MllMallee BllCBull Cuu--blbasemetal discovery · MllMallee BllCBull Cuu--blbasemetal discovery ......
Transcript of MllMallee BllCBull Cuu--blbasemetal discovery · MllMallee BllCBull Cuu--blbasemetal discovery ......
PEEL MINING’S GILGUNNIA PROSPECT:
M llM ll B ll CB ll C b lb l didiMalleeMallee Bull CuBull Cu--basemetalbasemetal discoverydiscovery
Nancy Vickery, SMEDG Nancy Vickery, SMEDG 31/5/201231/5/2012
Project Summary
• Key assets:– Mallee Bull Copper‐polymetallicDiscovery (Gilgunnia, NSW)
Emerging precious‐base metal resources company
– Ruby Silver project (Armidale, NSW)– Apollo Hill Gold project (Goldfields WA)– Attunga Tungsten project (Tamworth, NSW)
– Rise & Shine Gold project (Central Otago, NZ)
••Not Not theTHOMSONtheTHOMSON OROGENOROGEN••NEW ENGLANDNEW ENGLAND
••OROGENOROGEN
SYDNEYSYDNEY BOWENBOWENC bC b
••CobarCobar
••SYDNEY SYDNEY –– BOWENBOWEN•• BASINBASIN••CURNAMONACURNAMONA
••PROVINCEPROVINCE
••CobarCobar••Superbasin Superbasin
SystemSystem
••LACHLAN OROGENLACHLAN OROGEN••EASTERN BELTEASTERN BELT••WESTERN AND WESTERN AND
SOUTHWESTERN SOUTHWESTERN BELTBELT
••CENTRAL BELTCENTRAL BELT
•TMI imageTMI image
REGIONAL GEOLOGY•Modified from David (2010)
Exploration strategy
d l d i f i ifi i li i i l
• Explore for deeper targets in an area previously covered by
Focus on under‐explored regions of significant mineralisation potential
surface exploration methods (mapping, geochemistry, limited geophysics)
• Historic gold workings exist as shafts (4 Mile goldfield)• Historic gold workings exist as shafts (4 Mile goldfield)• Structurally favourable location near Nymagee‐Wagga lineamentlineament
• Understanding key features of well known Cobar‐style deposits in exploration methodology
• Use geophysics (VTEM) and IP to find suitable anomalies at depth
• Understanding the surface geology to interpret drillcoreintercepts
4 Mile historic workings
S tt d l t d li f t• Scattered clusters and lines of up to 30 deep shafts (Au only)
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Mallee Bull Discovery
ll d illi fi ll ll “ b l ” di
• Initial work comprised heliborne VTEM, shallow RAB drilling and follow up fixed loop EM surveys which identified a strong conductor
Follow‐up drilling confirms Mallee Bull as a “Cobar‐style” discovery
loop EM surveys which identified a strong conductor
• Initial RC drilling intersected weak mineralisation (Pb, Zn, Ag±Cu), and with down‐hole EM, refined the location and size of the conductor
• One diamond tail was drilled based on geophysical modeling; intersected high grade base metal mineralisation
• Subsequent diamond and RC drilling confirmed significant base metal q g gmineralisation coincident with the EM/IP anomaly
Cobar-style deposits
• Variable metallogeny copper‐gold, but also silver, lead and zinc• Massive to disseminated sulphides, complex metallogenyP h tit b d t ti d/ ti• Pyrrhotite abundant – magnetic and/or non‐magnetic
• Mineralisation steeply plunging, pipe‐like• Structurally hosted within the Cobar Supergroup near regional• Structurally hosted within the Cobar Supergroup near regional structures
• Orebodies can be very large e.g. CSA estimated to hold >1.6Mt copper metal and is open as ore grade averaging 5.5% Cu below 1800m
• Include CSA New Cobar Peak Great Cobar New Occidental• Include CSA, New Cobar, Peak, Great Cobar, New Occidental, Chesney, Nymagee, Hera, Mallee Bull
Winduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck Shelf
Stoney Tank
Kirry
COBAR SUPERBASIN
Simplified Geology and
Winduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck ShelfWinduck Shelf
Stoney Tank
Kirry
COBAR SUPERBASIN
Simplified Geology and Mi l d it i thWiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf
Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf
Elura
Girilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone Mine
EluraEluraEluraEluraEluraEluraEluraEluraElura Rooker
on Fau
lt
p gy Mineral Deposits
Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Wiiltagoona Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf Kopyje Shelf
Elura
Girilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone Mine
EluraEluraEluraEluraEluraEluraEluraEluraElura Rooker
on Fau
lt
p gy Mineral Deposits Mineral deposits in the
Cobar Superbasin
••1. Intrusion related deposits1. Intrusion related depositsCobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough
Wiralong
Lillvale
Girilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone Mine
TrittonTrittonTrittonTrittonTrittonTrittonTrittonTrittonTritton
Mt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew Occidental
Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine PerseverancePerseverancePerseverancePerseverancePerseverancePerseverancePerseverancePerseverancePerseverance
Great CobarGreat CobarGreat CobarGreat CobarGreat CobarGreat CobarGreat CobarGreat CobarGreat Cobar
CSA MineCSA MineCSA MineCSA MineCSA MineCSA MineCSA MineCSA MineCSA Mine
CnesneyCnesneyCnesneyCnesneyCnesneyCnesneyCnesneyCnesneyCnesney
New CobarNew CobarNew CobarNew CobarNew CobarNew CobarNew CobarNew CobarNew CobarCOBARCOBARCOBARCOBARCOBARCOBARCOBARCOBARCOBAR
r y Faul t
Plug Tank F
Amphitheatre Fault
Jackermaroo F
Buckw
aroon
Coonara Fault
Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough Cobar Trough
Wiralong
Lillvale
Girilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone MineGirilambone Mine
TrittonTrittonTrittonTrittonTrittonTrittonTrittonTrittonTritton
Mt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineMt Boppy MineNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew OccidentalNew Occidental
Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine Peak Mine PerseverancePerseverancePerseverancePerseverancePerseverancePerseverancePerseverancePerseverancePerseverance
Great CobarGreat CobarGreat CobarGreat CobarGreat CobarGreat CobarGreat CobarGreat CobarGreat Cobar
CSA MineCSA MineCSA MineCSA MineCSA MineCSA MineCSA MineCSA MineCSA Mine
CnesneyCnesneyCnesneyCnesneyCnesneyCnesneyCnesneyCnesneyCnesney
New CobarNew CobarNew CobarNew CobarNew CobarNew CobarNew CobarNew CobarNew CobarCOBARCOBARCOBARCOBARCOBARCOBARCOBARCOBARCOBAR
r y Faul t
Plug Tank F
Amphitheatre Fault
Jackermaroo F
Buckw
aroon
Coonara Fault
••2. VMS deposits2. VMS deposits
••3. Cobar 3. Cobar –– style massive sulphide deposits style massive sulphide deposits
Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone
ggg
Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Boomerang Tank White Tank
Rookery Lerrida
McKinnons Tank
Pipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline Ridge
Nymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - Hera
ShutteltonShutteltonShutteltonShutteltonShutteltonShutteltonShutteltonShutteltonShuttelton
Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons TankTankTankTankTankTankTankTankTank
Nymage Fault
S re
Fault
Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Canbelego - Mineral Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone Hill Rift Zone
ggg
Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Boomerang Tank White Tank
Rookery Lerrida
McKinnons Tank
Pipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline RidgePipeline Ridge
Nymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee Copper MineNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - HeraNymagee - Hera
ShutteltonShutteltonShutteltonShutteltonShutteltonShutteltonShutteltonShutteltonShuttelton
Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons Mc Kinnons TankTankTankTankTankTankTankTankTank
Nymage Fault
S re
Fault
••5 Massive sulphide base5 Massