cycles of quartz-pebble conglomerategrading into quartz wacke and quartzndashmuscovite siltstonecan be observed These cycles are underlain by fine-grained chloritic shale interbedded with quartz wackeThis chloritic shale with detrital ilmenite is derived froma mafic precursor probably the Narracoota Formation(Windh 1992) Occhipinti et al (1998a) recognizedcomparable lsquomaficrsquo clastic rocks as a mappable unit(Beatty Park Member mdash see below) at the top of theWilthorpe Formation on PADBURY

The conglomerate contains well-rounded slightlyelongate or faceted vein-quartz clasts and less commonlychert quartzite quartz wacke and rare siltstonendashmudstoneclasts in a quartz wacke matrix Clasts range in size frompebbles to boulders Quartzite pebbles locally containfolded foliation fabrics Bunting et al (1977) suggestedthat large quartzite boulders in the southern part of thetype area were derived from the basal Finlayson Memberof the Juderina Formation (Yerrida Group) Martin (19941998) recognized two polymictic conglomerate intervalsin the type area which included silicified dolomite clastsThese intervals are similar to the polymictic conglomerateand sandstone of the Heines Member defined on BRYAH

(Pirajno and Occhipinti 1998) Siltstone forms a distinctmappable upper unit along the gradational contact withthe Robinson Range Formation

Beatty Park and Heines Members

The Beatty Park Member outcrops in the Mount Padburyarea on PADBURY and contains clastic rocks that werepossibly sourced at least in part from the mafic volcanicrocks of the underlying Narracoota Formation (BryahGroup) with sedimentary chert lenses towards its top Asensitive high-resolution ion microprobe (SHRIMP)UndashPb date obtained from detrital zircons in one of these

chert lenses suggests a maximum age of 1996 plusmn 35 Ma(Nelson 1997) The clastic rocks of the Beatty ParkMember are dominated by metamorphosed chloritendashquartzshale siltstone and wacke several conglomeratic orbreccia lenses and finely laminated chert layers in places(Occhipinti et al 1997) The contact between the BeattyPark Member and the overlying Robinson RangeFormation is gradational with chloritic siltstone and chertlayers and lenses grading into sericitendashquartz siltstone Thelower contact of the Beatty Park Member with theWilthorpe Formation appears to be gradational in the areawest of the Fraser Synclinorium (see Structure) whereferruginized kaolinitic siltstone and quartz wacke gradeinto chloritic siltstone In this area the minimum thicknessof 470 m is implied because the upper part of the BeattyPark Member is not exposed

The shalendashsiltstone layers are well bedded to finelylaminated and consist of quartz and chlorite with minorsericite epidote feldspar titanite and detrital hornblendeThese layers are accompanied by very fine grainedrecrystallized white chert beds in the upper part of theBeatty Park Member West of the Fraser Synclinoriumsedimentary structures such as bedding-parallel lamin-ations flame structures and contorted bedding can beobserved within chloritic siltstone Two types of wackeunits are present one containing quartz dolomite chloritefeldspar sericite epidote sphene and opaque minerals(either magnetite or pyrite) and the other containingquartz feldspar muscovite epidote chlorite carbonateand opaque minerals Lithic fragments in wacke layersinclude metabasalt and mafic schists in which leucoxenepseudomorphs of iron oxides can still be recognizedLenses of coarse-grained lithic wacke and conglomeratecomprise rock fragments of basalt mafic schist chertchloritendashquartz wacke and coarse detrital grains (quartzfeldspar) in a sericitendashchloritendashquartz matrix Coarseclastic rocks fill channels that cut into the fine-grainedrocks and contain numerous rip-up clasts This suggeststhat at least in part the Beatty Park Member wasdeposited distally from the source region Locally whitechert lenses crosscut erosional contacts indicating that thechert is diagenetic or epigenetic

Within all rocks of the Beatty Park Member sericiteand muscovite are of metamorphic origin They replacechlorite in the fine-grained chloritic shalendashsiltstone layersand feldspar clasts in the wacke units In several examplesfine-grained muscovite has grown along late cleavageplanes

A quartzndashchloritoidndashsericitendashchlorite(ndashsulfide) unitpreviously interpreted to be a carbonate intrusion (Lewis1971 Elias and Williams 1980) has been assigned to theBeatty Park Member The chloritoid is crystallized insprays and displays a lsquobow-tiersquo texture The presence ofabundant chloritoid indicates that this rock has a highalumina content implying either a pelitic precursor or thatthe protolith was extensively metasomatized

The Heines Member consists of an upward-finingsuccession of sedimentary rocks with a polymicticconglomerate at its base followed by clastic sedimentaryunits (sandstone to shale) The type area is near Durack

20

Pirajno et al

Well on BRYAH At this locality the Heines Memberis folded into a syncline and its southern limb is in faultedcontact with the underlying Narracoota Formation Thenorthern contact is obscured here by the Cainozoic coverThe Heines Member includes those outcrops south of theRobinson Syncline at the Heines Find prospect RandellBore and 35 km northwest of Durack Well which werepreviously mapped as lsquoWilthorpe Conglomeratersquo byGee (1987) The succession is approximately 600 mthick although basal units may have been shearedoff along the faulted contact The basal polymicticconglomerate contains clasts of mafic lithic wackelimestone quartz arenite and hematitic shale supportedby a carbonate matrix This is followed upward by a seriesof sandstonendashshale units with the shale componentbecoming volumetrically greater with stratigraphic heightThe basal conglomerate of the Heines Member containsno volcanic clasts of the underlying Narracoota Formationand this is taken as evidence that the contact with the latterformation is tectonic The provenance of the various clastsin the basal conglomerate is not known In the Heines Findprospect area the Heines Member is overlain by theRobinson Range Formation


The Robinson Range Formation forms elongate outcropsthat extend from east to west in the centre of the BryahndashPadbury Basin and in a northerly direction on the easternmargin of the Yarlarweelor gneiss complex on MILGUN andPADBURY (Plate 1) The Robinson Range Formation isdefined by the appearance of ferruginous or hematiticshale followed by two iron formations mdash a well-definedlower banded unit separated by 100 m of ferruginousshale from an upper unit with clastic textures as mappedby Gee (1987) which is in turn overlain by hematitendashchlorite siltstone The Robinson Range Formation isconformably overlain by the Millidie Creek Formation

The Robinson Range Formation consists of asuccession of BIF siltstone and iron-rich shale Granulariron formation is present as irregular lenses The BIFconsists of laminae up to 3 cm thick These laminationscomprise various amounts of quartz iron oxides (hematiteor magnetite) biotite and locally ferro-actinolite Theshale and siltstone consist of fine-grained sericite quartzchlorite iron oxides and in a few places minor spheneThe mesostructure microstructure and petrology ofthe BIF are relatively simple Microbands or laminae lessthan 1 to 2ndash3 mm thick are made up of alternatingmicrocrystalline quartz(ndash iron oxides) greenndashbrownbiotite(ndash iron oxides) quartz grains(ndash acicular crystals ndashiron oxides) quartz grains(ndash iron oxides ndash biotite ndashacicular crystals) Commonly the quartz grain(ndash acicularcrystal) assemblage displays a polygonized texturesuggestive of annealing due to metamorphism Theacicular crystals are weathered to iron oxides but onthe basis of their morphology they could be eitherstilpnomelane crystals or amphiboles The iron oxides areeither hematite or magnetite Incident light microscopyreveals that a primary titaniferous magnetite is replacedby hematite which in turn is replaced by goethite in thesupergene environment The biotite is porphyroblastic and

mostly grown under conditions of peak metamorphism(see Metamorphism)

Granular iron-formation is characterized by a granulartexture and the presence of elongate peloids 1 to 4 mmlong The peloids consist of microcrystalline chert outlinedby rims of iron oxides (hematite with inclusions ofilmenite) The chert peloids are enclosed in finemicrocrystalline cherty or chalcedonic material Thepeloids and chert make up bands approximately 1 to15 cm thick with occasional laminae of fine chert(ndash ironoxides)

The ferruginous shale is composed of silt-sized quartzgrains and iron oxides with abundant interstitial biotiteand minor disseminated euhedral tourmaline crystals Thetourmaline was formed either during metamorphism or ahydrothermal event

The iron formations of the Robinson Range Formationhave been correlated with the granular iron-formation ofthe Frere Formation (Earaheedy Basin) 150 to 450 km tothe east-southeast by Hall and Goode (1978) whocompared them to those of the Lake Superior region inNorth America


The Millidie Creek Formation defined by Barnett (1975)and modified by Gee (1979) and Occhipinti et al (1997)forms comparatively small outcrops in the cores of theRobinson Syncline and Fraser Synclinorium (seeStructure)

Ferruginous shale and siltstone intercalated withirregularly banded manganiferous iron-formation formsthe basal unit of the formation This unit is locallylateritized and hosts many manganese deposits suchas the Millidie (or Elsa) mine (see Mineralization)The banded manganiferous iron-formation commonlyforms low ridges On PADBURY the Millidie CreekFormation consists of iron-rich shale and siltstoneirregularly banded manganiferous iron-formationdolomitic sandstone ferruginous quartz wacke andchloritic siltstone On BRYAH the Millidie Creek Formationconsists of ferruginous shales with a well-developed pencilcleavage sandstone and minor granular iron-formation

Dolomitic sandstone and quartz wacke are locallypresent within this formation The quartz wacke is wellbedded matrix supported and commonly containssubangular to subrounded quartz grains The matrix of thisrock is composed of randomly oriented fine-grainedbiotite and includes late sphene and minor sericite Thedolomitic sandstone comprises carbonate quartz andmuscovite

In low hills 3 km north of 5 Mile Well (Plate 1) finelybedded micaceous siltstonendashshale with interbeddedquartzndashdolomite siltstone layers previously assigned to theLabouchere Formation (Elias et al 1982) have beenassigned to the Millidie Creek Formation These rocks arefolded about northwesterly trending D4 fold axes andcontain S4 foliation They are unconformably overlain by

21


subhorizontal to shallowly dipping basal quartz arenite ofthe Bangemall Group

Chloritic siltstone at the top of the Millidie CreekFormation is compositionally similar to the Beatty ParkMember and comprises quartz feldspar lithic fragmentsof sericitendashquartz schist and detrital cordierite grains ina foliated matrix of chlorite

Unassigned units of the Padbury Group

Metasedimentary rocks and biotitendashsericite schist whichoutcrop within the Despair Granite near the Wilthorpegold mine (Plate 1) were previously referred to aschloritendashmuscovitendashquartz schist and not assigned to anygroup (Elias et al 1982) Occhipinti and Myers (1999)tentatively assigned these units to the Padbury GroupThere are two main outcrops one in the Wilthorpe mineand the other just outside the mine as a fault-boundedinclusion within the granite

Sedimentary rock found within the Despair Graniteis heterogeneously deformed and metamorphosedSedimentary structures such as cross-bedding andbedding-parallel laminations are present This rockconsists of alternating layers of very fine grained biotitequartz sericite and feldspar Accessory minerals includeopaque minerals In a few places this rock contains afoliation parallel to faults or fold-axial planes Opaqueminerals commonly crosscut the dominant (bedding)fabric The preservation of the primary sedimentarytextures suggests that strong deformation did notaccompany low-grade greenschist-facies metamorphism ofthese rocks

Within the Wilthorpe mine the metasedimentary rockscontain a slightly different mineralogy and are in faultedcontact with the sericitized Despair Granite For instancein one sample there are two distinct layers composed ofeither sericite quartz biotite and opaque minerals orbiotite sericite quartz and minor opaque minerals Thisvariation in bedding composition is consistent with thatobserved in the metasedimentary rocks outcroppingoutside the mine The rocks within the mine are coarsergrained and comprise quartz biotite sericite andandalusite Sericite and biotite overprint the foliation inthe rock

StructureThe Padbury and Bryah Basins are pervasively deformedThis deformation may have solely occurred duringthe c 18 Ga Capricorn Orogeny a period of obliquecollision between the Archaean Pilbara and YilgarnCratons (Tyler and Thorne 1990 Tyler et al 1998Fig 2) or in part during the earlier c 20 Ga GlenburghOrogeny (Occhipinti et al 1999) In addition to deformingthe Bryah and Padbury Groups this deform-ation also resulted in the reworking of parts of theArchaean Narryer Terrane and the Marymia Inlier of theYilgarn Craton (Fig 2) to form the Yarlarweelor gneisscomplex and Peak Hill Schist The rocks of the Bryah

and Padbury Groups are locally interleaved with theYarlarweelor gneiss complex in the western part of theregion (Fig 18) To the south the Bryah and PadburyGroups are tectonically juxtaposed against autochthonousrocks of the Archaean Murchison Terrane of the YilgarnCraton and the Palaeoproterozoic Yerrida Group (Fig 2)

The Yarlarweelor gneiss complex dominantly consistsof Archaean granitic gneisses that were intruded by felsicmagmas at c 1960 Ma (Sheppard and Swager 1999) and1820ndash1800 Ma (Occhipinti et al 1998b Sheppard andSwager 1999) Granite sheets and veins intruded into theArchaean gneisses were pervasively deformed into opento tight folds and metamorphosed at medium to highgrades during the Capricorn Orogeny Occhipinti andMyers (1999) suggested that these folds were originallynortherly trending however they are probably more likelyto have been northeasterly trending Dextral strike-slipshear movement involved a transition from early ductileto later brittle deformation (Occhipinti et al 1998b)coincident with uplift which probably progressed fromnortheast to southwest in the region This deformationproduced regional-scale fault-bend folds in both theYarlarweelor gneiss complex and overlying Palaeo-proterozoic Bryah and Padbury Group rocks

Deformation histories presented for the Yerrida Bryahand Padbury Groups by various authors (including Windh1992 and Gee 1990) have many elements in common(Table 5) This includes major northndashsouth compressionthat was responsible for the development of prominentregional easterly trending upright folds such as theRobinson Syncline (Fig 18) Northerly striking folds andfaults in the domain just east of the Yarlarweelor gneisscomplex have been recognized as a later deformation stage(Windh 1992 Martin 1994) Gee (1990) Windh (1992)and Martin (1994) proposed that eastward movement ofthe Narryer Terrane (here referred to as the Yarlarweelorgneiss complex) was responsible for the development ofthese northerly trending folds In their interpretation thenortherly striking folds formed in front of an advancingthrust sheet of Archaean gneiss and granite overriding theBryah and Padbury Groups Myers (1989 1990) andMyers et al (1996) on the other hand regarded the Bryahand Padbury Groups as allochthonous sheets that werethrust over Archaean granitendashgneiss

Contacts of the Bryah and Padbury Groups with theNarryer Terrane Yarlarweelor gneiss complex MarymiaInlier Murchison Terrane and the PalaeoproterozoicYerrida Group are zones of high strain and thereforeinferred to be faults Unconformable contacts between theBryah and Padbury Groups were reported by Martin(1994 1998) whereas sheared and faulted contacts werereported by Pirajno and Occhipinti (1998) Occhipintiet al (1998ac) and Occhipinti and Myers (1999) Forexample the Bryah Group is in faulted contact with theYarlarweelor gneiss complex north of Livingstones Findand the Murchison and Narryer Terranes are separatedfrom the Bryah and Padbury Groups by the steep easterlytrending Murchison Fault which has a sinistral strike-slipcomponent (Plate 1 Fig 2)

The Goodin Fault a high-angle reverse fault (Pirajnoand Occhipinti 1998) is the boundary between the

22

Pirajno et al

Yerrida and Bryah Groups (Fig 2 Plate 1) East of thisfault the Doolgunna Formation (Yerrida Group) is foldedinto isoclinal upright folds however much of thedeformation in the Yerrida Group dies out rapidly to theeast and southeast To the west the Goodin Fault mergeswith the Murchison Fault which has juxtaposed the Bryahand Padbury Groups against the Yilgarn Craton TheMurchison Fault has a sinistral strike-slip componentwhich offsets Archaean structures in the Murchison andNarryer Terranes

In this Report four distinct groups of structuresD1ndashD4 representing progressive compressional deform-ation are recognized (Table 5) This deformation historyalthough in broad agreement with the previously publishedstructural histories (eg Windh 1992) recognizes separateearly layer parallel structures The structures resultingfrom the four deformation events are not developedeverywhere or with the same intensity everywhere

The earliest deformation events are defined in the PeakHill Anticline area as D1 layer-parallel mylonitic thrustfaults and originally subhorizontal folds overprinted byD2 upright eastndashwest striking regional folds Both D1 andD2 structures developed by northndashsouth compression and

can be interpreted as successive stages of progressivedeformation Northerly trending regional D3 folds andupright foliations recording eastndashwest compression areweakly developed in the Peak Hill Anticline but betterdeveloped and largely restricted to a domain immediatelyeast of the Yarlarweelor gneiss complex However thesenortherly trending structures do not always overprint oldereasterly trending structures and in places these two setsof structures (D2 and D3) tend to be mutually exclusivesuggesting that they probably developed during the sameprogressive deformation event Late medium-scale D4structures include west-northwesterly to northwesterlytrending subvertical foliations shear zones zones ofsmall-scale folding and faults now outlined by quartzblows These locally developed structures suggest latenorth-northeast to south-southwest compression

Major fold structures in the Padbury and Bryah Basinsare the Peak Hill Anticline Robinson Syncline MillidieSyncline Fraser Synclinorium Horseshoe Anticline andPadbury Syncline (Plate 1 and Fig 18) The Peak HillAnticline Robinson Syncline Fraser Synclinorium andMillidie Syncline all represent refolded folds The easterlytrending doubly plunging Robinson Syncline andPeak Hill Anticline are D2 folds refolded during D3 D1

Figure 18 Major regional structures in the Bryah and Padbury Groups (after Occhipinti et al 1998a)

FMP371

MARYMIAINLIER

YILGARNCRATON

Goodin

Fault

GROUPBANGEMALL

Murchison Fault

118deg30 119deg30

30 km

020300

YERRIDAGROUPPeak Hill

Anticli

ne

Robinso

n

Synclin

e

Nathan Syncline

Zone of D folding3

Padbury

Horseshoe Anticline

Wilthorpe F

t

BRYAH ANDPADBURYGROUPS

GOODININLIER

EARAHEEDYGROUP

25deg30

26deg00

Syncline

Millidie Syncline

FaultD fold trace3

D fold trace2

1

D fault1

Anticline

SynclineD ndash D thrust fault2

Yarlarweelorgneiss

complex

FraserSynclinorium

23


folds are also present within these structures (see D1structures) The Horseshoe Anticline appears to be a D3fold contained within the fault-bounded Horseshoeanticlinal block This fault-bounded block also appears tobe cut by northwesterly trending (D4) faults

D1 structuresThe first Palaeoproterozoic deformation event (D1)produced layer-parallel folds a locally pervasive S1schistosity mylonites and faults However because thesestructures were pervasively overprinted by D2 structuresthey are rarely observed F1 folds are locally observed inthe Peak Hill Antiform Robinson Syncline FraserSynclinorium an area 5 km northeast of Mount Fraserand the Millidie Syncline These folds are also observednear the Peak Hill mine in F2 foldndashhinge zones of quartzblastomylonites of the Peak Hill Schist (Fig 6) Here theyare small-scale rootless isoclinal plunge shallowlytowards the east and strike eastndashwest In the FraserSynclinorium and Millidie Syncline the F1 folds are small-scale isoclinal folds that plunge gently towards the east-northeast or west-southwest and strike east-northeasterlyF1 folds are also inferred from aeromagnetic data to bepresent within the Fraser Synclinorium and MillidieSyncline (Figs 18 and 19)

The Goodin and Murchison Faults may be D1 faultsthat were reactivated during D2 (Occhipinti et al 1998c)The Murchison Fault (Figs 18 and 19 Plate 1) separateslargely undeformed basaltic hyaloclastite rocks in thesouth from foliated mafic schists to the north

Mesoscale F1 folds in the shale and banded iron-formation of the Robinson Range Formation are observednear Mount Padbury north-northwest of Beatty Park Bore

(Plate 1) in the hinge zone of the Robinson Synclinenorth of Tank Well and northeast of Randell Bore TheseF1 folds are tight to isoclinal with shallow plunges thattrend to the east or west The F1 folds in the area areinterpreted as originally recumbent D1 zones of highstrain and mylonite developed locally mainly in thePeak Hill Schist (Pirajno and Occhipinti 1998) andalong contacts between the Yarlarweelor gneiss complexand Palaeoproterozoic cover rocks These mylonite zonesare not observed at higher stratigraphic levels within thebasin suggesting that they are restricted to a deeper crustallevel represented by the Peak Hill Schist and basementndashcover contacts Quartz blastomylonites and the CrispinMylonite (Pirajno and Occhipinti 1998) form continuousunits within the Peak Hill Schist (Plate 1) The internalstructure of these units suggests that they may be D1shear zones which were refolded during the laterdeformation events The original nature and orientation ofthese shear zones is not known The Crispin Myloniteconsists of quartzite pebble-and boulder-sized clasts in asericitendashquartz-rich matrix and has the appearance of aconglomerate For that reason it was mapped by Gee(1987) as the lsquoCrispin Conglomeratersquo However meso-scopic and microscopic structures indicate that it is amylonite (Figs 4 and 7) Both the quartzite clasts andmatrix contain a mylonitic fabric The Crispin Myloniteis interpreted as a lsquopseudo-conglomeratersquo (Raymond1984ab) formed by shearing probably along or close toa fault plane that separated an arkosic or granitic unit froma quartz-rich unit

Like the Crispin Mylonite the quartz blastomylonitesform arcuate lenses within quartzndashmuscovite schist of thePeak Hill Schist and are refolded by F2 and F3 folds Thequartz blastomylonites contain isoclinal and sometimesrootless F1 folds and are interpreted to have beendeformed in a ductile high-strain zone (fault or shear zone)during D1 It is not possible to determine the sense ofmovement during D1 because no shear sense indicatorswere observed during mapping

D2 structuresThe D2 deformation produced large-scale uprightregional F2 folds with variably developed S2 foliationas well as faults and shear zones These structuresare easterly trending recording northndashsouth shorteningHowever more complex patterns in the Mount Fraserarea suggest complicated refolding patterns ProminentD2 folds include the doubly plunging Robinson Synclineand the Padbury Syncline which has the hinge zonelargely sheared out (Fig 18 Plate 1) Mesoscale F2folds show steeper plunges and the S2 foliation becomesmore intense to the north A pervasive S2 foliation isdeveloped over large areas in the mafic schists ofthe Narracoota Formation The Goodin Fault is a high-angle reverse fault that forms the boundary between theYerrida and Bryah Groups This fault may have developedduring D2 because south of the fault the DoolgunnaFormation is folded into tight to isoclinal upright folds(with fold-axial surfaces subparallel to the Goodin Fault)that are similar to D2 folds in the Bryah and PadburyBasins

Table 5 Sequence of deformation events in the Bryah and PadburyBasins

Deformation Compressionevent

D4 North-northeastndashsouth-southwest compressionSmall-scale folds subvertical foliation shearzones faults with quartz blows all trending

280degndash310deg

D3 Eastndashwest compressionnorthndashsouth trending folds subvertical foliationsubvertical faults or shear zones localized eastof Narryer Terrane increasingly disharmoniceast-northeasterly trending folds eastwards

D2 Northndashsouth compressionupright tightndashisoclinal eastndashwest folds andsubvertical foliation eastndashwest shear zonessouth-verging thrust faults

D1 Northndashsouth compressionsubhorizontal mylonites thrusts and foldsmesoscale recumbent folds tightndashisoclinalrootless

24

Pirajno et al

The Livingstone Synform a steep easterly plungingtight fold on MOORARIE may be part of a larger scale D2fold structure that is confined between the Kerba Fault inthe north and the Mount Seabrook Fault in the south(Occhipinti and Myers 1999)

Within the Yarlarweelor gneiss complex graniticgneisses form open to isoclinal easterly to northeasterlyand northerly trending shallowly to steeply plungingfolds These folds plunge either to the east and northeastor to the west and west-southwest indicating that on a

Figure 19 Simplified geological map of the Bryah and Padbury Groups (after Occhipinti et al 1998a) See Figures20 22 and 23 for cross sections

118deg 119deg

25deg45

10 km

MarymiaInlier

YilgarnCraton

BangemallBasin

Bill

ara

Fa

ult

Wilt

horp

eF

Fortnum

25deg30

Goo

din

Faul

t

Kinders FaultNathan

Peak Hill

B

AC

Mt Fraser

Yarlarweelor gneisscomplex

(reworked NarryerTerrane)

YerridaBasin

PADBURY GROUP

BRYAH GROUP

RAVELSTONE FORMATION lithic wacke

KARALUNDI FORMATION clastic rocks

quartzndashmuscovitendashbiotitendashstaurolite schist

HORSESHOE FORMATION shale banded iron-formation

YERRIDA GROUP

WILTHORPE FORMATION conglomerate siltstone

PA

LA

EO

PR

OT

ER

OZ

OIC

Greenstone

Peak Hill Schist

AR

CH

AE

AN

Fault

Anticline

Syncline

ME

TA

MO

RP

HO

SE

D

NARRACOOTA FORMATION maficndashultramafic volcanic rocks

LABOUCHERE FORMATION quartz wacke siltstone

Unconformity

Mine

Cross-section

Undifferentiated rocks

MILLIDIE CREEK FORMATION Lithic wacke dolomitic sandstone siltstone banded iron-formation

Granite and graniticgneiss

ROBINSON RANGE FORMATION shale granular iron-formation banded iron-formation

140300FMP373

25


regional scale they are doubly plunging possiblyrecording later refolding and eastndashwest shortening (D3)These folds deform both the Archaean gneiss and c 1960and c 1820 Ma granite sheets that intruded the gneiss(Sheppard and Swager 1999 Occhipinti et al 1998c)They refold tight to isoclinal subhorizontal to shallowlyplunging folds in the Archaean granitic gneisses whichmay have developed during the Archaean

The sense of shear of the steeply dipping D2 shearzones could not be determined South of the Robinson andFraser Synclines regional anastomosing D2 shear zonesdeveloped in the basaltic rocks of the NarracootaFormation To the northeast this regional structurebecomes the Jensen Fault (Pirajno and Adamides 2000)which can be shown to have displaced the Meso-proterozoic Bangemall Group suggesting that the faultwas reactivated after this time Along the southern limbof the Fraser Syncline another fault extends into the D2shear zones mentioned above A shear zone cuts thesouthern limb of the Heines Syncline which lies betweenthe Robinson and Fraser Synclines

D3 structures and theirrelationship to D2 structuresNortherly trending D3 folds faults and locally an uprightS3 foliation indicating an eastndashwest compression are welldeveloped in the area east of the Yarlarweelor gneisscomplex Further east F3 fold intensities decrease andfolds are locally more disharmonic The D3 event wasresponsible for the doubly plunging nature of theRobinson Syncline and the Peak Hill Anticline

The Kinders Fault (Fig 20 Elias and Williams 1980)is a northerly trending D3 fault separating a wedge ofmafic volcanic schists of the Narracoota Formation(Bryah Group) from the Robinson Range Wilthorpeand Labouchere Formation rocks (Padbury Group) Thisfault lies along the western limb of the sheared-out hingeof the F3 Nathan Syncline (Plate 1 and Fig 18) Thissyncline was previously correlated with the PadburySyncline to the south (Elias and Williams 1980 Martin1994 1998) Part of the southerly plunging fold hingeof the Nathan Syncline is preserved in the Nathan minearea and the closure of this syncline can be traced furthernorth The wedge of maficndashultramafic schists of theNarracoota Formation was interpreted by Occhipinti et al(1998c) and Martin (1994 1998) to represent an F3anticlinal fold-thrust wedge overlying pervasively foliatedand metamorphosed quartz wacke of the LabouchereFormation to the west (Figs 19 and 20)

West of the Kinders Fault along the Billara Faultsericitendashquartz schist locally with quartz-pebbleconglomerate layers contains a pervasive S3 fabricF3 folds however are difficult to trace East of theKinders Fault open to close and locally tight to isoclinalfolds are outlined by marker beds in the Labouchere andHorseshoe Formations S3 foliations and moderate tosteep southerly plunging small-scale F3 folds are welldeveloped in the area of the Horseshoe Syncline andfurther north

Several observations suggest that D2 and D3 structuresmay not reflect two separate events but may havedeveloped contemporaneously in different domainsIntense D3 folding is largely restricted to the area betweentwo basement highs represented by the Yarlarweelorgneiss complex in the west and the Peak Hill Schist in theeast (Figs 18 and 19) In the domain just east of andadjacent to the Yarlarweelor gneiss complex there is noevidence for D3 refolding D2 (ie upright northerlytrending D3 folds overprinting upright easterly trending D2folds) even though weak northerly trending D3 foldsdeform easterly trending F2 folds around and within thePeak Hill Anticline

In the Mount Fraser area complex fold and foliationpatterns show orientations different from and transitionalto both the regional D2 and D3 deformation Large-scaleeast-northeasterly trending F2 folds such as the RobinsonSyncline and Peak Hill Anticline die out in this area TheMillidie Syncline can be traced from a west-northwesterlystrike (subparallel to and en echelon with the RobinsonSyncline) to a west-southwesterly strike and is then cutoff to the south by D3 faults (Figs 18 and 19)

These observations suggest that the intensity and trendof the D2 and D3 structures were influenced by their spatialrelationship to the Yarlarweelor gneiss complex and PeakHill Schist

D4 structuresD4 structures include mesoscopic chevron folds kinksshear zones and faults and were locally accompanied bythe development of a foliation These D4 structuresdeveloped locally throughout the Bryah and PadburyBasins Yarlarweelor gneiss complex and the northern-most part of the Murchison Terrane In the PadburyndashBryahdomain most structures trend between west-northwest andnorthwest although in the Yarlarweelor gneiss complexa few late structures trend between north-northwest tonorth Brittle faults cutting the Yarlarweelor gneisscomplex often show dextral strike-slip shear movement

MetamorphismRegional metamorphic zones within the volcano-sedimentary succession are related to the geometry of thePeak Hill Anticline and Yarlarweelor gneiss complex Thehighest metamorphic grade assemblages are found in thecontact zones between the Yarlarweelor gneiss complexand overlying metasedimentary rocks Assemblages inthe Peak Hill Schist and within quartzndashmica schists(Labouchere Formation) along faulted contacts withthe Yarlarweelor gneiss complex record upper greenschist-to lower amphibolite-facies conditions Within theYarlarweelor gneiss complex upper amphibolite-faciesconditions were reached as incipient (minimum) meltpatches within granitic gneiss and amoeboid textures inPalaeoproterozoic coarse-grained granite probablydeveloped during D2 (Sheppard and Swager 1999) In theBryah and Padbury Groups however metamorphismtypically does not exceed greenschist facies and east of

26

Pirajno et al

0

2

4

6

Fault

Kilo

met

res

Southwest Northeast

FMP372

0

2

4

6

Kilo

met

res

West East

Billara

Fault

Kilo

met

res

0 Padbury

South North

SynclineDome

2

4

6

Yarlar-weelor

170300

Fault

Kinders

MIDDLE PROTEROZOIC

ARCHAEAN (reworked during Early Proterozoic)

Bangemall Group

Unconformity

Bedding or layering trend

Foliation

High-strain zone

Fault

Movement along fault

Movement away and towards observer

2

BRYAH GROUP

Geological boundary

Padbury Basin

Bryah Group

S N

d)

sediment fluxsediment flux

EARLY PROTEROZOICPADBURY GROUP

ARCHAEAN (in situ)

Peak Hill Schist quartzndashmuscovite schistquartz mylonite phyllonite

Granitendashgreenstone Murchison Terrane

Millidie Creek Formation sandstoneshale dolomitic siltstone

Robinson Range Formation ferruginous shalebanded iron-formation

Wilthorpe Formation quartz-pebbleconglomerate

Labouchere Formation quartz wackesiltstone quartz arenite

Horseshoe Formation ferruginous shaleiron formation

YERRIDA GROUP

Narracoota Formation metabasalt subordinatedolerite picrite and peridotite

Goodin

Normal fault reworked during D thrusting

Granite gneiss and granite with lenses of supracrustal rock Narryer Terrane

GranitendashgreenstoneMarymia Inlier ndash Murchison Terrane

Ravelstone Formation lithic wacke

Karalundi Formation clastic rocks

a) Cross section A

b) Cross section B c) Cross section C


27


the Goodin Fault in the Yerrida Group metamorphic gradedecreases to subgreenschist facies (prehnitendashpumpellyite)The relationships between metamorphic mineral growthand deformation are summarized in Table 6

M1 was a prograde regional metamorphic event thattypically reached greenschist facies (Pirajno andOcchipinti 1998) and was probably coincident withD1 in the Bryah and Padbury Groups and Peak Hill SchistThornett (1995) suggested that some parts of the Peak HillSchist reached amphibolite-facies metamorphism withtemperatures between 500deg and 620degC and pressures of65 ndash 7 kbar Metamorphic mineral assemblages observedhowever commonly do not concur with these data Thesecond metamorphic episode M2 was commonly one ofretrogression throughout most of the Bryah and PadburyBasin and probably associated with metasomatismin high-strain zones during D2ndashD3 During M2 inthe western part of the Bryah and Padbury Basinsadjacent to the Billara Fault (Fig 18) staurolitendashandalusitendashbiotitendashmuscovitendashquartz schist developedfrom the metamorphism of Padbury Group sedimentaryrocks These rocks indicate metamorphism at amphibolitefacies Inclusion trails in staurolite and andalusiteporphyroblasts suggest that the porphyroblastic growthoccurred after D1 but before D2 The S2 foliation is definedby the alignment of muscovite and biotite which wrapsaround the porphyroblasts and probably developed in D2during M2 As staurolite is locally partially replaced byfine-grained muscovite this foliation may have developedin the greenschist facies This foliation is locallyoverprinted by chloritoid Further west at the contactbetween the Palaeoproterozoic Kerba Granite and theNarracoota Formation a quartzndashkyanitendashtremolitendashfeldspar schist indicates upper greenschist-faciesmetamorphism with the pressure of metamorphismestimated to have been between 3 and 4 kbar (Spear 1993Occhipinti and Myers 1999)

For the most part M2 involved retrogression meta-somatism and local hydrothermal alteration Mineralassemblages formed during M2 are commonly observedin high-strain zones where the S2 schistosity is welldeveloped These include a domain of well-developed D2shear zones south of the Robinson Syncline wherepervasive retrogression of metabasalts to actinolitendashchlorite schist is observed (Pirajno et al 1995a) In

addition in the Mount Pleasant opencut growth of albiteporphyroblasts and the development of chlorite at theexpense of biotite and epidote also occurred during M2

Banded iron-formation in the Robinson RangeFormation shows a change in metamorphic mineralassemblage from east to west across the trend of the D2Robinson Syncline To the west randomly oriented biotiteoverprinted quartz stilpnomelane and iron oxides Theappearance of this late-stage biotite coincides withregional geochemical trends (elevated Sb As and WDavy et al 1999) along the same structure suggesting alate- or post-D2 low-temperature metasomatic eventAlbite porphyroblasts in alteration zones associated withgold mineralization in the Peak Hill Schist also grew at alate stage because they overprint S2

South of the Murchison Fault little-deformed basaltichyaloclastites contain mineral assemblages characteristicof prehnitendashpumpellyite to lower greenschist facies Thissuggests that rocks south of the Murchison Fault were notexposed to the regional greenschist-facies metamorphismor moderate- to high-grade metamorphism that occurredelsewhere in the region

Structural synthesisA number of models have previously been presented toexplain the structural and metamorphic history of theBryahndashPadbury region For these models the driving forcewas assumed to be collisional tectonics related to theCapricorn Orogeny (eg Tyler et al 1998 Occhipintiet al 1998c Pirajno et al 1998b)

Gee (1990 p 207 Gee and Grey 1993) interpretedthe movement of the lsquoYarlarweelor Gneiss Beltrsquo andlsquoMarymia Domersquo in terms of rising lsquosolid-state crystalndashplasticrsquo domes They suggested that the resulting rise andsouthward movement of the lsquoYarlarweelor Gneiss Beltrsquoand lsquoMarymia Domersquo produced recumbent folds in theoverlying sedimentary rocks of the Bryah Basin Furtherrise and convergence of the domes following depositionof the Padbury Group caused complex refolding ThelsquoYarlarweelor Gneiss Beltrsquo was thrust to the east overthe Bryah and Padbury Groups at this time Martin(1994) interpreted the emplacement of the lsquoNarryer

Figure 20 Selected idealized cross sections through the Bryah and Padbury Groups (after Occhipinti et al 1998a) Locationsof a) to c) are shown on Figure 19 (note difference in scale)a) Northeastndashsouthwest section in the central-eastern part of the Bryah and Padbury Basins showing the fault-bendfold model for the Peak Hill Anticline and inferred suture between the Yilgarn Craton (Murchison Terrane) andreworked Archaean Marymia Inlier The extensional fault slice along the northern margin of the craton formed duringearly development of the Bryah Basin (lsquopassive marginrsquo) and was preserved in this idealized section after basinclosureb) Eastndashwest section across the zone of D3 fold and fault structures The section highlights the intense deformationacross the zone between the Billara and Kinders Faults and shows an inferred major detachment (within underlyingmafic volcanic rocks of the Narracoota Formation) zone of highly disharmonic F3 folding mapped at the surfacec) Northndashsouth section in the central-western part of the Bryah and Padbury Basins showing the Yarlarweelor Domethe sheared-out Padbury Syncline and the Murchison Fault as the suture between in situ and reworked ArchaeanNarryer Terrane Note the inferred detachment of the BryahndashPadbury succession along the contact with the NarryerTerraned) The development and onlap of the Padbury Basin onto the underlying Bryah Group

28

Pirajno et al

Gneiss Complexrsquo (lsquoYarlarweelor Gneiss Beltrsquo) as due tolsquolateral escape tectonicsrsquo resulting from the lsquotranscurrentsuturingrsquo of the Yilgarn and Pilbara Cratons during theCapricorn Orogeny Martin (1994) suggested that earlynorthndashsouth movements which changed to localized eastndashwest movements indicate the onset of lsquolateral escapetectonicsrsquo and the eastward expulsion of the northeasternpart of the lsquoYarlarweelor Gneiss Beltrsquo along the Wilthorpeand Kinders Faults In contrast Myers (1989 1990)regarded both the lsquoYarlarweelor Gneiss Beltrsquo and thevolcano-sedimentary rocks of the Bryah and PadburyGroups as allochthonous sheets that were thrust over the

Yilgarn Craton basement and subsequently folded abouteastndashwest axes

An alternative model was presented by Occhipintiet al (1998c Fig 21) who suggested that the Bryah Basindeveloped initially as a rift and the Padbury Basindeveloped over the Bryah Basin in a retroarc foreland-basin setting (see also Martin 1994) Formation of thePadbury Basin in a compressional regime was essentiallyconcommitant with the closure of the Bryah Basin and thedevelopment of D1 structures as subhorizontal shear zonesbetween the Archaean Narryer Terrane basement and the

Table 6 Mineral paragenesis of the Bryah Group and relationships between diagnostic metamorphic minerals of the Bryah Group anddeformation fabrics

Formation Rock type Mineralogy Pre-S1 S1 Post-S1 S2ndashS3 Post-tectonicM1 M2

Peak Hill Schist pelite quartz biotite muscovite chlorite albite tourmaline

chemical sediment quartz spessartine magnetite

calc-silicate quartz epidote chlorite actinolite titanite magnetite

psammite quartz muscovite andesine opaques

Narracoota metabasite quartz actinolite epidote chlorite sericite arfvedsonite titanite calcite

volcanic breccia albite pumpellyite

Ravelstone pelitic tourmalinite quartz muscovite tourmaline garnet feldspar

subarkosic wacke quartz biotite albite sericite tourmaline

Horseshoe banded iron-formation quartz biotite grunerite spessartine chlorite

Robinson Range banded iron-formation quartz stilpnomelane biotite

NOTE No data are available for the Labouchere and Wilthorpe Formations

29


supracrustal rocks of the Bryah and Padbury Groups Theoverall movement direction was interpreted as being fromnorth to south but locally because of the possible effectof later dextral shear movement may actually have been

ram

p

Peak Hill Anticline

N S

eg Kinders Fault Peak HillAnticline

Thrust flatrsquo Lateral

ramp Obliq

ue

lateral ramp

Yarlarweelor

Basalthrustplane

2Dc)

d)

2D thrust flat

rsquo

eg Yarlarweelor gneiss complex

gneiss complex

Padbury Group

Bryah Group

Reworked Archaean granite

a)

Archaean granite

b)

2prospective D crustal thrustwith frontal ramp

1D tectonic interleaving zone(eg Peak Hill Schist)

1 2Post-D and pre-D

D tectonic interleaving between reworked Archaeancrust ( underplate) and BryahndashPadbury succession

rsquo1

Post-D D2 3

W E

Thrust ramp

Thrustfrontal

Later

al ra

mp

FMP374 011199

W E

N

Thrust flatrsquo

movement

Thrust

North to south

e)

ramprsquo

flatrsquorsquo

2D thrust flat ndash frontal ramp ndash lateral ramp geometry

Figure 21 Model of the structural development of the BryahndashPadbury Group succession (after Occhipinti et al1998a)a) Zone of D1 subhorizontal tectonic interleaving(by thrust duplexing) between reworked Archaeancrust and overlying rocks of the BryahndashPadburysuccession This zone includes high-strain ormylonitic rocks formed by lsquounderplatingrsquo of theArchaean rocks beneath the volcano-sedimentaryrocks during initial closure of the Bryah back-arcbasinb) Post-D1 geometry with trace of incipient D2crustal-scale thrust with frontal rampc) D2 geometry with fault-bend anticline developedabove the crustal D2 thrust ramp Upright folds inthe volcano-sedimentary succession (eg Padburyand Robinson Synclines) formed ahead of themain thrustd) Post-D2D3 geometry along schematic eastndashwestsection D2 fault-bend anticlines are not shownNorth-to-south movement ie movement towardsviewer leads to eastndashwest compression and hencenorthndashsouth folds and reverse or thrust faults in thedepression between (oblique) lateral ramps at thesame time as eastndashwest D2 folding occurredelsewheree) Schematic view looking north-northwest of thebasal thrust fault with frontal and lateral rampshighlighting the north-to-south movement directionof the thrust sheet

northwest to southeast Substantial movement and highstrains can be inferred from tectonic interleaving (egbetween the Billara and Wilthorpe Faults Fig 19) andfrom the development of the mylonitic zones in possiblethrust duplexes in the Peak Hill Schist Other possibleD1 structures in particular subhorizontal thrust faultsmay have locally developed along the contacts betweenthe Bryah and Padbury Groups Small-scale earlylayer-parallel folds in chert and BIF layers particularlyfrom within the Padbury Group suggest that subhorizontalD1 structures locally formed within the volcano-sedimentary succession (Pirajno and Occhipinti 1998Swager and Myers 1999) Deposition of the PadburyGroup in a retroarc foreland basin (Martin 1994)was probably contemporaneous with the early stagesof D1

The Yarlarweelor gneiss complex and Peak Hill Schistwere described by Occhipinti et al (1998c) as lsquobasement-cored anticlinesrsquo that developed above frontal thrust rampsThe overlying supracrustal rocks and their high-strain D1contact zones were folded by north to south movementover these ramps during D2 deformation In the Peak HillSchist subhorizontal D1 folds are refolded about anupright apparently easterly trending D2 antiformThe hinge of this fold may be sheared out along thecontact with the Marymia Inlier which is marked by aquartz blastomylonite previously mapped as deformedquartzite of the Juderina Formation (Adamides 1998) Theoriginal orientation of the D2 fold may have been east-northeasterly The Peak Hill Schist outcrops around adomal structure produced by refolding of the D2 fold aboutan approximately northerly trending D3 fold-axial surfaceIt was argued by Occhipinti et al (1998c) that the D3 foldsdeveloped in a structural lsquodepressionrsquo between the two

30

Pirajno et al

basement-cored anticlines which acted as lateral rampsin the thrust plane Northerly trending structures developedduring northndashsouth compression as the lateral ramps wereslightly oblique to the movement direction leading tospace problems between the basement-cored anticlinesThis resulted in either lateral shortening or verticalexpulsion (or both) of the Bryah and Padbury Groups

Occhipinti et al (1998c) assumed that the Yarlarweelorgneiss complex (referred to by them as the NarryerTerrane) was an Archaean crustal fragment that influencedthe structural deformation in the Palaeoproterozoic Bryahand Padbury Groups but was not itself largely deformedduring the Palaeoproterozoic Subsequently Sheppard andSwager (1999) and Occhipinti and Myers (1999)recognized Palaeoproterozoic deformation meta-morphism and felsic magmatism within the Yarlarweelorgneiss complex This indicates that the Yarlarweelor gneisscomplex was extensively reworked during the Palaeo-proterozoic and underwent the same D2ndashM2 metamorphicevent that has been recognized in the Bryah and PadburyGroups and Peak Hill Schist

Occhipinti et al (1998b) found that Palaeoproterozoiccoarse-grained granites and pegmatites with ages between1820 and 1780 Ma (Nelson 1998) intruded as sheetssynchronously with the D2 deformation event D McBMartin (1999 pers comm) interpreted granite exposedsouthwest of the Labouchere opencut as intruding thePadbury Group sedimentary rocks and suggested that thisgranite may also be of this age Intrusion of granitoiddykes and sheet-like plutons accompanied uplift of theYarlarweelor gneiss complex and is interpreted as beingconcomitant with dextral shearing in the region andpossibly D3 (Occhipinti et al 1998a Sheppard andSwager 1999) This movement was attributed to anoblique northndashsouth to northwestndashsoutheast collision ofthe Pilbara and Yilgarn Cratons during the CapricornOrogeny (Occhipinti et al 1998b 1999)

In the northwestern part of the Bryah and PadburyBasins the metamorphic grade increases from greenschistfacies in the east to amphibolite facies in the west Furtherwest in the Yarlarweelor gneiss complex the metamorphicgrade reached at least upper amphibolite facies (Sheppardand Swager 1999) Uplift of the Yarlarweelor gneisscomplex from 9ndash10 kbar to greenschist facies occurredbetween c 1812 and c 1800 Ma (Occhipinti et al 1998b)The c 1812 Ma granitoid sheets and dykes were meta-morphosed at high grade (see below) whereas c 1800 Magranites were only metamorphosed to greenschist facies(Occhipinti et al 1998b) Medium-grade metamorphismof the Padbury Group is solely preserved adjacent to theYarlarweelor gneiss complex between the Billara andWilthorpe Faults (see Metamorphism Fig 18 Plate 1)The drop in metamorphic grade to greenschist facies only15 ndash 25 km east of the contact suggests either a rapidincrease in temperature close to the Yarlarweelor gneisscomplex or that amphibolite-facies or upper greenschist-facies (or both) Bryah and Padbury Group rocks have beenfaulted out The latter explanation is preferred because theboundary between amphibolite-facies and lower to middlegreenschist-facies rocks of the Labouchere Formation issharp

In the Bryah and Padbury Groups and Peak Hill Schistmetasomatism accompanied retrogression of D1ndashM1assemblages to greenschist facies during M2 particularlyin D2 shear zones In the Yarlarweelor gneiss complexthere is no evidence for D1ndashM1 and M2 was initially ahigh-grade metamorphic event with the formation ofincipient minimum melt during the early stages of D2(Occhipinti et al 1998b) Post-M2 the metamorphic gradedropped significantly to greenschist facies

In the proposed model shown in Figure 22 the BryahGroup developed in a back-arc lsquorift-type settingrsquo (Pirajnoet al 1998b see Tectonic model and conclusions) If theBryah and Padbury Groups are c 20 Ga or older then D1structures could have developed during the c 20 GaGlenburgh Orogeny (Occhipinti et al 1999 Tyler 1999)as a result of west to east or northwest to southeastcompression Plutonism in the future Yarlarweelor gneisscomplex produced the 1960 Ma felsic granitoid rocksduring the late stages of D1 (Sheppard et al 1999Fig 22c) Alternatively if the Bryah and Padbury Groupswere deposited sometime between c 1945 and 1812 MaD1 could have developed during the c 18 Ga CapricornOrogeny due to north-northwest to south-southeastcompression (Figs 22 and 23) Further geochronologicalwork is required to establish the age of D1 and thedepositional age of the Bryah and Padbury Groups

In either case closure of the Bryah Basin took placeduring D1 with deposition of the Padbury Group in aretroarc foreland basin overlying the Bryah Group andpossibly the lsquofuturersquo Yarlarweelor gneiss complex(Fig 22b) D1 deacutecollements would have developedbetween the Bryah and Padbury Groups the futureYarlarweelor gneiss complex and the Peak Hill Schist(Figs 22b and 23a) Duplexes developed in the Peak HillSchist during D1 and it was detached from the MarymiaInlier (Fig 23b) In addition early D1 faults and foldsformed between and within the Bryah and PadburyGroups

The second deformation event D2 occurred during theCapricorn Orogeny Early in D2 approximately northwestto southeast compression caused further thickening of theBryah and Padbury Groups over the Yarlarweelor gneisscomplex destabilizing this piece of crust (Figs 22b and22c) The resulting increased pressure and temperaturemay have caused the underlying Archaean crust to startto melt This melt produced the c 1820 to c 1812 Mafelsic granitoid rocks (Occhipinti et al 1998a Sheppardand Swager 1999 Sheppard et al 1999) that intruded theupper parts of the Yarlarweelor gneiss complex as veinsand sheets (Sheppard and Swager 1999 Fig 22c) Asthese developed synchronously with the deformation (D2)they were commonly folded into upright steeply toshallowly plunging isoclinal to open folds These rockswere also metamorphosed at high grade during the D2deformation event Regionally this metamorphismcorresponds to M2

Padbury Group sedimentary rocks were meta-morphosed to medium grade along contact zones withthe Yarlarweelor gneiss complex during M2 This high- andmedium-grade metamorphism may have releasedfluid that moved through faults and shear zones and

31


Figure 22 Schematic sections illustrating the proposed model of the structural development of the BryahndashPadburyGroup succession in the westa) Development of the Bryah Group pre-D1 over the Proto-Yarlarweelor gneiss complex and the northernmargin of the Yilgarn Craton in an extensional-rift settingb) Early- and syn-D1 deposition of the Padbury Group in a fold-and-thrust belt foreland-basin type settingover the Bryah Group Inversion of the Bryah rift-basin by possible reversal of D1 normal faultsDevelopment of D1 faults between the Bryah Group Padbury Group Yarlarweelor gneiss complex andYilgarn Cratonc) D2 to D3 local interleaving of the Bryah and Padbury Groups with the development of folds and faultsDeformation of the Bryah and Padbury Groups above basal detachments Early D1 faults refolded aboutD2 or D3 folds Formation of c 1810 Ma leucocratic granite locally associated with incipient minimum meltin the Archaean gneiss component of the Yarlarweelor gneiss complex Later at c 1800 Ma sheet-likeplutons developed particularly along the faulted boundaries between the Yarlarweelor gneiss complexand Bryah and Padbury Groups

Deposition of Padbury GroupEarly D

Development of fold and thrustbelt in D

1 1

Inversion of Bryah rift

1

Murchison Fault

Karalundi Formationequivalents Bryah Group

Hyaloclastites

Proto-Yarlarweelorgneiss complex

Post-rift phase

Thickening of supra-crustal succession over


a)

b)

c)

v

SAO62 130300

Formation of c 1810 Ma leucocratic coarse-grained granitein Yarlarweelor gneiss complex (Sheppard et al 1999)

Deformation of the Yarlarweelor gneiss complex

NNW1

SSE

1

2 3

Early- and syn-D

Mafic and ultramaficvolcanic rocks

Early reversal of D normal faults some possible back thrustingof volcanic rocks below detachments cut by detachments

Folded c 1960 MaYamagee granite

Local plutonism into Proto-Yarlarweelor gneiss complex

at c 1960 Ma forming Yamageegranite of Sheppard and Swager (1999)

Pre-D extensionndashrift phase

D ndashD

Bryah Group


Padbury Group

32

Pirajno et al

metasomatized M1 assemblages in the Bryah Group andPeak Hill Schist rocks during M2ndashD2 Elsewhere in theregion during D2 the Peak Hill Schist and Bryah andPadbury Group rocks were folded into tight to isoclinalupright folds with mainly easterly to northeasterly trends(Occhipinti et al 1998c) Post-D2 during D3 theYarlarweelor gneiss complex was uplifted and retrogressedto greenschist facies This uplift in a dextral strike-slipregime may have been accommodated by steeply dippingnormal faults between the Yarlarweelor gneiss complexand the Bryah and Padbury Groups (Figs 17 and 18) thathave now been inverted (Fig 24)

In the Peak Hill Schist subhorizontal D1 mylonitezones and rootless folds are refolded about an easterly oreast-northeasterly trending upright D2 antiform The domalshape of the Peak Hill Schist is an artefact of a northerlytrending upright D3 antiform refolding the D2 antiformThe Yarlarweelor gneiss complex apparently does notcontain D1 folds although shearing along basementndashcovercontacts between the Yarlarweelor gneiss complex and theBryah and Padbury Groups may have developed duringD1 (Fig 22b) The D2 fold-axial surfaces within the

Yarlarweelor gneiss complex parallel the arcuate faultedboundary with the Bryah and Padbury Group rocks Thischange in the trend of D2 may be explained in terms of afault-bend fold developed during dextral shearing(Occhipinti and Myers 1999) that may have accompanieduplift during D3

MineralizationThe mineral resources of the Peak Hill SchistBryah Group and Padbury Group are considerableconsidering the relatively small total area of thesebasins (about 6000 km2) These resources include goldmanganese iron ore talc and silver Pirajno andOcchipinti (1995) discussed the mineral potential of theBryah Basin and Pirajno and Preston (1998) described themineral deposits of the BryahndashPadbury region and PeakHill Schist Mineral production and defined resourceswithin these tectonic units as at 30 June 1999 arepresented in Tables 7 and 8 Known deposits andoccurrences are listed in Table 9

Figure 23 Schematic section illustrating the proposed model for the structural development of theBryahndashPadbury Group succession and the Peak Hill Schist a) Development of the BryahGroup in a rift setting pre-D1 over the Marymia Inlier (Yilgarn Craton) b) D1 closure of theBryah lsquoriftrsquo inversion of normal faults deposition of the Padbury Group and formation ofthe Peak Hill Schist

Future D fault

NNW SSE

Bryah Group

Basement

Proto-Peak Hill Schist

Pre-D extensionndashrift phase1

1Peak Hill Schist

D faults1

1

Rift closes Peak HillSchist develops as a

strongly duplexed packageof rock

Marymia Inlier

a)

b)

SAO63 150300

Padbury Group

Early- and syn-D

Mafic and ultramafic volcanic rocks

33


The mineral deposits of the Peak Hill Schist andBryah and Padbury Groups include mesothermal-stylegold-only lodes volcanogenic massive sulfide (VMS)copperndashgold supergene-enriched manganese bandediron-formation iron ore and talc in metasomatizeddolomitic rocks The distribution of these mineral depositsis shown in Figures 25 and 26 and Plate 1

Gold depositsThe most important mineral deposits exploited to datehave been the mesothermal-style gold-only lodes all ofwhich are in the Peak Hill Schist and the Bryah andPadbury Groups If the area occupied by these groupsalone is taken into account (about 6000 km2) then theidentified contained gold per unit area is 125 kg goldkm2The mesothermal gold deposits including past and presentproducers include Peak Hill Jubilee and Mount Pleasantin the Peak Hill Schist Harmony Mikhaburra WembleyCashman and Ruby Well in the Bryah Group (Figs 25and 26) and Horseshoe Labouchere Nathans DeepSouth and Fortnum in the Padbury Group The Wilthorpedeposit is hosted in Upper Archaean granitic rocks whichare tectonically interleaved with rocks of the Bryah andPadbury Groups

The total gold produced is 595 t with total (producedplus remaining inferred indicated and measured)resources estimated at approximately 75 t of containedgold The Labouchere and Fortnum areas containthe regionrsquos largest pre-mining resource estimated as 333 tof contained gold at a grade of about 24 gt goldApproximately two-thirds (225 t) has been exploited

largely between 1989 and 1995 with the remainingresource (107 t) being in the Fortnum area Details of theLabouchere and Fortnum deposits can be found in Hannaand Ivey (1990) and Hill and Cranney (1990) respectivelyThe area around the Peak Hill opencut (includingRavelstone) has produced approximately 20 t of fine goldat an average grade of 4 gt gold more than half of whichhas been extracted in the last 13 years Remainingmeasured and indicated resources are estimated at about47 t of contained gold The Harmony deposit (NewBaxters Find) which was recently exhausted had totalpre-mining resources estimated at about 92 t with a gradeof 35 gt gold

The lode deposits are hosted in mylonitic schistmetasedimentary rocks metavolcanic rocks or along theircontact zones They are spatially associated with high-strain zones and hydrothermal alteration dominated bypyrite quartz muscovite biotite and alkali feldspars Themineralization is in ductile and brittlendashductile shears (egPeak Hill) and in discrete brittle fractures (eg Cashman)indicating a relationship of structural style with therheology of the host rocks The development of ductilebrittlendashductile and brittle structures (zones of highpermeability) was accompanied by infiltration ofhydrothermal fluids which produced alteration andmineralization The precise timing of the mineralizationis difficult to ascertain Windh (1992) suggested syn-D3but from field and petrological observations it is morelikely that circulation of mineralizing fluids occurredduring a continuum related to D1ndashD2 tectonism andmetamorphism under conditions of ductile or brittlendashductile regimes with perhaps some remobilization intobrittle structures occurring during D3 Lead isotope data

Figure 24 Schematic north-northwest to south-southeast cross section from the Bangemall Basin into the Yarlarweelor gneisscomplex and then into the Bryah and Padbury Basins showing the possible present-day configuration of these units

Kerba FaultBangemall BasinFault boundary

YILGARNCRATON

vv

v

vv

v

vv

vv v

v

v

v vv v

vvv

vvv

vvv

vv

Errabiddy

Shear ZoneGascoyneComplex

Possible currenterosion level

SAO64 130300

NW SE

SeabrookndashMurchison Fault

v v

Bangemall Group

Yarlarweelor gneiss complex

Bryah and Padbury Group rocks

Cooinbar Fault

34

Pirajno et al

Table 7 Gold production and remaining resources in the Bryah and Padbury Groups

_______________________ Production (P) _______________________ _______ Remaining resources (R) ________ TotalMining centre Ore Contained Alluvial Dollied Total Resource Ore Contained pre-miningor mine metal contained type metal resources

metal (P+R)(kt) (kg) (kg) (kg) (kg) (kt) (kg) (kg)

Pre-1986

Mount Fraser Mining Centre 09 24 27 13 288 ndash ndash ndash 288Mount Seabrook Mining Centre 17 383 ndash 02 385 ndash ndash ndash 385Ravelstone Mining Centre 49 1058 ndash 32 109 ndash ndash ndash 109Wilthorpe Mining Centre 01 15 ndash ndash 15 ndash ndash ndash 15Peak Hill sundry parcels 27 7706 889 139 8734 ndash ndash ndash 8734Peak Hill Mint deposits(a) ndash ndash 25 33 58 ndash ndash ndash 58Ruby Well Mining Centre 85 146 325 142 1927 ndash ndash ndash 1927Horseshoe Mining Centre 9049 2 9669 352 889 3 091 ndash ndash ndash 3 091Peak Hill Mining Centre 6217 8 200 367 628 8 2995 ndash ndash ndash 8 2995

1986 to 30 June 1999

Horseshoe Lights(b) mine 9059 3 7373 217 ndash 3 759 ndash ndash ndash 3 759Fortnum mine 5 832 15 6025 377 ndash 15 6402 MES + IND 2 221 7 542 23 1822

INF 991 3 194 3 194Labouchere mine 2 9108 6 9052 ndash ndash 6 9052 ndash ndash ndash 6 9052Mount Pleasant mine 1449 433 ndash ndash 433 ndash ndash ndash 433Peak Hill mine 6 5738 20 1266 908(c) ndash 20 2174 MES + IND 2 200 4 760 24 9774

Total 17 9128 59 0577 3487 1878 59 595 5 412 15 496 75 091

NOTES (a) Gold from the Peak Hill Mining Centre deposited at the Perth Mint(b) Horseshoe Lights also produced 261 675 t of copper concentrates containing 25803 kg of gold(c) Includes 625 kg of gold produced from retreated tailingsMES Measured resources IND Indicated resources INF Inferred resources

SOURCE Data are from the Western Australia Department of Minerals and Energyrsquos mines and mineral deposits information (MINEDEX) database

35

GSW

A R

eport 59G

eology and mineralization of the P

alaeoproterozoic Bryah and P

adbury Basins W

A

Table 8 Mineral production and remaining resources in the Bryah and Padbury Groups

_____ Production (P) to 300699 _____ __________________ Remaining resources (R) __________________ Total resource (P+R)Commodity Mine Ore or concentrate Contained metal Resource type Ore or concentrate Contained metal Contained metal

(t) (t) (t) (t) (t)

Copper and Cashman 7 11 ndash ndash ndash 11cupreous ore Peak Hill sundry 63 223 223

Horseshoe Lights 261 675 49 159 Indicated 2 080 000 22 897 72 056Inferred 3 340 000 22 879 22 879

Total 261 745 49 1824 5 420 000 45776 94 9584

Manganese Horseshoe 489 895 203 899 Measured + Indicated 80 000 21 000 224 899Inferred 205 000 100 000 100 000

Mount Fraser 228 108 Measured + Indicated 32 000 9 000 9 108Mount Padbury 7 319 3 498 Measured + Indicated 5 000 2 000 5 498Ravelstone (Peak Hill) 76 237 36 938 ndash ndash ndash 36 938Total 573 679 244 443 Measured + Indicated 117 000 32 000 276 443

Inferred 205 000 100 000 100 000

Iron Robinson Range ndash ndash Inferred 10 000 000 6 000 000 6 000 000

Talc Mount Seabrook ndash Livingstone ndash 540 416 Indicated ndash 1 470 000 2 010 416Inferred ndash 250 000 250 000

Total ndash 540 416 ndash 1 720 000 2 260 416

Silver Horseshoe Lights (post-1982) ndash 72 7194 kg ndash ndash ndash 72 7194 kg(by-product) Peak Hill general ndash 1182 kg ndash ndash ndash 1182 kg

(including Horseshoe pre-1983)Total ndash 72 8376 kg ndash ndash ndash 72 8376 kg


36

Pirajno et al

Figure 25 Distribution of mineral deposits and occurrences in the BryahndashPadbury and Yerrida Basins (modified from Pirajnoand Preston 1998 see also Plate 1)

Table 9 Mineral deposits and occurrences in the Bryah and Padbury Basins

Mine (M) AMG coordinates Principal Mineralization style Expression Ore minerals Relationshipprospect (P) or Easting Northing commodity to hostoccurrence (O)

Cashman (M) 662129 7126994 Gold Regolith enrichment Outcrop Gold Discordantand mesothermal lode

Durack (P) 670440 7150520 Gold Mesothermal lode Drill Gold pyrite Discordantintersections magnetite

Harmony (M) 664145 7161267 Gold Regolith enrichment Drill Gold chalcopyrite Discordantand primary intersections pyrrhotite scheelitemesothermal lode pentlandite pyrite

Heines Find (P) 682759 7145164 Gold Mesothermal lode Outcrop Gold Discordant

Horseshoe (P) 656994 7183734 Gold Eluvial Gold ndash



Horseshoe (P) Copperndashgold Multiple veins Outcrop Gold Discordant

Horseshoe 662648 7193894 Copperndashgold Supergene enrichment Gossan Chalcocite pyrite DiscordantLights (M) of VHMS chalcopyrite native

copper and gold

Jubilee (M) 671889 7165443 Gold Mesothermal lode Quartz vein Gold pyrite Discordant

Labouchere (M) 627730 7204710 Gold Mesothermal lode Not known Gold pyrite Discordant

Livingstone (M) 567540 7171032 Talc Replacement Outcrop Talc Discordant

Mikhaburra (P) 656252 7130396 Gold Multiple veins Outcrop Gold Discordant

Mount Pleasant (M) 674287 7162089 Gold Mesothermal lode Outcrop Gold pyrite Discordant

Mount Seabrook (M) 572631 7168338 Talc Replacement Outcrop Talc Discordant

Nathans Deep 631713 7198812 Gold Mesothermal lode Not known Gold pyrite DiscordantSouth (M)

Peak Hill (M) 672190 7163003 Gold Mesothermal lode Quartz vein Gold pyrite altaite Discordantchalcopyritebismuthotelluridemolybdenite magnetite

Ravelstone (M) 665734 7166777 Manganese Supergene enrichment Outcrop Mn oxides Stratabound


Ruby Well area (M) 674665 7129915 Gold Eluvial ndash Gold ndash

Ruby Well area (P) 672600 7124378 Gold Eluvial ndash Gold ndash




St Crispin (P) 691358 7158940 Gold Mesothermal lode Outcrop Gold Discordant

Trevs Starlight (M) 636412 7198887 Gold Mesothermal lode Not known Gold pyrite Discordant

Unnamed (O) 611598 7168985 Variscite Not known Not known Variscite Discordant


Unnamed (P) 656664 7185310 Manganese Supergene enrichment Outcrop Mn oxides Stratabound

Wembley (P) 663983 7149044 Gold Mesothermal lode Outcrop Gold Discordant

Wilgeena (M) 685369 7155622 Gold Mesothermal lode Outcrop Gold Discordant

Wilthorpe (M) 630414 7176521 Gold Mesothermal lode Outcrop Gold pyrite galena Discordantarsenopyrite

Yarlarweelor (M) 636723 7196423 Gold Mesothermal lode Not known Gold pyrite Discordant

37


MARYMIAINLIER

MARYMIAINLIER

Jenkin

FaultGROUPBANGEMALL

Murchison Fault

NARRYERGNEISS

TERRANE

Padbury Bryahand

Yerrida Basins

FMP100b 181099

1000 km

5

67 16

8

9

17

23

4

11

10

15

1213 14

19

18

21

20

1

GOODININLIER

YILGARNCRATON

YILGARN

CRATON

Goodin

Fault

118deg30 119deg30

Killara

Narracoota

Mt Padbury

PILBARACRATON

CAPRICORN OROGEN

CRATONYILGARN

Yandil

119deg30

Milgun30 km

Jamindi Three Rivers Marymia

PEAK HILLROBINSON

RANGE

Padbury Bryah Doolgunna Thaduna

Glengarry Mooloogool Mount Bartle

MerewetherYanganooGabanintha

119deg00

25deg30

26deg30

26deg00

25deg30

GLENGARRY

Milgun

Mesothermal Au AundashCu

Shear zone-hosted Cu

Epigenetic Pb

Supergene Mn

2 Jubilee

5 Labouchere

7 Fortnum group8 Horseshoe Lights9 Horseshoe gold

10 Wilthorpe11 Wembley

12 Mikhaburra13 Cashman14 Ruby Well

group (including Elsa)

16 Horseshoe magnagese17 Ravelstone18 Robinson Range BIF

(no specific locality)19 Thaduna20 PGE-bearing gossan21 Magellan

3 Mount Pleasant4 Harmony

(New Baxters Find)Fault

Geological boundary

Bouguer gravity anomaly

Peak Hill Schist

Karalundi FormationGR

OU

PB

RY

AH

Padbury Group

Horseshoe and Ravelstone Formations

schistmetabasaltic hyaloclastiteNarracoota Formation mafic and ultramafic

Archaean basement

Earaheedy Group

WindplainSubgroup

MooloogoolSubgroup

YE

RR

IDA

GR

OU

P

Maraloou Formationintercalated Killara and Maraloou FormationsDoolgunna and Thaduna Formationswith intercalated Killara FormationJuderina and Johnson Cairn Formations

Homestead

Bangemall Group

Microgabbro dyke

BryahPEAK HILL

1100 000 map sheet 1250 000 map sheet

Aeromagnetic lineament

6 Nathans Deep South

15 Mount Padbury ndash Mount Fraser

Volcanogenic massive sulfide

Shale-hosted stratabound sulfides

MINERALIZATION STYLE

MINERAL DEPOSITS

38

Pirajno et al

Figure 26 Distribution of mineral deposits and occurrences in the Bryah Group within the BRYAH

1100 000 map sheet (after Pirajno and Occhipinti 1998)


Karalundi Formation

Horseshoe Formation

Granitoid rock and gneiss


10 km

040400

Yerrida Group

Bangemall Group

Earaheedy Group

Padbury Group

Bry

ah G

roup

Prospect

Producer

JubileeGroup

Peak Hill

Harmony

Wilgeena

Wembley

DurackWell

HeinesFind

Mikhaburra

CashmanGroup

Ruby WellGroup

Goodin Find

Ravelstone Group

(Hit or Miss)

St CrispinWilsons Find

25deg30

118deg

30

119deg

00

26deg00

Mar

ymia

Inlie

r mylonite

Syncline

Anticline

Overturned syncline

Peak Hill Schist

Thrust fault

Fault

Strike-slip fault

FMP162a

Supergene manganese deposit

Alluvialndasheluvial gold deposit

Mesothermal gold lodes

Mount Pleasant

39


(palaeo-isochrons) suggest that in the Bryah and PadburyBasins mineralization occurred between 192 and 17 Ga(Windh 1992 Thornett 1995) The results of lead isotopicstudies also indicate that the lead was derived from YilgarnCraton rocks (Dyer 1991 Windh 1992 Thornett 1995)although there is a suggestion that the lead from thePeak Hill deposit is similar to that from a galena in theMarymia gold deposit in the Marymia Inlier (McMillan1993)

The nature of the mineralizing fluids is poorlyconstrained Alteration assemblages at the Peak Hill andMount Pleasant deposits indicate that the ore fluids wereenriched in Fe K Na S B CO2 SiO2 and H2O (Thornett1995) Fluid inclusion studies of mineralized materialsfrom the Fortnum and Labouchere gold deposits (Dyer1991 Windh 1992) indicate that the ore fluids wererich in H2O and H2OndashCO2 with salinities of 7ndash12 wtand 5ndash17 wt NaCl equivalent respectively Micro-thermometric measurements (Dyer 1991 Windh 1992)indicate temperatures ranging from approximately 170degto 320degC

Peak Hill Jubilee and Mount Pleasantdeposits

Mine geologists subdivided the Peak Hill Jubilee andMount Pleasant lithologies into the Core sequence HoneyQuartzite Intermediate sequence Mine sequence MarkerQuartzite and Hangingwall sequence

The Core sequence is at the structural base and wellexposed in the Mount Pleasant opencut where it reachesa thickness of 55 m The contact with the Intermediatesequence is marked by the Honey Quartzite which is amylonite consisting of laminated or ribbon quartz TheCore sequence rocks have a mylonitic fabric and are madeup of quartzndashbiotitendashcarbonatendashmuscovite(ndashepidotendashhornblendendashgarnetndashmagnetitendashpyrite) locally withabundant very fine zircons and monazite in the biotite-richvarieties (Barrett 1989) At Mount Pleasant as mentionedabove graphitic schist is present near the top andassociated with a zone of chloritendashbiotite(ndashgarnet) schistwith albite porphyroblasts (Fig 27) containing inclusionsof monazite and zircon Geochemical discriminant plotsusing immobile elements suggest either a granitic (Nb SrLa and Ce) or maficndashintermediate (Ni Cr and Ti)protolith (Thornett 1995) Barrett (1989) on the otherhand proposed that much of the Core sequence could bederived from a sedimentary protolith The origin of thealbite porphyroblasts is uncertain Based on geochemistrypetrology and textural features Thornett (1995) advocateda combined hydrothermal ndash retrograde metamorphicorigin and compared the Peak Hill ndash Mount Pleasantalbites to those studied by Watkins (1983) in the Dalradianschists of Scotland Another possibility that could accountfor the presence of the albite porphyroblasts is lsquoreactionsofteningrsquo as proposed by Dixon and Williams (1983)These authors advanced the hypothesis supported bygeochemical and mineralogical data that mylonitizationof a quartzofeldspathic parent may be accompanied bymineralogical changes involving the breakdown ofplagioclase with release of Na2O and to a lesser extent

CaO and formation of muscovite This would result in theproduction of quartzndashmuscovite mylonites and sodium-rich fluids

The Intermediate sequence is discontinuous withlayers up to 2 m thick and is composed of a quartzndashmylonite-bearing white mica The Intermediate sequencelies above the Honey Quartzite has an estimated thicknessof between 200 and 400 m and forms the footwall to theMine sequence at Peak Hill and the hangingwall to theore zones at Mount Pleasant The Intermediate sequenceis dominantly quartzndashmuscovite schist with minorplagioclase biotite microcline carbonate and chloriteBarrett (1989) interpreted this rock as either a felsicporphyry or an arkose The lower part of the Intermediatesequence consists of mainly biotite schist with garnet andepidote Rocks of the Intermediate sequence exhibitmillimetre-scale metamorphic differentiation layeringwhich define a dominant S2 schistosity (Thornett 1995)This is interpreted by the present authors as a typicalmylonitic structure

The Mine sequence mostly found in drillholes ischaracterized by biotite ndash white mica(ndashchloritendashcarbonatendashamphibolendashgarnetndashalbite) schist and graphite schist(Fig 28) and may be 40 to 50 m thick Drillcore samplesof a hornblendendashplagioclasendashquartz rock (with garnetporphyroblasts) have been interpreted as an unalteredamphibolite (Barrett 1989 Thornett 1995)

The Marker Quartzite is a recrystallized quartzmylonite (lsquoMarker Chertrsquo of mine geologists)1 to 3 m thick at the top of the Mine sequenceOutcrops of Marker Quartzite exhibit radiating iron-oxidepseudomorphs after acicular crystals and iron-oxidepseudomorphs after porphyroblasts Windh (1992)identified these acicular crystals using the scanningelectron microscope as grunerite The porphyroblastpseudomorphs are possibly after garnet

The Hangingwall sequence can be up to 700 m thickand is made up of white mica ndash magnetite(ndashgarnetndashchlorite) mafic schist and metabasite The latter is locally

Figure 27 Albite porphyroblasts in mylonitic schist at theMount Pleasant deposit

40

Pirajno et al

garnetiferous and characterized by a metamorphic (andhydrothermal) assemblage containing variable amountsof hornblende plagioclase quartz garnet epidote andtitanite The metabasite is overlain by mylonitic schistcontaining mainly quartzndashplagioclasendashbiotite and locallyassociated with zones of albitendashmuscovite and garnetndashepidote (calc-silicate)

The Peak Hill Jubilee and Mount Pleasant depositswere studied by Barrett (1989) who based most of hiswork on drillcore samples and Thornett (1995) Theseauthors provided much of the information summarizedbelow augmented by data from this study The Peak HillJubilee and Mount Pleasant gold deposits are situated inthe west-northwestern portion of the Peak Hill Anticlineand hosted in the Peak Hill Schist (Figs 4ndash7 and 26) Inthe mine areas the rocks are intensely weathered to depthslocally exceeding 200 m Weathering products arepredominantly kaolinitic clays and iron oxyhydroxidesThis weathering is particularly well developed in zonesof hydrothermal alteration which in turn are related tohigh-strain zones the latter having facilitated percolationof meteoric waters Hydrothermal alteration is dominatedby sulfidation (pyrite) and alkali metasomatism (biotiteand albite) and contained within late-stage quartzndashcarbonate veins hosted in highly strained metabasites andquartz mylonites Other important alteration mineralsinclude iron-rich chlorite sericite garnet tourmalinedolomite and calcite In all about 20 t of gold has beenproduced

The Peak Hill mineralization was exploited in threeadjoining pits which from north to south are FivewaysPeak Hill Main and Mini In plan view (Fig 29) the entirePeak Hill mineralized system is contained within apackage of mylonitic schist (Mine sequence) at thefootwall of northerly trending and westerly dippingshear zones The mylonitic schist contains quartz podsveins lenses and stringers and locally graphitic quartzmylonite units (Marker Quartzite see below and Fig 30)The Mine sequence contains lenses of mafic rocks (egmetadolerite) The overall picture is one of a complex zoneof shearing and tectonic interleaving between rocks of the

FIVEWAYSPIT

MINIPIT

MAINPIT

100 m

sequence

Mine sequence

Intermediate sequence

Vein quartz

Marker Quartzite

Shear zone

Anticline

FMP160 271099

Hangingwall

Geology notmapped

Geology notmapped

N40

42

45

40

25

45

45 26

30

42

45

Fault42

Cleavage

Foliation

Figure 28 The Mine Sequence schist at the Peak Hill depositshowing biotite alteration the biotite is partlyretrogressed to chlorite plane polarized light

Figure 29 Schematic geological map of the Fiveways Mainand Mini opencuts Peak Hill deposit (after Thornett1995)

Figure 30 Peak Hill Mini opencut showing the ore-bearingmylonitic schist graphitic schist (dark bands) andMarker quartzite unit (above the upper graphiticschist)

41


Narracoota Formation and Peak Hill Schist Kinematicindicators (CndashS surfaces) indicate a thrust movement fromwest to east (Thornett 1995)

The main orebody has a westerly dip ranging from20deg to 50deg (averaging 35deg) and is hosted in rocks of theMine sequence High-grade zones can contain up to30ndash40 gt gold The ore zones are characterized bypervasive alteration consisting of chloritendashbiotitendashquartzndashcarbonatendashgraphite The principal ore minerals arepyrite chalcopyrite and gold Other ore minerals includealtaite tetrahedrite bismuthotelluride molybdenite andvarious bismuthndashleadndashtellurium compounds The goldmineralization is thought to have been emplaced in at leasttwo stages In the first stage gold mineralization wasemplaced along the contact between the Marker Quartziteand the Mine sequence (see below) During the secondstage cross-faults were formed with the gold beingredistributed or rearranged along these cross-faults

The Jubilee deposit was at first mined underground in1892 from a number of workings but the production isunknown In 1992 a small pit was excavated based onprobable reserves of approximately 50 000 t at 4 gt goldIn this pit gold mineralization is hosted in rocks of theHangingwall sequence and is in a complex quartzstockwork system emplaced along the margins of a 250 m-thick undeformed metabasite The gold is on both thehangingwall and footwall sides of the metabasite bodyTourmaline is present in the ore-bearing material Near theJubilee pit a northerly striking westerly dipping quartzvein almost perpendicular to the dominant foliation trendextends for about 200 m This vein was mined in the pastand contained maximum grades of approximately 30 gtgold

Mining at Mount Pleasant began at the turn of thecentury with the production of 8000 t of ore with anaverage grade of 9 gt gold Mining resumed in the 1980swhen about 145 000 t of ore was extracted with anaverage grade of 3 gt gold and 04 t of gold wasproduced The ore zones are nearly flat lying and wereemplaced in subparallel fashion one above the other Thedeeper northern zone is hosted by the Core sequence Goldis in quartzndashcarbonate veins associated with zones ofalbite (Fig 27) iron-rich chlorite sericite carbonate andpyrite alteration as well as zones of nearly flat lyinggraphitic schist (dip is 10deg to the south) The veins areeither vertical or of saddle-reef type lodged in anticlinalfolds

Harmony deposit

The Harmony (also known as New Baxters Find orContact) gold deposit is located approximately 10 km westof Peak Hill in a featureless area of no outcrops andcovered by colluvium lateritic duricrust and hardpanmaterial Details of the geology of the Harmony depositcan be found in Harper et al (1998) from whom the briefreview that follows is taken

The Harmony gold deposit consists of a subhorizontalsupergene zone hosted in ferruginous lateritic materials

(transported and residual regolith) a northeasterlytrending subvertical primary vein system and carbonate-bearing breccias Most of the ore is contained within thevein system which is hosted in rocks of the NarracootaFormation and at the contact between the Narracoota andRavelstone Formation (Fig 31) with lesser low-grademineralization in laterite The Harmony mineralization ishosted in a northwesterly plunging antiform (Enigmastructural zone) of a southwesterly dipping succession ofaltered mafic rocks at the top of the Narracoota Formationand within a shear zone along the contact with overlyingmetasedimentary rocks of the Ravelstone Formation Themineralized array of quartz veins become locally closelyspaced forming a stockwork that is commonly associatedwith high-grade ore Primary ore minerals include pyritewith gold inclusions pyrrhotite pentlandite chalcopyriteand scheelite The primary mineralization was enrichedby supergene processes

Hydrothermal alteration is characterized mainly bysilicification carbonitization and locally chloritizationHarper et al (1998) reported that mafic rocks show aparagenetic sequence of early albite and quartz followedby muscovite and chlorite Alteration in the metasedi-mentary rocks in the hangingwall is characterized mainlyby sericite and chlorite This primary alteration grades intozones of supergene alteration containing limonitekaolinite smectite group minerals and hematite Theweathered bedrock extends to approximately 60 m depthRegolith studies from drillholes have revealed anomalousAu W As Sb and Se in the ferruginous materials

Labouchere Nathans and Fortnumdeposits

In the northwestern part of the BryahndashPadbury Basin (onMILGUN) three distinct zones of gold mineralization havebeen recognized in high-strain zones associated with themargin of the Yarlarweerlor gneiss complex (Fig 25 andPlate 1) The Labouchere group (Labouchere and CentralValley deposits) and Nathans group (Labouchere-NathansNathan Bitter and Nathans Deep South deposits) had early

Figure 31 Diagrammatic cross section of the Harmony orezones (modified from Harper et al 1998)

50 m

FMP159

Supergene ore

Primary ore

Pit outline

50

100

150

200

Met

res

Mafic rocks

Formation)

Ultramafic rocks

Formation)(Ravelstone

(Narracoota

(NarracootaFormation)

Pelitic rocks

SW NE

211099

42

Pirajno et al

mining activity recorded from 1939 to the early 1940swith additional discoveries in the mid-1980s (Hanna andIvey 1990) The Fortnum deposits (Trevs StarlightTwilight Ricks Toms Hill Alton Eldorado Callies D39and Yarlarweelor) were discovered in the early 1980s (Hilland Cranney 1990)

Gold mineralization is structurally controlled in hostrocks of both the Bryah and Padbury Groups (Hill andCranney 1990) Windh (1992) concluded from detailedstudies at the Labouchere Nathans Deep South andFortnum mines that aqueous fluids of high temperatureand moderate salinity were responsible for mineralizationConstraints on temperature are derived from the lowerto middle greenschist-facies alteration assemblages(muscovitendashchloritendashalbite(ndashbiotite)) and fluid inclusiontrapping temperatures of up to 320degC Based on leadisotope work (galena from Nathans Deep South) Windh(1992) suggested that the syn-D4 gold mineralizationoccurred between 19 and 18 Ga The main features ofthe ore deposits are described below from the availableliterature

At the Labouchere-Nathans mine gold mineralizationis hosted in pyritic chert lenses or pods that lie withinmaficndashultramafic schist and along the contact withoverlying quartz wacke of the Labouchere FormationWindh (1992) described volcanic breccia (with high Niand Cr) with fuchsitic ultramafic and chert clasts similarto the reworked clastic rocks immediately overlying themaficndashultramafic volcanic rocks in the NarracootaFormation at the Fortnum mine The maficndashultramaficschist lies in the core of a southerly plunging anticlineand is here interpreted as part of the NarracootaFormation The Narracoota Formation ndash LabouchereFormation contact is interpreted as an early (D1ndashD2) faultor shear zone that was tightly folded during D3 Thestructure is crosscut and slightly offset by D4 faultstrending 270degndash290deg including a shear that forms thesouthern limit to the mineralization (Hanna and Ivey1990) Gold is associated with quartz veining and pyritein the altered chert with sideritendashmuscovitendashpyritealteration around the veins (Windh 1992) Productionfigures are only known for the combined output of theLabouchere-Nathans and Nathans Deep South opencuts(nearly 7 t of gold over five years Table 7)

At the Nathans group of workings the Nathan Bittershafts within the upper Labouchere Formation or lowerWilthorpe Formation have a recorded production of about8 kg over the period 1943ndash1950 (Swager and Myers1999) About 500 m to the north-northwest shallow shaftslie along the Kinders Fault between coarse and pebblyquartz wacke to the east and ultramafic schist of theNarracoota Formation to the west The Nathans DeepSouth mineralization lies approximately 1 km south-southeast of Nathan Bitter and was discovered in 1986(Hanna and Ivey 1990) The mineralization is hosted byfinely laminated chloritic shale interbedded with coarsequartz wacke and overlain by coarse units grading fromquartz-pebble conglomerate to quartzndashsericite shale Theentire succession is here described as part of the WilthorpeFormation including the chloritic shale which is mostlikely derived from mafic volcanic precursors (Hanna and

Ivey 1990 Windh 1992) Occhipinti et al (1998a)mapped similar units in the Wilthorpe Formation as aseparate member the Beatty Park Member The westerlyyounging succession contains a northndashsouth S3 foliationaxial planar to a few small-scale parasitic D3 foldsplunging steeply south and is overprinted by F4microfolds and kinks trending 290deg Gold mineralizationis within pyrite which has replaced finely bedded chloriteshale near crosscutting D4 quartzndashankerite veins Highestgrades are found adjacent to D4 faults These and otherstructural observations led Windh (1992) to infer a syn-D4 timing of mineralization However small quartz-veinnetworks possibly related to low-grade mineralization inthe overlying coarsely graded units are deformed by D4microfolding

The Fortnum gold mineralization is hosted by theNarracoota Formation which is truncated to the northagainst the Fortnum Fault and wedges out to the southThe package contains maficndashultramafic schist withoverlying reworked fragmental and volcaniclastic rocksincluding rocks with a supposed felsic volcanic derivationoverlain by the Ravelstone Formation (Hill and Cranney1990)

Mineralization at Trevs (and closely associatedorebodies including a recent discovery named Starlight)is hosted by quartz-vein systems in a westerly dippingsuccession of graded sericitic siltstone and coarse wackewith medium- to coarse-grained feldspar quartz and lithicfragments at least partly derived from the underlyingmaficndashultramafic volcanic rocks The Yarlarweelormineralization is hosted by ovoid lenses of jasperoidalchert within variably schistose maficndashultramafic volcanicrocks including interleaved fine tuffaceous and coarsefragmental layers (Hill and Cranney 1990) The chertlenses are within a westerly dipping reverse D3 shear zonecharacterized by quartzndashchloritendashsericite alteration Gold-bearing quartz(ndashpyrite) veins within the chert pods andwithin magnetite-bearing chlorite schist trend at 120deg dipsteeply north and are parallel to small sinistral D4 faults(D3 in Windh 1992) Windh (1992) also reported a minorset of (dextral) faults trending 070deg and crosscutting theD3 shear zones This may suggest a conjugate fault setrecording eastndashwest compression possibly late during D3rather than during north-northeastndashwest-southwest D4compression

Mining at the Fortnum group of workings from 1990to 1998 yielded 11 928 kg of gold from 4685 Mt of orewith an average recovered grade of 254 gt gold (Swagerand Myers 1999) Remaining measured and indicatedresources at Fortnum including Trevs and Starlightcontain an additional 17 970 kg of gold with a further4340 kg of gold estimated within inferred resources(Perilya Mines NL 1998)

Wembley deposit

The Wembley deposit is located approximately 18 kmsouthwest of Peak Hill and 25 km southeast of MurphyWell (from the Peak Hill road) Although rewarding(average grade of 175 gt gold) ore production was verysmall (less than 1800 t)

43


The Wembley mineralization is hosted in alteredmetabasite rocks within a major shear zone trending 120degThe mineralized zone strikes at 075deg and dips 63deg to thenorthwest A quartz vein near the old workings strikes at060deg and dips 54deg to the northwest Sedimentary units areintercalated with the volcanic rocks and consist ofturbiditic rocks (greywackendashshale) As at the Durackprospect (see below) quartz mylonite units trending120degndash140deg are within the metabasites

Wilgeena deposit

The Wilgeena (or Hit or Miss) gold mine area is located15 km southeast of the Peak Hill mine Production wasless than 15 000 t at an average grade of 26 gt gold

The deposit is within rocks of the Peak Hill Schist andmore specifically along the contact between the mylonitesand quartzndashsericite schist A northerly trending easterlydipping stoped-out ore lens was approximately 2 m thickThe mineralization is hosted in quartzndashmuscovitendashmagnetite schist Grab samples from the old excavationsreturned values ranging from 3 to 14 gt gold (Mountford1984) Whitfield (1987) estimated inferred resources asapproximately 600 000 t at 244 gt gold

Durack St Crispin and Heines Findprospects

The Durack prospect lies about 12 km south of Peak Hillalong and immediately west of the Old Peak Hill telegraphroad This gold deposit is blind being covered by soil andlateritic material and consists of primary mineralizationand a supergene mineralized zone The prospect wasidentified by a soil anomaly containing up to 100 ppb gold(Sabminco Annual Report 1994)

The prospect area is underlain by rocks ofthe Narracoota Formation which include metabasite(medium- to coarse-grained metabasalts) and maficpyroclastic rocks Thin magnetite-bearing chert bands(possibly chemical sediments) intercalated within themetabasites define a broad synclinal structure A numberof mylonite zones trending 120degndash125deg cut across theNarracoota Formation rocks and contain most of theprimary mineralization Grades intersected during drillingare in the order of 15 gt gold over widths of 4 to 6 m

The primary mineralization is contained within quartzndashsulfide veins and stockworks hosted by altered metabasiterocks The mineralized area is about 14 km long and200 m wide Hydrothermal alteration is pervasive andconsists of quartz chlorite biotite and iron-rich carbonate(ankerite) Pyrite is present as fine disseminations andveinlets Selvages of silicandashpyritendashcarbonate surround themineralized zones

The supergene mineralization at the Durack prospectis controlled by subhorizontal redox fronts within theregolith material Supergene enrichment shows grades ofup to 12 gt gold over an interval of about 5 m In somecases the redox-front-related mineralization developed upto 45 m on each side of the primary zone

The St Crispin prospect is situated 20 km east-southeast of Peak Hill The mineralization is along a north-northwesterly trending structure and hosted in sericite(ndashgraphite) schist of the Peak Hill Schist Quartz veins arepresent in the schists and may host the mineralization

The Heines Find prospect is located 20 km south-southeast of Peak Hill Mineralization can be traced forabout 6 km along the easterly trending contact betweenrocks of the Narracoota Formation and the HeinesMember of the Wilthorpe Formation This contact has adip of 80deg to the north and is sheared In this area theNarracoota Formation consists of strongly deformedpillow lavas and chlorite schist The sedimentary rocks ofthe overlying Heines Member include a basal polymicticconglomerate

Ruby Well group

The Ruby Well area includes a number of mineral leasesfrom which gold has been produced either from surfacematerials or from hard rock (02 t Table 7) The RubyWell leases lie on the northern side of the Great NorthernHighway about 80 km from Meekatharra and 4ndash5 km eastof the Peak Hill turn-off

The area is underlain by the Narracoota Doolgunnaand Karalundi Formations The Hard To Find Ruby Anneand Lucky Call deposits within mafic schist of theNarracoota Formation were exploited between 1912 and1917 Most of the current production (figures notavailable) is from a number of dry-blowing workingssurrounding these old mines

Mikhaburra deposit

The old Mikhaburra gold mine (also known as HoldensFind) is in Narracoota Formation volcanic rocks in thesouthwestern part of BRYAH (Fig 25) The recordedproduction of the Mikhaburra mine is about 226 kg ofgold (MacLeod 1970) The mineralization is associatedwith a system of auriferous quartz veins emplaced alonga shear zone trending about 130deg to 150deg and dipping 68degto the southwest The volcanic rocks include mainlychlorite schist A quartz vein with a strike of 120deg and dipof 58deg southwest lies to the west of the old workings Thisvein is about 1 m wide and locally displays a laminatedstructure

Wilthorpe deposit

The Wilthorpe deposit is hosted by granitic rocks of theDespair Granite (Fig 32) which contains xenoliths ofmafic material Gold mineralization is confined to a zonecontaining quartz veins and flanked by bleached andsilicified wallrocks The ore zone is hydrothermallyaltered with assemblages of chloritendashsericitendashbiotite andquartzndashmuscovitendashbiotitendashtourmaline flanked by near-pervasive silicification In addition to gold the mineralizedveins also contain pyrite galena arsenopyrite andchalcopyrite The wallrock granite has a cataclastic textureand consists of quartz and feldspar lsquoeyesrsquo surrounded bya network of granulated quartz and sericite

44

Pirajno et al

Cashman deposit

The Cashman area on BRYAH includes a number of smallmineral occurrences and deposits containing copperand copperndashgold The old Cashman copper mine isapproximately 250 m from the gold workings In 1917 thismine produced about 7 t of copper ore grading 165copper (Marston 1979) The copper mineralizationconsists of a metre-wide cupriferous limonite vein with astrike of 042deg and a shallow dip to the northwest Oreminerals are chrysocolla and malachite as disseminationsand veinlets (Marston 1979)

In 1937 there was a small production of gold ore fromquartz veins In 1986ndash87 the gold potential of theCashman area was reassessed and on the basis of thiswork a small opencut was excavated from which 8000 tof ore material was produced and stockpiled (Whitfield1987) Gold mineralization is hosted in quartz veins withinmetabasaltic hyaloclastite A 01 m-thick quartz vein in thepit has a strike of 115deg and dips 35deg to the northeast Atand near the surface supergene enrichment is present ina horizon about 30 m wide and dipping about 20deg to thenorth (Whitfield 1987)

Volcanogenic copperndashgolddepositsThe Horseshoe Lights copperndashgold deposit on JAMINDI hasproduced nearly 9 t of gold of which almost 26 t wasrecovered from the copper concentrate operation between1988 and 1993 (Table 7) The Horseshoe Lights depositis hosted in felsic schist of the Narracoota Formation(Bryah Group) The mineralization consists of massivesulfides overlying and flanked by disseminated andstringer sulfides Ore minerals are mainly chalcocitepyrite and chalcopyrite Native copper is also present(Parker and Brown 1990) The host rocks are mylonitizedchlorite schist kaolinitendashsericite schist and quartzndashsericiteschist The geometry of the ore zones (massive sulfidesand stringer zone) alteration patterns (silicificationsericitic and chloritic alteration) predominantly felsiccomposition of the host rocks and metal association (CundashAundashAgndashPbndashZn) suggest that the deposit was originally ofthe volcanogenic massive sulfide type but subsequentlyenriched by supergene processes Average grades havebeen about 8 gt gold about 10 copper and 300 ppmsilver The stringer mineralization is of low gradeaveraging between 02 and 03 gt gold Production ceasedin 1994 Remaining resources (Table 8) are of low-grademineralization

Supergene manganese depositsManganese mineralization is part of a historicallyimportant manganese field first recognized in 1905 withdeposits in the Mount Fraser Mount Padbury Ravelstone(Peak Hill) and Horseshoe areas The manganesemineralization is of supergene origin and related tomanganiferous and hematitic shale units and BIF of theHorseshoe Formation (Bryah Group) as well as units ofthe Padbury Group The chief ore minerals are pyrolusiteand cryptomelane The ore is lateritic locally pisolitic innature and in places forms caps overlying the primarymanganese-rich sedimentary material In places notablyat Horseshoe there is evidence to suggest that someenrichment may have taken place in a palaeodrainagechannel lake or swamp environment (MacLeod 1970)In the Ravelstone area just north of the Peak Hill golddeposit the manganese supergene enrichment appears tohave a structural control

The Horseshoe area has been the main producingregion with production from two deposits 2 and 3 kmnorth and northwest of the Horseshoe townsite (Plate 1)The main production period was from 1948 to 1971 when490 000 t was mined (Table 8) all but 5000 t of whichwas classified as metallurgical-grade ore The enrichedzone was 3 to 45 m thick and typically extended overlengths of 400 to 500 m The North deposit averaged 30 min width whereas the South deposit was fan shapedopening from 20 to 300 m wide at its maximum extentOre consisted of mixed manganese and iron oxides withhighly variable manganese and iron contents Gradesprogressively decreased from 42 to 35ndash38 after 1966

There are several small deposits in the Mount Fraserndash Mount Padbury area about 30 km west of Peak Hill

Figure 32 The west wall of the Wilthorpe opencut showingthe contact between biotitendashsericitendashquartz schistand deformed Despair Granite

45


They contain patches of high-grade ore within largedeposits of ferruginous manganese material Productionof high-grade ore occurred sporadically since 1949 andamounted to 7547 t at grades in excess of 46 manganeseA third mining operation commenced at the Millidie (orElsa) deposit in the early 1990s but this has notprogressed to a full-scale commercial operation High-grade mineralization in the area is estimated to containmeasured plus indicated resources of approximately11 000 t of manganese (Table 8)

In the Ravelstone area immediately north-northwestof Peak Hill mining occurred between 1956 and 1964producing 76 237 t of ore at 70ndash90 manganese oxide(Table 8) Remainng measured and indicated resources areestimated as 132 000 t of contained metal (Table 8)Manganese production at Ravelstone was from easterlystriking orebodies reaching lengths of up to 100 m andwidths of 30 m but commonly small and narrow Detailedexamination of one specimen of ore revealed that it wascomposed mainly of cryptomelane and accessorypyrolusite A partial geochemical analysis of the samesample provided the following results 064 wt SiO2465 wt Al2O3 0011 wt P 033 wt MgO 268 wtK2O 7038 wt MnO 119 wt Fe 005 ppm Au650 ppm Co 31 ppm Cu 53 ppm Ni 20 ppm Pb and98 ppm Zn

The manganese ore is characterized by high bariumabundances (3000 ppm to 30 at Mount Fraser3000 ppm to 1 at Horseshoe and 3943 to 9000 ppm atRavelstone)

Iron oreThe Robinson Range Formation (Padbury Group) containsunits of banded iron-formation (Fig 2) within which areareas of supergene enrichment of hematite and goethiteThese constitute demonstrated (pre-JORC code) iron-oreresources estimated at approximately 10 Mt with gradesin excess of 60 iron (Table 8) Enrichment is above twoBIF units approximately 100 m thick separated by ahematitic shale horizon Iron grades of the primary BIFvary between 20 and 50 Hematite and hematitendashgoethite surficial enrichment contains grades in excess of50 iron as determined from the sampling of one ofabout 200 small pods of potentially ore grade material(Sofoulis 1970)

TalcTalc in the Mount Seabrook ndash Livingstone ndash Trillbarregion is present within metasedimentary and meta-volcanic rocks and minor mafic and ultramafic rocks Talcis hosted in metasomatized dolomite orebodies (Plate 1)as a series of steeply plunging lenses (Lipple 1990) TheMount Seabrook deposit was discovered in 1965 and hasproduced over 540 000 t of talc mostly of cosmetic gradebetween 1973 and 1995 Indicated and inferred resourcesredefined at Mount Seabrook and Livingstone amount to172 Mt of ore with a significantly greater potentialbecause the orebodies are open along strike

DiscussionThe Horseshoe Lights VMS-type copperndashgold deposit issyn-volcanic and pre-orogenic All other deposits are ofepigenetic origin and syn- to post-orogenic

Figure 33 schematically depicts a simple regionalmodel of ore genesis for the epigenetic mineral depositsin the BryahndashPadbury ndash Peak Hill Schist (BPPS) tectono-metamorphic domain and the adjacent Yerrida Basin TheYerrida Basin and BPPS domain were tectonicallyjuxtaposed along the northeasterly trending Goodin FaultDeformation which affected the BPPS domain wastransmitted across the Goodin Fault for a few kilometresinto the Yerrida Basin This deformation becomes weakerfrom the Goodin Fault eastward The BPPS domain wassubjected to metamorphism (upper to lower greenschistfacies) At least two phases of metamorphism arerecognized a prograde phase overprinted by a retrogradephase Geothermometry and geobarometry studies inthe area around Peak Hill by Thornett (1995)indicated temperatures of around 500ndash620degC for peakprograde metamorphism and 65 to 7 kbar for minimumpressure of the prograde assemblages The timing ofthis metamorphism is probably linked to the collisionbetween the Pilbara and Yilgarn Cratons (see Tectonicmodel and conclusions) which is postulated to haveoccurred between 1820 and 1800 Ma (Occhipinti et al1999)

A genetic model proposed by Pirajno and Preston(1998) envisages that fluids were generated during phasesof dynamic and thermal metamorphism in the BPPSdomain and that these fluids were largely responsible forthe deposition of mesothermal gold-only and shear-zone-hosted deposits The paragenesis of the alterationassemblages associated with the mesothermal depositsand textural relationships suggest that metamorphism

Figure 33 Sketch illustrating a conceptual model for the originof precious and base metal epigenetic deposits inthe BryahndashPadbury and Yerrida Basins (after Pirajnoand Preston 1998)

FMP71a

Bryah and Padbury Groups

Mooloogool Subgroup

Windplain Subgroup

Direction of fluid movement

170300

Fault Cleavagedevelopment

ARCHAEANBASEMENT

NARRYERTERRANE

Area of Au deposition

Collisionzone

Cleavagelate epigeneticmineralisation

Metamorphism

Basin fluids

YERRIDA

and deformation

Goo

din

Faul

t

development

BRYAHndashPADBURYBASINS BASIN

NW SE

46

Pirajno et al

and mineralization were broadly contemporaneousalthough alteration was in most cases from peak toretrograde metamorphism Exceptions to this are localizedzones of sodium metasomatism (albite and arfvedsonite)which overprint the retrograde assemblages This sodiummetasomatism may be related to central zones ofhigher temperatures within the mineralized structuresOne possible explanation for the widespread sodiummetasomatism is granite magmatism however there is noevidence in either the Bryah or the Padbury Basin ofgranitic plutons intruding the volcano-sedimentarysuccessions Therefore a possible role of graniticmagmatism as one of the heat and metal sources for thehydrothermal solutions based on our present knowledgeis excluded

Hydrothermal solutions responsible for the emplace-ment of mesothermal lodes are considered to be generatedin tectonically active regions and are associated withcompressional and extensional tectonics (Kerrich andCassidy 1994) The mesothermal-style gold-only lodesof the BPPS domain were formed in a compressionalsetting characterized by thin-skinned thrusting associatedwith prograde and retrograde mineral assemblages(Pirajno 1996) Dyer (1991) concluded that the hydro-thermal mineralization in the LaboucherendashFortnumarea was generated by the mixing of two fluids ofdifferent density and salinity Deeply sourced hot salineCO2-bearing fluids were mixed with cooler less salinenear-surface aqueous fluids The available evidencepoints to the conclusion that the mineralizing fluids wereat first generated during compression and dehydrationand moved along ductile to brittle structures Duringsubsequent phases meteoric fluids would have infiltratedalong the same structures and mixed with the hottermetamorphic solutions The whole mechanism couldhave been repeated again in the next phase of compressionand extension leading to multiphase ore genesis processesin which the latest phase leaves the most detect-able imprint There is no obvious link with magmaticactivity

Other metal deposits in the BryahndashPadbury Basin aresupergene manganese and iron ore (Pirajno and Preston1998) The timing of the weathering event that led to thesupergene enrichment of the manganese and iron ores isnot known although it may be possible that the warm andhumid climate during the middle Tertiary (Cockbain andHocking 1990) played a major role in the genesis of thissupergene mineralization

Tectonic model andconclusions

Gee (1979) Hynes and Gee (1986) Windh (1992) andGee and Grey (1993) interpreted the geodynamicevolution of the lsquoGlengarry Basinrsquo as defined by Gee andGrey (1993) in terms of an ensialic or intracontinentalbasin Tyler and Thorne (1990) Myers (1993) Martin(1994) and Myers et al (1996) proposed models in whichthe former lsquoGlengarry Basinrsquo would have formed in aback-arc setting during the convergence of the Pilbara andYilgarn Cratons between 2000 and 1800 Ma

In the light of the re-interpretation of the formerlsquoGlengarry Basinrsquo into the Bryah Padbury and YerridaBasins some modification of the above tectonic schemesis necessary Lack of sufficient geochronological datahowever poses the problem of the precise timing ofevents This lack of information must be taken intoaccount when modelling basin tectonics Pirajno (1996)and Pirajno et al (1998b) suggested two models for thegeodynamic evolution of the BryahndashPadbury and YerridaBasins 1) the basins were formed during convergence andsubsequent collision in a back-arcndashforeland basin settingin which these basins were opened and infilled duringsouthward subduction of oceanic crust (extensional backarc) and subsequently overlain by sediments in a newlydeveloped foreland basin (syn-collisional) and 2) thebasins were formed at the time of the oblique collisionbetween the Pilbara and Yilgarn Cratons as pull-apartstructures in a strike-slip setting with transitions fromextensional (transtension) to compressional (transpression)regimes

In this study we propose a model whereby the BryahBasin was formed as a back-arc rift with a component ofrifting along the Yilgarn continental margin a kind ofproto-oceanic rift comparable to that of the present-day Guayamas Basin in the Gulf of California (Lonsdaleand Becker 1985) The Padbury Basin developed as aforeland basin on top of the Bryah Basin during theoblique collision of the Pilbara and Yilgarn Cratons Ourmodel is shown in Figure 34 in which two stages areschematically depicted and briefly discussed below

The Bryah Basin was formed by processes of back-arc opening during subduction of oceanic crust beneaththe northern margin of the Yilgarn Craton approximately

Figure 34 Schematic illustration showing the preferred model of the tectonic evolution of the Bryah and Padbury Basins withinthe context of the Capricorn Orogen (modified from Myers 1990 1993 and Myers et al 1996)a) At about 1960ndash1950 Ma development of Andean-type magmatic arc on a microcontinental active margin back-arcrifting and spreading with creation of oceanic crust (dominantly high-Mg and high-Fe tholeiite associated withsubvolcanic peridotitic cumulates representing future maficndashultramafic schist of the Narracoota Formation) anderuption of basaltic hyaloclastites probably from the same source as the maficndashultramafic material occurs on passivemargin of Yilgarn Craton Insets schematically show geochemical signatures of these volcanic rocks (see text fordetails)b) Capricorn Orogeny involved collision between the Pilbara and Yilgarn Cratons with formation of fold-and-thrustbelts on both northern and southern sides of orogen and thrusting of oceanic crust over hyaloclastite and margin ofYilgarn Craton The thrust separating oceanic crust material from hyaloclastite is represented by the Murchison Fault(see Plate 1) Chondrite-normalized REE patterns for metabasites and hyaloclastites of the Narracoota Formation areshown in the insets

47


N S

N S

Marymia In

lier

YILGARN

Backarc riftMicrocontinent

andvolcanic arc

Seafloor

Seafloor

Oceaniccrust

lt 1960ndash1950 Ma

PILBARA

PILBARAYILGARN

Fold-and-thrustbelt

PadburyBasin Bryah Basin

1820ndash1800 Ma

Present-dayBryahndashPadbury

area

Lithosphere

FMP376 170300

4000

3000

2000

1000

00 21 3

FeOMgO FeOMgO Ni Cr

1

2

0

3

0 1 2

La Eu Lu

Sam

ple

chon

drite

100

10

16

Sam

ple

chon

drite

100

10

2La Eu Lu

2

Cr

(ppm

)

TiO

(

)

TiO x1002

Mid-oc

ean r

idge

2

Clastic rocks

Padbury Group

Archaean basement

Metabasic rocksof Narracoota FormationHyaloclastites(Narracoota Formation)

Karalundi Formation

Oceanic crust

a)

b)

48

Pirajno et al

between 1960 and 1950 Ma (Occhipinti et al 1999Fig 34a) Myers (1993) speculated that a southwardoceanic subduction system with a south-facing Andean-type magmatic arc had developed off the northern passivemargin of the Yilgarn Craton Remnants of arc magmaticsuites have not been found but may be buried under theMesoproterozoic Bangemall Basin Back-arc rifting alsoaffected the northern margin of the Yilgarn Craton whererift propagation is postulated to have progressivelyadvanced from west to east through a succession ofcrustalndashlithospheric thinning rupture and grabenformation In this model the Marymia Inlier is a remnantof a rift shoulder (Fig 34a)

The closing of the ocean between the Pilbara andYilgarn Cratons was followed by the oblique collisionbetween the rifted passive margin on the Pilbara side aninferred active magmatic arc and the passive northernmargin of the Yilgarn Craton Closure of the interveningocean (1820ndash1800 Ma) resulted in inversion of the Bryahback-arc rift and thrusting of oceanic crust (nowNarracoota Formation) over the Yilgarn Cratonrsquos northernmargin (Fig 34b) During and following this collisionevent the southern side of the Pilbara was tectonicallysliced by major thrusts whereas most of the tectonictransport of the inferred magmatic and oceanic crust rockswas towards the south (Myers 1993)

High-Mg tholeiitic rocks with pillow structuressheeted dykes the Trillbar layered complex sea-floor metasomatism and trace and rare-earth elementgeochemistry support the oceanic crust model for theorigin of the mafic and ultramafic schist of the NarracootaFormation The hyaloclastites on the other hand wereerupted in shallow waters and locally characterized byexplosive activity and have mixed and overlappinggeochemical signatures with the mafic schist This featurecan be interpreted as suggesting a more continentalenvironment of emplacement and therefore were emplacedon Yilgarn crust (Fig 34a) In contrast to the maficndashultramafic schist the hyaloclastites are relativelytectonically undeformed Their contact with the maficndashultramafic schist is along the Murchison Fault (Plate 1)We conclude that the Murchison Fault represents atectonic boundary between these two components of theNarracoota Formation and that oceanic crust material(precursors of the maficndashultramafic schist) were thrustover the continental hyaloclastites during the CapricornOrogeny as shown in Figure 34b The suggested Gulf ofCalifornia-type palaeoenvironmental setting with thefuture Marymia Inlier as one of the rift shoulders(analogous to the California peninsula) is shown inFigure 34a

The absence of volcanic rocks of intermediate(andesitic) compositions suggests that the NarracootaFormation metabasites were not formed in a subduction-related volcanic-arc setting as proposed by Myers et al(1996) However we concur with Sun (1997) that theboninitic component in the chemistry of the metabasites(see inset of Fig 34 and Figs 12ndash15) needs explanationWe suggest that these boninitic characteristics of theNarracoota Formation can be compared to the boninitesof the Koh Ophiolite in New Caledonia (Meffre et al

1996) which are considered to have formed in a back-arc spreading centre

The overall high MgO and low TiO2 abundancesdepleted REE and low LaYb ratios of the NarracootaFormation are also consistent with the origin of theNarracoota Formation metabasites from a mantle plume(Pirajno et al 1998a)

The Padbury Basin was interpreted by Martin (1994)as a retroarc foreland basin recording the collision of theYilgarn and Pilbara Cratons During and followingcollision between 1820 and 1800 Ma (Occhipinti et al1999) back-arc volcanism ceased and a foreland basindeveloped on top of the back-arc succession (BryahGroup) This basin was filled by siliciclastic rocks only(Padbury Group) During continued regional compressionthe BryahndashPadbury Basin developed into a fold-and-thustbelt and was partly thrust over the Yerrida Basin alongthe Goodin Fault

In summary the convergence between the ArchaeanPilbara and Yilgarn Cratons resulted in progressivecompressional deformation that affected the Bryah andPadbury Groups as a coherent package At least fourgroups of structures are recognized in the regionaldeformation of the volcano-sedimentary succession andtheir reworked basement (ie Yarlarweelor GneissComplex) This same deformation and associatedmetamorphism was responsible for the mesothermal gold-only lodes of the Bryah and Padbury Basins

AcknowledgementsWe acknowledge the contribution of colleagues whoparticipated in the Glengarry mapping program JohnMyers N G Adamides and P G Le Blanc SmithRichard Davy first introduced the senior author to the areaWe are also grateful to the local pastoral community fortheir hospitality The geological staff of LabouchereFortnum Peak Hill and Harmony gold mines are thankedfor sharing their knowledge with us

49


References

ADAMIDES N G 1998 Geology of the Doolgunna 1100 000 sheetWestern Australia Geological Survey 1100 000 Geological SeriesExplanatory Notes 23p

BAGAS L B 1998 Geology of the Marymia 1100 000 sheetWestern Australia Geological Survey 1100 000 Geological SeriesExplanatory Notes 23p

BARNETT J C 1975 Some probable Lower Proterozoic sedimentsin the Mount Padbury area Western Australia Geological SurveyAnnual Report 1974 p 52ndash54

BARRETT F 1989 A study of wallrock alteration associated withgold mineralization mdash Peak Hill and Mt Pleasant area WesternAustralia Geological Survey M-series Item 7706 A41555(unpublished)

BRADLEY J J FAULKNER J A and SANDERS A J 1997Geochemical mapping of the Robinson Range 1250 000 sheetWestern Australia Geological Survey 1250 000 RegolithGeochemistry Series Explanatory Notes 57p

BREITKOPF J H and MAIDEN K J 1988 Tectonic setting of theMatchless Belt pyritic copper deposits Namibia EconomicGeology v 83 p 710ndash723

BUNTING J A COMMANDER D P and GEE R D 1977Preliminary synthesis of Lower Proterozoic stratigraphy andstructure adjacent to the northern margin of the Yilgarn BlockWestern Australia Geological Survey Annual Report 1976p 43ndash48

BURKE K C KIDD W S F TURCOTTE L DEWEY J FMOUGINIS-MARK P J PARMENTIER E M SENGORA M and TAPPONIER P E 1981 Tectonics of basalticvolcanism in Basaltic volcanism on the terrestrial planets HoustonLunar and Planetary Institute p 803ndash898

COCKBAIN A E and HOCKING R M 1990 Regolith in Geologyand mineral resources of Western Australia Western AustraliaGeological Survey Memoir 3 p 591ndash602

CRAWFORD R A FAULKNER J A SANDERS A J LEWISJ D and GOZZARD J R 1996 Geochemical mapping ofthe Glengarry 1250 000 sheet Western Australia GeologicalSurvey 1250 000 Regolith Geochemistry Series Explanatory Notes57p

DAVY R PIRAJNO F SANDERS A J and MORRIS P A1999 Regolith geochemical mapping as an adjunct to geologicalmapping and exploration examples from three contiguousProterozoic basins in Western Australia Journal of GeochemicalExploration v 66 p 37ndash53

DIXON J and WILLIAMS G 1983 Reaction softening in mylonitesfrom the Arnaboll thrust Sutherland Scottish Journal of Geologyv 19 p 157ndash168

DUNCAN A R 1987 The Karoo igneous province mdash a problemarea for inferring tectonic setting from basalt geochemistry Journalof Volcanology and Geothermal Research v 32 p 13ndash34

DYER F L 1991 The nature and origin of gold mineralization atthe Fortnum Nathans and Labouchere deposits Glengarry BasinWestern Australia University of Western Australia BSc Honoursthesis (unpublished)

ELIAS M 1982 Belele WA Western Australia Geological Survey1250 000 Geological Series Explanatory Notes 21p

ELIAS M BUNTING J A and WHARTON P H 1982 GlengarryWA Western Australia Geological Survey 1250 000 GeologicalSeries Explanatory Notes 27p

ELIAS M and WILLIAMS S J 1980 Robinson Range WAWestern Australia Geological Survey 1250 000 Geological SeriesExplanatory Notes 32p

FISHER R V and SCHMINCKE H-U 1984 Pyroclastic rocksBerlin Springer-Verlag 472p

GEE R D 1979 The geology of the Peak Hill area Western AustraliaGeological Survey Annual Report 1978 p 55ndash62

GEE R D 1987 Peak Hill WA (2nd edition) Western AustraliaGeological Survey 1250 000 Geological Series Explanatory Notes24p

GEE R D 1990 Nabberu Basin in Geology and mineral resourcesof Western Australia Western Australia Geological SurveyMemoir 3 p 202ndash210

GEE R D and GREY K 1993 Proterozoic rocks on the Glengarry1250 000 sheet mdash stratigraphy structure and stromatolitebiostratigraphy Western Australia Geological Survey Report 4130p

HALL W D M and GOODE A D T 1978 The Early ProterozoicNabberu Basin and associated iron formations of Western AustraliaPrecambrian Research v 7 p 129ndash184

HANNA J P and IVEY M E 1990 Labouchere and Deep Southgold deposits in Geology of the mineral deposits of Australia andPapua New Guinea Volume 1 edited by F E HUGHESAustralasian Institute of Mining and Metallurgy Monograph 14p 667ndash670

HARPER M HILL M G RENTON J I and THORNETTS E 1998 Gold deposits of the Peak Hill area WesternAustralia in Geology of the mineral deposits of Australia andPapua New Guinea Volume 1 edited by F E HUGHESAustralasian Institute of Mining and Metallurgy Monograph 14p 81ndash87

HILL A D and CRANNEY P J 1990 Fortnum golddeposit in Geology of the mineral deposits of Australia andPapua New Guinea Volume 1 edited by F E HUGHESAustralasian Institute of Mining and Metallurgy Monograph 14p 665ndash666

HYNES A and GEE R D 1986 Geological setting andpetrochemistry of the Narracoota Volcanics Capricorn OrogenWestern Australia Precambrian Research v 31 p 107ndash132

JENSEN L S 1976 A new cation plot for classifying subalkalicvolcanic rocks Canada Ontario Division of Mines MP 66 22p

KERRICH R and CASSIDY K F 1994 Temporal relationships oflode gold mineralization to accretion magmatism metamorphismand deformation mdash Archaean to present a review Ore GeologyReviews v 9 p 263ndash310

LE MAITRE R W 1989 A classification of igneous rocksand glossary of terms Oxford Blackwell Scientific Publications193p

50

Pirajno et al

LEWIS J D 1971 The geology of some carbonate intrusions in theMount Fraser area Peak Hill Goldfield Western Australia WesternAustralia Geological Survey Annual Report 1970 p 50ndash56

LIPPLE S L 1990 Talc in Geology and mineral resources of WesternAustralia Western Australia Geological Survey Memoir 3p 678ndash679

LISTER G S and SNOKE A W 1984 SndashC mylonites Journal ofStructural Geology v 6 p 617ndash638

LONSDALE P and BECKER K 1985 Hydrothermal plumes hotsprings and conductive heat flow in the southern trough ofGuayamas Basin Earth and Planetary Science Letters v 73p 211ndash225

LUCAS S B STERN R A SYME E C REILLY B A andTHOMAS D J 1996 Intraoceanic tectonics and the developmentof continental crust 192 ndash 184 Ga evolution of the Flin Flon beltCanada Geological Society of America Bulletin 108 p 602ndash629

MacLEOD W N 1970 Peak Hill WA (1st edition) WesternAustralia Geological Survey 1250 000 Geological SeriesExplanatory Notes 21p

MARSHAK S TINKHAM D ALKMIN F BRUECKNER Hand BORNHORST T 1997 Dome-and-keel provinces formedduring Palaeoproterozoic orogenic collapse mdash core complexesdiapirs or neither examples from the Quadrilatero Ferrifero andthe Penkean orogen Geology v 25 p 415ndash418

MARSTON R J 1979 Copper mineralization in Western AustraliaWestern Australia Geological Survey Bulletin 13 208p

MARTIN D McB 1992 Turbidite facies and depositionalenvironment of the Precambrian Labouchere Formation PadburyGroup Western Australia Geological Society of AustraliaAbstracts 32 p 168ndash170

MARTIN D McB 1994 Sedimentology sequence stratigraphy andtectonic setting of a Palaeoproterozoic turbidite complex LowerPadbury Group Western Australia University of Western AustraliaPhD thesis (unpublished)

MARTIN D McB 1998 Lithostratigraphy and structure of thePalaeoproterozoic Padbury Group Milgun 1100 000 sheet WesternAustralia Western Australia Geological Survey Report 62 57p

McDONALD I R 1994 Final Report on the Glengarry nickel projectES502 and E51384 Western Australia Geological SurveyM-series Item 7706 A41555 (unpublished)

McMILLAN N M 1993 Structure metamorphism alteration andtiming of gold mineralisation at Marymia Gold Project in theMarymia Dome in An international conference on crustal evolutionmetallogeny and exploration of the Eastern Goldfields ExtendedAbstracts compiled by P R WILLIAMS and J A HALDANEAustralian Geological Survey Organisation Record 199354p 243ndash244

McPHIE J DOYLE M and ALLEN R 1993 Volcanic texturesHobart Tasmanian Government Printing Office 198p

MEFFRE S AITCHISON J C and CRAWFORD A J 1996Geochemical and tectonic significance of boninites and tholeiitesfrom the Koh Ophiolite New Caledonia Tectonics v 15p 67ndash83

MOUNTFORD B R 1984 Preliminary geological report onProspecting Licences 52104 and 52105 Mt Padbury area WesternAustralia Western Australia Geological Survey M-series Item3688 A16393 (unpublished)

MYERS J S 1989 Thrust sheets on the southern foreland of theCapricorn Orogen Robinson Range Western Australia WesternAustralia Geological Survey Report 26 Professional Papersp 127ndash130

MYERS J S 1990 Capricorn Orogen in Geology and mineralresources of Western Australia Western Australia GeologicalSurvey Memoir 3 p 197ndash198

MYERS J S 1993 Precambrian history of the West Australian cratonand adjacent orogens Annual Reviews of Earth and PlanetaryScience v 21 p 453ndash485

MYERS J S SHAW R D and TYLER I M 1996 Tectonicevolution of Proterozoic Australia Tectonics v 15 p 1431ndash1446

NELSON D R 1997 Compilation of SHRIMP UndashPb zircongeochronology data 1996 Western Australia Geological SurveyRecord 19972 189p


OrsquoNIONS R K PANKHURST R J and GRONVOLD K 1976Nature and development of basalt magma sources beneath Icelandand the Reykjanes ridge Journal of Petrology v 17 p 315ndash338

OCCHIPINTI S A GREY K PIRAJNO F ADAMIDES N GBAGAS L DAWES P and LE BLANC SMITH G 1997Stratigraphic revision of Palaeoproterozoic rocks of the YerridaBryah and Padbury Basins (former Glengarry Basin) WesternAustralia Geological Survey Record 19973 57p

OCCHIPINTI S A and MYERS J S 1999 Geology of the Moorarie1100 000 sheet Western Australia Geological Survey 1100 000Geological Series Explanatory Notes 20p

OCCHIPINTI S A MYERS J S and SWAGER C P 1998aGeology of the Padbury 1100 000 sheet Western AustraliaGeological Survey 1100 000 Geological Series Explanatory Notes29p

OCCHIPINTI S A SHEPPARD S NELSON D R MYERS J Sand TYLER I M 1998b Syntectonic granite in the southernmargin of the Palaeoproterozoic Capricorn Orogen WesternAustralia Australian Journal of Earth Sciences v 45 p 509ndash512

OCCHIPINTI S A SHEPPARD S and TYLER I M 1999Palaeoproterozoic tectonic evolution of the southern margin of theCapricorn Orogen Western Australia Last Conference of theMillenium Halls Gap WA Abstract volume p 173ndash174

OCCHIPINTI S A SWAGER C P and PIRAJNO F 1998cStructuralndashmetamorphic evolution of the Palaeoproterozoic Bryahand Padbury Groups during the Capricorn Orogeny WesternAustralia Precambrian Research v 90 p 141ndash158

PARKER T W H and BROWN T 1990 Horseshoe goldndashcopperndashsilver deposit in Geology of the mineral deposits of Australia andPapua New Guinea Volume 1 edited by F E HUGHESAustralasian Institute of Mining and Metallurgy Monograph 14p 671ndash675

PEARCE J A ERNEWEIN M BLOOMER S H PARSON L MMURTON B J and JOHNSON L E 1995 Geochemistry ofLau Basin volcanic rocks influence of ridge segmentation and arcproximity Geological Society Special Publication v 81p 53ndash75

PEARCE T H GORMAN B E and BIRKETT T C 1977 Therelationship between major element chemistry and tectonicenvironment of basic and intermediate volcanic rocks Earth andPlanetary Science Letters v 36 p 121ndash132

PERILYA MINES NL 1998 Annual report for the year ending30 June 1998 60p

PETERS S G 1993 Polygenetic meacutelange in the Hodgkinsongoldfield Northern Tasman Orogenic Zone Australian Journal ofEarth Sciences v 40 p 115ndash129

PIRAJNO F 1996 Models for the geodynamic evolution of thePalaeoproterozoic Glengarry Basin Western Australia WesternAustralia Geological Survey Annual Review 1995ndash96 p 96ndash103

PIRAJNO F and ADAMIDES N G 2000 Geology andmineralization of the Palaeoproterozoic Yerrida Basin WesternAustralia Western Australia Geological Survey Report 60 43p

51


PIRAJNO F and ADAMIDES N G 1998 Geology of the Thaduna1100 000 sheet Western Australia Geological Survey 1100 000Geological Series Explanatory Notes 24p

PIRAJNO F ADAMIDES N G and FERDINANDO D D 1998aGeology of the Glengarry 1100 000 sheet Western AustraliaGeological Survey 1100 000 Geological Series Explanatory Notes16p

PIRAJNO F ADAMIDES N G OCCHIPINTI S A SWAGERC P and BAGAS L 1995a Geology and tectonic evolution ofthe early Proterozoic Glengarry Basin Western Australia WesternAustralia Geological Survey Annual Review 1994ndash95 p 71ndash80

PIRAJNO F BAGAS L SWAGER C P OCCHIPINTI S A andADAMIDES N G 1996 A reappraisal of the stratigraphy of theGlengarry Basin Western Australia Western Australia GeologicalSurvey Annual Review 1995ndash96 p 81ndash87

PIRAJNO F and DAVY R 1996 Mafic volcanism in thePalaeoproterozoic Glengarry Basin Western Australia andimplications for its tectonic evolution Geological Society ofAustralia Abstracts no 41 p 343

PIRAJNO F and OCCHIPINTI S A 1995 Base metal potential ofthe Palaeoproterozoic Glengarry and Bryah Basins WesternAustralia Recent developments in base metal geology andexploration Australian Institute of Geoscientists Bulletin 16p 51ndash56

PIRAJNO F and OCCHIPINTI S A 1998 Geology of the Bryah1100 000 sheet Western Australia Geological Survey 1100 000Geological Series Explanatory Notes 41p

PIRAJNO F OCCHIPINTI S LE BLANC SMITH G andADAMIDES N G 1995b Pillow lavas in the Peak Hill terranesWestern Australia Geological Survey Annual Review 1993ndash94p 63ndash66

PIRAJNO F OCCHIPINTI S A and SWAGER C P 1998bGeology and tectonic evolution of the Palaeoproterozoic BryahPadbury and Yerrida Basins (formerly Glengarry Basin) WesternAustralia Precambrian Research v 90 p 119ndash140

PIRAJNO F and PRESTON W A 1998 Mineral deposits of thePadbury Bryah and Yerrida Basins in Geology of Australian andPapua New Guinean mineral deposits edited by D A BERKMANand D H MACKENZIE Australasian Institute of Mining andMetallurgy Monograph 22 p 63ndash69

RAYMOND L A 1984a Classification of meacutelanges GeologicalSociety of America Special Paper 198 p 7ndash20

RAYMOND L A 1984b Meacutelanges their nature origin andsignificance Geological Society of America Special Paper 198170p

ROLLINSON H R 1993 Using geochemical data evaluationpresentation interpretation Singapore Longman 352p

SABMINCO ANNUAL REPORT 1994 Annual report on miningleases M52202ndash203 vol 1 2 and 3 Western Australia GeologicalSurvey M-series Item 8967 A42856 (unpublished)

SCHILLING J-G 1982 Galapagos hot spot ndash spreading centersystem 1 Spatial petrological and geochemical variations (83degWndash101degW) Journal of Geophysical Research v 87p 5593ndash5610

SCHILLING J-G MEYER P S and KINGSLEY R H 1982Evolution of the Iceland hot spot Nature v 296 p 313ndash320

SHEPPARD S and SWAGER C P 1999 Geology of the Marquis1100 000 sheet Western Australia Geological Survey 1100 000Geological Series Explanatory Notes 21p

SHEPPARD S OCCHIPINTI S A NELSON D and TYLERI M 1999 Granites of the southern Capricorn Orogen WesternAustralia Geological Society of Australia Abstracts no 56p44-46

SOFOULIS J 1970 Iron deposits of the Robinson Range Peak HillGoldfield WA Western Australia Geological Survey Record19706 10p

SPEAR F S 1993 Metamorphic phase equilibria and pressurendashtemperaturendashtime paths Mineralogical Society of AmericaMonograph p 799

STERN R A SYME E C and LUCAS S B 1995 Geochemistryof 19 Ga MORB and OIB-like basalts from the Amisk collageFlin Flon belt Canada evidence for an intra-oceanic originGeochimica et Cosmochimica Acta v 59 p 3131ndash3154

SUBRAMANYA A G FAULKNER J A SANDERS A J andGOZZARD J R 1995 Geochemical mapping of the Peak Hill1250 000 sheet Western Australia Geological Survey 1250 000Regolith Geochemistry Series Explanatory Notes 59p

SUN S-S 1982 Chemical composition and origin of the Earthrsquosprimitive mantle Geochimica et Cosmochimica Acta v 46p 179ndash192

SUN S-S 1997 Chemical and isotopic features of Palaeoproterozoicmafic igneous rocks of Australia implications for tectonic processesAustralian Geological Survey Organisation Record 19974p 119ndash122

SWAGER C P and MYERS J S 1999 Geology of the Milgun1100 000 sheet Western Australia Geological Survey 1100 000Geological Series Explanatory Notes 27p

THORNETT S E 1995 The nature origin and timing of goldmineralization in Proterozoic rocks of the Peak Hill District WAUniversity of Western Australia MSc thesis (unpublished)

TYLER I M 1999 Palaeoproterozoic orogeny in Western AustraliaGeological Society of Australia Abstracts no 56 p 47ndash49

TYLER I M PIRAJNO F BAGAS L MYERS J S andPRESTON W A 1998 The geology and mineral deposits of theProterozoic in Western Australia Australian Geological SurveyOrganisation Journal of Geology and Geophysics v 17p 223ndash244

TYLER I M and THORNE A M 1990 The northern margin ofthe Capricorn Orogen Western Australia mdash an example of anEarly Proterozoic collision zone Journal of Structural Geologyv 12 p 685ndash701

WANG P and GLOVER L 1992 A tectonic test of the mostcommonly used geochemical discriminant diagrams and patternsEarth Science Reviews v 33 p 111ndash131

WATKINS K P 1983 Petrogenesis of Dalradian albite porphyroblastschists Journal of the Geological Society of London v 140p 601ndash618

WHITFIELD G B 1987 Wilgeena gold mine Progress report MS52111 and 112 Western Australia Geological Survey M-seriesItem 5862 A28194 (unpublished)

WINDH J 1992 Tectonic evolution and metallogenesis of the EarlyProterozoic Glengarry Basin Western Australia University ofWestern Australia PhD thesis (unpublished)

52

Pirajno et al

Appendix

Gazetteer of localities

Locality AMG coordinateEasting Northing

5 Mile Well 616500 7158100Beatty Park Bore 632200 7163500Cashman opencut 662129 7126994Dandy Well 646400 7188740Despair Bore 625300 7169600Durack prospect 670440 7150520Durack Well 671600 7143000Fortnum mine 636372 7197627Friday Pool 558620 7178625Harmony (New Baxters Find) opencut 664145 7161267Heines Find prospect 682759 7145164Horseshoe Lights opencut 662648 7193894Horseshoe Mn mine 656990 7186510Horseshoe Au prospect 661219 7182977Jubilee mine 671889 7165443Labouchere mine 627730 7204710Livingstone mine 567540 7171032Lucky Call prospect (Ruby Well group) 676747 7127188Mikhaburra (Holdens Find) opencut 656252 7130396Millidie (Elsa) deposit 643000 7160000Mount Fraser 639200 7163300Mount Labouchere 630360 7212620Mount Padbury 627400 7164100Mount Padbury mine 635100 7165100Mount Pleasant opencut 674287 7161900Mount Seabrook mine 572631 7168338Nathan Bitter mine 631100 7199820Nathans Deep South mine 631713 7198812Peak Hill opencut 672190 7163003Peak Hill townsite 673000 7163150Randell Bore 688000 7145200Ravelstone Group 669000 7167500Ravelstone opencut (Mn) 665734 7166777Ravelstone opencut (Mn) 669313 7166423Ruby Duffer Well 675290 7136000Ruby Well group 677900 7129700St Crispin prospect 691358 7158940Tank Well 675400 7147000Top Dimble Well 616600 7167600Trevs (and Starlight) opencut 636412 7198887Trillbar Homestead 576023 7170846Wembley mine 663983 7149044Wilgeena (Hit or Miss) mine 685369 7155622Wilthorpe mine 630414 7176521Yarlarweelor opencut 636723 7196423

Further details of geological publications and maps produced by theGeological Survey of Western Australia can be obtained by contacting

The Palaeoproterozoic Bryah and Padbury Basins are part of the Capricorn Orogen a collisionzone between the Archaean Pilbara and Yilgarn Cratons The Bryah Basin contains maficndashultramafic igneous rocks turbidites and chemical sedimentary rocks formed duringback-arc sea-floor spreading and rifting on the northern margin of the Yilgarn Cratonat or near a mid-oceanic ridge The Padbury Basin contains a succession ofclastic and chemical sedimentary rocks and was formed on top of theBryah Basin as a foreland structure resulting from either thec 1800 Ma oblique collision of the Pilbara and YilgarnCratons (Capricorn Orogeny) or the c 2000 Ma collisionof the Glenburgh Terrane and the Yilgarn Craton (GlenburghOrogeny) Important mineral deposits include orogenicgold-only lode deposits copperndashgold volcanogenic massivesulfides sedimentary and lateritic manganese and iron oreThe origin of the gold mineralization is related tometamorphism and deformation linked to the CapricornOrogeny at c 18 Ga The formation of other deposits isrelated to pre-orogenic syngenetic processes

Information CentreDepartment of Minerals and Energy100 Plain StreetEast Perth WA 6004Phone (08) 9222 3459 Fax (08) 9222 3444wwwdmewagovau

Wandery

Creek

Wandery

Gum

Creek

Beda

burra

Easter

nCr

eek

Dim

ble

Dimble

Cree

k

Mt Fr

aser

Creek

Creek

Mt Fraser

Millidie CreekMURCHISONRIVER

MURCHISON

RIVER

GASCOYNE

RIVE

R

GASCOYNE

RIVER

Ck

Cree

k

Creek

Beatty Park B (abd)

Reefer W(abd)

YARLAR

WEELOR

MILGUN

ROAD

MEEKATHARRA

ROAD

ASHBURTON DOWNS

TrillbarYarlarweelor

ROADTRILLBAR

Mt Padbury

Yd

Yd

Yd

Yd

Yd Yd

Yd

Yd

Yd

Yd

Yd

Yd

YdYd

MT CLARE

MEEKATHARRA

ROAD

Bryah

Narracoota

Old Peak Hill (ruin)

Mikhaburra

Yd

Yd

Yd

Yd

(ruin)Bilyuin Hotel

Yulga Jinna Community

Doolgunna

Yd

YdYd

Yd

THADUNACOPPER MINE ROAD

Yd

Karalundi

Yd

Yd

Yd

Yd

Bryah

Yd

Mikhaburra

Yarla

rwee

lor H

omes

tead

44

km

Milgun Homestead 4 km


Meekatharra 108 km

Meekatharra 53 km

Mooloog

ool Ho

mestead

35 km

Diamond

Well

Homest

ead 68

km

Neds

Creek

Homest

ead 33

km

Kumerina Homestead 98 km

Three Rivers Homestead 42 km

MT LABOUCHERE

MT ARAPILES

CM 15

MT BEASLEY

MT SEABROOK

TALB

OT

DIVIDE

RED HILL

722 m

Yd

Yd

Yd

Yds

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

YdYd Yd

Yd

Yd

Yd

Yd

628 m

MT PADBURYMT FRASER

MT MAITLAND

R O B I N S O N

591 m

695 m

799 m

Yd

Yd

GREAT

NORTH

ERN

HIGH

WAY

HILL

THRE

E RIVER

S

ROAD

PEAK

MEEKATHARRA

ROAD

ROAD

PEAK HILL

R A N G E

Peak Hill

MC 14

NOONYEREENA HILL

MT LEAKE

MC 13

MC 12

MC 11

ASHBURTON DOWNS

core yard

602 m

605 m

640 m

Peak Hill

Yd

Earrie W Daulby W

Jilly Jilly W

Outcamp W (abd)

Watt W

Curly W

B

6 Mile B4 Corners W

Laurel W (abd)Bull W

Labouchere W

Sam W

Duffey W

Horseshoe W

Dandy W (PD)(abd)

Carlyon B (PD)

Kinder B (PD)

Vacation B

Garret W

Kylie B

Camel B

W (abd)Billarra W

Bull Paddock WAlarm B

Carlyon RH (PD)

Yaddyarra W

Mowara BGullgogo B

Horseshoe No 2 W (PD)Horseshoe No 1 W (PD)

Stink W (PD)

Crain B

Windalah B

Yandinhah W

Coomballey B

No 1 B

4 Corners W (abd)

Cement Tank W (abd)

Cork Tree B

Southern Cross W3 Corners B

Thompson B (abd)

W (abd)

Tommy B

Seabrook W17 Mile W (abd)

Midnight B

Gidgie WW (abd)

Snake W Dry W

Black Hill W

Minniarra W

Top Minniarra W

Doherty W

The Hut W

W

Red Hill W

Randall W

Dooley W

Walebie W

Mandora B

Babbawiri Pool

Winja B

WHWH

PBedaburra P

Friday P

Kerba P

S

Wandery P

W

Valley B

Quartz B

House WSouthern Cross W

P

Peak Hill B Shed W

Boundary B

No 3 W

McPherson B

Pinnacle B

WH

Mt Leake B

Hill B

Jack W

W

Mt Leake B

John B

No 2 B

Cow Hole B

WH

Red B

WH

No 6 W

Marck W

No 11 W

Limestone W

Dummy B

No 1 B

No 8 B

D

Government W

Central B

Gale W

W

West W

No 6 B

Ealgareengunna WH

Noonyereena P

Beefwood T

Narracoota B

WH

WH

Railway B

Meek W32 Mile W (Govt)

32 Mile W

Ruby W

Ruby South W

W (abd)

Scotty W

Ord W

Little Mill B

Killarney W

West WMillie W

D

Ord W (abd)

W(abd)

Eastern Stock W No 8(abd)

Gigbywabby W (PD)(abd)

No1 W

Paddy B (abd)

Kelly BRelief B

Top Dimble W

Despair B

Boundary B (PD)

B (abd)

Padbury W

Govt W (abd)

Bottom Dimble WHaystack W

Wandarrie W

Middle B

W

WW

W

No 3 B

Fish Pond B

Wooly Paddock B

5 Mile W

Knox W

Sleepy Hollow W (abd)

Old Homestead WB

Widespread W

W

Kennedy W

W

Deep W

Ross B

Gibbywabby WDandy W (PD)

Brunsden W

17 Mile WBrown Creek B (abd)

7 Mile BDavid W

17 Mile B (PD)

Lefeuvre W

Mick W

W (abd)

WH

WHWH

WH

WH

WH WH

S

Gum W (abd)

Wilthorpe W (PD)

1 Mile W

Bullgullan B

Wongawar B

Jinglegunna W

No 13 B

Orchard W

Fraser WW

Sorenson B

Central B

Tank W (abd)Bitter W (abd)

Murphy W

Trudgeon W

Moore W Spelling W

Randell B

Deadhorse W (abd) McLean W

Bore Hole BOHara W

Murchison W (abd)

McCarthy W2 Tank W (abd)

Hill W

Telegraph W

Cashman B (abd)

Ruby Centre W

White WW

McCann W (abd)

Holden W

Gum W

McDonald W

Don BNo 2 BNo 1 B

Bull W

D

D

DD

Gum Well P

Malleah P

Fremanga P

Yallaginda W (abd)

No 7 B (abd)

Stalley W (abd)

Durack W

No 26 W (abd)

Ruby Duffer W (abd)

WHs

WHs

WHWH

WH

WHWH

WH

P

PP

P

P

P

P

P

P

P

P

P

Ruby W (abd)

Narracoota W (abd)

WH S

P

B W

D T

(abd) (PD)

Cheroona W(abd)

Ti Tree B

56ocircocircocircocircYacute E 58 62 64 66 68 72

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14

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18

20


56ocircocircocircocircYacute E 58 60 62 64 66 68 70 72 icirc40ocircocircocircocircYacute E


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16

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20


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Yarlarweelor

Horseshoe

NathanDeep

Mt Seabrook

Labouchere

Wilthorpe

Wilgeena

Wembley

Livingstone

Harmony

Jubilee

Peak HillMt Pleasant

St Crispin

Durack

Heines Find

Mikhaburra

Cashman

Horseshoe Lights

Horseshoe

Yarlarweelor

Mn

T

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Au

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HOLDENS

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Ruby Well

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M U R C H I S O N M I N E R A L F I E L D

M E E K A T H A R R A D I S T R I C T

P E A K H I L L M I N E R A L F I E L D

Goodin Fault Murchison Fault


thrust

latera

l ramp

Billara Fault Kinders Fault

NARRYER

TERRANE

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CRATON

Goodin F

ault

GOODIN

INLIER

Jenkin

Fault

Fault

Goodin

MARYMIA

INLIER

thrust ramp

Robinson Syncline

Peak Hill Anticline

Peak Hill Anticline

Horseshoe Anticline Millidie Syncline

Yarlarweelor gneiss belt

Marymia Inlier

40

MOUNT LEAKE FORMATION quartz arenite

DESPAIR GRANITE foliated to locally massive coarse-grained biotite granite late Archaean

30 km

Bangemall Group

Earaheedy Group

Padbury Group

Bryah Group

Mooloogool SubgroupDoolgunna_Thaduna Formations

Windplain Subgroup

Geological boundary

Fault

Finlayson Member quartz arenite

117frac34Yacute30Agrave


45Agrave118frac34Yacute00Agrave 15Agrave 30Agrave 45Agrave 119frac34Yacute00Agrave 15Agrave 119frac34Yacute30Agrave


15Agrave

30Agrave

45Agrave



119frac34Yacute30Agrave15Agrave119frac34Yacute00Agrave45Agrave15Agrave 30Agrave

118frac34Yacute00Agrave45Agrave117frac34Yacute30Agrave



45Agrave

30Agrave

15Agrave

Proterozoic granite

Q TR S

SEA LEVEL

5 km

11 km

F G

SEA LEVEL

5 km

11 km

L M O

SEA LEVEL

5 km

11 km

N

J K

SEA LEVEL

5 km

10 km

10 km

SEA LEVEL

5 km

H I

Archaean granitoid rock and greenstone

YerridaGroup

Maraloou_Killara Formations

SEA LEVEL

5 km

10 km

C D E

SEA LEVEL

5 km

10 km

A B

MILLIDIE CREEK FORMATION sandstone and shale minor granular iron-formation

ROBINSON RANGE FORMATION ferruginous shale and siltstone minor banded iron-formation

Beatty Park Member chloritic siltstone sandstone and breccia numerous mafic volcanic fragments

Heines Member quartz wacke siltstone and shale with minor polymictic conglomerate

LABOUCHERE FORMATION quartz wacke and siltstone local quartz pebble conglomerate layers turbiditic

KARALUNDI FORMATION sandstone with minor shale and conglomerate

JOHNSON CAIRN FORMATION siltstone and shale minor sandstone

JUDERINA FORMATION quartz wacke siltstone quartz arenite and quartz pebble conglomerate

PEAK HILL SCHIST quartz muscovite schist mylonitic schist and phyllonite

GEOLOGICAL SURVEY OF WESTERN AUSTRALIA REPORT 59 PLATE 1

BRYAH AND PADBURY BASINS REPORT 59 PLATE 1

2

Trillbar Complexwith local magmatic layering well-preserved

interleaved foliated and metamorphosed basalt gabbro microgabbro pyroxenite and serpentinized peridotite

HORSESHOE FORMATION ferruginous chloritic shale and quartzEcircfeldspar wacke partly manganiferous andcalcareous minor iron-formation and chert

BANGEMALL

EARAHEEDY

PADBURYBASIN

BASINBRYAH

YERRIDABASIN

WILTHORPE FORMATION quartz pebble to boulder conglomerate predominant vein quartz clasts and some chert quartz wackeand granitoid rock clasts quartz wacke and finely bedded siltstone locally chloritic graded beds

1 2 3 4

C

58

78

75

20

15

SHEET INDEX

intruded by granite during the Capricorn Orogeny

High-grade gneissic granite and granite foliated derived predominantly from biotite monzogranite with numerouslenses of supracrustal rocks early middle and late Archaean components overprinted by structures and

NARRACOOTA FORMATION metabasalt and maficEcircultramafic schist locally pillowed with interflow sedimentary layers

Capr

icorn

Oro

geny

Mar

ymia

Inlie

r_re

work

ed d

uring

the

met

amor

phism

_Ca

prico

rn O

roge

nyup

per g

reen

schist to

lowe

r am

phib

olite

facie

s

gree

nsto

ne b

eltM

ount

Mai

tland

2672YacuteucircYacute3

lt1996YacuteucircYacute35

High-grade granitic gneiss derived predominantly from biotite monzogranite with numerous lenses ofsupracrustal rocks early middle and late Archaean components includes Palaeoproterozoicgranite sheets and dykes extensively deformed during Capricorn Orogeny

SCHEMATIC TECTONIC RELATIONSHIPS

BANGEMALL BASIN

1600 Ma and youngerc

EARAHEEDY BASIN

2000 Ma and youngercBRYAH BASIN

2000 Mac

YERRIDA BASIN


YILGARN CRATON

2600 Ma and olderc

PADBURY BASINyounger than 2000 Ma

BASIN

BASIN

igraveAn

igraveAndigraveAnhigraveAnuigraveAnxigraveAncigraveAnt

igraveAnf

ntildeg

ntildegn

ntildeng

igraveM

igraveE

igraved

igraveg

igraveP

igravePm

igravePmi

igravePmc

igravePr

igravePrg

igravePri

igravePw

igravePwb

igravePwh

igravePl

igravePli

igravePla

igraveAh

igraveAhi

igraveAr

igraveArc

igraveAnigraveAnd igraveAnh igraveAnu igraveAnx igraveAnc igraveAnt

igraveAk

igraveYm

igraveYc

igraveYj

igraveYjf

ntildegMl

ntilderMM

ntildegde

igraveAnf

igravePi

ethp

ethpm

ntildegMli

ntildegMla

igraveYjf

igraveYjf

igraveYj

igraved

igraved

igraveYm

igravePmigravePrg

igravePrigravePri

igravePwh

igraveAn

igraveAk ethp

igraveAnh igraveAnd

ntildegMl

igraveAnh

igraveAnxigraveYcigraveYj

igraveYjf

igraveAn

ethp

igraveAr igraveAr

igravePwh

ethpm igraveAn

igraveAn

igraveM

igravePrigravePri

igravePriigravePr

igraveAr

igraveAn

ethp

ethpm

igravePriigravePr igravePri

igravePw

igravePligravePla

igraveAh

igraveAn

igraveArc igraveAn

igraveArcigraveAnf

igraveAnd

igraveM

igraved

igraveAhiigravePm

igravePl

igraveAn

igraveAr

igravePr

igravePriigravePl

igravePla igraveAhigraveAnc

igraveAn igraveAhigraveM

ntildegMl

igraveArc

ntildegMl

ntildegMl

ntildegMl

igraveAnd

igravePrigravePri

igravePwb

igravePl

igraveAn

igraveAhigravePwb

igravePr

igravePri

igravePmi

igraveAr

igraved

igraveAn

igravePm

igravePwb

igravePr

igravePr

igravePri

igravePwigraveAnu

igravePm

igravePmc

igraveAr

igraveAk

igravePw

igraveM

ntildegMla

ntildegntildeg

ntildeg

ntildegntildeng

igraveM igraveM

igravePligraveAhi

igraveAhigraveAh

igraveAn

igraveAnigraveAr

ntildegMl

ethp

ntildeng

igraved igraved

igraved

WA

NT

SA

NSW

Vic

Qld

Tas

ACT

GEOLO

G IC A L SUR VEY

WE

ST

E R N A U S T R AL

IA

GEOLOGICAL SURVEY OF

WESTERN AUSTRALIA

DAVID BLIGHT DIRECTOR

DEPARTMENT OF MINERALS

AND ENERGY

L C RANFORD DIRECTOR GENERAL

GOVERNMENT OF WESTERN AUSTRALIA

HON NORMAN MOORE MLC

MINISTER FOR MINES

Bangemall Group undivided

Mafic dyke interpreted from aeromagnetic data + positive anomaly - negative anomaly

Granite includes muscovite-bearing leucogranite and pegmatite

Padbury Group undivided metamorphosed and variably foliated metasedimentary rocks

Iron-formation and chert

Banded iron-formation minor ferruginous sandstone and shale

Bedded dolomite and dolomitic siltstone

Granular iron-formation

Banded iron-formation

Banded iron-formation and ferruginous chert

Quartz arenite minor interleaved quartz wacke and siltstone

Iron-formation and quartzEcircmagnetite(Ecircstilpnomelane) schist garnetiferous white chert in lenses

lithic wacke and siltstone turbiditic

Chert

Felsic schist derived from felsic volcanic and volcaniclastic rockDolerite in sills and dykesBasaltic hyaloclastiteMetaperidotite and picrite ultramafic schistBasaltic vent brecciaJasperoidal chert

Quartz mylonite

Foliated to mylonitic and massive granitoid rock

Amphibolite


Granite with minor greenstone locally overprinted by structures formed during Capricorn Orogeny

Basalt ultramafic rock dolerite felsic schist banded iron-formation and chert

RAVELSTONE FORMATION

MES

OPRO

TERO

ZOIC

PALA

EOPR

OTER

OZOI

CAR

CHAE

AN

Bang

emal

lGr

oup

Eara

heed

yGr

oup

Padb

ury G

roup

Brya

h Gr

oup

Yerri

da G

roup

Win

dpla

in S

ubgr

oup

Moo

loog

ool S

ubgr

oup

Yarla

rwee

lor g

neiss

belt

Narry

er T

erra

ne

lowe

r gre

ensc

hist to

upp

er a

mph

ibol

ite fa

cies

met

amor

phism

_Ca

prico

rn O

roge

ny

Mur

chiso

n Te

rrane

YILG

ARN

CRAT

ONYE

RRID

A BA

SIN

BRYA

H BA

SIN

preh

niteEcirc

pum

pelly

ite to

mid

-gre

ensc

hist fa

cies

met

amor

phism

_Ca

prico

rn O

roge

ny

PADB

URY

BASI

N

Undivided MARALOOU DOOLGUNNA THADUNA and KILLARA FORMATIONS

Contact Bryah Group_Padbury Group

Structural symbols are numbered according totheir age of formation where known

Middle Proterozoic

Early Proterozoic

interpreted movement

Fold showing direction of plunge

Small-scale fold axial surface showing strike and dip

Bedding showing strike and dip

Foliation showing strike and dip

Lineation showing direction of plunge

Single zircon UEcircPb SHRIMP geochronology data

Nutman A P Bennett V C Kinny P D and Price R 1993 Large scale crustalstructure of the northwestern Yilgarn Craton Western Australia evidence fromNd isotopic data and zircon geochronology Tectonics v12 p 971-981

Nelson D R 1997 Geological Survey of Western Australia Record 19972

Nelson D R in prep Geological Survey of Western Australia Record 19982Mineral occurrence

Edited by D Ferdinando and G Loan

Cartography by P Taylor and B Williams

Topography from the Department of Land Administration Sheets SG 50-7 -8 -11 -12with modifications from geological field survey

Published by the Geological Survey of Western Australia Copies available fromthe Information Centre Department of Minerals and Energy 100 Plain StreetEast Perth WA 6004 Phone (08) 9222 3459 Fax (08) 9222 3444

This map is also available in digital form

Printed by the Sands Print Group Western Australia

The recommended reference for this map isSWAGER C P OCCHIPINTI S A and PIRAJNO F 1998 Interpreted Geology of thePalaeoproterozoic Bryah and Padbury Basins Western Australia Geological Survey Report 59 Plate 1

Unconformity (section only)

unconformity with local major onlap reworked as a fault

Geological boundary

Edmund fold belt unspecified

Capricorn Orogeny unspecified

Capricorn Orogeny DOtilde DUcirc Dccedil Deacute

Fault

Reactivated normal fault

lateral (plan view) dip slip (section)

away from observer

Strongly foliated rock

anticline

syncline

overturned anticline

overturned syncline

towards observer

Minor fold showing direction of plunge

inclined

vertical

inclined

vertical

overturned

bedding or layering trend

inclined

vertical

trend (section only)

GSWA identification number

mineral lineation

intersection lineation

Nutman et al identification number

interpreted age of intrusion in Ma with reference number

youngest detrital zircon

Highway with national route marker

Formed road

Track

Landing ground

Townsite population less than 1000

Mineral field boundary

Homestead

Locality

Building yard

Microwave repeater station

Horizontal control major

Watercourse ephemeral pool

Waterhole spring

Bore well windpump

Dam tank

Abandoned position doubtful

Mining centre

Mining locality

Mine (gold unless otherwise indicated)

Major opencut

Opencut

Alluvial workings

Prospect

Copper

Gold

Manganese

Talc

PILBARACRATON

CAPRICORN OROGEN

CRATONYILGARN

0 5 10 15 20 255000

Metres Kilometres

VERTICAL DATUM AUSTRALIAN HEIGHT DATUM

SCALE 1Yacute250Yacute000

Grid lines indicate 20Yacute000 metre interval of the Map Grid Australia Zone 50

HORIZONTAL DATUM GEOCENTRIC DATUM OF AUSTRALIA 1994UNIVERSAL TRANSVERSE MERCATOR PROJECTION

The Map Grid Australia (MGA) is based on the Geocentric Datum of Australia 1994 (GDA94)

GEOCENTRIC DATUM OF AUSTRALIA

GDA94 positions are compatible within one metre of the datum WGS84 positions

Reference points to align maps based on the previous datum AGD84 have been placed near the map corners


REPORT 59 PLATE 1

BRYAH AND PADBURY BASINS

2344

2345

2346

2347

2444

2445

2446

2447

2544

2545

2546

2547

2644

2645

2646

2647

2744

2745

2746

2747

2844

2845

2846

2847

KALLI

MILEURA

GOULD

ERRABIDDY

MADOONGA

KOONMARRA

MOORARIE

MARQUIS

MEEKATHARRA

TIERACO

PADBURY

MILGUN

GABANINTHA

GLENGARRY

BRYAH

JAMINDI

YAGANOO

MOOLOOGOOL

DOOLGUNNA

MEREWETHER

THADUNA

MARYMIA

MOUNT BARTLE

THREE RIVERS

118958

88YacuteEcirc168

BELELE GLENGARRY

ROBINSON RANGE PEAK HILL

SG 50-7 SG 50-8

SG 50-11 SG 50-12

1100Yacute000 maps shown in black

Compiled by C P Swager S A Occhipinti and F Pirajno 1997

N

P

Geology from 1100Yacute000 GSWA maps (see sheet index)

See current GSWA map catalogue for the full range of published products

and by S A Occhipinti C P Swager 1995 1997 and J S Myers 1995

Published 1100Yacute000 maps used in compilation

1250Yacute000 maps shown in brown

+ means declination is east and correction must be

subtracted from compass bearing to give true bearing

Annual change is 1Agrave easterly

The lines indicate magnetic declination 1995

added to compass bearing to give true bearing

- means declination is west and correction must be

SEA LEVEL

5 km

11 km

brvbar Western Australia 1998

117frac34 30Agrave25frac3400Agrave

118frac3400Agrave 119frac3400Agrave 120frac3400Agrave

26frac3400Agrave

INTERPRETED GEOLOGY OF THE PALAEOPROTEROZOIC

AREA OF THIS MAP

GSWA

REPORT 60

PLATE 1

E

Version 11 _ May 2004

Q

R

S

T

F

G

L

M

O

P

N

J

K

C

D

E

A

B

H

I

1 2 3

1

2

3

cc 3300

1






3

cc 3300

1

3300

1









Report 59 Geology and mineralization of the Palaeoproterozoic Bryah and Padbury Basins Western Australia

Contents

Abstract

Introduction

Regional tectonic setting

Geology stratigraphy and geochronology

Peak Hill Schist and Marymia Inlier

Bryah Group

Karalundi Formation






Felsic schist



Jasperoidal chert



Horseshoe Formation

Padbury Group


Wilthorpe Formation





Structure

D1 structures

D2 structures

D3 structures and their relationship to D2 structures

D4 structures

Metamorphism

Structural synthesis

Mineralization

Gold deposits

Peak Hill Jubilee and Mount Pleasant deposits

Harmony deposit

Labouchere Nathans and Fortnum deposits

Wembley deposit

Wilgeena deposit

Durack St Crispin and Heines Find prospects

Ruby Well group

Mikhaburra deposit

Wilthorpe deposit

Cashman deposit

Volcanogenic copperndashgold deposits

Supergene manganese deposits

Iron ore

Talc

Discussion

Tectonic model and conclusions

Acknowledgements

References

Appendix Gazetteer of localities

Plate 1 Interpreted geology of the Palaeoproterozoic Bryah and Padbury Basins

Figures


Figure 2 Simplified geology of the Bryah Padbury and Yerrida Basins

Figure 3 Rotated orthoclase porphyroblast Peak Hill Schist

Figure 4 Partially recrystallized mylonite Peak Hill Schist

Figure 5 Peak Hill Schist mylonite from the Hangingwall Sequence

Figure 6 Outcrop of quartz mylonite Peak Hill Schist

Figure 7 Peak Hill Schist (Crispin Mylonite) illustrating a typical mylonitic fabric

Figure 8 Maficndashultramafic volcanic rocks of the Narracoota Formation (Dimble Belt)

Figure 9 Basaltic hyaloclastite Narracoota Formation

Figure 10 Mafic volcaniclastic rock Narracoota Formation

Figure 11 Volcanic breccia intersected in diamond drillhole BD1

Figure 12 Total alkali versus silica diagram for rocks the Narracoota Formation

Figure 13 Total alkali versus silica diagram defining limits of alkaline and subalkaline basalts of the Narracoota Formation

Figure 14 Geochemical characteristics of the Narracoota Formation rocks

Figure 15 Geochemical discriminant plots for Narracoota Formation

Figure 16 TiO2 versus FeOMgO plot for maficndashultramafic rocks of the Narracoota Formation

Figure 17 Schematic stratigraphy of the Horseshoe Formation

Figure 18 Major regional structures in the Bryah and Padbury Groups

Figure 19 Simplified geological map of the Bryah and Padbury Groups

Figure 20 Selected hypothetical cross sections through the Bryah and Padbury Groups

Figure 21 Model of the structural development of the BryahndashPadbury Group succession

Figure 22 New model of the structural development of the BryahndashPadbury Group succession

Figure 23 New model for the structural development of the BryahndashPadbury Group succession and the Peak Hill Schist

Figure 24 Schematic north-northwest to south-southeast cross section from the Bangemall Basin into the Yarlarweelor gneiss complex and then into the Bryah and Padbury Basins

Figure 25 Distribution of mineral deposits and occurrences in the BryahndashPadbury and Yerrida Basins

Figure 26 Distribution of mineral deposits and occurrences in the Bryah Group within the BRYAH 1100 000 map sheet

Figure 27 Albite porphyroblasts in mylonitic schist at Mount Pleasant

Figure 28 The Mine Sequence schist

Figure 29 Schematic geological map of the Fiveways Main and Mini opencuts Peak Hill deposit

Figure 30 Peak Hill Mini opencut showing the ore-bearing mylonitic schist graphitic schist and Marker quartzite unit

Figure 31 Diagrammatic cross section of the Harmony ore zones

Figure 32 The west wall opencut showing the contact between biotitendashsericitendashquartz schist and deformed Despair Granite

Figure 33 Sketch illustrating a conceptual model for the origin of precious and base metal deposits in the BryahndashPadbury and Yerrida Basins

Figure 34 Schematic illustration showing the preferred model of the tectonic evolution of the Bryah and Padbury Basins within the context of the Capricorn Orogen

Tables




Table 4 Selected geochemical parameters for the Narracoota Formation

Table 5 Sequence of deformation events in the Bryah and Padbury Basins

Table 6 Mineral paragenesis of the Bryah Group and relationships between diagnostic metamorphic minerals of the Bryah Group and deformation fabrics




GEOCHEMICAL ANALYSES OF ROCKS FROM THE NARRACOOTA FORMATION For details of analytical techniques see in text of Report 59

Sample Easting Northing SiO2 TiO2 Al2O3 Fe2O3 FeO MnO MgO CaO Na2O K2O P2O5 LOI H2O- H2O+ TOTAL CO2 Ag As Au Ba Bi Cd Ce Cr Co Cu Ga Ge La Li Mo Mn Nb Ni Pb Pd Pt Rb Sb Sc Sn Sr Ta Te Th Ti U V Y W Zn Zr Hf Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

86342 746314 7198282 5151 032 1523 928 018 1049 1007 269 019 003 673 166 1 95 12 11

86383 670171 7163822 5353 091 1468 115 019 744 863 299 005 008 253 100 1 85 21 53

86384 670171 7163822 5048 062 1444 991 016 1135 933 362 004 005 640 209 1 157 16 33

86397 799422 7201118 5529 026 1502 817 017 1136 416 549 005 002 1174 244 0 44 15 8

104248 722651 7168587 4925 022 1137 963 017 1818 948 159 009 002 1 80 9 6

104249 722651 7168587 4911 026 1065 973 017 2016 855 126 009 003 1 34 11 7

104254 715830 7171470 4948 023 1121 95 016 2035 706 194 005 002 1877 647 1 49 11 7

104255 715830 7171470 52 033 143 847 017 1071 1087 31 002 003 664 209 0 133 13 13

104256 715830 7171470 5244 067 1455 1007 019 834 983 376 007 007 0 140 17 34

104257 713820 7171502 5144 092 1453 1078 02 689 1244 248 023 009 265 79 3 195 18 53

104264 685287 7155494 5303 062 1391 94 017 768 1239 265 01 006 720 222 1 90 15 32

104265 685287 7155494 5332 025 1592 97 017 658 1215 184 003 004 353 67 1 30 15 11

104288 661877 7126843 5979 024 1346 798 016 522 1265 042 004 004 283 46 0 17 15 11

104289 656054 7130760 5446 014 1559 955 017 826 957 204 019 003 358 116 4 43 8 6

104292 657132 7123177 5103 09 1369 971 017 827 1334 272 009 008 0 165 18 51

104294 664424 7119210 5108 095 1449 1021 018 879 1094 283 046 008 523 141 5 123 19 52

104295 664424 7119210 5228 096 1446 1022 018 946 856 364 016 009 465 132 2 79 19 54

104298 669014 7106533 5233 087 1367 939 017 778 1189 373 01 008 514 116 1 116 17 49

104299 669014 7106533 5166 093 1404 982 018 823 1183 305 017 009 491 117 3 124 18 53

104300 669014 7106533 477 05 173 984 019 747 1484 197 016 004 3 142 12 22

104386 676392 7146500 5373 037 1501 846 016 864 977 373 009 004 557 152 0 106 18 18

104391 687552 7144198 5002 023 845 934 016 2281 88 014 002 002 0 15 11 6

104392 687552 7144198 5391 027 92 998 014 2087 515 017 027 003 2508 1103 12 16 22 10

104393 687539 7143275 508 023 965 1025 01 289 004 0 001 001 0 3 5 6

104394 687539 7143275 5594 05 1494 867 019 73 697 537 006 006 363 88 0 90 19 24

104397 670399 7142584 4687 019 1023 1015 017 2496 726 015 001 001 2786 971 0 7 8 4

104398 669575 7143518 5329 035 1453 813 014 828 1207 315 002 004 574 124 0 78 13 14

104399 670423 7144430 5183 036 1491 866 016 932 1147 323 002 003 682 173 0 42 14 14

104400 670023 7145280 4958 037 1577 987 019 1044 1082 291 002 003 510 124 0 68 17 15

109487 638809 7157725 5719 043 1423 73 013 868 626 569 004 004 442 116 0 18 11 19

109492 663796 7149130 5231 011 617 72 015 24 1002 001 001 001 0 7 5 1

109493 663796 7149130 5246 047 1508 881 019 766 1218 247 064 005 478 90 6 72 15 21

109504 670124 7121353 5396 048 149 859 015 716 1237 231 003 005 445 96 0 61 17 22

109513 732634 7164722 5396 197 1434 953 02 638 686 592 064 019 16 117 24 97

112601 668775 7146298 5332 179 1568 102 025 644 561 601 053 017 10 105 21 90

112603 672130 7147178 108 034 2 1698 lt10 462 lt4 lt5 lt6 559 54 12 lt3 6 lt2 lt7 115 lt4 87 4 lt4 114 lt5 lt6 lt2 lt2 167 19 92 203

112604 672238 7155486 202 lt001 3 lt4 40 34 8 lt5 73 3639 69 16 lt3 38 lt2 lt7 143 20 lt2 lt4 lt4 10 lt5 lt6 lt2 lt2 453 29 20 34

112620 626709 7204920 33 001 2 lt4 220 35 lt4 lt5 19 1377 78 22 lt3 25 lt2 9 127 26 lt2 lt4 lt4 10 lt5 lt6 10 lt2 358 22 13 182

112621 626709 7204920 116 011 1 144 lt10 lt11 lt4 lt5 lt6 2354 82 8 lt3 lt5 lt2 lt7 1589 lt4 lt2 9 lt4 11 lt5 lt6 lt2 lt2 131 6 72 20

112624 661284 7183319 507 074 139 274 769 018 791 104 244 025 007 358 1007 1 lt4 lt10 54 lt4 lt5 lt6 186 92 13 lt3 lt5 lt2 lt7 96 lt4 6 lt4 lt4 97 lt5 lt6 lt2 lt2 264 18 77 51


112628 661284 7183319 49 08 138 357 726 018 738 14 143 008 007 277 1006 2 lt4 lt10 147 lt4 lt5 6 167 91 14 lt3 lt5 lt2 lt7 101 lt4 lt2 lt4 lt4 310 lt5 lt6 lt2 lt2 265 19 77 63

112629 661284 7183319 642 049 103 271 402 012 438 113 051 013 005 18 1001 lt1 lt4 lt10 109 lt4 lt5 lt6 113 58 12 lt3 lt5 lt2 lt7 60 lt4 2 lt4 lt4 86 lt5 lt6 lt2 lt2 166 11 50 39

112640 675227 7128672 49 052 147 272 517 014 915 148 142 011 005 221 1002 1 lt4 lt10 90 lt4 lt5 lt6 277 38 13 lt3 lt5 lt2 lt7 160 lt4 2 5 lt4 184 lt5 lt6 lt2 lt2 212 11 54 37

112641 675215 7127749 508 079 142 308 703 017 744 118 207 012 008 299 1008 1 lt4 90 26 lt4 lt5 lt6 266 102 14 lt3 lt5 lt2 lt7 120 lt4 lt2 lt4 lt4 148 lt5 lt6 lt2 lt2 258 16 80 63

112643 675190 7125902 275 205 lt1 10 40 767 lt4 lt5 175 994 257 12 3 12 2 lt7 lt3 34 lt2 lt4 lt4 43 lt5 lt6 lt2 lt2 272 13 96 25

112645 663956 7162053 23 059 lt1 7 lt10 227 lt4 lt5 34 2117 390 3 12 lt2 8 lt3 12 lt2 lt4 8 10 lt5 lt6 6 lt2 467 14 81 132

112646 663956 7162053 507 076 139 224 796 018 771 991 258 063 007 375 1005 1 lt4 lt10 164 lt4 lt5 6 207 79 13 lt3 lt5 lt2 lt7 123 lt4 16 lt4 lt4 338 lt5 lt6 lt2 lt2 245 15 77 55

112647 663956 7162053 356 002 1 133 1170 lt11 lt4 lt5 13 489 846 6 4 6 lt2 lt7 533 1491 lt2 4 lt4 lt2 lt5 8 lt2 lt2 104 12 180 8

112650 663956 7162053 573 424 959 166 036 lt005 12 226 012 028 005 75 999 1 lt4 lt10 423 lt4 lt5 152 481 119 20 lt3 90 lt2 27 171 10 12 lt4 lt4 61 lt5 lt6 6 lt2 365 37 54 296

112652 663956 7162053 526 088 133 253 762 022 745 741 31 081 008 474 1009 1 lt4 lt10 242 lt4 lt5 lt6 149 158 12 lt3 lt5 lt2 lt7 99 6 17 5 lt4 87 lt5 lt6 2 lt2 260 22 88 63

112672 734725 7164593 628 07 136 355 364 034 337 494 286 093 009 313 1001 1 lt4 20 258 lt4 lt5 76 122 16 17 lt3 34 lt2 17 75 13 19 lt4 4 164 lt5 lt6 22 2 99 26 73 216

112673 734708 7165209 69 108 111 258 508 009 415 016 312 036 007 361 1006 1 lt4 lt10 386 lt4 lt5 30 56 lt4 14 lt3 18 lt2 17 24 lt4 17 lt4 lt4 79 lt5 lt6 8 lt2 239 19 79 119

112673 734708 7165209 633 136 113 297 736 012 617 025 21 012 018 499 1004 1 lt4 20 460 lt4 lt5 18 19 56 14 lt3 10 lt2 17 32 12 4 lt4 lt4 30 lt5 lt6 9 3 312 32 109 153

112674 734644 7166319 631 137 115 248 803 009 662 024 211 lt005 016 496 1008 1 lt4 20 28 lt4 lt5 37 21 203 17 lt3 17 3 19 30 6 lt2 lt4 lt4 27 lt5 lt6 9 3 336 24 107 158

112674 734644 7166319 129 697 lt1 4 1250 1768 lt4 lt5 69 597 472 11 lt3 53 lt2 lt7 327 22 90 lt4 lt4 226 lt5 lt6 8 2 181 19 118 101

112675 734644 7166319 569 025 767 183 429 013 153 768 303 007 lt005 396 1013 1 lt4 lt10 55 lt4 lt5 lt6 541 26 4 lt3 lt5 lt2 lt7 262 lt4 2 lt4 lt4 22 lt5 lt6 lt2 lt2 117 9 46 13

112678 734655 7166965 715 009 411 133 335 006 112 341 016 lt005 lt005 442 999 1 lt4 lt10 32 lt4 lt5 lt6 1537 11 3 lt3 lt5 lt2 lt7 659 lt4 lt2 lt4 lt4 4 lt5 lt6 lt2 lt2 69 5 33 8


112680 735675 7172519 515 037 148 282 565 015 864 991 357 lt005 lt005 314 1008 1 lt4 lt10 83 lt4 lt5 lt6 470 88 12 lt3 lt5 lt2 lt7 192 lt4 lt2 5 lt4 88 lt5 lt6 lt2 lt2 216 17 62 23

116407 603693 7169737 279 lt001 1 4 lt10 126 lt4 lt5 12 140 34 lt3 3 7 lt2 11 191 7 lt2 lt4 lt4 7 lt5 lt6 3 lt2 36 11 21 5

116410 608442 7170499 211 lt01 lt1 lt4 lt10 726 lt4 lt5 6 696 17 lt3 lt3 5 lt2 lt7 82 4 lt2 lt4 lt4 24 lt5 lt6 2 lt2 40 5 10 lt5

116415 611248 7168937 904 lt005 265 094 095 lt005 248 005 005 lt005 lt005 263 1005 lt1 4 lt10 947 lt4 lt5 lt6 944 13 lt3 lt3 5 lt2 lt7 394 lt4 lt2 lt4 lt4 28 lt5 lt6 lt2 lt2 35 7 22 lt5

116428 614781 7170999 484 016 723 188 628 014 215 813 077 lt005 lt005 61 1011 1 4 lt10 14 lt4 lt5 lt6 2275 12 4 lt3 lt5 lt2 lt7 998 lt4 lt2 lt4 lt4 22 lt5 lt6 lt2 lt2 126 8 60 11

116429 614810 7171215 113 029 13 129 10 66 lt4 lt5 lt6 2489 60 7 lt5 15 lt7 1344 lt4 3 89 25 lt4 75 lt5 8 lt2 lt2 183 11 127 14

116430 614807 7170845 217 002 10 12 2570 32 lt4 lt5 22 1581 463 4 lt5 lt6 lt7 286 109 lt2 lt4 53 lt4 lt2 lt5 lt6 lt2 lt2 348 13 95 23

116432 614348 7169311 101 009 6 5 80 44 lt4 lt5 15 1757 116 lt3 7 lt6 11 683 lt4 lt2 lt4 37 lt4 27 lt5 lt6 lt2 lt2 327 18 119 86

116433 614232 7168820 211 029 lt5 7 60 2075 lt4 lt5 35 254 126 5 26 lt6 13 186 13 27 4 12 lt4 56 lt5 lt6 4 lt2 152 25 120 100

116442 632664 7159418 414 022 21 7 10 710 lt4 lt5 lt6 39 716 lt3 lt5 lt6 lt7 35 4 lt2 lt4 40 lt4 28 lt5 6 lt2 lt2 1073 16 137 23

116443 634091 7159896 461 035 144 279 528 018 746 165 174 005 lt005 545 1005 2 lt4 lt10 23 lt4 lt5 lt6 443 62 15 lt3 lt5 lt2 lt7 164 lt4 lt2 lt4 lt4 63 lt5 lt6 lt2 lt2 233 17 56 22

116444 633832 7161837 11 021 lt1 13 lt10 1185 lt4 lt5 42 173 66 13 lt3 24 lt2 14 67 10 23 lt4 lt4 28 lt5 lt6 4 lt2 245 18 61 87


116454 653363 7152948 174 01 lt1 15 130 111 lt4 lt5 lt6 389 106 21 lt3 lt5 lt2 lt7 204 lt4 16 lt4 lt4 12 lt5 lt6 lt2 lt2 450 10 122 55

116477 645436 7177439 178 007 lt1 lt4 30 52 lt4 lt5 lt6 689 88 21 lt3 55 lt2 lt7 456 5 13 lt4 lt4 5 lt5 lt6 lt2 lt2 435 98 350 69

116485 655767 7129994 225 018 lt1 lt4 lt10 78 lt4 lt5 lt6 5612 129 8 3 lt5 2 7 88 4 lt2 lt4 lt4 7 lt5 lt6 lt2 lt2 119 7 39 38

116487 655561 7129043 168 013 1 lt4 lt10 191 lt4 lt5 11 4578 8 6 lt3 lt5 lt2 lt7 464 11 10 lt4 lt4 11 lt5 lt6 lt2 lt2 87 7 70 35

116488 655420 7128860 156 012 lt1 lt4 40 119 lt4 lt5 19 135 279 31 lt3 7 2 7 313 21 23 lt4 lt4 15 lt5 lt6 3 3 585 10 97 149

116489 655489 7127659 128 007 lt1 lt4 170 169 lt4 lt5 lt6 5588 63 4 lt3 lt5 lt2 lt7 687 14 12 lt4 lt4 6 lt5 8 2 2 75 7 81 30

116489 655489 7127659 681 02 2 8 lt10 34 lt4 lt5 lt6 967 299 6 lt3 9 lt2 lt7 348 lt4 lt2 lt4 lt4 lt2 lt5 lt6 lt2 lt2 469 35 110 37

116490 655978 7126699 491 078 147 315 779 017 816 994 274 065 008 371 1012 1 lt4 20 228 lt4 lt5 lt6 191 103 13 lt3 lt5 lt2 lt7 116 lt4 9 lt4 lt4 300 lt5 lt6 lt2 lt2 267 17 87 56

116491 656084 7126206 50 07 133 216 817 019 999 939 208 035 007 402 1007 1 lt4 10 329 lt4 lt5 lt6 471 104 12 lt3 lt5 lt2 lt7 249 lt4 6 4 lt4 157 lt5 lt6 lt2 lt2 241 16 82 49

116492 656023 7125806 10 27 10 213 lt4 lt5 lt6 17 170 lt3 lt5 7 lt7 40 lt4 49 4 49 lt4 38 803 lt6 lt2 lt2 434 28 45 58

116493 655992 7125530 13 25 60 150 lt4 lt5 lt6 24 393 lt3 6 10 lt7 118 6 79 lt4 55 lt4 31 269 lt6 lt2 lt2 464 37 239 67

116498 709849 7162239 11 19 5000 269 lt4 lt5 lt6 140 92 lt3 lt5 6 lt7 83 lt4 74 lt4 47 lt4 50 301 lt6 lt2 lt2 316 25 123 67

116500 709011 7162160 9 29 10 155 lt4 lt5 lt6 27 121 lt3 lt5 6 lt7 39 5 33 lt4 66 lt4 20 155 lt6 lt2 lt2 535 34 28 86

116501 708508 7162137 11 6 20 23 lt4 lt5 lt6 29 146 lt3 lt5 6 lt7 102 lt4 98 lt4 57 lt4 31 195 6 lt2 lt2 416 35 144 74

116502 708368 7162139 756 052 lt1 8 lt10 368 lt4 lt5 11 25 398 lt3 lt3 12 2 lt7 151 6 lt2 lt4 4 23 lt5 lt6 lt2 lt2 207 15 211 13


120337 668950 7146475 508 075 142 254 825 019 774 103 223 024 007 342 nd 4 lt4 lt10 140 lt4 lt5 lt6 168 nd 117 13 lt5 nd lt2 lt7 104 lt4 nd nd 5 lt4 nd lt4 129 lt2 44963 lt2 275 21 nd 94 59

120340 669175 7145725 505 077 144 347 666 015 731 118 234 008 007 314 1009 1 lt4 lt10 625 lt4 lt5 7 263 92 14 lt3 lt5 lt2 lt7 118 lt4 4 4 lt4 132 lt5 lt6 2 lt2 259 18 76 57

120369 665175 7156150 505 077 144 347 666 015 731 118 234 008 007 314 nd 1 lt4 lt10 625 lt4 lt5 7 263 nd 92 14 lt5 nd lt2 lt7 118 lt4 nd nd 4 40 nd lt4 132 2 46162 lt2 259 18 nd 76 57

120373 675250 7167875 50 078 146 288 732 017 757 112 256 lt005 008 328 328 1006 nd lt1 lt4 lt10 101 lt4 lt5 lt6 224 nd 100 14 lt3 lt5 nd lt2 lt7 125 lt4 nd nd lt2 lt4 nd lt4 120 lt5 lt6 lt2 46761 lt2 262 16 nd 84 57

120432 673950 7171700 52 077 146 219 763 015 753 793 429 lt005 008 326 326 1006 nd 1 4 lt10 126 lt4 lt5 lt6 266 nd 109 12 lt3 lt5 nd lt2 lt7 123 lt4 nd nd lt2 lt4 nd lt4 97 lt5 lt6 lt2 46162 lt2 257 21 nd 84 59

120549 709110 7163260 851 045 827 064 028 lt005 066 02 025 252 lt005 211 1007 1 lt4 lt10 516 lt4 lt5 49 56 lt4 10 lt3 18 lt2 9 17 18 135 5 lt4 13 lt5 lt6 13 5 139 21 8 114

120550 709190 7162721 516 087 135 324 901 021 646 957 246 031 008 362 101 1 4 lt10 145 lt4 lt5 lt6 17 70 15 lt3 lt5 lt2 lt7 70 lt4 7 lt4 lt4 93 lt5 lt6 2 52157 lt2 267 20 85 62

120566 734201 7165328 733 003 1 lt4 10 261 lt4 lt5 8 257 24 24 lt3 lt5 2 8 97 12 lt2 lt4 lt4 376 lt5 lt6 lt2 lt2 962 5 59 61

120593 707343 7160447 48 046 116 248 735 017 14 101 148 lt005 005 464 1007 lt1 lt4 lt10 35 lt4 lt5 lt6 1617 39 11 lt3 lt5 lt2 lt7 611 lt4 lt2 lt4 lt4 91 lt5 lt6 lt2 lt2 220 13 72 37

120630 722750 7168750 38 014 733 088 695 014 207 725 095 lt005 lt005 18 1009 1 lt4 10 41 lt4 lt5 lt6 2746 46 6 lt3 lt5 lt2 lt7 1110 lt4 lt2 lt4 lt4 32 lt5 lt6 lt2 lt2 137 6 56 13

120688 739099 7173927 521 084 139 322 775 017 658 104 288 017 008 277 101 lt1 lt4 lt10 86 lt4 lt5 lt6 160 35 13 lt3 lt5 lt2 lt7 133 lt4 lt2 lt4 lt4 124 lt5 lt6 lt2 lt2 317 20 78 59

120692 738903 7174351 496 032 134 271 658 015 115 101 223 009 lt005 405 101 lt1 lt4 lt10 149 lt4 lt5 lt6 941 57 12 lt3 lt5 lt2 lt7 334 lt4 lt2 lt4 lt4 129 lt5 lt6 lt2 lt2 205 13 61 32

120698 735588 7172781 546 059 136 26 576 014 727 101 346 006 006 246 1008 lt1 15 lt10 71 lt4 lt5 lt6 315 60 11 lt3 lt5 lt2 lt7 100 lt4 lt2 lt4 lt4 67 lt5 lt6 lt2 lt2 228 16 65 44

120727 456 015 815 227 694 016 225 686 045 lt005 lt005 726 1009 lt1 lt4 lt10 27 lt4 lt5 lt6 2788 31 6 lt3 lt5 lt2 lt7 1075 lt4 lt2 lt4 lt4 14 lt5 lt6 lt2 lt2 141 7 69 25

120728 687200 7128470 545 04 141 225 609 015 916 624 5 lt005 005 324 1014 lt1 23 lt10 61 lt4 lt5 lt6 479 103 7 lt3 lt5 lt2 lt7 202 lt4 lt2 lt4 lt4 68 lt5 lt6 lt2 lt2 213 14 70 36

120729 686100 7128750 833 027 1 814 lt10 298 lt4 lt5 lt6 2024 80 4 lt3 lt5 lt2 9 796 4 46 17 lt4 46 lt5 lt6 lt2 lt2 115 15 50 13

120730 686300 7128650 383 003 1 9 lt10 73 lt4 lt5 lt6 3998 203 5 lt3 lt5 lt2 15 1785 lt4 lt2 4 lt4 8 lt5 lt6 lt2 lt2 270 19 108 8

120770 675368 7143153 11 138 lt1 246 lt10 458 lt4 lt5 lt6 1351 50 7 lt3 lt5 lt2 12 259 4 57 5 lt4 114 lt5 6 lt2 lt2 155 9 45 31

120801 686900 7143160 916 213 1 169 660 1736 lt4 lt5 66 1275 594 5 lt3 26 lt2 13 101 24 41 lt4 lt4 94 lt5 11 lt2 lt2 147 35 98 37


120873 697233 7155938 518 133 142 374 907 02 572 106 23 044 016 117 1009 lt1 lt4 lt10 204 lt4 lt5 23 72 232 18 lt3 8 lt2 lt7 58 lt4 40 lt4 lt4 134 lt5 lt6 3 lt2 239 33 95 108



120877 694754 7155096 509 085 142 399 735 018 709 105 209 034 008 34 1011 lt1 lt4 lt10 103 lt4 lt5 lt6 119 158 15 lt3 lt5 lt2 lt7 107 lt4 4 lt4 lt4 182 lt5 lt6 2 lt2 269 19 95 70


120891 677938 7168840 4880 082 1430 385 717 018 765 1280 174 008 008 330 10077 1 4 10 86 4 5 6 137 107 15 5 2 7 105 4 2 4 4 142 2 2 257 24 83 60

124203 685884 7169152 496 089 14 329 852 02 733 981 233 009 008 36 998 lt1 lt4 lt10 53 lt4 lt5 lt6 65 122 14 lt3 lt5 lt2 lt7 91 lt4 lt2 lt4 lt4 124 lt5 lt6 2 lt2 280 19 104 66



132787 630625 7198600 492 07 142 265 735 017 857 126 176 009 006 335 1008 1 lt4 lt10 75 lt4 lt5 lt6 136 105 16 lt3 lt5 lt2 lt7 158 5 lt2 lt4 lt4 126 lt5 lt6 lt2 lt2 247 17 70 52

132788 630625 7198600 218 lt001 lt1 lt4 lt10 864 lt4 lt5 lt6 454 9 lt3 lt3 lt5 lt2 lt7 67 lt4 lt2 lt4 lt4 9 lt5 lt6 2 lt2 41 3 7 lt5

132789 602460 7168288 556 021 138 329 587 016 612 111 131 lt005 lt005 303 303 1005 nd lt1 lt4 lt10 130 lt4 lt5 lt6 158 nd 76 8 lt3 lt5 nd lt2 lt7 98 lt4 nd nd lt2 lt4 nd lt4 16 lt2 12590 lt2 204 13 nd 72 17

132790 613877 7170789 527 035 138 239 605 016 83 113 189 lt005 lt005 338 338 1006 nd lt1 lt4 lt10 81 lt4 lt5 lt6 503 nd 81 10 lt5 nd lt2 lt7 190 lt4 nd nd lt2 lt4 nd lt4 27 lt5 9 lt2 20983 lt2 211 14 nd 65 24

132791 621561 7169810 499 057 133 308 649 015 96 121 204 005 006 316 316 1007 nd lt1 4 lt10 71 lt4 lt5 lt6 633 nd 80 12 lt3 lt5 nd lt2 lt7 281 lt4 nd nd lt2 lt4 nd lt4 75 lt5 lt6 lt2 34172 lt2 233 16 nd 74 40

132792 616685 7171750 503 084 134 527 637 017 813 104 107 005 007 432 1006 lt1 lt4 lt10 12 lt4 lt5 lt6 314 144 13 lt3 6 lt2 lt7 204 5 lt2 lt4 lt4 114 lt5 lt6 lt2 lt2 285 28 95 59

132793 622866 7161836 4860 031 1350 362 510 013 1040 1090 231 001 003 321 9812 2 4 3 29 4 5 6 872 45 61 11 3 97 7 379 4 3 2 2 4 4 72 2 2 216 14 4 60 21

132794 622866 7161786 4840 014 576 203 615 015 2160 863 033 001 001 549 9870 2 4 4 11 6 5 6 2460 71 22 5 3 2 7 1020 4 4 3 2 4 4 11 2 2 155 7 4 63 13

133033 638351 7157551 4450 156 1110 611 440 020 318 1330 468 034 021 906 9864 01 05 5 323 07 01 296 190 36 84 05 126 01 11 75 19 11 11 51 02 1 07 135 22 07 276 241 05 73 108

133034 638351 7157551 4710 013 836 237 696 014 1980 764 012 001 003 596 9862 02 12 2 18 45 01 32 3448 69 22 16 16 23 32 1048 11 5 9 17 18 42 19 52 15 01 133 58 84 72 108

133035 638300 7157750 4740 013 668 349 512 014 2200 801 022 003 001 521 9844 02 07 6 52 14 01 11 2608 73 34 22 12 03 33 1295 15 10 9 22 06 29 1 12 16 02 116 72 58 61 447

133038 632615 7159390 5060 048 1600 316 443 012 572 1410 150 032 006 267 022 102 lt05 70 110 lt05 lt01 216 392 29 93 57 147 10 12 28 138 29 lt2 3 179 297 31 74 141 21 28776 02 181 14 139 59 709

133039 632600 7159000 5160 034 1550 281 555 014 644 1090 252 026 002 309 026 lt01 lt05 30 80 lt05 lt01 06 422 36 88 47 lt05 6 05 33 183 lt05 lt2 lt2 46 115 32 29 139 lt05 20383 lt01 216 148 77 66 338

133043 632906 7159832 4970 073 1490 272 790 018 626 1260 171 031 006 236 022 03 21 30 412 09 01 46 66 37 129 05 61 8 06 41 121 48 lt2 9 99 44 11 27 119 13 43764 02 268 203 33 88 470

133046 633939 7161905 4980 051 1280 263 708 016 1070 1060 163 014 005 309 016 lt01 lt05 lt2 48 lt05 lt01 18 678 43 85 47 53 8 04 05 327 lt05 lt2 lt2 06 68 34 15 123 lt05 30575 lt01 227 147 51 76 443

133047 633939 7161905 5200 079 1400 280 738 017 548 1080 227 039 007 264 022 118 lt05 lt2 60 lt05 lt01 36 116 36 74 56 48 12 04 44 81 lt05 lt2 lt2 95 46 38 09 101 lt05 47361 lt01 261 193 45 77 673

133048 633939 7161905 4800 053 1050 391 746 018 972 1360 100 034 004 390 015 lt01 lt05 30 63 lt05 lt01 37 200 55 192 55 10 11 02 19 156 36 lt2 3 55 08 43 lt05 110 lt05 31774 lt01 276 126 12 76 410

133049 634427 7166123 4900 059 1390 361 656 016 658 1300 190 019 005 328 015 lt01 lt05 30 45 lt05 lt01 25 120 42 164 66 12 10 07 32 143 24 lt2 lt2 20 33 24 lt05 101 lt05 35371 lt01 220 145 82 67 442


133051 635603 7169579 0 74 0 02 15 12 114 114 24 91 13 05 84 73 27 12 11 24 0 40 15 158 173 043 256 18 05 74 62

133052 635259 7169444 5160 086 1360 411 719 016 569 1030 155 048 008 344 9906 038 01 05 2 151 05 01 94 148 37 136 33 11 03 34 93 05 2 2 105 02 24 05 145 05 01 296 191 05 85 718

133054 634952 7169267 0 62 05 0 38 5 105 44 18 25 41 12 13 57 48 5 6 12 0 26 18 411 6 166 182 18 08 38 104

133060 648256 7160919 0 23 0 02 19 6 89 129 18 10 5 12 88 62 27 3 0 92 0 38 21 251 111 037 318 25 08 85 76

133063 648467 7150024 4400 018 889 410 531 015 2270 702 037 003 002 705 9982 011 01 05 2 7 05 01 05 3170 83 19 53 05 03 18 1370 15 9 13 09 04 23 05 135 05 01 123 76 27 72 139

133064 647573 7150076 5150 032 1450 307 514 015 634 1390 178 001 003 244 9918 015 01 05 3 50 05 01 05 456 29 40 65 14 04 09 191 05 11 11 05 04 36 05 577 05 01 222 144 21 61 26

133073 626850 7161292 5150 033 1440 273 573 014 748 1250 232 001 003 264 9981 011 01 05 3 43 05 01 05 467 38 78 32 19 02 29 202 14 13 12 05 03 32 05 497 05 01 219 137 05 61 258

133076 626850 7161292 4990 074 1490 410 612 015 546 1320 148 006 007 297 9915 022 01 05 3 42 05 01 85 154 33 55 65 34 03 34 93 05 7 11 05 02 33 05 151 05 01 263 169 16 84 678

133096 645954 7171243 4500 013 916 192 711 014 2110 744 015 002 001 699 9917 022 01 05 2 75 05 01 23 3100 93 69 6 146 06 14 1620 17 7 7 07 17 26 05 27 05 01 132 212 21 69 103

133098 636053 7155351 4950 057 1510 228 646 014 728 1380 135 010 006 307 9971 015 01 05 6 174 05 01 08 487 31 81 47 58 05 37 165 05 12 16 15 02 26 05 112 35 02 220 135 05 64 429

136749 667073 7199167 5080 072 1420 410 567 015 601 1330 166 022 007 221 9911 011 01 05 4 222 05 01 42 331 37 82 57 59 04 29 131 1 12 11 32 07 31 05 237 05 01 257 175 15 75 665

136751 659000 7122223 0 12 0 0 98 3 209 68 15 62 34 04 44 86 2 9 7 43 0 34 09 304 053 021 207 15 09 48 23

139131 621200 7215100 4790 065 1470 301 746 019 682 1290 254 004 006 319 9946 026 01 05 3 211 05 01 43 358 43 103 07 4 02 46 154 05 8 14 05 02 29 05 616 05 02 281 19 05 77 484

139132 621190 7215090 0 14 0 01 11 0 66 18 46 59 40 05 95 11 14 0 0 108 0 51 21 242 87 124 389 7 24 51 134

139133 666700 7193500 0 09 0 02 56 0 0 18 37 39 92 05 63 4 62 0 0 63 0 53 19 33 21 24 29 18 08 25 290

139134 621755 7169255 0 08 0 0 85 3 3 3 15 63 14 09 06 0 2 0 0 73 0 06 08 76 129 05 4 3 03 3 35

139135 621000 7169500 5016 037 1406 241 647 017 918 1126 248 006 003 15 5812 222 438 53 65 10 438 077 1320 100E-07 171 100E-07 500E-08 54 2 53 500E-08 500E-08 212 15 72 19 036 194 094 048 190 038 289 071 222 034 232

139136 621000 7169500 5236 027 1373 239 577 016 897 1068 21 007 003 15 5265 210 491 53 162 10 491 086 1290 100E-07 196 100E-07 1 48 200E-07 62 500E-08 500E-08 189 13 63 13 036 161 078 041 160 039 259 068 214 038 221

139137 620904 7169533 4737 108 1123 33 789 018 1191 106 203 008 012 15 13407 2170 1150 82 119 15 1150 897 1380 6 525 2 500E-08 39 4 143 1 500E-08 265 17 90 65 278 1143 314 124 391 066 391 084 222 031 187

139138 620992 7169508 5075 03 141 177 678 017 996 925 264 044 002 05 7628 124 660 56 61 10 660 042 1310 100E-07 232 100E-07 55 49 2 62 500E-08 500E-08 194 12 65 14 019 104 062 031 135 030 225 055 166 026 175

139139 620992 7169508 4747 018 1006 141 804 017 1989 829 089 002 001 500E-08 7171 148 1770 95 53 75 1770 089 1320 100E-07 835 100E-07 500E-08 39 2 225 500E-08 500E-08 139 8 60 7 019 098 063 028 124 028 206 051 157 026 160

139140 620992 7169508 5201 117 1269 224 762 016 761 1089 239 025 013 05 8447 2455 212 52 161 15 212 982 1210 5 135 100E-07 45 42 4 228 1 500E-08 270 17 87 80 308 1270 330 120 387 061 364 074 200 028 161

139141 620992 7169488 6179 081 147 284 594 006 496 012 007 32 01 1 74341 6413 414 41 31 19 414 2988 410 12 163 3 161 29 4 11 155 3 90 19 132 198 677 2282 433 094 430 059 295 058 166 026 170

104256h 715830 7171470 6528 068 1179 412 511 004 551 013 005 24 012 1 44782 7429 348 39 2 15 348 3419 300 10 176 3 121 21 4 9 19 3 73 27 83 266 834 2926 592 121 584 082 451 089 249 038 231

104393s 687539 7143275 3634 015 744 519 582 02 1191 1139 002 001 002 177 2109 066 2020 175 257 6 043 1440 00000001 1000 00000001 000000005 24 2 42 000000005 05 108 6 35 13 016 080 044 022 067 014 094 022 074 012 090 015

112601s 668775 7146298 1248 005 339 812 262 026 1592 217 005 001 0 156 1400 058 850 63 46 25 066 1990 00000001 1010 1 000000005 10 2 66 000000005 000000005 87 11 22 3 024 085 052 025 083 021 145 034 111 017 131 021

112604s 672238 7155486 7639 017 1136 256 551 022 087 002 002 01 001 457 15133 087 2260 9 10 8 031 1590 00000001 228 1 45 21 00000002 17 000000005 05 149 2 17 9 009 043 014 012 017 004 028 006 023 004 035 005

112643h 675190 7125902 5583 097 1236 543 726 045 595 128 308 005 015 195 2804 1728 46 41 13 145 738 3010 2 63 1 2 58 2 38 000000005 000000005 278 24 111 58 201 930 276 073 275 049 297 064 202 031 236 038

116454s 653363 7152948 2576 011 467 59 024 018 1282 1816 172 064 003 695 7663 012 1570 58 23 35 042 1370 00000001 620 2 34 15 00000002 385 000000005 000000005 76 5 30 4 013 027 019 018 037 010 069 017 060 009 070 011

116477s 645436 7177439 2009 0 084 152 0 038 1639 2363 022 04 003 6 6838 126 31 10 19 000000005 107 2940 00000001 93 1 75 00000001 00000002 103 000000005 000000005 9 10 4 00000001 034 113 036 118 051 012 084 027 105 017 142 020

116485h 655767 7129994 5901 078 1092 14 102 013 1024 016 003 0 008 65 744 774 86 47 39 125 276 965 2 136 00000001 000000005 62 2 15 000000005 000000005 304 15 85 45 099 490 138 035 148 026 164 036 114 018 143 023

116487h 655561 7129043 2488 011 535 29 312 04 1401 2084 003 004 005 110 4392 265 1410 69 15 5 175 3200 00000001 685 1 15 19 2 140 000000005 05 99 5 42 14 048 147 045 021 054 010 063 013 045 007 052 008

116493h 655992 7125530 5148 073 1516 172 1092 013 932 024 26 03 009 15 10919 1023 98 58 72 155 430 935 2 98 00000001 45 69 2 75 000000005 1 357 18 113 42 127 601 174 057 201 036 234 054 176 028 217 036

116501h 708508 7162137 4773 039 1372 423 456 016 666 527 438 098 006 1 120917 449 56 49 35 13 1277 1170 1 192 2 31 67 00000002 51 000000005 000000005 284 29 114 20 154 703 155 116 228 033 198 048 147 020 136 024

116518s 685232 7155526 3765 02 609 573 0 152 597 1736 007 218 005 100 218361 3411 55 39 15 7 1396 11070 4 70 5 65 8 00000002 77 55 1 60 12 38 38 321 1160 235 171 234 031 155 028 088 013 096 015

120303 655250 7126000 2302 011 404 31 071 059 074 3572 004 141 004 53 20581 1117 285 7 4 45 720 4740 1 51 12 435 00000001 2 96 25 000000005 36 9 21 17 141 504 105 042 126 021 127 030 097 015 109 019

120339A 669650 7146425 9409 001 03 425 065 002 003 005 0 006 003 155 1042 267 29 6 65 05 117 110 00000001 15 10 85 1 00000002 5 05 05 55 1 10 4 023 092 016 004 021 003 014 003 009 001 012 002

120339B 669650 7146425 9632 0 002 319 053 001 0 001 0 0 001 5 2442 083 6 3 9 000000005 039 40 00000001 3 1 000000005 00000001 00000002 1 000000005 000000005 10 00000001 3 2 008 030 006 004 009 001 005 002 006 001 008 001

120369s 665175 7156150 6131 098 1297 175 906 025 457 058 144 134 007 285 27950 3230 284 43 121 15 1406 1690 6 128 13 54 41 4 305 65 1 178 16 119 106 355 1340 286 087 269 039 202 036 119 017 130 021

120373s 675250 7167875 5541 088 1306 795 346 014 199 144 005 004 009 1 7754 1109 26 29 74 225 521 1040 2 41 3 05 48 4 67 000000005 000000005 494 25 50 55 161 716 213 067 256 050 325 074 237 035 267 041

120432s 673950 7171700 5469 078 1137 81 399 02 311 1468 016 005 006 2 11068 1433 62 44 22 20 634 1490 1 88 8 15 55 4 495 1 000000005 346 24 49 49 202 897 283 137 343 070 452 104 321 048 354 051

82137A not available 6241 067 991 186 893 019 924 011 0 005 01 15 2345 6927 595 43 123 12 3489 1470 10 235 4 25 21 4 55 175 2 77 16 112 288 734 2545 453 074 448 050 239 041 129 019 143 023

82137B not available 6118 074 1029 19 912 019 96 011 0 009 01 1 3042 6659 780 45 121 12 2999 1430 10 218 6 4 22 4 4 175 25 80 27 116 312 704 2493 499 095 542 075 415 083 249 037 262 039

82144 not available 6901 044 1124 143 288 021 188 365 27 14 013 15 38750 6263 117 22 22 12 3381 1690 8 48 37 67 11 2 107 175 25 46 19 61 199 679 2348 436 093 441 056 304 052 157 022 154 022

82148 not available 6314 07 124 312 581 017 717 01 005 197 01 1 41557 6431 505 53 22 15 3168 1310 10 211 4 99 23 4 8 165 25 72 18 121 227 689 2407 462 095 440 055 281 050 159 022 168 025

82150 not available 9469 001 012 45 062 001 001 001 0 0 001 1150 13761 225 10 2 7 000000005 310 40 00000001 11 00000001 000000005 00000001 6 000000005 000000005 3800 00000001 700 300 044 122 021 012 021 002 013 002 004 000 005 001

82153 not available 41767 296 256 047 214 049 031 072 013 090 023 077 010 072 010

82155 not available 4977 081 1429 329 833 02 718 945 255 018 007 2 10432 1154 175 65 117 135 175 395 1540 2 135 100E-07 3 57 4 75 500E-08 500E-08 290 18 104 45 174 807 287 119 400 083 496 117 328 056 311 053


82160 not available 4799 033 127 192 57 017 1261 1352 09 004 002 115 5413 491 1360 52 50 105 1360 183 1370 100E-07 269 100E-07 05 46 4 87 500E-08 500E-08 159 8 50 18 074 333 108 052 167 030 198 045 131 019 116 016

82179 not available 5338 053 1381 255 679 016 722 774 466 004 006 500E-08 3625 1347 326 50 48 115 326 523 1290 2 137 100E-07 500E-08 53 2 103 1 1 239 16 74 40 168 721 230 080 334 068 459 107 321 049 296 044

82180 not available 462 02 998 154 752 017 1869 845 1 003 002 500E-08 749 081 2240 93 46 8 2240 029 1320 100E-07 795 100E-07 500E-08 40 200E-07 365 500E-08 500E-08 148 10 56 8 015 081 051 034 110 026 192 050 157 026 167 028


82225 not available 4701 022 1065 127 739 015 1732 727 233 002 001 500E-08 2735 106 1730 84 32 75 1730 062 1180 100E-07 690 100E-07 500E-08 43 2 415 500E-08 500E-08 159 11 58 9 023 128 063 031 125 028 204 050 161 026 162 025

82226 not available 4256 014 689 357 494 011 2593 578 016 003 001 75 3377 038 2280 102 8 55 2280 015 835 100E-07 1380 100E-07 1 31 200E-07 205 500E-08 500E-08 104 5 46 6 008 042 027 010 058 013 097 025 075 012 078 011




82234 not available 4847 087 1468 1174 022 874 1394 099 027 008 332 83 3 225 21 48

82236 not available 5135 087 1461 1117 02 757 1032 274 109 008 228 70 15 329 19 49

135482 Trillbar Complex 5137 037 1481 232 561 016 869 1068 306 006 003 014 260 10014 39 2 593 59 61 00 08 08 1 124 1 1 51 00 08 235 17 61 20 0 5




REPORT 59

GEOLOGY AND MINERALIZATIONOF THE PALAEOPROTEROZOICBRYAH AND PADBURY BASINSWESTERN AUSTRALIA

byF Pirajno S A Occhipinti and C P Swager


Perth 2000











5531099413

ISSN 0508ndash4741





iii

Contents













Appendix


Plate


iv

Figures











Tables





MIGSDAF
File Attachment
narracootacsv
MIGSDAF
Note

1




by











2

Pirajno et al






Gee (1987)P

AD

BU

RY

BA

SIN

GR

OU

PG

LEN

GA

RR

Y B

AS

ING

RO

UP



Wilthorpe Formation


Horseshoe Formation


Karalundi Formation

Doolgunna Formation

Johnson Cairn Shale

Thaduna Greywacke

Juderina Formation

Maraloou Formation


Finlayson Sandstone


GLE

NG

AR

RY

BA

SIN

GR

OU

P

Maraloou Formation

Thaduna Greywacke


Doolgunna Formation

Johnson Cairn Shale


YE

RR

IDA

BA

SIN

GR

OU

P

Win

dpla

in S

ubgr

oup

Moo

loog

ool S

ubgr

oup

Peak Hill Schist

BR

YA

H B

AS

ING

RO

UP

PA

DB

UR

Y B

AS

ING

RO

UP

TE

CT

ON

IC C

ON

TA

CT


Wilthorpe Formation


Horseshoe Formation

Karalundi Formation




Doolgunna Formation

Thaduna Formation

Juderina Formation

170100



Unconformity

Unconformity




ARCHAEAN BASEMENT

FMP409a

3




















faulted contact



4

Pirajno et al





MARYMIAINLIER

GOODININLIER

Goodin

Fault

Fault

Killara

Narracoota

30 km

PILBARACRATON

CAPRICORN OROGEN

CRATONYILGARN

FMP375

117deg

30

118deg

30

26deg00

25deg00

Murchison

FaultMorris

Earaheedy Group

Padbury Group

Yerrida Group


Bangemall Group

Bryah Group


Fault

Moorarie Padbury

MilgunMarquis

FaultCooinbar

NarryerTerrane

Murchison

Terrane

Kerba Fault

119deg

30

Gabanintha Yanganoo

MooloogoolGlengarry

Bryah Doolgunna


010300

BRYAH-PADBURY

BASINS

PROTEROZOIC

5










6

Pirajno et al





Karalundi Formation





7















8

Pirajno et al









9













Felsic schist



10

Pirajno et al










11






Jasperoidal chert









12

Pirajno et al



Percent


Mg 6687 6615 6795 6692 6736 6377 6142 6816 792 85 843 ndash ndash

Parts per million






13















35 45 55 650

1

2

3

4

foidite andesite

basalt

boninite

basalticandesite

MgOgt18 picrite

basanite

tephrite


picrobasalt

FMP365 021199

22

2

2

2

2


SiO (wt)

Na

O +

K O

(w

t)


14

Pirajno et al




20

16

12

8

4

0

Na

O +

KO

(w

t)

22

857565554535

SiO (wt)2 11999FMP367

Hyaloclastite

Mafic schist

Ultramafic schist

Subalkaline

Alkaline


3

2

1

0

TiO

(wt

)2

1 2FeO MgO (wt)

Hyaloclastite

Mafic schist

Ultramafic schist

4000

3000

2000

1000

0

Cr

(ppm

)

1 2 3FeO MgO (wt)

Hyaloclastite

Mafic schist

Ultramafic schist

TiO 1002

Ni Cr91199FMP368a

Hyaloclastite

Mafic schist

Ultramafic schist

a)

b)

c)

15





a)

c)

b)

d)

MgO

TA

TDTR

CR CDCA

HFTBK

PKCB

HMT

Sam

ple

chon

drite

100

10




Sam

ple

chon

drite

100

10

1

6

FeO

MgO

221199

Al O32

FeO + TiO2

Al O32

FMP154




16

Pirajno et al








Horseshoe Formation



CFB

MORB

20

18

15

13

10

08

05

03

000 1 2

TiO

2


Mafic schist

Hyaloclastite rocks

(tot)FeO MgO


17








FMP156 020300

0

100

200

300


Garnetiferous BIF





(m)



Micaceous wacke


18

Pirajno et al











19



Wilthorpe Formation












20

Pirajno et al














21














22

Pirajno et al







FMP371

MARYMIAINLIER

YILGARNCRATON

Goodin

Fault

GROUPBANGEMALL

Murchison Fault

118deg30 119deg30

30 km

020300


Anticli

ne

Robinso

n

Synclin

e

Nathan Syncline

Zone of D folding3

Padbury

Horseshoe Anticline

Wilthorpe F

t


GOODININLIER

EARAHEEDYGROUP

25deg30

26deg00

Syncline

Millidie Syncline

FaultD fold trace3

D fold trace2

1

D fault1

Anticline


Yarlarweelorgneiss

complex

FraserSynclinorium

23












280degndash310deg




24

Pirajno et al




118deg 119deg

25deg45

10 km

MarymiaInlier

YilgarnCraton

BangemallBasin

Bill

ara

Fa

ult

Wilt

horp

eF

Fortnum

25deg30

Goo

din

Faul

t

Kinders FaultNathan

Peak Hill

B

AC

Mt Fraser



YerridaBasin

PADBURY GROUP

BRYAH GROUP





YERRIDA GROUP


PA

LA

EO

PR

OT

ER

OZ

OIC

Greenstone

Peak Hill Schist

AR

CH

AE

AN

Fault

Anticline

Syncline

ME

TA

MO

RP

HO

SE

D



Unconformity

Mine

Cross-section





140300FMP373

25












26

Pirajno et al

0

2

4

6

Fault

Kilo

met

res

Southwest Northeast

FMP372

0

2

4

6

Kilo

met

res

West East

Billara

Fault

Kilo

met

res

0 Padbury

South North

SynclineDome

2

4

6

Yarlar-weelor

170300

Fault

Kinders

MIDDLE PROTEROZOIC


Bangemall Group

Unconformity


Foliation

High-strain zone

Fault



2

BRYAH GROUP

Geological boundary

Padbury Basin

Bryah Group

S N

d)



ARCHAEAN (in situ)








YERRIDA GROUP


Goodin






a) Cross section A



27











28

Pirajno et al

















29



ram

p

Peak Hill Anticline

N S



ramp Obliq

ue

lateral ramp

Yarlarweelor

Basalthrustplane

2Dc)

d)

2D thrust flat

rsquo


gneiss complex

Padbury Group

Bryah Group


a)

Archaean granite

b)



1 2Post-D and pre-D


rsquo1

Post-D D2 3

W E

Thrust ramp

Thrustfrontal

Later

al ra

mp

FMP374 011199

W E

N

Thrust flatrsquo

movement

Thrust

North to south

e)

ramprsquo

flatrsquorsquo





30

Pirajno et al










31





1 1


1

Murchison Fault


Hyaloclastites


Post-rift phase



a)

b)

c)

v

SAO62 130300



NNW1

SSE

1

2 3

Early- and syn-D







D ndashD

Bryah Group


Padbury Group

32

Pirajno et al






Future D fault

NNW SSE

Bryah Group

Basement



1Peak Hill Schist

D faults1

1



Marymia Inlier

a)

b)

SAO63 150300

Padbury Group

Early- and syn-D


33









YILGARNCRATON

vv

v

vv

v

vv

vv v

v

v

v vv v

vvv

vvv

vvv

vv

Errabiddy



SAO64 130300

NW SE


v v

Bangemall Group



Cooinbar Fault

34

Pirajno et al




Pre-1986


1986 to 30 June 1999



Total 17 9128 59 0577 3487 1878 59 595 5 412 15 496 75 091



35

GSW

A R

eport 59G



adbury Basins W

A



(t) (t) (t) (t) (t)



Total 261 745 49 1824 5 420 000 45776 94 9584



Inferred 205 000 100 000 100 000







36

Pirajno et al













copper and gold

























37


MARYMIAINLIER

MARYMIAINLIER

Jenkin

FaultGROUPBANGEMALL

Murchison Fault

NARRYERGNEISS

TERRANE

Padbury Bryahand

Yerrida Basins

FMP100b 181099

1000 km

5

67 16

8

9

17

23

4

11

10

15

1213 14

19

18

21

20

1

GOODININLIER

YILGARNCRATON

YILGARN

CRATON

Goodin

Fault

118deg30 119deg30

Killara

Narracoota

Mt Padbury

PILBARACRATON

CAPRICORN OROGEN

CRATONYILGARN

Yandil

119deg30

Milgun30 km


PEAK HILLROBINSON

RANGE




119deg00

25deg30

26deg30

26deg00

25deg30

GLENGARRY

Milgun



Epigenetic Pb

Supergene Mn

2 Jubilee

5 Labouchere









Geological boundary


Peak Hill Schist


OU

PB

RY

AH

Padbury Group



Archaean basement

Earaheedy Group

WindplainSubgroup

MooloogoolSubgroup

YE

RR

IDA

GR

OU

P


Homestead

Bangemall Group

Microgabbro dyke

BryahPEAK HILL








MINERAL DEPOSITS

38

Pirajno et al




Karalundi Formation

Horseshoe Formation



10 km

040400

Yerrida Group

Bangemall Group

Earaheedy Group

Padbury Group

Bry

ah G

roup

Prospect

Producer

JubileeGroup

Peak Hill

Harmony

Wilgeena

Wembley

DurackWell

HeinesFind

Mikhaburra

CashmanGroup

Ruby WellGroup

Goodin Find

Ravelstone Group

(Hit or Miss)


25deg30

118deg

30

119deg

00

26deg00

Mar

ymia

Inlie

r mylonite

Syncline

Anticline

Overturned syncline

Peak Hill Schist

Thrust fault

Fault

Strike-slip fault

FMP162a




Mount Pleasant

39













40

Pirajno et al




FIVEWAYSPIT

MINIPIT

MAINPIT

100 m

sequence

Mine sequence


Vein quartz

Marker Quartzite

Shear zone

Anticline

FMP160 271099

Hangingwall

Geology notmapped

Geology notmapped

N40

42

45

40

25

45

45 26

30

42

45

Fault42

Cleavage

Foliation




41






Harmony deposit








50 m

FMP159

Supergene ore

Primary ore

Pit outline

50

100

150

200

Met

res

Mafic rocks

Formation)

Ultramafic rocks


(Narracoota


Pelitic rocks

SW NE

211099

42

Pirajno et al









Wembley deposit


43



Wilgeena deposit










Ruby Well group



Mikhaburra deposit


Wilthorpe deposit


44

Pirajno et al

Cashman deposit








45











FMP71a


Mooloogool Subgroup

Windplain Subgroup


170300


ARCHAEANBASEMENT

NARRYERTERRANE


Collisionzone


Metamorphism

Basin fluids

YERRIDA

and deformation

Goo

din

Faul

t

development


NW SE

46

Pirajno et al










47


N S

N S

Marymia In

lier

YILGARN


andvolcanic arc

Seafloor

Seafloor

Oceaniccrust

lt 1960ndash1950 Ma

PILBARA

PILBARAYILGARN

Fold-and-thrustbelt


1820ndash1800 Ma


area

Lithosphere

FMP376 170300

4000

3000

2000

1000

00 21 3

FeOMgO FeOMgO Ni Cr

1

2

0

3

0 1 2

La Eu Lu

Sam

ple

chon

drite

100

10

16

Sam

ple

chon

drite

100

10

2La Eu Lu

2

Cr

(ppm

)

TiO

(

)

TiO x1002

Mid-oc

ean r

idge

2

Clastic rocks

Padbury Group

Archaean basement


Karalundi Formation

Oceanic crust

a)

b)

48

Pirajno et al










49


References































50

Pirajno et al





































51



































52

Pirajno et al

Appendix







Wandery

Creek

Wandery

Gum

Creek

Beda

burra

Easter

nCr

eek

Dim

ble

Dimble

Cree

k

Mt Fr

aser

Creek

Creek

Mt Fraser


MURCHISON

RIVER

GASCOYNE

RIVE

R

GASCOYNE

RIVER

Ck

Cree

k

Creek

Beatty Park B (abd)

Reefer W(abd)

YARLAR

WEELOR

MILGUN

ROAD

MEEKATHARRA

ROAD

ASHBURTON DOWNS


ROADTRILLBAR

Mt Padbury

Yd

Yd

Yd

Yd

Yd Yd

Yd

Yd

Yd

Yd

Yd

Yd

YdYd

MT CLARE

MEEKATHARRA

ROAD

Bryah

Narracoota


Mikhaburra

Yd

Yd

Yd

Yd

(ruin)Bilyuin Hotel


Doolgunna

Yd

YdYd

Yd


Yd

Karalundi

Yd

Yd

Yd

Yd

Bryah

Yd

Mikhaburra

Yarla

rwee

lor H

omes

tead

44

km



Meekatharra 108 km

Meekatharra 53 km

Mooloog

ool Ho

mestead

35 km

Diamond

Well

Homest

ead 68

km

Neds

Creek

Homest

ead 33

km



MT LABOUCHERE

MT ARAPILES

CM 15

MT BEASLEY

MT SEABROOK

TALB

OT

DIVIDE

RED HILL

722 m

Yd

Yd

Yd

Yds

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

YdYd Yd

Yd

Yd

Yd

Yd

628 m

MT PADBURYMT FRASER

MT MAITLAND

R O B I N S O N

591 m

695 m

799 m

Yd

Yd

GREAT

NORTH

ERN

HIGH

WAY

HILL

THRE

E RIVER

S

ROAD

PEAK

MEEKATHARRA

ROAD

ROAD

PEAK HILL

R A N G E

Peak Hill

MC 14

NOONYEREENA HILL

MT LEAKE

MC 13

MC 12

MC 11

ASHBURTON DOWNS

core yard

602 m

605 m

640 m

Peak Hill

Yd

Earrie W Daulby W

Jilly Jilly W

Outcamp W (abd)

Watt W

Curly W

B

6 Mile B4 Corners W


Labouchere W

Sam W

Duffey W

Horseshoe W

Dandy W (PD)(abd)

Carlyon B (PD)

Kinder B (PD)

Vacation B

Garret W

Kylie B

Camel B

W (abd)Billarra W


Carlyon RH (PD)

Yaddyarra W

Mowara BGullgogo B


Stink W (PD)

Crain B

Windalah B

Yandinhah W

Coomballey B

No 1 B

4 Corners W (abd)

Cement Tank W (abd)

Cork Tree B


Thompson B (abd)

W (abd)

Tommy B


Midnight B

Gidgie WW (abd)

Snake W Dry W

Black Hill W

Minniarra W

Top Minniarra W

Doherty W

The Hut W

W

Red Hill W

Randall W

Dooley W

Walebie W

Mandora B

Babbawiri Pool

Winja B

WHWH

PBedaburra P

Friday P

Kerba P

S

Wandery P

W

Valley B

Quartz B


P

Peak Hill B Shed W

Boundary B

No 3 W

McPherson B

Pinnacle B

WH

Mt Leake B

Hill B

Jack W

W

Mt Leake B

John B

No 2 B

Cow Hole B

WH

Red B

WH

No 6 W

Marck W

No 11 W

Limestone W

Dummy B

No 1 B

No 8 B

D

Government W

Central B

Gale W

W

West W

No 6 B

Ealgareengunna WH

Noonyereena P

Beefwood T

Narracoota B

WH

WH

Railway B


32 Mile W

Ruby W

Ruby South W

W (abd)

Scotty W

Ord W

Little Mill B

Killarney W

West WMillie W

D

Ord W (abd)

W(abd)



No1 W

Paddy B (abd)

Kelly BRelief B

Top Dimble W

Despair B

Boundary B (PD)

B (abd)

Padbury W

Govt W (abd)


Wandarrie W

Middle B

W

WW

W

No 3 B

Fish Pond B

Wooly Paddock B

5 Mile W

Knox W


Old Homestead WB

Widespread W

W

Kennedy W

W

Deep W

Ross B


Brunsden W


7 Mile BDavid W

17 Mile B (PD)

Lefeuvre W

Mick W

W (abd)

WH

WHWH

WH

WH

WH WH

S

Gum W (abd)

Wilthorpe W (PD)

1 Mile W

Bullgullan B

Wongawar B

Jinglegunna W

No 13 B

Orchard W

Fraser WW

Sorenson B

Central B


Murphy W

Trudgeon W

Moore W Spelling W

Randell B


Bore Hole BOHara W

Murchison W (abd)


Hill W

Telegraph W

Cashman B (abd)

Ruby Centre W

White WW

McCann W (abd)

Holden W

Gum W

McDonald W

Don BNo 2 BNo 1 B

Bull W

D

D

DD

Gum Well P

Malleah P

Fremanga P

Yallaginda W (abd)

No 7 B (abd)

Stalley W (abd)

Durack W

No 26 W (abd)

Ruby Duffer W (abd)

WHs

WHs

WHWH

WH

WHWH

WH

P

PP

P

P

P

P

P

P

P

P

P

Ruby W (abd)

Narracoota W (abd)

WH S

P

B W

D T

(abd) (PD)

Cheroona W(abd)

Ti Tree B



14

16

18

20




14

16

18

20




1frac34

Chalba Fault

CoolinbarFault

Fortnum Fault

BillaraFault

Wilthorpe

Fault

KindersFault

GoodinFault

Goodi

n

Fault

Murchison

Fault

Goodin

Fault

Padbury

Syncline

Millidie

Syncline

Peak HillAnticline

Robinso

n

Synclin

e

HorseshoeAnticline

3

33

3 3

3

3

3

3

30

85

8035

54

2

2

2

2

2

2

2

2

2

2

2

2

2

2

40

2

2

2

2

40

36

30

40

45

3

36

7081

62

51

6270

86

80

60

87

85

85 72

63

70

80

55

3

4

3

3

3

3

3

8583

68

55

74

85

75

71

61

706260

3

3

3

3

3

3

87

66

70

60

7075

88

8081

4

4

4

4 44 4

4

4

3

3

81 83

80

7872

87

55

33

3

4

4

71

78

73

47

25

85

75

70

2

2

48

62

45

80 63

4785

75

60

60

70

85

15

72

80

60

32

85

60

6030

3565

4

4

4

2 2

4

4

3

3

3

4

3

3

2

42

2

4

4

86

86

73 75

8570 70

85

75

4

5264

58

45

60

80

70

60

78

65

46

80

5051

7050

60

38

80

84

50

70

60

74

56

48

42

70

8278

5058

35

70

80

55

46

58

70

77

85

53

80 52

2

2

2 2

1

1

11

1

2

2

2

2

2

1

1

1

1

1

2

2

2

2

2

2

2

2

2

2

65

50

55 85

80

60

30

70

40

5545 82

80

80

60

78

70

42

60

70

88

60

70

70

80

70

70

75

48

42

45

80

40

30

85

69

74

68

68

52

68

40

50

2

11

65

65

118958

118957

28

70

62

6884

10

72

75

4740

8878

60

74

80

1

2

2

2

2

4

56

80

48

78

85

56

60

6470

80

60

8572

80

65

88

76 85

70

2

2

2

2

2

2

2

2

2

2

2

2

4

3460

64

75

74

72

85

7830

85

8488

75

50

4

60

66

75

48

64

66

10

45

35

80

48

75

58

66

60

72

70

35

80

36

2

88

70

78

25

70

58

45

86

2

80

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igraveAnigraveAnc

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igravePla

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igraveAhiigraveAhi

igraveAhi

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igraveAnc

igraveE

igraveAnx

igraveAnh

igraveYm

ethp

igraveAnh

igravePwh

igravePrg

igravePri

igraveAn

igravePr

igraveYm

igraveYc

igraveYjigraveYm

igraveAk

igraveE

igraveE

igraveYjf

igraveYjf

igraveAk

igraveAk

igravePmi

igravePmc

igravePw

igraved

igraved

igravedigraveAhi

igraveAhi

igraved

igraveAn

igraved

igravePla

igravePwh

igraveAnd

igraved

igravePr

igravePr

igraveYj

igraved

igraveAnd

igraveAnd

igraveAr

igraved

igravePl

igravePl

igravePl

igravePla

igravePla

igravePla

igravePla

igravePla

igravePla igravePl

igraveArc

igraveArc

igraveArc

igravePla

igraveAk

ntildegde

ntildegMl

ntildegMl

igraveYjf

igraveYj


ntildegMla

ntildegMla

ntildeg

ntildeg

ntildeg

ntildegn

ntildeng

ntildeng

E

E

E

E

E

E

E 118961

118956

142851

88YacuteEcirc168

igraveAnd


Yarlarweelor

Horseshoe

NathanDeep

Mt Seabrook

Labouchere

Wilthorpe

Wilgeena

Wembley

Livingstone

Harmony

Jubilee


St Crispin

Durack

Heines Find

Mikhaburra

Cashman

Horseshoe Lights

Horseshoe

Yarlarweelor

Mn

T

MnMn

CuAu

Cu

Au

Mn

T

CuAu

HOLDENS

BAXTER

RAVELSTONE

PEAK HILL

HORSESHOE

HOLDENS

Ruby Well

Fortnum

Fortnum






thrust

latera

l ramp


NARRYER

TERRANE

YILGARN

CRATON

Goodin F

ault

GOODIN

INLIER

Jenkin

Fault

Fault

Goodin

MARYMIA

INLIER

thrust ramp

Robinson Syncline

Peak Hill Anticline

Peak Hill Anticline



Marymia Inlier

40



30 km

Bangemall Group

Earaheedy Group

Padbury Group

Bryah Group


Windplain Subgroup

Geological boundary

Fault






15Agrave

30Agrave

45Agrave







45Agrave

30Agrave

15Agrave

Proterozoic granite

Q TR S

SEA LEVEL

5 km

11 km

F G

SEA LEVEL

5 km

11 km

L M O

SEA LEVEL

5 km

11 km

N

J K

SEA LEVEL

5 km

10 km

10 km

SEA LEVEL

5 km

H I


YerridaGroup


SEA LEVEL

5 km

10 km

C D E

SEA LEVEL

5 km

10 km

A B












2




BANGEMALL

EARAHEEDY

PADBURYBASIN

BASINBRYAH

YERRIDABASIN


1 2 3 4

C

58

78

75

20

15

SHEET INDEX




Capr

icorn

Oro

geny

Mar

ymia

Inlie

r_re

work

ed d

uring

the

met

amor

phism

_Ca

prico

rn O

roge

nyup

per g

reen

schist to

lowe

r am

phib

olite

facie

s

gree

nsto

ne b

eltM

ount

Mai

tland





BANGEMALL BASIN


EARAHEEDY BASIN


2000 Mac

YERRIDA BASIN


YILGARN CRATON

2600 Ma and olderc


BASIN

BASIN

igraveAn


igraveAnf

ntildeg

ntildegn

ntildeng

igraveM

igraveE

igraved

igraveg

igraveP

igravePm

igravePmi

igravePmc

igravePr

igravePrg

igravePri

igravePw

igravePwb

igravePwh

igravePl

igravePli

igravePla

igraveAh

igraveAhi

igraveAr

igraveArc


igraveAk

igraveYm

igraveYc

igraveYj

igraveYjf

ntildegMl

ntilderMM

ntildegde

igraveAnf

igravePi

ethp

ethpm

ntildegMli

ntildegMla

igraveYjf

igraveYjf

igraveYj

igraved

igraved

igraveYm

igravePmigravePrg

igravePrigravePri

igravePwh

igraveAn

igraveAk ethp

igraveAnh igraveAnd

ntildegMl

igraveAnh


igraveYjf

igraveAn

ethp

igraveAr igraveAr

igravePwh

ethpm igraveAn

igraveAn

igraveM

igravePrigravePri

igravePriigravePr

igraveAr

igraveAn

ethp

ethpm


igravePw

igravePligravePla

igraveAh

igraveAn

igraveArc igraveAn

igraveArcigraveAnf

igraveAnd

igraveM

igraved

igraveAhiigravePm

igravePl

igraveAn

igraveAr

igravePr

igravePriigravePl



ntildegMl

igraveArc

ntildegMl

ntildegMl

ntildegMl

igraveAnd

igravePrigravePri

igravePwb

igravePl

igraveAn

igraveAhigravePwb

igravePr

igravePri

igravePmi

igraveAr

igraved

igraveAn

igravePm

igravePwb

igravePr

igravePr

igravePri

igravePwigraveAnu

igravePm

igravePmc

igraveAr

igraveAk

igravePw

igraveM

ntildegMla

ntildegntildeg

ntildeg

ntildegntildeng

igraveM igraveM

igravePligraveAhi

igraveAhigraveAh

igraveAn

igraveAnigraveAr

ntildegMl

ethp

ntildeng

igraved igraved

igraved

WA

NT

SA

NSW

Vic

Qld

Tas

ACT

GEOLO

G IC A L SUR VEY

WE

ST

E R N A U S T R AL

IA


WESTERN AUSTRALIA



AND ENERGY




MINISTER FOR MINES














Chert


Quartz mylonite


Amphibolite





MES

OPRO

TERO

ZOIC

PALA

EOPR

OTER

OZOI

CAR

CHAE

AN

Bang

emal

lGr

oup

Eara

heed

yGr

oup

Padb

ury G

roup

Brya

h Gr

oup

Yerri

da G

roup

Win

dpla

in S

ubgr

oup

Moo

loog

ool S

ubgr

oup

Yarla

rwee

lor g

neiss

belt

Narry

er T

erra

ne

lowe

r gre

ensc

hist to

upp

er a

mph

ibol

ite fa

cies

met

amor

phism

_Ca

prico

rn O

roge

ny

Mur

chiso

n Te

rrane

YILG

ARN

CRAT

ONYE

RRID

A BA

SIN

BRYA

H BA

SIN

preh

niteEcirc

pum

pelly

ite to

mid

-gre

ensc

hist fa

cies

met

amor

phism

_Ca

prico

rn O

roge

ny

PADB

URY

BASI

N




Middle Proterozoic

Early Proterozoic




















Geological boundary




Fault



away from observer


anticline

syncline


overturned syncline

towards observer


inclined

vertical

inclined

vertical

overturned


inclined

vertical



mineral lineation






Formed road

Track

Landing ground



Homestead

Locality

Building yard




Waterhole spring

Bore well windpump

Dam tank


Mining centre

Mining locality


Major opencut

Opencut

Alluvial workings

Prospect

Copper

Gold

Manganese

Talc

PILBARACRATON

CAPRICORN OROGEN

CRATONYILGARN

0 5 10 15 20 255000

Metres Kilometres










REPORT 59 PLATE 1


2344

2345

2346

2347

2444

2445

2446

2447

2544

2545

2546

2547

2644

2645

2646

2647

2744

2745

2746

2747

2844

2845

2846

2847

KALLI

MILEURA

GOULD

ERRABIDDY

MADOONGA

KOONMARRA

MOORARIE

MARQUIS

MEEKATHARRA

TIERACO

PADBURY

MILGUN

GABANINTHA

GLENGARRY

BRYAH

JAMINDI

YAGANOO

MOOLOOGOOL

DOOLGUNNA

MEREWETHER

THADUNA

MARYMIA

MOUNT BARTLE

THREE RIVERS

118958

88YacuteEcirc168

BELELE GLENGARRY


SG 50-7 SG 50-8

SG 50-11 SG 50-12



N

P












SEA LEVEL

5 km

11 km




26frac3400Agrave


AREA OF THIS MAP

GSWA

REPORT 60

PLATE 1

E


Q

R

S

T

F

G

L

M

O

P

N

J

K

C

D

E

A

B

H

I

1 2 3

1

2

3

cc 3300

1






3

cc 3300

1

3300

1










Contents

Abstract

Introduction




Bryah Group

Karalundi Formation






Felsic schist



Jasperoidal chert



Horseshoe Formation

Padbury Group


Wilthorpe Formation





Structure

D1 structures

D2 structures


D4 structures

Metamorphism


Mineralization

Gold deposits


Harmony deposit


Wembley deposit

Wilgeena deposit


Ruby Well group

Mikhaburra deposit

Wilthorpe deposit

Cashman deposit



Iron ore

Talc

Discussion


Acknowledgements

References



Figures



































Tables












86342 746314 7198282 5151 032 1523 928 018 1049 1007 269 019 003 673 166 1 95 12 11

86383 670171 7163822 5353 091 1468 115 019 744 863 299 005 008 253 100 1 85 21 53

86384 670171 7163822 5048 062 1444 991 016 1135 933 362 004 005 640 209 1 157 16 33

86397 799422 7201118 5529 026 1502 817 017 1136 416 549 005 002 1174 244 0 44 15 8

104248 722651 7168587 4925 022 1137 963 017 1818 948 159 009 002 1 80 9 6

104249 722651 7168587 4911 026 1065 973 017 2016 855 126 009 003 1 34 11 7

104254 715830 7171470 4948 023 1121 95 016 2035 706 194 005 002 1877 647 1 49 11 7

104255 715830 7171470 52 033 143 847 017 1071 1087 31 002 003 664 209 0 133 13 13

104256 715830 7171470 5244 067 1455 1007 019 834 983 376 007 007 0 140 17 34

104257 713820 7171502 5144 092 1453 1078 02 689 1244 248 023 009 265 79 3 195 18 53

104264 685287 7155494 5303 062 1391 94 017 768 1239 265 01 006 720 222 1 90 15 32

104265 685287 7155494 5332 025 1592 97 017 658 1215 184 003 004 353 67 1 30 15 11

104288 661877 7126843 5979 024 1346 798 016 522 1265 042 004 004 283 46 0 17 15 11

104289 656054 7130760 5446 014 1559 955 017 826 957 204 019 003 358 116 4 43 8 6

104292 657132 7123177 5103 09 1369 971 017 827 1334 272 009 008 0 165 18 51

104294 664424 7119210 5108 095 1449 1021 018 879 1094 283 046 008 523 141 5 123 19 52

104295 664424 7119210 5228 096 1446 1022 018 946 856 364 016 009 465 132 2 79 19 54

104298 669014 7106533 5233 087 1367 939 017 778 1189 373 01 008 514 116 1 116 17 49

104299 669014 7106533 5166 093 1404 982 018 823 1183 305 017 009 491 117 3 124 18 53

104300 669014 7106533 477 05 173 984 019 747 1484 197 016 004 3 142 12 22

104386 676392 7146500 5373 037 1501 846 016 864 977 373 009 004 557 152 0 106 18 18

104391 687552 7144198 5002 023 845 934 016 2281 88 014 002 002 0 15 11 6

104392 687552 7144198 5391 027 92 998 014 2087 515 017 027 003 2508 1103 12 16 22 10

104393 687539 7143275 508 023 965 1025 01 289 004 0 001 001 0 3 5 6

104394 687539 7143275 5594 05 1494 867 019 73 697 537 006 006 363 88 0 90 19 24

104397 670399 7142584 4687 019 1023 1015 017 2496 726 015 001 001 2786 971 0 7 8 4

104398 669575 7143518 5329 035 1453 813 014 828 1207 315 002 004 574 124 0 78 13 14

104399 670423 7144430 5183 036 1491 866 016 932 1147 323 002 003 682 173 0 42 14 14

104400 670023 7145280 4958 037 1577 987 019 1044 1082 291 002 003 510 124 0 68 17 15

109487 638809 7157725 5719 043 1423 73 013 868 626 569 004 004 442 116 0 18 11 19

109492 663796 7149130 5231 011 617 72 015 24 1002 001 001 001 0 7 5 1

109493 663796 7149130 5246 047 1508 881 019 766 1218 247 064 005 478 90 6 72 15 21

109504 670124 7121353 5396 048 149 859 015 716 1237 231 003 005 445 96 0 61 17 22

109513 732634 7164722 5396 197 1434 953 02 638 686 592 064 019 16 117 24 97

112601 668775 7146298 5332 179 1568 102 025 644 561 601 053 017 10 105 21 90















































































120891 677938 7168840 4880 082 1430 385 717 018 765 1280 174 008 008 330 10077 1 4 10 86 4 5 6 137 107 15 5 2 7 105 4 2 4 4 142 2 2 257 24 83 60










132793 622866 7161836 4860 031 1350 362 510 013 1040 1090 231 001 003 321 9812 2 4 3 29 4 5 6 872 45 61 11 3 97 7 379 4 3 2 2 4 4 72 2 2 216 14 4 60 21

132794 622866 7161786 4840 014 576 203 615 015 2160 863 033 001 001 549 9870 2 4 4 11 6 5 6 2460 71 22 5 3 2 7 1020 4 4 3 2 4 4 11 2 2 155 7 4 63 13

133033 638351 7157551 4450 156 1110 611 440 020 318 1330 468 034 021 906 9864 01 05 5 323 07 01 296 190 36 84 05 126 01 11 75 19 11 11 51 02 1 07 135 22 07 276 241 05 73 108

133034 638351 7157551 4710 013 836 237 696 014 1980 764 012 001 003 596 9862 02 12 2 18 45 01 32 3448 69 22 16 16 23 32 1048 11 5 9 17 18 42 19 52 15 01 133 58 84 72 108

133035 638300 7157750 4740 013 668 349 512 014 2200 801 022 003 001 521 9844 02 07 6 52 14 01 11 2608 73 34 22 12 03 33 1295 15 10 9 22 06 29 1 12 16 02 116 72 58 61 447

133038 632615 7159390 5060 048 1600 316 443 012 572 1410 150 032 006 267 022 102 lt05 70 110 lt05 lt01 216 392 29 93 57 147 10 12 28 138 29 lt2 3 179 297 31 74 141 21 28776 02 181 14 139 59 709


133043 632906 7159832 4970 073 1490 272 790 018 626 1260 171 031 006 236 022 03 21 30 412 09 01 46 66 37 129 05 61 8 06 41 121 48 lt2 9 99 44 11 27 119 13 43764 02 268 203 33 88 470






133051 635603 7169579 0 74 0 02 15 12 114 114 24 91 13 05 84 73 27 12 11 24 0 40 15 158 173 043 256 18 05 74 62

133052 635259 7169444 5160 086 1360 411 719 016 569 1030 155 048 008 344 9906 038 01 05 2 151 05 01 94 148 37 136 33 11 03 34 93 05 2 2 105 02 24 05 145 05 01 296 191 05 85 718

133054 634952 7169267 0 62 05 0 38 5 105 44 18 25 41 12 13 57 48 5 6 12 0 26 18 411 6 166 182 18 08 38 104

133060 648256 7160919 0 23 0 02 19 6 89 129 18 10 5 12 88 62 27 3 0 92 0 38 21 251 111 037 318 25 08 85 76

133063 648467 7150024 4400 018 889 410 531 015 2270 702 037 003 002 705 9982 011 01 05 2 7 05 01 05 3170 83 19 53 05 03 18 1370 15 9 13 09 04 23 05 135 05 01 123 76 27 72 139

133064 647573 7150076 5150 032 1450 307 514 015 634 1390 178 001 003 244 9918 015 01 05 3 50 05 01 05 456 29 40 65 14 04 09 191 05 11 11 05 04 36 05 577 05 01 222 144 21 61 26

133073 626850 7161292 5150 033 1440 273 573 014 748 1250 232 001 003 264 9981 011 01 05 3 43 05 01 05 467 38 78 32 19 02 29 202 14 13 12 05 03 32 05 497 05 01 219 137 05 61 258

133076 626850 7161292 4990 074 1490 410 612 015 546 1320 148 006 007 297 9915 022 01 05 3 42 05 01 85 154 33 55 65 34 03 34 93 05 7 11 05 02 33 05 151 05 01 263 169 16 84 678

133096 645954 7171243 4500 013 916 192 711 014 2110 744 015 002 001 699 9917 022 01 05 2 75 05 01 23 3100 93 69 6 146 06 14 1620 17 7 7 07 17 26 05 27 05 01 132 212 21 69 103

133098 636053 7155351 4950 057 1510 228 646 014 728 1380 135 010 006 307 9971 015 01 05 6 174 05 01 08 487 31 81 47 58 05 37 165 05 12 16 15 02 26 05 112 35 02 220 135 05 64 429

136749 667073 7199167 5080 072 1420 410 567 015 601 1330 166 022 007 221 9911 011 01 05 4 222 05 01 42 331 37 82 57 59 04 29 131 1 12 11 32 07 31 05 237 05 01 257 175 15 75 665

136751 659000 7122223 0 12 0 0 98 3 209 68 15 62 34 04 44 86 2 9 7 43 0 34 09 304 053 021 207 15 09 48 23

139131 621200 7215100 4790 065 1470 301 746 019 682 1290 254 004 006 319 9946 026 01 05 3 211 05 01 43 358 43 103 07 4 02 46 154 05 8 14 05 02 29 05 616 05 02 281 19 05 77 484

139132 621190 7215090 0 14 0 01 11 0 66 18 46 59 40 05 95 11 14 0 0 108 0 51 21 242 87 124 389 7 24 51 134

139133 666700 7193500 0 09 0 02 56 0 0 18 37 39 92 05 63 4 62 0 0 63 0 53 19 33 21 24 29 18 08 25 290

139134 621755 7169255 0 08 0 0 85 3 3 3 15 63 14 09 06 0 2 0 0 73 0 06 08 76 129 05 4 3 03 3 35

139135 621000 7169500 5016 037 1406 241 647 017 918 1126 248 006 003 15 5812 222 438 53 65 10 438 077 1320 100E-07 171 100E-07 500E-08 54 2 53 500E-08 500E-08 212 15 72 19 036 194 094 048 190 038 289 071 222 034 232

139136 621000 7169500 5236 027 1373 239 577 016 897 1068 21 007 003 15 5265 210 491 53 162 10 491 086 1290 100E-07 196 100E-07 1 48 200E-07 62 500E-08 500E-08 189 13 63 13 036 161 078 041 160 039 259 068 214 038 221

139137 620904 7169533 4737 108 1123 33 789 018 1191 106 203 008 012 15 13407 2170 1150 82 119 15 1150 897 1380 6 525 2 500E-08 39 4 143 1 500E-08 265 17 90 65 278 1143 314 124 391 066 391 084 222 031 187

139138 620992 7169508 5075 03 141 177 678 017 996 925 264 044 002 05 7628 124 660 56 61 10 660 042 1310 100E-07 232 100E-07 55 49 2 62 500E-08 500E-08 194 12 65 14 019 104 062 031 135 030 225 055 166 026 175

139139 620992 7169508 4747 018 1006 141 804 017 1989 829 089 002 001 500E-08 7171 148 1770 95 53 75 1770 089 1320 100E-07 835 100E-07 500E-08 39 2 225 500E-08 500E-08 139 8 60 7 019 098 063 028 124 028 206 051 157 026 160

139140 620992 7169508 5201 117 1269 224 762 016 761 1089 239 025 013 05 8447 2455 212 52 161 15 212 982 1210 5 135 100E-07 45 42 4 228 1 500E-08 270 17 87 80 308 1270 330 120 387 061 364 074 200 028 161

139141 620992 7169488 6179 081 147 284 594 006 496 012 007 32 01 1 74341 6413 414 41 31 19 414 2988 410 12 163 3 161 29 4 11 155 3 90 19 132 198 677 2282 433 094 430 059 295 058 166 026 170

104256h 715830 7171470 6528 068 1179 412 511 004 551 013 005 24 012 1 44782 7429 348 39 2 15 348 3419 300 10 176 3 121 21 4 9 19 3 73 27 83 266 834 2926 592 121 584 082 451 089 249 038 231

104393s 687539 7143275 3634 015 744 519 582 02 1191 1139 002 001 002 177 2109 066 2020 175 257 6 043 1440 00000001 1000 00000001 000000005 24 2 42 000000005 05 108 6 35 13 016 080 044 022 067 014 094 022 074 012 090 015

112601s 668775 7146298 1248 005 339 812 262 026 1592 217 005 001 0 156 1400 058 850 63 46 25 066 1990 00000001 1010 1 000000005 10 2 66 000000005 000000005 87 11 22 3 024 085 052 025 083 021 145 034 111 017 131 021

112604s 672238 7155486 7639 017 1136 256 551 022 087 002 002 01 001 457 15133 087 2260 9 10 8 031 1590 00000001 228 1 45 21 00000002 17 000000005 05 149 2 17 9 009 043 014 012 017 004 028 006 023 004 035 005

112643h 675190 7125902 5583 097 1236 543 726 045 595 128 308 005 015 195 2804 1728 46 41 13 145 738 3010 2 63 1 2 58 2 38 000000005 000000005 278 24 111 58 201 930 276 073 275 049 297 064 202 031 236 038

116454s 653363 7152948 2576 011 467 59 024 018 1282 1816 172 064 003 695 7663 012 1570 58 23 35 042 1370 00000001 620 2 34 15 00000002 385 000000005 000000005 76 5 30 4 013 027 019 018 037 010 069 017 060 009 070 011

116477s 645436 7177439 2009 0 084 152 0 038 1639 2363 022 04 003 6 6838 126 31 10 19 000000005 107 2940 00000001 93 1 75 00000001 00000002 103 000000005 000000005 9 10 4 00000001 034 113 036 118 051 012 084 027 105 017 142 020

116485h 655767 7129994 5901 078 1092 14 102 013 1024 016 003 0 008 65 744 774 86 47 39 125 276 965 2 136 00000001 000000005 62 2 15 000000005 000000005 304 15 85 45 099 490 138 035 148 026 164 036 114 018 143 023

116487h 655561 7129043 2488 011 535 29 312 04 1401 2084 003 004 005 110 4392 265 1410 69 15 5 175 3200 00000001 685 1 15 19 2 140 000000005 05 99 5 42 14 048 147 045 021 054 010 063 013 045 007 052 008

116493h 655992 7125530 5148 073 1516 172 1092 013 932 024 26 03 009 15 10919 1023 98 58 72 155 430 935 2 98 00000001 45 69 2 75 000000005 1 357 18 113 42 127 601 174 057 201 036 234 054 176 028 217 036

116501h 708508 7162137 4773 039 1372 423 456 016 666 527 438 098 006 1 120917 449 56 49 35 13 1277 1170 1 192 2 31 67 00000002 51 000000005 000000005 284 29 114 20 154 703 155 116 228 033 198 048 147 020 136 024

116518s 685232 7155526 3765 02 609 573 0 152 597 1736 007 218 005 100 218361 3411 55 39 15 7 1396 11070 4 70 5 65 8 00000002 77 55 1 60 12 38 38 321 1160 235 171 234 031 155 028 088 013 096 015

120303 655250 7126000 2302 011 404 31 071 059 074 3572 004 141 004 53 20581 1117 285 7 4 45 720 4740 1 51 12 435 00000001 2 96 25 000000005 36 9 21 17 141 504 105 042 126 021 127 030 097 015 109 019

120339A 669650 7146425 9409 001 03 425 065 002 003 005 0 006 003 155 1042 267 29 6 65 05 117 110 00000001 15 10 85 1 00000002 5 05 05 55 1 10 4 023 092 016 004 021 003 014 003 009 001 012 002

120339B 669650 7146425 9632 0 002 319 053 001 0 001 0 0 001 5 2442 083 6 3 9 000000005 039 40 00000001 3 1 000000005 00000001 00000002 1 000000005 000000005 10 00000001 3 2 008 030 006 004 009 001 005 002 006 001 008 001

120369s 665175 7156150 6131 098 1297 175 906 025 457 058 144 134 007 285 27950 3230 284 43 121 15 1406 1690 6 128 13 54 41 4 305 65 1 178 16 119 106 355 1340 286 087 269 039 202 036 119 017 130 021

120373s 675250 7167875 5541 088 1306 795 346 014 199 144 005 004 009 1 7754 1109 26 29 74 225 521 1040 2 41 3 05 48 4 67 000000005 000000005 494 25 50 55 161 716 213 067 256 050 325 074 237 035 267 041

120432s 673950 7171700 5469 078 1137 81 399 02 311 1468 016 005 006 2 11068 1433 62 44 22 20 634 1490 1 88 8 15 55 4 495 1 000000005 346 24 49 49 202 897 283 137 343 070 452 104 321 048 354 051

82137A not available 6241 067 991 186 893 019 924 011 0 005 01 15 2345 6927 595 43 123 12 3489 1470 10 235 4 25 21 4 55 175 2 77 16 112 288 734 2545 453 074 448 050 239 041 129 019 143 023

82137B not available 6118 074 1029 19 912 019 96 011 0 009 01 1 3042 6659 780 45 121 12 2999 1430 10 218 6 4 22 4 4 175 25 80 27 116 312 704 2493 499 095 542 075 415 083 249 037 262 039

82144 not available 6901 044 1124 143 288 021 188 365 27 14 013 15 38750 6263 117 22 22 12 3381 1690 8 48 37 67 11 2 107 175 25 46 19 61 199 679 2348 436 093 441 056 304 052 157 022 154 022

82148 not available 6314 07 124 312 581 017 717 01 005 197 01 1 41557 6431 505 53 22 15 3168 1310 10 211 4 99 23 4 8 165 25 72 18 121 227 689 2407 462 095 440 055 281 050 159 022 168 025

82150 not available 9469 001 012 45 062 001 001 001 0 0 001 1150 13761 225 10 2 7 000000005 310 40 00000001 11 00000001 000000005 00000001 6 000000005 000000005 3800 00000001 700 300 044 122 021 012 021 002 013 002 004 000 005 001

82153 not available 41767 296 256 047 214 049 031 072 013 090 023 077 010 072 010












82234 not available 4847 087 1468 1174 022 874 1394 099 027 008 332 83 3 225 21 48

82236 not available 5135 087 1461 1117 02 757 1032 274 109 008 228 70 15 329 19 49















5531099413

ISSN 0508ndash4741





iii

Contents













Appendix


Plate


iv

Figures











Tables





MIGSDAF
File Attachment
narracootacsv
MIGSDAF
Note

1




by











2

Pirajno et al






Gee (1987)P

AD

BU

RY

BA

SIN

GR

OU

PG

LEN

GA

RR

Y B

AS

ING

RO

UP



Wilthorpe Formation


Horseshoe Formation


Karalundi Formation

Doolgunna Formation

Johnson Cairn Shale

Thaduna Greywacke

Juderina Formation

Maraloou Formation


Finlayson Sandstone


GLE

NG

AR

RY

BA

SIN

GR

OU

P

Maraloou Formation

Thaduna Greywacke


Doolgunna Formation

Johnson Cairn Shale


YE

RR

IDA

BA

SIN

GR

OU

P

Win

dpla

in S

ubgr

oup

Moo

loog

ool S

ubgr

oup

Peak Hill Schist

BR

YA

H B

AS

ING

RO

UP

PA

DB

UR

Y B

AS

ING

RO

UP

TE

CT

ON

IC C

ON

TA

CT


Wilthorpe Formation


Horseshoe Formation

Karalundi Formation




Doolgunna Formation

Thaduna Formation

Juderina Formation

170100



Unconformity

Unconformity




ARCHAEAN BASEMENT

FMP409a

3




















faulted contact



4

Pirajno et al





MARYMIAINLIER

GOODININLIER

Goodin

Fault

Fault

Killara

Narracoota

30 km

PILBARACRATON

CAPRICORN OROGEN

CRATONYILGARN

FMP375

117deg

30

118deg

30

26deg00

25deg00

Murchison

FaultMorris

Earaheedy Group

Padbury Group

Yerrida Group


Bangemall Group

Bryah Group


Fault

Moorarie Padbury

MilgunMarquis

FaultCooinbar

NarryerTerrane

Murchison

Terrane

Kerba Fault

119deg

30

Gabanintha Yanganoo

MooloogoolGlengarry

Bryah Doolgunna


010300

BRYAH-PADBURY

BASINS

PROTEROZOIC

5










6

Pirajno et al





Karalundi Formation





7















8

Pirajno et al









9













Felsic schist



10

Pirajno et al










11






Jasperoidal chert









12

Pirajno et al



Percent


Mg 6687 6615 6795 6692 6736 6377 6142 6816 792 85 843 ndash ndash

Parts per million






13















35 45 55 650

1

2

3

4

foidite andesite

basalt

boninite

basalticandesite

MgOgt18 picrite

basanite

tephrite


picrobasalt

FMP365 021199

22

2

2

2

2


SiO (wt)

Na

O +

K O

(w

t)


14

Pirajno et al




20

16

12

8

4

0

Na

O +

KO

(w

t)

22

857565554535

SiO (wt)2 11999FMP367

Hyaloclastite

Mafic schist

Ultramafic schist

Subalkaline

Alkaline


3

2

1

0

TiO

(wt

)2

1 2FeO MgO (wt)

Hyaloclastite

Mafic schist

Ultramafic schist

4000

3000

2000

1000

0

Cr

(ppm

)

1 2 3FeO MgO (wt)

Hyaloclastite

Mafic schist

Ultramafic schist

TiO 1002

Ni Cr91199FMP368a

Hyaloclastite

Mafic schist

Ultramafic schist

a)

b)

c)

15





a)

c)

b)

d)

MgO

TA

TDTR

CR CDCA

HFTBK

PKCB

HMT

Sam

ple

chon

drite

100

10




Sam

ple

chon

drite

100

10

1

6

FeO

MgO

221199

Al O32

FeO + TiO2

Al O32

FMP154




16

Pirajno et al








Horseshoe Formation



CFB

MORB

20

18

15

13

10

08

05

03

000 1 2

TiO

2


Mafic schist

Hyaloclastite rocks

(tot)FeO MgO


17








FMP156 020300

0

100

200

300


Garnetiferous BIF





(m)



Micaceous wacke


18

Pirajno et al











19



Wilthorpe Formation












20

Pirajno et al














21














22

Pirajno et al







FMP371

MARYMIAINLIER

YILGARNCRATON

Goodin

Fault

GROUPBANGEMALL

Murchison Fault

118deg30 119deg30

30 km

020300


Anticli

ne

Robinso

n

Synclin

e

Nathan Syncline

Zone of D folding3

Padbury

Horseshoe Anticline

Wilthorpe F

t


GOODININLIER

EARAHEEDYGROUP

25deg30

26deg00

Syncline

Millidie Syncline

FaultD fold trace3

D fold trace2

1

D fault1

Anticline


Yarlarweelorgneiss

complex

FraserSynclinorium

23












280degndash310deg




24

Pirajno et al




118deg 119deg

25deg45

10 km

MarymiaInlier

YilgarnCraton

BangemallBasin

Bill

ara

Fa

ult

Wilt

horp

eF

Fortnum

25deg30

Goo

din

Faul

t

Kinders FaultNathan

Peak Hill

B

AC

Mt Fraser



YerridaBasin

PADBURY GROUP

BRYAH GROUP





YERRIDA GROUP


PA

LA

EO

PR

OT

ER

OZ

OIC

Greenstone

Peak Hill Schist

AR

CH

AE

AN

Fault

Anticline

Syncline

ME

TA

MO

RP

HO

SE

D



Unconformity

Mine

Cross-section





140300FMP373

25












26

Pirajno et al

0

2

4

6

Fault

Kilo

met

res

Southwest Northeast

FMP372

0

2

4

6

Kilo

met

res

West East

Billara

Fault

Kilo

met

res

0 Padbury

South North

SynclineDome

2

4

6

Yarlar-weelor

170300

Fault

Kinders

MIDDLE PROTEROZOIC


Bangemall Group

Unconformity


Foliation

High-strain zone

Fault



2

BRYAH GROUP

Geological boundary

Padbury Basin

Bryah Group

S N

d)



ARCHAEAN (in situ)








YERRIDA GROUP


Goodin






a) Cross section A



27











28

Pirajno et al

















29



ram

p

Peak Hill Anticline

N S



ramp Obliq

ue

lateral ramp

Yarlarweelor

Basalthrustplane

2Dc)

d)

2D thrust flat

rsquo


gneiss complex

Padbury Group

Bryah Group


a)

Archaean granite

b)



1 2Post-D and pre-D


rsquo1

Post-D D2 3

W E

Thrust ramp

Thrustfrontal

Later

al ra

mp

FMP374 011199

W E

N

Thrust flatrsquo

movement

Thrust

North to south

e)

ramprsquo

flatrsquorsquo





30

Pirajno et al










31





1 1


1

Murchison Fault


Hyaloclastites


Post-rift phase



a)

b)

c)

v

SAO62 130300



NNW1

SSE

1

2 3

Early- and syn-D







D ndashD

Bryah Group


Padbury Group

32

Pirajno et al






Future D fault

NNW SSE

Bryah Group

Basement



1Peak Hill Schist

D faults1

1



Marymia Inlier

a)

b)

SAO63 150300

Padbury Group

Early- and syn-D


33









YILGARNCRATON

vv

v

vv

v

vv

vv v

v

v

v vv v

vvv

vvv

vvv

vv

Errabiddy



SAO64 130300

NW SE


v v

Bangemall Group



Cooinbar Fault

34

Pirajno et al




Pre-1986


1986 to 30 June 1999



Total 17 9128 59 0577 3487 1878 59 595 5 412 15 496 75 091



35

GSW

A R

eport 59G



adbury Basins W

A



(t) (t) (t) (t) (t)



Total 261 745 49 1824 5 420 000 45776 94 9584



Inferred 205 000 100 000 100 000







36

Pirajno et al













copper and gold

























37


MARYMIAINLIER

MARYMIAINLIER

Jenkin

FaultGROUPBANGEMALL

Murchison Fault

NARRYERGNEISS

TERRANE

Padbury Bryahand

Yerrida Basins

FMP100b 181099

1000 km

5

67 16

8

9

17

23

4

11

10

15

1213 14

19

18

21

20

1

GOODININLIER

YILGARNCRATON

YILGARN

CRATON

Goodin

Fault

118deg30 119deg30

Killara

Narracoota

Mt Padbury

PILBARACRATON

CAPRICORN OROGEN

CRATONYILGARN

Yandil

119deg30

Milgun30 km


PEAK HILLROBINSON

RANGE




119deg00

25deg30

26deg30

26deg00

25deg30

GLENGARRY

Milgun



Epigenetic Pb

Supergene Mn

2 Jubilee

5 Labouchere









Geological boundary


Peak Hill Schist


OU

PB

RY

AH

Padbury Group



Archaean basement

Earaheedy Group

WindplainSubgroup

MooloogoolSubgroup

YE

RR

IDA

GR

OU

P


Homestead

Bangemall Group

Microgabbro dyke

BryahPEAK HILL








MINERAL DEPOSITS

38

Pirajno et al




Karalundi Formation

Horseshoe Formation



10 km

040400

Yerrida Group

Bangemall Group

Earaheedy Group

Padbury Group

Bry

ah G

roup

Prospect

Producer

JubileeGroup

Peak Hill

Harmony

Wilgeena

Wembley

DurackWell

HeinesFind

Mikhaburra

CashmanGroup

Ruby WellGroup

Goodin Find

Ravelstone Group

(Hit or Miss)


25deg30

118deg

30

119deg

00

26deg00

Mar

ymia

Inlie

r mylonite

Syncline

Anticline

Overturned syncline

Peak Hill Schist

Thrust fault

Fault

Strike-slip fault

FMP162a




Mount Pleasant

39













40

Pirajno et al




FIVEWAYSPIT

MINIPIT

MAINPIT

100 m

sequence

Mine sequence


Vein quartz

Marker Quartzite

Shear zone

Anticline

FMP160 271099

Hangingwall

Geology notmapped

Geology notmapped

N40

42

45

40

25

45

45 26

30

42

45

Fault42

Cleavage

Foliation




41






Harmony deposit








50 m

FMP159

Supergene ore

Primary ore

Pit outline

50

100

150

200

Met

res

Mafic rocks

Formation)

Ultramafic rocks


(Narracoota


Pelitic rocks

SW NE

211099

42

Pirajno et al









Wembley deposit


43



Wilgeena deposit










Ruby Well group



Mikhaburra deposit


Wilthorpe deposit


44

Pirajno et al

Cashman deposit








45











FMP71a


Mooloogool Subgroup

Windplain Subgroup


170300


ARCHAEANBASEMENT

NARRYERTERRANE


Collisionzone


Metamorphism

Basin fluids

YERRIDA

and deformation

Goo

din

Faul

t

development


NW SE

46

Pirajno et al










47


N S

N S

Marymia In

lier

YILGARN


andvolcanic arc

Seafloor

Seafloor

Oceaniccrust

lt 1960ndash1950 Ma

PILBARA

PILBARAYILGARN

Fold-and-thrustbelt


1820ndash1800 Ma


area

Lithosphere

FMP376 170300

4000

3000

2000

1000

00 21 3

FeOMgO FeOMgO Ni Cr

1

2

0

3

0 1 2

La Eu Lu

Sam

ple

chon

drite

100

10

16

Sam

ple

chon

drite

100

10

2La Eu Lu

2

Cr

(ppm

)

TiO

(

)

TiO x1002

Mid-oc

ean r

idge

2

Clastic rocks

Padbury Group

Archaean basement


Karalundi Formation

Oceanic crust

a)

b)

48

Pirajno et al










49


References































50

Pirajno et al





































51



































52

Pirajno et al

Appendix







Wandery

Creek

Wandery

Gum

Creek

Beda

burra

Easter

nCr

eek

Dim

ble

Dimble

Cree

k

Mt Fr

aser

Creek

Creek

Mt Fraser


MURCHISON

RIVER

GASCOYNE

RIVE

R

GASCOYNE

RIVER

Ck

Cree

k

Creek

Beatty Park B (abd)

Reefer W(abd)

YARLAR

WEELOR

MILGUN

ROAD

MEEKATHARRA

ROAD

ASHBURTON DOWNS


ROADTRILLBAR

Mt Padbury

Yd

Yd

Yd

Yd

Yd Yd

Yd

Yd

Yd

Yd

Yd

Yd

YdYd

MT CLARE

MEEKATHARRA

ROAD

Bryah

Narracoota


Mikhaburra

Yd

Yd

Yd

Yd

(ruin)Bilyuin Hotel


Doolgunna

Yd

YdYd

Yd


Yd

Karalundi

Yd

Yd

Yd

Yd

Bryah

Yd

Mikhaburra

Yarla

rwee

lor H

omes

tead

44

km



Meekatharra 108 km

Meekatharra 53 km

Mooloog

ool Ho

mestead

35 km

Diamond

Well

Homest

ead 68

km

Neds

Creek

Homest

ead 33

km



MT LABOUCHERE

MT ARAPILES

CM 15

MT BEASLEY

MT SEABROOK

TALB

OT

DIVIDE

RED HILL

722 m

Yd

Yd

Yd

Yds

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

YdYd Yd

Yd

Yd

Yd

Yd

628 m

MT PADBURYMT FRASER

MT MAITLAND

R O B I N S O N

591 m

695 m

799 m

Yd

Yd

GREAT

NORTH

ERN

HIGH

WAY

HILL

THRE

E RIVER

S

ROAD

PEAK

MEEKATHARRA

ROAD

ROAD

PEAK HILL

R A N G E

Peak Hill

MC 14

NOONYEREENA HILL

MT LEAKE

MC 13

MC 12

MC 11

ASHBURTON DOWNS

core yard

602 m

605 m

640 m

Peak Hill

Yd

Earrie W Daulby W

Jilly Jilly W

Outcamp W (abd)

Watt W

Curly W

B

6 Mile B4 Corners W


Labouchere W

Sam W

Duffey W

Horseshoe W

Dandy W (PD)(abd)

Carlyon B (PD)

Kinder B (PD)

Vacation B

Garret W

Kylie B

Camel B

W (abd)Billarra W


Carlyon RH (PD)

Yaddyarra W

Mowara BGullgogo B


Stink W (PD)

Crain B

Windalah B

Yandinhah W

Coomballey B

No 1 B

4 Corners W (abd)

Cement Tank W (abd)

Cork Tree B


Thompson B (abd)

W (abd)

Tommy B


Midnight B

Gidgie WW (abd)

Snake W Dry W

Black Hill W

Minniarra W

Top Minniarra W

Doherty W

The Hut W

W

Red Hill W

Randall W

Dooley W

Walebie W

Mandora B

Babbawiri Pool

Winja B

WHWH

PBedaburra P

Friday P

Kerba P

S

Wandery P

W

Valley B

Quartz B


P

Peak Hill B Shed W

Boundary B

No 3 W

McPherson B

Pinnacle B

WH

Mt Leake B

Hill B

Jack W

W

Mt Leake B

John B

No 2 B

Cow Hole B

WH

Red B

WH

No 6 W

Marck W

No 11 W

Limestone W

Dummy B

No 1 B

No 8 B

D

Government W

Central B

Gale W

W

West W

No 6 B

Ealgareengunna WH

Noonyereena P

Beefwood T

Narracoota B

WH

WH

Railway B


32 Mile W

Ruby W

Ruby South W

W (abd)

Scotty W

Ord W

Little Mill B

Killarney W

West WMillie W

D

Ord W (abd)

W(abd)



No1 W

Paddy B (abd)

Kelly BRelief B

Top Dimble W

Despair B

Boundary B (PD)

B (abd)

Padbury W

Govt W (abd)


Wandarrie W

Middle B

W

WW

W

No 3 B

Fish Pond B

Wooly Paddock B

5 Mile W

Knox W


Old Homestead WB

Widespread W

W

Kennedy W

W

Deep W

Ross B


Brunsden W


7 Mile BDavid W

17 Mile B (PD)

Lefeuvre W

Mick W

W (abd)

WH

WHWH

WH

WH

WH WH

S

Gum W (abd)

Wilthorpe W (PD)

1 Mile W

Bullgullan B

Wongawar B

Jinglegunna W

No 13 B

Orchard W

Fraser WW

Sorenson B

Central B


Murphy W

Trudgeon W

Moore W Spelling W

Randell B


Bore Hole BOHara W

Murchison W (abd)


Hill W

Telegraph W

Cashman B (abd)

Ruby Centre W

White WW

McCann W (abd)

Holden W

Gum W

McDonald W

Don BNo 2 BNo 1 B

Bull W

D

D

DD

Gum Well P

Malleah P

Fremanga P

Yallaginda W (abd)

No 7 B (abd)

Stalley W (abd)

Durack W

No 26 W (abd)

Ruby Duffer W (abd)

WHs

WHs

WHWH

WH

WHWH

WH

P

PP

P

P

P

P

P

P

P

P

P

Ruby W (abd)

Narracoota W (abd)

WH S

P

B W

D T

(abd) (PD)

Cheroona W(abd)

Ti Tree B



14

16

18

20




14

16

18

20




1frac34

Chalba Fault

CoolinbarFault

Fortnum Fault

BillaraFault

Wilthorpe

Fault

KindersFault

GoodinFault

Goodi

n

Fault

Murchison

Fault

Goodin

Fault

Padbury

Syncline

Millidie

Syncline

Peak HillAnticline

Robinso

n

Synclin

e

HorseshoeAnticline

3

33

3 3

3

3

3

3

30

85

8035

54

2

2

2

2

2

2

2

2

2

2

2

2

2

2

40

2

2

2

2

40

36

30

40

45

3

36

7081

62

51

6270

86

80

60

87

85

85 72

63

70

80

55

3

4

3

3

3

3

3

8583

68

55

74

85

75

71

61

706260

3

3

3

3

3

3

87

66

70

60

7075

88

8081

4

4

4

4 44 4

4

4

3

3

81 83

80

7872

87

55

33

3

4

4

71

78

73

47

25

85

75

70

2

2

48

62

45

80 63

4785

75

60

60

70

85

15

72

80

60

32

85

60

6030

3565

4

4

4

2 2

4

4

3

3

3

4

3

3

2

42

2

4

4

86

86

73 75

8570 70

85

75

4

5264

58

45

60

80

70

60

78

65

46

80

5051

7050

60

38

80

84

50

70

60

74

56

48

42

70

8278

5058

35

70

80

55

46

58

70

77

85

53

80 52

2

2

2 2

1

1

11

1

2

2

2

2

2

1

1

1

1

1

2

2

2

2

2

2

2

2

2

2

65

50

55 85

80

60

30

70

40

5545 82

80

80

60

78

70

42

60

70

88

60

70

70

80

70

70

75

48

42

45

80

40

30

85

69

74

68

68

52

68

40

50

2

11

65

65

118958

118957

28

70

62

6884

10

72

75

4740

8878

60

74

80

1

2

2

2

2

4

56

80

48

78

85

56

60

6470

80

60

8572

80

65

88

76 85

70

2

2

2

2

2

2

2

2

2

2

2

2

4

3460

64

75

74

72

85

7830

85

8488

75

50

4

60

66

75

48

64

66

10

45

35

80

48

75

58

66

60

72

70

35

80

36

2

88

70

78

25

70

58

45

86

2

80

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igraveAnigraveAnc

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igraveAhiigraveAhi

igraveAhi

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q

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igravePri


igraveAnigraved

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igraveM


igraved

igravePr igravePri

igraveAn

igraveAh

igraveAn

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igravePrg

igravePri

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igravePri

igravePri

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igraveM

igraveAhi

igraveAhi

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igravePli

igraveAh

igraveAhi

igraveAhi

igraveAh

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ethpm

ethpmigravePri

igravePri

igraveAn

igravePr

igravePwh

igravePrg igravePr

igravePri

igravePri

igravePri

igraveAndigraveAnd

igraveAnd

igraveAnd igraveAnd

igravePm

igraveEigraveAk

igraveAnh

igraveAnc

igraveE

igraveAnx

igraveAnh

igraveYm

ethp

igraveAnh

igravePwh

igravePrg

igravePri

igraveAn

igravePr

igraveYm

igraveYc

igraveYjigraveYm

igraveAk

igraveE

igraveE

igraveYjf

igraveYjf

igraveAk

igraveAk

igravePmi

igravePmc

igravePw

igraved

igraved

igravedigraveAhi

igraveAhi

igraved

igraveAn

igraved

igravePla

igravePwh

igraveAnd

igraved

igravePr

igravePr

igraveYj

igraved

igraveAnd

igraveAnd

igraveAr

igraved

igravePl

igravePl

igravePl

igravePla

igravePla

igravePla

igravePla

igravePla

igravePla igravePl

igraveArc

igraveArc

igraveArc

igravePla

igraveAk

ntildegde

ntildegMl

ntildegMl

igraveYjf

igraveYj


ntildegMla

ntildegMla

ntildeg

ntildeg

ntildeg

ntildegn

ntildeng

ntildeng

E

E

E

E

E

E

E 118961

118956

142851

88YacuteEcirc168

igraveAnd


Yarlarweelor

Horseshoe

NathanDeep

Mt Seabrook

Labouchere

Wilthorpe

Wilgeena

Wembley

Livingstone

Harmony

Jubilee


St Crispin

Durack

Heines Find

Mikhaburra

Cashman

Horseshoe Lights

Horseshoe

Yarlarweelor

Mn

T

MnMn

CuAu

Cu

Au

Mn

T

CuAu

HOLDENS

BAXTER

RAVELSTONE

PEAK HILL

HORSESHOE

HOLDENS

Ruby Well

Fortnum

Fortnum






thrust

latera

l ramp


NARRYER

TERRANE

YILGARN

CRATON

Goodin F

ault

GOODIN

INLIER

Jenkin

Fault

Fault

Goodin

MARYMIA

INLIER

thrust ramp

Robinson Syncline

Peak Hill Anticline

Peak Hill Anticline



Marymia Inlier

40



30 km

Bangemall Group

Earaheedy Group

Padbury Group

Bryah Group


Windplain Subgroup

Geological boundary

Fault






15Agrave

30Agrave

45Agrave







45Agrave

30Agrave

15Agrave

Proterozoic granite

Q TR S

SEA LEVEL

5 km

11 km

F G

SEA LEVEL

5 km

11 km

L M O

SEA LEVEL

5 km

11 km

N

J K

SEA LEVEL

5 km

10 km

10 km

SEA LEVEL

5 km

H I


YerridaGroup


SEA LEVEL

5 km

10 km

C D E

SEA LEVEL

5 km

10 km

A B












2




BANGEMALL

EARAHEEDY

PADBURYBASIN

BASINBRYAH

YERRIDABASIN


1 2 3 4

C

58

78

75

20

15

SHEET INDEX




Capr

icorn

Oro

geny

Mar

ymia

Inlie

r_re

work

ed d

uring

the

met

amor

phism

_Ca

prico

rn O

roge

nyup

per g

reen

schist to

lowe

r am

phib

olite

facie

s

gree

nsto

ne b

eltM

ount

Mai

tland





BANGEMALL BASIN


EARAHEEDY BASIN


2000 Mac

YERRIDA BASIN


YILGARN CRATON

2600 Ma and olderc


BASIN

BASIN

igraveAn


igraveAnf

ntildeg

ntildegn

ntildeng

igraveM

igraveE

igraved

igraveg

igraveP

igravePm

igravePmi

igravePmc

igravePr

igravePrg

igravePri

igravePw

igravePwb

igravePwh

igravePl

igravePli

igravePla

igraveAh

igraveAhi

igraveAr

igraveArc


igraveAk

igraveYm

igraveYc

igraveYj

igraveYjf

ntildegMl

ntilderMM

ntildegde

igraveAnf

igravePi

ethp

ethpm

ntildegMli

ntildegMla

igraveYjf

igraveYjf

igraveYj

igraved

igraved

igraveYm

igravePmigravePrg

igravePrigravePri

igravePwh

igraveAn

igraveAk ethp

igraveAnh igraveAnd

ntildegMl

igraveAnh


igraveYjf

igraveAn

ethp

igraveAr igraveAr

igravePwh

ethpm igraveAn

igraveAn

igraveM

igravePrigravePri

igravePriigravePr

igraveAr

igraveAn

ethp

ethpm


igravePw

igravePligravePla

igraveAh

igraveAn

igraveArc igraveAn

igraveArcigraveAnf

igraveAnd

igraveM

igraved

igraveAhiigravePm

igravePl

igraveAn

igraveAr

igravePr

igravePriigravePl



ntildegMl

igraveArc

ntildegMl

ntildegMl

ntildegMl

igraveAnd

igravePrigravePri

igravePwb

igravePl

igraveAn

igraveAhigravePwb

igravePr

igravePri

igravePmi

igraveAr

igraved

igraveAn

igravePm

igravePwb

igravePr

igravePr

igravePri

igravePwigraveAnu

igravePm

igravePmc

igraveAr

igraveAk

igravePw

igraveM

ntildegMla

ntildegntildeg

ntildeg

ntildegntildeng

igraveM igraveM

igravePligraveAhi

igraveAhigraveAh

igraveAn

igraveAnigraveAr

ntildegMl

ethp

ntildeng

igraved igraved

igraved

WA

NT

SA

NSW

Vic

Qld

Tas

ACT

GEOLO

G IC A L SUR VEY

WE

ST

E R N A U S T R AL

IA


WESTERN AUSTRALIA



AND ENERGY




MINISTER FOR MINES














Chert


Quartz mylonite


Amphibolite





MES

OPRO

TERO

ZOIC

PALA

EOPR

OTER

OZOI

CAR

CHAE

AN

Bang

emal

lGr

oup

Eara

heed

yGr

oup

Padb

ury G

roup

Brya

h Gr

oup

Yerri

da G

roup

Win

dpla

in S

ubgr

oup

Moo

loog

ool S

ubgr

oup

Yarla

rwee

lor g

neiss

belt

Narry

er T

erra

ne

lowe

r gre

ensc

hist to

upp

er a

mph

ibol

ite fa

cies

met

amor

phism

_Ca

prico

rn O

roge

ny

Mur

chiso

n Te

rrane

YILG

ARN

CRAT

ONYE

RRID

A BA

SIN

BRYA

H BA

SIN

preh

niteEcirc

pum

pelly

ite to

mid

-gre

ensc

hist fa

cies

met

amor

phism

_Ca

prico

rn O

roge

ny

PADB

URY

BASI

N




Middle Proterozoic

Early Proterozoic




















Geological boundary




Fault



away from observer


anticline

syncline


overturned syncline

towards observer


inclined

vertical

inclined

vertical

overturned


inclined

vertical



mineral lineation






Formed road

Track

Landing ground



Homestead

Locality

Building yard




Waterhole spring

Bore well windpump

Dam tank


Mining centre

Mining locality


Major opencut

Opencut

Alluvial workings

Prospect

Copper

Gold

Manganese

Talc

PILBARACRATON

CAPRICORN OROGEN

CRATONYILGARN

0 5 10 15 20 255000

Metres Kilometres










REPORT 59 PLATE 1


2344

2345

2346

2347

2444

2445

2446

2447

2544

2545

2546

2547

2644

2645

2646

2647

2744

2745

2746

2747

2844

2845

2846

2847

KALLI

MILEURA

GOULD

ERRABIDDY

MADOONGA

KOONMARRA

MOORARIE

MARQUIS

MEEKATHARRA

TIERACO

PADBURY

MILGUN

GABANINTHA

GLENGARRY

BRYAH

JAMINDI

YAGANOO

MOOLOOGOOL

DOOLGUNNA

MEREWETHER

THADUNA

MARYMIA

MOUNT BARTLE

THREE RIVERS

118958

88YacuteEcirc168

BELELE GLENGARRY


SG 50-7 SG 50-8

SG 50-11 SG 50-12



N

P












SEA LEVEL

5 km

11 km




26frac3400Agrave


AREA OF THIS MAP

GSWA

REPORT 60

PLATE 1

E


Q

R

S

T

F

G

L

M

O

P

N

J

K

C

D

E

A

B

H

I

1 2 3

1

2

3

cc 3300

1






3

cc 3300

1

3300

1










Contents

Abstract

Introduction




Bryah Group

Karalundi Formation






Felsic schist



Jasperoidal chert



Horseshoe Formation

Padbury Group


Wilthorpe Formation





Structure

D1 structures

D2 structures


D4 structures

Metamorphism


Mineralization

Gold deposits


Harmony deposit


Wembley deposit

Wilgeena deposit


Ruby Well group

Mikhaburra deposit

Wilthorpe deposit

Cashman deposit



Iron ore

Talc

Discussion


Acknowledgements

References



Figures



































Tables












86342 746314 7198282 5151 032 1523 928 018 1049 1007 269 019 003 673 166 1 95 12 11

86383 670171 7163822 5353 091 1468 115 019 744 863 299 005 008 253 100 1 85 21 53

86384 670171 7163822 5048 062 1444 991 016 1135 933 362 004 005 640 209 1 157 16 33

86397 799422 7201118 5529 026 1502 817 017 1136 416 549 005 002 1174 244 0 44 15 8

104248 722651 7168587 4925 022 1137 963 017 1818 948 159 009 002 1 80 9 6

104249 722651 7168587 4911 026 1065 973 017 2016 855 126 009 003 1 34 11 7

104254 715830 7171470 4948 023 1121 95 016 2035 706 194 005 002 1877 647 1 49 11 7

104255 715830 7171470 52 033 143 847 017 1071 1087 31 002 003 664 209 0 133 13 13

104256 715830 7171470 5244 067 1455 1007 019 834 983 376 007 007 0 140 17 34

104257 713820 7171502 5144 092 1453 1078 02 689 1244 248 023 009 265 79 3 195 18 53

104264 685287 7155494 5303 062 1391 94 017 768 1239 265 01 006 720 222 1 90 15 32

104265 685287 7155494 5332 025 1592 97 017 658 1215 184 003 004 353 67 1 30 15 11

104288 661877 7126843 5979 024 1346 798 016 522 1265 042 004 004 283 46 0 17 15 11

104289 656054 7130760 5446 014 1559 955 017 826 957 204 019 003 358 116 4 43 8 6

104292 657132 7123177 5103 09 1369 971 017 827 1334 272 009 008 0 165 18 51

104294 664424 7119210 5108 095 1449 1021 018 879 1094 283 046 008 523 141 5 123 19 52

104295 664424 7119210 5228 096 1446 1022 018 946 856 364 016 009 465 132 2 79 19 54

104298 669014 7106533 5233 087 1367 939 017 778 1189 373 01 008 514 116 1 116 17 49

104299 669014 7106533 5166 093 1404 982 018 823 1183 305 017 009 491 117 3 124 18 53

104300 669014 7106533 477 05 173 984 019 747 1484 197 016 004 3 142 12 22

104386 676392 7146500 5373 037 1501 846 016 864 977 373 009 004 557 152 0 106 18 18

104391 687552 7144198 5002 023 845 934 016 2281 88 014 002 002 0 15 11 6

104392 687552 7144198 5391 027 92 998 014 2087 515 017 027 003 2508 1103 12 16 22 10

104393 687539 7143275 508 023 965 1025 01 289 004 0 001 001 0 3 5 6

104394 687539 7143275 5594 05 1494 867 019 73 697 537 006 006 363 88 0 90 19 24

104397 670399 7142584 4687 019 1023 1015 017 2496 726 015 001 001 2786 971 0 7 8 4

104398 669575 7143518 5329 035 1453 813 014 828 1207 315 002 004 574 124 0 78 13 14

104399 670423 7144430 5183 036 1491 866 016 932 1147 323 002 003 682 173 0 42 14 14

104400 670023 7145280 4958 037 1577 987 019 1044 1082 291 002 003 510 124 0 68 17 15

109487 638809 7157725 5719 043 1423 73 013 868 626 569 004 004 442 116 0 18 11 19

109492 663796 7149130 5231 011 617 72 015 24 1002 001 001 001 0 7 5 1

109493 663796 7149130 5246 047 1508 881 019 766 1218 247 064 005 478 90 6 72 15 21

109504 670124 7121353 5396 048 149 859 015 716 1237 231 003 005 445 96 0 61 17 22

109513 732634 7164722 5396 197 1434 953 02 638 686 592 064 019 16 117 24 97

112601 668775 7146298 5332 179 1568 102 025 644 561 601 053 017 10 105 21 90















































































120891 677938 7168840 4880 082 1430 385 717 018 765 1280 174 008 008 330 10077 1 4 10 86 4 5 6 137 107 15 5 2 7 105 4 2 4 4 142 2 2 257 24 83 60










132793 622866 7161836 4860 031 1350 362 510 013 1040 1090 231 001 003 321 9812 2 4 3 29 4 5 6 872 45 61 11 3 97 7 379 4 3 2 2 4 4 72 2 2 216 14 4 60 21

132794 622866 7161786 4840 014 576 203 615 015 2160 863 033 001 001 549 9870 2 4 4 11 6 5 6 2460 71 22 5 3 2 7 1020 4 4 3 2 4 4 11 2 2 155 7 4 63 13

133033 638351 7157551 4450 156 1110 611 440 020 318 1330 468 034 021 906 9864 01 05 5 323 07 01 296 190 36 84 05 126 01 11 75 19 11 11 51 02 1 07 135 22 07 276 241 05 73 108

133034 638351 7157551 4710 013 836 237 696 014 1980 764 012 001 003 596 9862 02 12 2 18 45 01 32 3448 69 22 16 16 23 32 1048 11 5 9 17 18 42 19 52 15 01 133 58 84 72 108

133035 638300 7157750 4740 013 668 349 512 014 2200 801 022 003 001 521 9844 02 07 6 52 14 01 11 2608 73 34 22 12 03 33 1295 15 10 9 22 06 29 1 12 16 02 116 72 58 61 447

133038 632615 7159390 5060 048 1600 316 443 012 572 1410 150 032 006 267 022 102 lt05 70 110 lt05 lt01 216 392 29 93 57 147 10 12 28 138 29 lt2 3 179 297 31 74 141 21 28776 02 181 14 139 59 709


133043 632906 7159832 4970 073 1490 272 790 018 626 1260 171 031 006 236 022 03 21 30 412 09 01 46 66 37 129 05 61 8 06 41 121 48 lt2 9 99 44 11 27 119 13 43764 02 268 203 33 88 470






133051 635603 7169579 0 74 0 02 15 12 114 114 24 91 13 05 84 73 27 12 11 24 0 40 15 158 173 043 256 18 05 74 62

133052 635259 7169444 5160 086 1360 411 719 016 569 1030 155 048 008 344 9906 038 01 05 2 151 05 01 94 148 37 136 33 11 03 34 93 05 2 2 105 02 24 05 145 05 01 296 191 05 85 718

133054 634952 7169267 0 62 05 0 38 5 105 44 18 25 41 12 13 57 48 5 6 12 0 26 18 411 6 166 182 18 08 38 104

133060 648256 7160919 0 23 0 02 19 6 89 129 18 10 5 12 88 62 27 3 0 92 0 38 21 251 111 037 318 25 08 85 76

133063 648467 7150024 4400 018 889 410 531 015 2270 702 037 003 002 705 9982 011 01 05 2 7 05 01 05 3170 83 19 53 05 03 18 1370 15 9 13 09 04 23 05 135 05 01 123 76 27 72 139

133064 647573 7150076 5150 032 1450 307 514 015 634 1390 178 001 003 244 9918 015 01 05 3 50 05 01 05 456 29 40 65 14 04 09 191 05 11 11 05 04 36 05 577 05 01 222 144 21 61 26

133073 626850 7161292 5150 033 1440 273 573 014 748 1250 232 001 003 264 9981 011 01 05 3 43 05 01 05 467 38 78 32 19 02 29 202 14 13 12 05 03 32 05 497 05 01 219 137 05 61 258

133076 626850 7161292 4990 074 1490 410 612 015 546 1320 148 006 007 297 9915 022 01 05 3 42 05 01 85 154 33 55 65 34 03 34 93 05 7 11 05 02 33 05 151 05 01 263 169 16 84 678

133096 645954 7171243 4500 013 916 192 711 014 2110 744 015 002 001 699 9917 022 01 05 2 75 05 01 23 3100 93 69 6 146 06 14 1620 17 7 7 07 17 26 05 27 05 01 132 212 21 69 103

133098 636053 7155351 4950 057 1510 228 646 014 728 1380 135 010 006 307 9971 015 01 05 6 174 05 01 08 487 31 81 47 58 05 37 165 05 12 16 15 02 26 05 112 35 02 220 135 05 64 429

136749 667073 7199167 5080 072 1420 410 567 015 601 1330 166 022 007 221 9911 011 01 05 4 222 05 01 42 331 37 82 57 59 04 29 131 1 12 11 32 07 31 05 237 05 01 257 175 15 75 665

136751 659000 7122223 0 12 0 0 98 3 209 68 15 62 34 04 44 86 2 9 7 43 0 34 09 304 053 021 207 15 09 48 23

139131 621200 7215100 4790 065 1470 301 746 019 682 1290 254 004 006 319 9946 026 01 05 3 211 05 01 43 358 43 103 07 4 02 46 154 05 8 14 05 02 29 05 616 05 02 281 19 05 77 484

139132 621190 7215090 0 14 0 01 11 0 66 18 46 59 40 05 95 11 14 0 0 108 0 51 21 242 87 124 389 7 24 51 134

139133 666700 7193500 0 09 0 02 56 0 0 18 37 39 92 05 63 4 62 0 0 63 0 53 19 33 21 24 29 18 08 25 290

139134 621755 7169255 0 08 0 0 85 3 3 3 15 63 14 09 06 0 2 0 0 73 0 06 08 76 129 05 4 3 03 3 35

139135 621000 7169500 5016 037 1406 241 647 017 918 1126 248 006 003 15 5812 222 438 53 65 10 438 077 1320 100E-07 171 100E-07 500E-08 54 2 53 500E-08 500E-08 212 15 72 19 036 194 094 048 190 038 289 071 222 034 232

139136 621000 7169500 5236 027 1373 239 577 016 897 1068 21 007 003 15 5265 210 491 53 162 10 491 086 1290 100E-07 196 100E-07 1 48 200E-07 62 500E-08 500E-08 189 13 63 13 036 161 078 041 160 039 259 068 214 038 221

139137 620904 7169533 4737 108 1123 33 789 018 1191 106 203 008 012 15 13407 2170 1150 82 119 15 1150 897 1380 6 525 2 500E-08 39 4 143 1 500E-08 265 17 90 65 278 1143 314 124 391 066 391 084 222 031 187

139138 620992 7169508 5075 03 141 177 678 017 996 925 264 044 002 05 7628 124 660 56 61 10 660 042 1310 100E-07 232 100E-07 55 49 2 62 500E-08 500E-08 194 12 65 14 019 104 062 031 135 030 225 055 166 026 175

139139 620992 7169508 4747 018 1006 141 804 017 1989 829 089 002 001 500E-08 7171 148 1770 95 53 75 1770 089 1320 100E-07 835 100E-07 500E-08 39 2 225 500E-08 500E-08 139 8 60 7 019 098 063 028 124 028 206 051 157 026 160

139140 620992 7169508 5201 117 1269 224 762 016 761 1089 239 025 013 05 8447 2455 212 52 161 15 212 982 1210 5 135 100E-07 45 42 4 228 1 500E-08 270 17 87 80 308 1270 330 120 387 061 364 074 200 028 161

139141 620992 7169488 6179 081 147 284 594 006 496 012 007 32 01 1 74341 6413 414 41 31 19 414 2988 410 12 163 3 161 29 4 11 155 3 90 19 132 198 677 2282 433 094 430 059 295 058 166 026 170

104256h 715830 7171470 6528 068 1179 412 511 004 551 013 005 24 012 1 44782 7429 348 39 2 15 348 3419 300 10 176 3 121 21 4 9 19 3 73 27 83 266 834 2926 592 121 584 082 451 089 249 038 231

104393s 687539 7143275 3634 015 744 519 582 02 1191 1139 002 001 002 177 2109 066 2020 175 257 6 043 1440 00000001 1000 00000001 000000005 24 2 42 000000005 05 108 6 35 13 016 080 044 022 067 014 094 022 074 012 090 015

112601s 668775 7146298 1248 005 339 812 262 026 1592 217 005 001 0 156 1400 058 850 63 46 25 066 1990 00000001 1010 1 000000005 10 2 66 000000005 000000005 87 11 22 3 024 085 052 025 083 021 145 034 111 017 131 021

112604s 672238 7155486 7639 017 1136 256 551 022 087 002 002 01 001 457 15133 087 2260 9 10 8 031 1590 00000001 228 1 45 21 00000002 17 000000005 05 149 2 17 9 009 043 014 012 017 004 028 006 023 004 035 005

112643h 675190 7125902 5583 097 1236 543 726 045 595 128 308 005 015 195 2804 1728 46 41 13 145 738 3010 2 63 1 2 58 2 38 000000005 000000005 278 24 111 58 201 930 276 073 275 049 297 064 202 031 236 038

116454s 653363 7152948 2576 011 467 59 024 018 1282 1816 172 064 003 695 7663 012 1570 58 23 35 042 1370 00000001 620 2 34 15 00000002 385 000000005 000000005 76 5 30 4 013 027 019 018 037 010 069 017 060 009 070 011

116477s 645436 7177439 2009 0 084 152 0 038 1639 2363 022 04 003 6 6838 126 31 10 19 000000005 107 2940 00000001 93 1 75 00000001 00000002 103 000000005 000000005 9 10 4 00000001 034 113 036 118 051 012 084 027 105 017 142 020

116485h 655767 7129994 5901 078 1092 14 102 013 1024 016 003 0 008 65 744 774 86 47 39 125 276 965 2 136 00000001 000000005 62 2 15 000000005 000000005 304 15 85 45 099 490 138 035 148 026 164 036 114 018 143 023

116487h 655561 7129043 2488 011 535 29 312 04 1401 2084 003 004 005 110 4392 265 1410 69 15 5 175 3200 00000001 685 1 15 19 2 140 000000005 05 99 5 42 14 048 147 045 021 054 010 063 013 045 007 052 008

116493h 655992 7125530 5148 073 1516 172 1092 013 932 024 26 03 009 15 10919 1023 98 58 72 155 430 935 2 98 00000001 45 69 2 75 000000005 1 357 18 113 42 127 601 174 057 201 036 234 054 176 028 217 036

116501h 708508 7162137 4773 039 1372 423 456 016 666 527 438 098 006 1 120917 449 56 49 35 13 1277 1170 1 192 2 31 67 00000002 51 000000005 000000005 284 29 114 20 154 703 155 116 228 033 198 048 147 020 136 024

116518s 685232 7155526 3765 02 609 573 0 152 597 1736 007 218 005 100 218361 3411 55 39 15 7 1396 11070 4 70 5 65 8 00000002 77 55 1 60 12 38 38 321 1160 235 171 234 031 155 028 088 013 096 015

120303 655250 7126000 2302 011 404 31 071 059 074 3572 004 141 004 53 20581 1117 285 7 4 45 720 4740 1 51 12 435 00000001 2 96 25 000000005 36 9 21 17 141 504 105 042 126 021 127 030 097 015 109 019

120339A 669650 7146425 9409 001 03 425 065 002 003 005 0 006 003 155 1042 267 29 6 65 05 117 110 00000001 15 10 85 1 00000002 5 05 05 55 1 10 4 023 092 016 004 021 003 014 003 009 001 012 002

120339B 669650 7146425 9632 0 002 319 053 001 0 001 0 0 001 5 2442 083 6 3 9 000000005 039 40 00000001 3 1 000000005 00000001 00000002 1 000000005 000000005 10 00000001 3 2 008 030 006 004 009 001 005 002 006 001 008 001

120369s 665175 7156150 6131 098 1297 175 906 025 457 058 144 134 007 285 27950 3230 284 43 121 15 1406 1690 6 128 13 54 41 4 305 65 1 178 16 119 106 355 1340 286 087 269 039 202 036 119 017 130 021

120373s 675250 7167875 5541 088 1306 795 346 014 199 144 005 004 009 1 7754 1109 26 29 74 225 521 1040 2 41 3 05 48 4 67 000000005 000000005 494 25 50 55 161 716 213 067 256 050 325 074 237 035 267 041

120432s 673950 7171700 5469 078 1137 81 399 02 311 1468 016 005 006 2 11068 1433 62 44 22 20 634 1490 1 88 8 15 55 4 495 1 000000005 346 24 49 49 202 897 283 137 343 070 452 104 321 048 354 051

82137A not available 6241 067 991 186 893 019 924 011 0 005 01 15 2345 6927 595 43 123 12 3489 1470 10 235 4 25 21 4 55 175 2 77 16 112 288 734 2545 453 074 448 050 239 041 129 019 143 023

82137B not available 6118 074 1029 19 912 019 96 011 0 009 01 1 3042 6659 780 45 121 12 2999 1430 10 218 6 4 22 4 4 175 25 80 27 116 312 704 2493 499 095 542 075 415 083 249 037 262 039

82144 not available 6901 044 1124 143 288 021 188 365 27 14 013 15 38750 6263 117 22 22 12 3381 1690 8 48 37 67 11 2 107 175 25 46 19 61 199 679 2348 436 093 441 056 304 052 157 022 154 022

82148 not available 6314 07 124 312 581 017 717 01 005 197 01 1 41557 6431 505 53 22 15 3168 1310 10 211 4 99 23 4 8 165 25 72 18 121 227 689 2407 462 095 440 055 281 050 159 022 168 025

82150 not available 9469 001 012 45 062 001 001 001 0 0 001 1150 13761 225 10 2 7 000000005 310 40 00000001 11 00000001 000000005 00000001 6 000000005 000000005 3800 00000001 700 300 044 122 021 012 021 002 013 002 004 000 005 001

82153 not available 41767 296 256 047 214 049 031 072 013 090 023 077 010 072 010












82234 not available 4847 087 1468 1174 022 874 1394 099 027 008 332 83 3 225 21 48

82236 not available 5135 087 1461 1117 02 757 1032 274 109 008 228 70 15 329 19 49





iii

Contents













Appendix


Plate


iv

Figures











Tables





MIGSDAF
File Attachment
narracootacsv
MIGSDAF
Note

1




by











2

Pirajno et al






Gee (1987)P

AD

BU

RY

BA

SIN

GR

OU

PG

LEN

GA

RR

Y B

AS

ING

RO

UP



Wilthorpe Formation


Horseshoe Formation


Karalundi Formation

Doolgunna Formation

Johnson Cairn Shale

Thaduna Greywacke

Juderina Formation

Maraloou Formation


Finlayson Sandstone


GLE

NG

AR

RY

BA

SIN

GR

OU

P

Maraloou Formation

Thaduna Greywacke


Doolgunna Formation

Johnson Cairn Shale


YE

RR

IDA

BA

SIN

GR

OU

P

Win

dpla

in S

ubgr

oup

Moo

loog

ool S

ubgr

oup

Peak Hill Schist

BR

YA

H B

AS

ING

RO

UP

PA

DB

UR

Y B

AS

ING

RO

UP

TE

CT

ON

IC C

ON

TA

CT


Wilthorpe Formation


Horseshoe Formation

Karalundi Formation




Doolgunna Formation

Thaduna Formation

Juderina Formation

170100



Unconformity

Unconformity




ARCHAEAN BASEMENT

FMP409a

3




















faulted contact



4

Pirajno et al





MARYMIAINLIER

GOODININLIER

Goodin

Fault

Fault

Killara

Narracoota

30 km

PILBARACRATON

CAPRICORN OROGEN

CRATONYILGARN

FMP375

117deg

30

118deg

30

26deg00

25deg00

Murchison

FaultMorris

Earaheedy Group

Padbury Group

Yerrida Group


Bangemall Group

Bryah Group


Fault

Moorarie Padbury

MilgunMarquis

FaultCooinbar

NarryerTerrane

Murchison

Terrane

Kerba Fault

119deg

30

Gabanintha Yanganoo

MooloogoolGlengarry

Bryah Doolgunna


010300

BRYAH-PADBURY

BASINS

PROTEROZOIC

5










6

Pirajno et al





Karalundi Formation





7















8

Pirajno et al









9













Felsic schist



10

Pirajno et al










11






Jasperoidal chert









12

Pirajno et al



Percent


Mg 6687 6615 6795 6692 6736 6377 6142 6816 792 85 843 ndash ndash

Parts per million






13















35 45 55 650

1

2

3

4

foidite andesite

basalt

boninite

basalticandesite

MgOgt18 picrite

basanite

tephrite


picrobasalt

FMP365 021199

22

2

2

2

2


SiO (wt)

Na

O +

K O

(w

t)


14

Pirajno et al




20

16

12

8

4

0

Na

O +

KO

(w

t)

22

857565554535

SiO (wt)2 11999FMP367

Hyaloclastite

Mafic schist

Ultramafic schist

Subalkaline

Alkaline


3

2

1

0

TiO

(wt

)2

1 2FeO MgO (wt)

Hyaloclastite

Mafic schist

Ultramafic schist

4000

3000

2000

1000

0

Cr

(ppm

)

1 2 3FeO MgO (wt)

Hyaloclastite

Mafic schist

Ultramafic schist

TiO 1002

Ni Cr91199FMP368a

Hyaloclastite

Mafic schist

Ultramafic schist

a)

b)

c)

15





a)

c)

b)

d)

MgO

TA

TDTR

CR CDCA

HFTBK

PKCB

HMT

Sam

ple

chon

drite

100

10




Sam

ple

chon

drite

100

10

1

6

FeO

MgO

221199

Al O32

FeO + TiO2

Al O32

FMP154




16

Pirajno et al








Horseshoe Formation



CFB

MORB

20

18

15

13

10

08

05

03

000 1 2

TiO

2


Mafic schist

Hyaloclastite rocks

(tot)FeO MgO


17








FMP156 020300

0

100

200

300


Garnetiferous BIF





(m)



Micaceous wacke


18

Pirajno et al











19



Wilthorpe Formation












20

Pirajno et al














21














22

Pirajno et al







FMP371

MARYMIAINLIER

YILGARNCRATON

Goodin

Fault

GROUPBANGEMALL

Murchison Fault

118deg30 119deg30

30 km

020300


Anticli

ne

Robinso

n

Synclin

e

Nathan Syncline

Zone of D folding3

Padbury

Horseshoe Anticline

Wilthorpe F

t


GOODININLIER

EARAHEEDYGROUP

25deg30

26deg00

Syncline

Millidie Syncline

FaultD fold trace3

D fold trace2

1

D fault1

Anticline


Yarlarweelorgneiss

complex

FraserSynclinorium

23












280degndash310deg




24

Pirajno et al




118deg 119deg

25deg45

10 km

MarymiaInlier

YilgarnCraton

BangemallBasin

Bill

ara

Fa

ult

Wilt

horp

eF

Fortnum

25deg30

Goo

din

Faul

t

Kinders FaultNathan

Peak Hill

B

AC

Mt Fraser



YerridaBasin

PADBURY GROUP

BRYAH GROUP





YERRIDA GROUP


PA

LA

EO

PR

OT

ER

OZ

OIC

Greenstone

Peak Hill Schist

AR

CH

AE

AN

Fault

Anticline

Syncline

ME

TA

MO

RP

HO

SE

D



Unconformity

Mine

Cross-section





140300FMP373

25












26

Pirajno et al

0

2

4

6

Fault

Kilo

met

res

Southwest Northeast

FMP372

0

2

4

6

Kilo

met

res

West East

Billara

Fault

Kilo

met

res

0 Padbury

South North

SynclineDome

2

4

6

Yarlar-weelor

170300

Fault

Kinders

MIDDLE PROTEROZOIC


Bangemall Group

Unconformity


Foliation

High-strain zone

Fault



2

BRYAH GROUP

Geological boundary

Padbury Basin

Bryah Group

S N

d)



ARCHAEAN (in situ)








YERRIDA GROUP


Goodin






a) Cross section A



27











28

Pirajno et al

















29



ram

p

Peak Hill Anticline

N S



ramp Obliq

ue

lateral ramp

Yarlarweelor

Basalthrustplane

2Dc)

d)

2D thrust flat

rsquo


gneiss complex

Padbury Group

Bryah Group


a)

Archaean granite

b)



1 2Post-D and pre-D


rsquo1

Post-D D2 3

W E

Thrust ramp

Thrustfrontal

Later

al ra

mp

FMP374 011199

W E

N

Thrust flatrsquo

movement

Thrust

North to south

e)

ramprsquo

flatrsquorsquo





30

Pirajno et al










31





1 1


1

Murchison Fault


Hyaloclastites


Post-rift phase



a)

b)

c)

v

SAO62 130300



NNW1

SSE

1

2 3

Early- and syn-D







D ndashD

Bryah Group


Padbury Group

32

Pirajno et al






Future D fault

NNW SSE

Bryah Group

Basement



1Peak Hill Schist

D faults1

1



Marymia Inlier

a)

b)

SAO63 150300

Padbury Group

Early- and syn-D


33









YILGARNCRATON

vv

v

vv

v

vv

vv v

v

v

v vv v

vvv

vvv

vvv

vv

Errabiddy



SAO64 130300

NW SE


v v

Bangemall Group



Cooinbar Fault

34

Pirajno et al




Pre-1986


1986 to 30 June 1999



Total 17 9128 59 0577 3487 1878 59 595 5 412 15 496 75 091



35

GSW

A R

eport 59G



adbury Basins W

A



(t) (t) (t) (t) (t)



Total 261 745 49 1824 5 420 000 45776 94 9584



Inferred 205 000 100 000 100 000







36

Pirajno et al













copper and gold

























37


MARYMIAINLIER

MARYMIAINLIER

Jenkin

FaultGROUPBANGEMALL

Murchison Fault

NARRYERGNEISS

TERRANE

Padbury Bryahand

Yerrida Basins

FMP100b 181099

1000 km

5

67 16

8

9

17

23

4

11

10

15

1213 14

19

18

21

20

1

GOODININLIER

YILGARNCRATON

YILGARN

CRATON

Goodin

Fault

118deg30 119deg30

Killara

Narracoota

Mt Padbury

PILBARACRATON

CAPRICORN OROGEN

CRATONYILGARN

Yandil

119deg30

Milgun30 km


PEAK HILLROBINSON

RANGE




119deg00

25deg30

26deg30

26deg00

25deg30

GLENGARRY

Milgun



Epigenetic Pb

Supergene Mn

2 Jubilee

5 Labouchere









Geological boundary


Peak Hill Schist


OU

PB

RY

AH

Padbury Group



Archaean basement

Earaheedy Group

WindplainSubgroup

MooloogoolSubgroup

YE

RR

IDA

GR

OU

P


Homestead

Bangemall Group

Microgabbro dyke

BryahPEAK HILL








MINERAL DEPOSITS

38

Pirajno et al




Karalundi Formation

Horseshoe Formation



10 km

040400

Yerrida Group

Bangemall Group

Earaheedy Group

Padbury Group

Bry

ah G

roup

Prospect

Producer

JubileeGroup

Peak Hill

Harmony

Wilgeena

Wembley

DurackWell

HeinesFind

Mikhaburra

CashmanGroup

Ruby WellGroup

Goodin Find

Ravelstone Group

(Hit or Miss)


25deg30

118deg

30

119deg

00

26deg00

Mar

ymia

Inlie

r mylonite

Syncline

Anticline

Overturned syncline

Peak Hill Schist

Thrust fault

Fault

Strike-slip fault

FMP162a




Mount Pleasant

39













40

Pirajno et al




FIVEWAYSPIT

MINIPIT

MAINPIT

100 m

sequence

Mine sequence


Vein quartz

Marker Quartzite

Shear zone

Anticline

FMP160 271099

Hangingwall

Geology notmapped

Geology notmapped

N40

42

45

40

25

45

45 26

30

42

45

Fault42

Cleavage

Foliation




41






Harmony deposit








50 m

FMP159

Supergene ore

Primary ore

Pit outline

50

100

150

200

Met

res

Mafic rocks

Formation)

Ultramafic rocks


(Narracoota


Pelitic rocks

SW NE

211099

42

Pirajno et al









Wembley deposit


43



Wilgeena deposit










Ruby Well group



Mikhaburra deposit


Wilthorpe deposit


44

Pirajno et al

Cashman deposit








45











FMP71a


Mooloogool Subgroup

Windplain Subgroup


170300


ARCHAEANBASEMENT

NARRYERTERRANE


Collisionzone


Metamorphism

Basin fluids

YERRIDA

and deformation

Goo

din

Faul

t

development


NW SE

46

Pirajno et al










47


N S

N S

Marymia In

lier

YILGARN


andvolcanic arc

Seafloor

Seafloor

Oceaniccrust

lt 1960ndash1950 Ma

PILBARA

PILBARAYILGARN

Fold-and-thrustbelt


1820ndash1800 Ma


area

Lithosphere

FMP376 170300

4000

3000

2000

1000

00 21 3

FeOMgO FeOMgO Ni Cr

1

2

0

3

0 1 2

La Eu Lu

Sam

ple

chon

drite

100

10

16

Sam

ple

chon

drite

100

10

2La Eu Lu

2

Cr

(ppm

)

TiO

(

)

TiO x1002

Mid-oc

ean r

idge

2

Clastic rocks

Padbury Group

Archaean basement


Karalundi Formation

Oceanic crust

a)

b)

48

Pirajno et al










49


References































50

Pirajno et al





































51



































52

Pirajno et al

Appendix







Wandery

Creek

Wandery

Gum

Creek

Beda

burra

Easter

nCr

eek

Dim

ble

Dimble

Cree

k

Mt Fr

aser

Creek

Creek

Mt Fraser


MURCHISON

RIVER

GASCOYNE

RIVE

R

GASCOYNE

RIVER

Ck

Cree

k

Creek

Beatty Park B (abd)

Reefer W(abd)

YARLAR

WEELOR

MILGUN

ROAD

MEEKATHARRA

ROAD

ASHBURTON DOWNS


ROADTRILLBAR

Mt Padbury

Yd

Yd

Yd

Yd

Yd Yd

Yd

Yd

Yd

Yd

Yd

Yd

YdYd

MT CLARE

MEEKATHARRA

ROAD

Bryah

Narracoota


Mikhaburra

Yd

Yd

Yd

Yd

(ruin)Bilyuin Hotel


Doolgunna

Yd

YdYd

Yd


Yd

Karalundi

Yd

Yd

Yd

Yd

Bryah

Yd

Mikhaburra

Yarla

rwee

lor H

omes

tead

44

km



Meekatharra 108 km

Meekatharra 53 km

Mooloog

ool Ho

mestead

35 km

Diamond

Well

Homest

ead 68

km

Neds

Creek

Homest

ead 33

km



MT LABOUCHERE

MT ARAPILES

CM 15

MT BEASLEY

MT SEABROOK

TALB

OT

DIVIDE

RED HILL

722 m

Yd

Yd

Yd

Yds

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

Yd

YdYd Yd

Yd

Yd

Yd

Yd

628 m

MT PADBURYMT FRASER

MT MAITLAND

R O B I N S O N

591 m

695 m

799 m

Yd

Yd

GREAT

NORTH

ERN

HIGH

WAY

HILL

THRE

E RIVER

S

ROAD

PEAK

MEEKATHARRA

ROAD

ROAD

PEAK HILL

R A N G E

Peak Hill

MC 14

NOONYEREENA HILL

MT LEAKE

MC 13

MC 12

MC 11

ASHBURTON DOWNS

core yard

602 m

605 m

640 m

Peak Hill

Yd

Earrie W Daulby W

Jilly Jilly W

Outcamp W (abd)

Watt W

Curly W

B

6 Mile B4 Corners W


Labouchere W

Sam W

Duffey W

Horseshoe W

Dandy W (PD)(abd)

Carlyon B (PD)

Kinder B (PD)

Vacation B

Garret W

Kylie B

Camel B

W (abd)Billarra W


Carlyon RH (PD)

Yaddyarra W

Mowara BGullgogo B


Stink W (PD)

Crain B

Windalah B

Yandinhah W

Coomballey B

No 1 B

4 Corners W (abd)

Cement Tank W (abd)

Cork Tree B


Thompson B (abd)

W (abd)

Tommy B


Midnight B

Gidgie WW (abd)

Snake W Dry W

Black Hill W

Minniarra W

Top Minniarra W

Doherty W

The Hut W

W

Red Hill W

Randall W

Dooley W

Walebie W

Mandora B

Babbawiri Pool

Winja B

WHWH

PBedaburra P

Friday P

Kerba P

S

Wandery P

W

Valley B

Quartz B


P

Peak Hill B Shed W

Boundary B

No 3 W

McPherson B

Pinnacle B

WH

Mt Leake B

Hill B

Jack W

W

Mt Leake B

John B

No 2 B

Cow Hole B

WH

Red B

WH

No 6 W

Marck W

No 11 W

Limestone W

Dummy B

No 1 B

No 8 B

D

Government W

Central B

Gale W

W

West W

No 6 B

Ealgareengunna WH

Noonyereena P

Beefwood T

Narracoota B

WH

WH

Railway B


32 Mile W

Ruby W

Ruby South W

W (abd)

Scotty W

Ord W

Little Mill B

Killarney W

West WMillie W

D

Ord W (abd)

W(abd)



No1 W

Paddy B (abd)

Kelly BRelief B

Top Dimble W

Despair B

Boundary B (PD)

B (abd)

Padbury W

Govt W (abd)


Wandarrie W

Middle B

W

WW

W

No 3 B

Fish Pond B

Wooly Paddock B

5 Mile W

Knox W


Old Homestead WB

Widespread W

W

Kennedy W

W

Deep W

Ross B


Brunsden W


7 Mile BDavid W

17 Mile B (PD)

Lefeuvre W

Mick W

W (abd)

WH

WHWH

WH

WH

WH WH

S

Gum W (abd)

Wilthorpe W (PD)

1 Mile W

Bullgullan B

Wongawar B

Jinglegunna W

No 13 B

Orchard W

Fraser WW

Sorenson B

Central B


Murphy W

Trudgeon W

Moore W Spelling W

Randell B


Bore Hole BOHara W

Murchison W (abd)


Hill W

Telegraph W

Cashman B (abd)

Ruby Centre W

White WW

McCann W (abd)

Holden W

Gum W

McDonald W

Don BNo 2 BNo 1 B

Bull W

D

D

DD

Gum Well P

Malleah P

Fremanga P

Yallaginda W (abd)

No 7 B (abd)

Stalley W (abd)

Durack W

No 26 W (abd)

Ruby Duffer W (abd)

WHs

WHs

WHWH

WH

WHWH

WH

P

PP

P

P

P

P

P

P

P

P

P

Ruby W (abd)

Narracoota W (abd)

WH S

P

B W

D T

(abd) (PD)

Cheroona W(abd)

Ti Tree B



14

16

18

20




14

16

18

20




1frac34

Chalba Fault

CoolinbarFault

Fortnum Fault

BillaraFault

Wilthorpe

Fault

KindersFault

GoodinFault

Goodi

n

Fault

Murchison

Fault

Goodin

Fault

Padbury

Syncline

Millidie

Syncline

Peak HillAnticline

Robinso

n

Synclin

e

HorseshoeAnticline

3

33

3 3

3

3

3

3

30

85

8035

54

2

2

2

2

2

2

2

2

2

2

2

2

2

2

40

2

2

2

2

40

36

30

40

45

3

36

7081

62

51

6270

86

80

60

87

85

85 72

63

70

80

55

3

4

3

3

3

3

3

8583

68

55

74

85

75

71

61

706260

3

3

3

3

3

3

87

66

70

60

7075

88

8081

4

4

4

4 44 4

4

4

3

3

81 83

80

7872

87

55

33

3

4

4

71

78

73

47

25

85

75

70

2

2

48

62

45

80 63

4785

75

60

60

70

85

15

72

80

60

32

85

60

6030

3565

4

4

4

2 2

4

4

3

3

3

4

3

3

2

42

2

4

4

86

86

73 75

8570 70

85

75

4

5264

58

45

60

80

70

60

78

65

46

80

5051

7050

60

38

80

84

50

70

60

74

56

48

42

70

8278

5058

35

70

80

55

46

58

70

77

85

53

80 52

2

2

2 2

1

1

11

1

2

2

2

2

2

1

1

1

1

1

2

2

2

2

2

2

2

2

2

2

65

50

55 85

80

60

30

70

40

5545 82

80

80

60

78

70

42

60

70

88

60

70

70

80

70

70

75

48

42

45

80

40

30

85

69

74

68

68

52

68

40

50

2

11

65

65

118958

118957

28

70

62

6884

10

72

75

4740

8878

60

74

80

1

2

2

2

2

4

56

80

48

78

85

56

60

6470

80

60

8572

80

65

88

76 85

70

2

2

2

2

2

2

2

2

2

2

2

2

4

3460

64

75

74

72

85

7830

85

8488

75

50

4

60

66

75

48

64

66

10

45

35

80

48

75

58

66

60

72

70

35

80

36

2

88

70

78

25

70

58

45

86

2

80

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igraveAhi

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ethpm

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igraveAnh

igraveYm

ethp

igraveAnh

igravePwh

igravePrg

igravePri

igraveAn

igravePr

igraveYm

igraveYc

igraveYjigraveYm

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igraveE

igraveYjf

igraveYjf

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igravePmc

igravePw

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igravePwh

igraveAnd

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igravePr

igraveYj

igraved

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igraveAnd

igraveAr

igraved

igravePl

igravePl

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igravePla

igravePla

igravePla

igravePla

igravePla

igravePla igravePl

igraveArc

igraveArc

igraveArc

igravePla

igraveAk

ntildegde

ntildegMl

ntildegMl

igraveYjf

igraveYj


ntildegMla

ntildegMla

ntildeg

ntildeg

ntildeg

ntildegn

ntildeng

ntildeng

E

E

E

E

E

E

E 118961

118956

142851

88YacuteEcirc168

igraveAnd


Yarlarweelor

Horseshoe

NathanDeep

Mt Seabrook

Labouchere

Wilthorpe

Wilgeena

Wembley

Livingstone

Harmony

Jubilee


St Crispin

Durack

Heines Find

Mikhaburra

Cashman

Horseshoe Lights

Horseshoe

Yarlarweelor

Mn

T

MnMn

CuAu

Cu

Au

Mn

T

CuAu

HOLDENS

BAXTER

RAVELSTONE

PEAK HILL

HORSESHOE

HOLDENS

Ruby Well

Fortnum

Fortnum






thrust

latera

l ramp


NARRYER

TERRANE

YILGARN

CRATON

Goodin F

ault

GOODIN

INLIER

Jenkin

Fault

Fault

Goodin

MARYMIA

INLIER

thrust ramp

Robinson Syncline

Peak Hill Anticline

Peak Hill Anticline



Marymia Inlier

40



30 km

Bangemall Group

Earaheedy Group

Padbury Group

Bryah Group


Windplain Subgroup

Geological boundary

Fault






15Agrave

30Agrave

45Agrave







45Agrave

30Agrave

15Agrave

Proterozoic granite

Q TR S

SEA LEVEL

5 km

11 km

F G

SEA LEVEL

5 km

11 km

L M O

SEA LEVEL

5 km

11 km

N

J K

SEA LEVEL

5 km

10 km

10 km

SEA LEVEL

5 km

H I


YerridaGroup


SEA LEVEL

5 km

10 km

C D E

SEA LEVEL

5 km

10 km

A B












2




BANGEMALL

EARAHEEDY

PADBURYBASIN

BASINBRYAH

YERRIDABASIN


1 2 3 4

C

58

78

75

20

15

SHEET INDEX




Capr

icorn

Oro

geny

Mar

ymia

Inlie

r_re

work

ed d

uring

the

met

amor

phism

_Ca

prico

rn O

roge

nyup

per g

reen

schist to

lowe

r am

phib

olite

facie

s

gree

nsto

ne b

eltM

ount

Mai

tland





BANGEMALL BASIN


EARAHEEDY BASIN


2000 Mac

YERRIDA BASIN


YILGARN CRATON

2600 Ma and olderc


BASIN

BASIN

igraveAn


igraveAnf

ntildeg

ntildegn

ntildeng

igraveM

igraveE

igraved

igraveg

igraveP

igravePm

igravePmi

igravePmc

igravePr

igravePrg

igravePri

igravePw

igravePwb

igravePwh

igravePl

igravePli

igravePla

igraveAh

igraveAhi

igraveAr

igraveArc


igraveAk

igraveYm

igraveYc

igraveYj

igraveYjf

ntildegMl

ntilderMM

ntildegde

igraveAnf

igravePi

ethp

ethpm

ntildegMli

ntildegMla

igraveYjf

igraveYjf

igraveYj

igraved

igraved

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igravePrigravePri

igravePwh

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igraveAk ethp

igraveAnh igraveAnd

ntildegMl

igraveAnh


igraveYjf

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ethp

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igravePwh

ethpm igraveAn

igraveAn

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igravePrigravePri

igravePriigravePr

igraveAr

igraveAn

ethp

ethpm


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igravePriigravePl



ntildegMl

igraveArc

ntildegMl

ntildegMl

ntildegMl

igraveAnd

igravePrigravePri

igravePwb

igravePl

igraveAn

igraveAhigravePwb

igravePr

igravePri

igravePmi

igraveAr

igraved

igraveAn

igravePm

igravePwb

igravePr

igravePr

igravePri

igravePwigraveAnu

igravePm

igravePmc

igraveAr

igraveAk

igravePw

igraveM

ntildegMla

ntildegntildeg

ntildeg

ntildegntildeng

igraveM igraveM

igravePligraveAhi

igraveAhigraveAh

igraveAn

igraveAnigraveAr

ntildegMl

ethp

ntildeng

igraved igraved

igraved

WA

NT

SA

NSW

Vic

Qld

Tas

ACT

GEOLO

G IC A L SUR VEY

WE

ST

E R N A U S T R AL

IA


WESTERN AUSTRALIA



AND ENERGY




MINISTER FOR MINES














Chert


Quartz mylonite


Amphibolite





MES

OPRO

TERO

ZOIC

PALA

EOPR

OTER

OZOI

CAR

CHAE

AN

Bang

emal

lGr

oup

Eara

heed

yGr

oup

Padb

ury G

roup

Brya

h Gr

oup

Yerri

da G

roup

Win

dpla

in S

ubgr

oup

Moo

loog

ool S

ubgr

oup

Yarla

rwee

lor g

neiss

belt

Narry

er T

erra

ne

lowe

r gre

ensc

hist to

upp

er a

mph

ibol

ite fa

cies

met

amor

phism

_Ca

prico

rn O

roge

ny

Mur

chiso

n Te

rrane

YILG

ARN

CRAT

ONYE

RRID

A BA

SIN

BRYA

H BA

SIN

preh

niteEcirc

pum

pelly

ite to

mid

-gre

ensc

hist fa

cies

met

amor

phism

_Ca

prico

rn O

roge

ny

PADB

URY

BASI

N




Middle Proterozoic

Early Proterozoic




















Geological boundary




Fault



away from observer


anticline

syncline


overturned syncline

towards observer


inclined

vertical

inclined

vertical

overturned


inclined

vertical



mineral lineation






Formed road

Track

Landing ground



Homestead

Locality

Building yard




Waterhole spring

Bore well windpump

Dam tank


Mining centre

Mining locality


Major opencut

Opencut

Alluvial workings

Prospect

Copper

Gold

Manganese

Talc

PILBARACRATON

CAPRICORN OROGEN

CRATONYILGARN

0 5 10 15 20 255000

Metres Kilometres










REPORT 59 PLATE 1


2344

2345

2346

2347

2444

2445

2446

2447

2544

2545

2546

2547

2644

2645

2646

2647

2744

2745

2746

2747

2844

2845

2846

2847

KALLI

MILEURA

GOULD

ERRABIDDY

MADOONGA

KOONMARRA

MOORARIE

MARQUIS

MEEKATHARRA

TIERACO

PADBURY

MILGUN

GABANINTHA

GLENGARRY

BRYAH

JAMINDI

YAGANOO

MOOLOOGOOL

DOOLGUNNA

MEREWETHER

THADUNA

MARYMIA

MOUNT BARTLE

THREE RIVERS

118958

88YacuteEcirc168

BELELE GLENGARRY


SG 50-7 SG 50-8

SG 50-11 SG 50-12



N

P












SEA LEVEL

5 km

11 km




26frac3400Agrave


AREA OF THIS MAP

GSWA

REPORT 60

PLATE 1

E


Q

R

S

T

F

G

L

M

O

P

N

J

K

C

D

E

A

B

H

I

1 2 3

1

2

3

cc 3300

1






3

cc 3300

1

3300

1










Contents

Abstract

Introduction




Bryah Group

Karalundi Formation






Felsic schist



Jasperoidal chert



Horseshoe Formation

Padbury Group


Wilthorpe Formation





Structure

D1 structures

D2 structures


D4 structures

Metamorphism


Mineralization

Gold deposits


Harmony deposit


Wembley deposit

Wilgeena deposit


Ruby Well group

Mikhaburra deposit

Wilthorpe deposit

Cashman deposit



Iron ore

Talc

Discussion


Acknowledgements

References



Figures



































Tables












86342 746314 7198282 5151 032 1523 928 018 1049 1007 269 019 003 673 166 1 95 12 11

86383 670171 7163822 5353 091 1468 115 019 744 863 299 005 008 253 100 1 85 21 53

86384 670171 7163822 5048 062 1444 991 016 1135 933 362 004 005 640 209 1 157 16 33

86397 799422 7201118 5529 026 1502 817 017 1136 416 549 005 002 1174 244 0 44 15 8

104248 722651 7168587 4925 022 1137 963 017 1818 948 159 009 002 1 80 9 6

104249 722651 7168587 4911 026 1065 973 017 2016 855 126 009 003 1 34 11 7

104254 715830 7171470 4948 023 1121 95 016 2035 706 194 005 002 1877 647 1 49 11 7

104255 715830 7171470 52 033 143 847 017 1071 1087 31 002 003 664 209 0 133 13 13

104256 715830 7171470 5244 067 1455 1007 019 834 983 376 007 007 0 140 17 34

104257 713820 7171502 5144 092 1453 1078 02 689 1244 248 023 009 265 79 3 195 18 53

104264 685287 7155494 5303 062 1391 94 017 768 1239 265 01 006 720 222 1 90 15 32

104265 685287 7155494 5332 025 1592 97 017 658 1215 184 003 004 353 67 1 30 15 11

104288 661877 7126843 5979 024 1346 798 016 522 1265 042 004 004 283 46 0 17 15 11

104289 656054 7130760 5446 014 1559 955 017 826 957 204 019 003 358 116 4 43 8 6

104292 657132 7123177 5103 09 1369 971 017 827 1334 272 009 008 0 165 18 51

104294 664424 7119210 5108 095 1449 1021 018 879 1094 283 046 008 523 141 5 123 19 52

104295 664424 7119210 5228 096 1446 1022 018 946 856 364 016 009 465 132 2 79 19 54

104298 669014 7106533 5233 087 1367 939 017 778 1189 373 01 008 514 116 1 116 17 49

104299 669014 7106533 5166 093 1404 982 018 823 1183 305 017 009 491 117 3 124 18 53

104300 669014 7106533 477 05 173 984 019 747 1484 197 016 004 3 142 12 22

104386 676392 7146500 5373 037 1501 846 016 864 977 373 009 004 557 152 0 106 18 18

104391 687552 7144198 5002 023 845 934 016 2281 88 014 002 002 0 15 11 6

104392 687552 7144198 5391 027 92 998 014 2087 515 017 027 003 2508 1103 12 16 22 10

104393 687539 7143275 508 023 965 1025 01 289 004 0 001 001 0 3 5 6

104394 687539 7143275 5594 05 1494 867 019 73 697 537 006 006 363 88 0 90 19 24

104397 670399 7142584 4687 019 1023 1015 017 2496 726 015 001 001 2786 971 0 7 8 4

104398 669575 7143518 5329 035 1453 813 014 828 1207 315 002 004 574 124 0 78 13 14

104399 670423 7144430 5183 036 1491 866 016 932 1147 323 002 003 682 173 0 42 14 14

104400 670023 7145280 4958 037 1577 987 019 1044 1082 291 002 003 510 124 0 68 17 15

109487 638809 7157725 5719 043 1423 73 013 868 626 569 004 004 442 116 0 18 11 19

109492 663796 7149130 5231 011 617 72 015 24 1002 001 001 001 0 7 5 1

109493 663796 7149130 5246 047 1508 881 019 766 1218 247 064 005 478 90 6 72 15 21

109504 670124 7121353 5396 048 149 859 015 716 1237 231 003 005 445 96 0 61 17 22

109513 732634 7164722 5396 197 1434 953 02 638 686 592 064 019 16 117 24 97

112601 668775 7146298 5332 179 1568 102 025 644 561 601 053 017 10 105 21 90















































































120891 677938 7168840 4880 082 1430 385 717 018 765 1280 174 008 008 330 10077 1 4 10 86 4 5 6 137 107 15 5 2 7 105 4 2 4 4 142 2 2 257 24 83 60










132793 622866 7161836 4860 031 1350 362 510 013 1040 1090 231 001 003 321 9812 2 4 3 29 4 5 6 872 45 61 11 3 97 7 379 4 3 2 2 4 4 72 2 2 216 14 4 60 21

132794 622866 7161786 4840 014 576 203 615 015 2160 863 033 001 001 549 9870 2 4 4 11 6 5 6 2460 71 22 5 3 2 7 1020 4 4 3 2 4 4 11 2 2 155 7 4 63 13

133033 638351 7157551 4450 156 1110 611 440 020 318 1330 468 034 021 906 9864 01 05 5 323 07 01 296 190 36 84 05 126 01 11 75 19 11 11 51 02 1 07 135 22 07 276 241 05 73 108

133034 638351 7157551 4710 013 836 237 696 014 1980 764 012 001 003 596 9862 02 12 2 18 45 01 32 3448 69 22 16 16 23 32 1048 11 5 9 17 18 42 19 52 15 01 133 58 84 72 108

133035 638300 7157750 4740 013 668 349 512 014 2200 801 022 003 001 521 9844 02 07 6 52 14 01 11 2608 73 34 22 12 03 33 1295 15 10 9 22 06 29 1 12 16 02 116 72 58 61 447

133038 632615 7159390 5060 048 1600 316 443 012 572 1410 150 032 006 267 022 102 lt05 70 110 lt05 lt01 216 392 29 93 57 147 10 12 28 138 29 lt2 3 179 297 31 74 141 21 28776 02 181 14 139 59 709


133043 632906 7159832 4970 073 1490 272 790 018 626 1260 171 031 006 236 022 03 21 30 412 09 01 46 66 37 129 05 61 8 06 41 121 48 lt2 9 99 44 11 27 119 13 43764 02 268 203 33 88 470






133051 635603 7169579 0 74 0 02 15 12 114 114 24 91 13 05 84 73 27 12 11 24 0 40 15 158 173 043 256 18 05 74 62

133052 635259 7169444 5160 086 1360 411 719 016 569 1030 155 048 008 344 9906 038 01 05 2 151 05 01 94 148 37 136 33 11 03 34 93 05 2 2 105 02 24 05 145 05 01 296 191 05 85 718

133054 634952 7169267 0 62 05 0 38 5 105 44 18 25 41 12 13 57 48 5 6 12 0 26 18 411 6 166 182 18 08 38 104

133060 648256 7160919 0 23 0 02 19 6 89 129 18 10 5 12 88 62 27 3 0 92 0 38 21 251 111 037 318 25 08 85 76

133063 648467 7150024 4400 018 889 410 531 015 2270 702 037 003 002 705 9982 011 01 05 2 7 05 01 05 3170 83 19 53 05 03 18 1370 15 9 13 09 04 23 05 135 05 01 123 76 27 72 139

133064 647573 7150076 5150 032 1450 307 514 015 634 1390 178 001 003 244 9918 015 01 05 3 50 05 01 05 456 29 40 65 14 04 09 191 05 11 11 05 04 36 05 577 05 01 222 144 21 61 26

133073 626850 7161292 5150 033 1440 273 573 014 748 1250 232 001 003 264 9981 011 01 05 3 43 05 01 05 467 38 78 32 19 02 29 202 14 13 12 05 03 32 05 497 05 01 219 137 05 61 258

133076 626850 7161292 4990 074 1490 410 612 015 546 1320 148 006 007 297 9915 022 01 05 3 42 05 01 85 154 33 55 65 34 03 34 93 05 7 11 05 02 33 05 151 05 01 263 169 16 84 678

133096 645954 7171243 4500 013 916 192 711 014 2110 744 015 002 001 699 9917 022 01 05 2 75 05 01 23 3100 93 69 6 146 06 14 1620 17 7 7 07 17 26 05 27 05 01 132 212 21 69 103

133098 636053 7155351 4950 057 1510 228 646 014 728 1380 135 010 006 307 9971 015 01 05 6 174 05 01 08 487 31 81 47 58 05 37 165 05 12 16 15 02 26 05 112 35 02 220 135 05 64 429

136749 667073 7199167 5080 072 1420 410 567 015 601 1330 166 022 007 221 9911 011 01 05 4 222 05 01 42 331 37 82 57 59 04 29 131 1 12 11 32 07 31 05 237 05 01 257 175 15 75 665

136751 659000 7122223 0 12 0 0 98 3 209 68 15 62 34 04 44 86 2 9 7 43 0 34 09 304 053 021 207 15 09 48 23

139131 621200 7215100 4790 065 1470 301 746 019 682 1290 254 004 006 319 9946 026 01 05 3 211 05 01 43 358 43 103 07 4 02 46 154 05 8 14 05 02 29 05 616 05 02 281 19 05 77 484

139132 621190 7215090 0 14 0 01 11 0 66 18 46 59 40 05 95 11 14 0 0 108 0 51 21 242 87 124 389 7 24 51 134

139133 666700 7193500 0 09 0 02 56 0 0 18 37 39 92 05 63 4 62 0 0 63 0 53 19 33 21 24 29 18 08 25 290

139134 621755 7169255 0 08 0 0 85 3 3 3 15 63 14 09 06 0 2 0 0 73 0 06 08 76 129 05 4 3 03 3 35

139135 621000 7169500 5016 037 1406 241 647 017 918 1126 248 006 003 15 5812 222 438 53 65 10 438 077 1320 100E-07 171 100E-07 500E-08 54 2 53 500E-08 500E-08 212 15 72 19 036 194 094 048 190 038 289 071 222 034 232

139136 621000 7169500 5236 027 1373 239 577 016 897 1068 21 007 003 15 5265 210 491 53 162 10 491 086 1290 100E-07 196 100E-07 1 48 200E-07 62 500E-08 500E-08 189 13 63 13 036 161 078 041 160 039 259 068 214 038 221

139137 620904 7169533 4737 108 1123 33 789 018 1191 106 203 008 012 15 13407 2170 1150 82 119 15 1150 897 1380 6 525 2 500E-08 39 4 143 1 500E-08 265 17 90 65 278 1143 314 124 391 066 391 084 222 031 187

139138 620992 7169508 5075 03 141 177 678 017 996 925 264 044 002 05 7628 124 660 56 61 10 660 042 1310 100E-07 232 100E-07 55 49 2 62 500E-08 500E-08 194 12 65 14 019 104 062 031 135 030 225 055 166 026 175

139139 620992 7169508 4747 018 1006 141 804 017 1989 829 089 002 001 500E-08 7171 148 1770 95 53 75 1770 089 1320 100E-07 835 100E-07 500E-08 39 2 225 500E-08 500E-08 139 8 60 7 019 098 063 028 124 028 206 051 157 026 160

139140 620992 7169508 5201 117 1269 224 762 016 761 1089 239 025 013 05 8447 2455 212 52 161 15 212 982 1210 5 135 100E-07 45 42 4 228 1 500E-08 270 17 87 80 308 1270 330 120 387 061 364 074 200 028 161

139141 620992 7169488 6179 081 147 284 594 006 496 012 007 32 01 1 74341 6413 414 41 31 19 414 2988 410 12 163 3 161 29 4 11 155 3 90 19 132 198 677 2282 433 094 430 059 295 058 166 026 170

104256h 715830 7171470 6528 068 1179 412 511 004 551 013 005 24 012 1 44782 7429 348 39 2 15 348 3419 300 10 176 3 121 21 4 9 19 3 73 27 83 266 834 2926 592 121 584 082 451 089 249 038 231

104393s 687539 7143275 3634 015 744 519 582 02 1191 1139 002 001 002 177 2109 066 2020 175 257 6 043 1440 00000001 1000 00000001 000000005 24 2 42 000000005 05 108 6 35 13 016 080 044 022 067 014 094 022 074 012 090 015

112601s 668775 7146298 1248 005 339 812 262 026 1592 217 005 001 0 156 1400 058 850 63 46 25 066 1990 00000001 1010 1 000000005 10 2 66 000000005 000000005 87 11 22 3 024 085 052 025 083 021 145 034 111 017 131 021

112604s 672238 7155486 7639 017 1136 256 551 022 087 002 002 01 001 457 15133 087 2260 9 10 8 031 1590 00000001 228 1 45 21 00000002 17 000000005 05 149 2 17 9 009 043 014 012 017 004 028 006 023 004 035 005

112643h 675190 7125902 5583 097 1236 543 726 045 595 128 308 005 015 195 2804 1728 46 41 13 145 738 3010 2 63 1 2 58 2 38 000000005 000000005 278 24 111 58 201 930 276 073 275 049 297 064 202 031 236 038

116454s 653363 7152948 2576 011 467 59 024 018 1282 1816 172 064 003 695 7663 012 1570 58 23 35 042 1370 00000001 620 2 34 15 00000002 385 000000005 000000005 76 5 30 4 013 027 019 018 037 010 069 017 060 009 070 011

116477s 645436 7177439 2009 0 084 152 0 038 1639 2363 022 04 003 6 6838 126 31 10 19 000000005 107 2940 00000001 93 1 75 00000001 00000002 103 000000005 000000005 9 10 4 00000001 034 113 036 118 051 012 084 027 105 017 142 020

116485h 655767 7129994 5901 078 1092 14 102 013 1024 016 003 0 008 65 744 774 86 47 39 125 276 965 2 136 00000001 000000005 62 2 15 000000005 000000005 304 15 85 45 099 490 138 035 148 026 164 036 114 018 143 023

116487h 655561 7129043 2488 011 535 29 312 04 1401 2084 003 004 005 110 4392 265 1410 69 15 5 175 3200 00000001 685 1 15 19 2 140 000000005 05 99 5 42 14 048 147 045 021 054 010 063 013 045 007 052 008

116493h 655992 7125530 5148 073 1516 172 1092 013 932 024 26 03 009 15 10919 1023 98 58 72 155 430 935 2 98 00000001 45 69 2 75 000000005 1 357 18 113 42 127 601 174 057 201 036 234 054 176 028 217 036

116501h 708508 7162137 4773 039 1372 423 456 016 666 527 438 098 006 1 120917 449 56 49 35 13 1277 1170 1 192 2 31 67 00000002 51 000000005 000000005 284 29 114 20 154 703 155 116 228 033 198 048 147 020 136 024

116518s 685232 7155526 3765 02 609 573 0 152 597 1736 007 218 005 100 218361 3411 55 39 15 7 1396 11070 4 70 5 65 8 00000002 77 55 1 60 12 38 38 321 1160 235 171 234 031 155 028 088 013 096 015

120303 655250 7126000 2302 011 404 31 071 059 074 3572 004 141 004 53 20581 1117 285 7 4 45 720 4740 1 51 12 435 00000001 2 96 25 000000005 36 9 21 17 141 504 105 042 126 021 127 030 097 015 109 019

120339A 669650 7146425 9409 001 03 425 065 002 003 005 0 006 003 155 1042 267 29 6 65 05 117 110 00000001 15 10 85 1 00000002 5 05 05 55 1 10 4 023 092 016 004 021 003 014 003 009 001 012 002

120339B 669650 7146425 9632 0 002 319 053 001 0 001 0 0 001 5 2442 083 6 3 9 000000005 039 40 00000001 3 1 000000005 00000001 00000002 1 000000005 000000005 10 00000001 3 2 008 030 006 004 009 001 005 002 006 001 008 001

120369s 665175 7156150 6131 098 1297 175 906 025 457 058 144 134 007 285 27950 3230 284 43 121 15 1406 1690 6 128 13 54 41 4 305 65 1 178 16 119 106 355 1340 286 087 269 039 202 036 119 017 130 021

120373s 675250 7167875 5541 088 1306 795 346 014 199 144 005 004 009 1 7754 1109 26 29 74 225 521 1040 2 41 3 05 48 4 67 000000005 000000005 494 25 50 55 161 716 213 067 256 050 325 074 237 035 267 041

120432s 673950 7171700 5469 078 1137 81 399 02 311 1468 016 005 006 2 11068 1433 62 44 22 20 634 1490 1 88 8 15 55 4 495 1 000000005 346 24 49 49 202 897 283 137 343 070 452 104 321 048 354 051

82137A not available 6241 067 991 186 893 019 924 011 0 005 01 15 2345 6927 595 43 123 12 3489 1470 10 235 4 25 21 4 55 175 2 77 16 112 288 734 2545 453 074 448 050 239 041 129 019 143 023

82137B not available 6118 074 1029 19 912 019 96 011 0 009 01 1 3042 6659 780 45 121 12 2999 1430 10 218 6 4 22 4 4 175 25 80 27 116 312 704 2493 499 095 542 075 415 083 249 037 262 039

82144 not available 6901 044 1124 143 288 021 188 365 27 14 013 15 38750 6263 117 22 22 12 3381 1690 8 48 37 67 11 2 107 175 25 46 19 61 199 679 2348 436 093 441 056 304 052 157 022 154 022

82148 not available 6314 07 124 312 581 017 717 01 005 197 01 1 41557 6431 505 53 22 15 3168 1310 10 211 4 99 23 4 8 165 25 72 18 121 227 689 2407 462 095 440 055 281 050 159 022 168 025

82150 not available 9469 001 012 45 062 001 001 001 0 0 001 1150 13761 225 10 2 7 000000005 310 40 00000001 11 00000001 000000005 00000001 6 000000005 000000005 3800 00000001 700 300 044 122 021 012 021 002 013 002 004 000 005 001

82153 not available 41767 296 256 047 214 049 031 072 013 090 023 077 010 072 010












82234 not available 4847 087 1468 1174 022 874 1394 099 027 008 332 83 3 225 21 48

82236 not available 5135 087 1461 1117 02 757 1032 274 109 008 228 70 15 329 19 49





report 59: geology and mineralization of the ......copper–gold volcanogenic massive sulfides,...

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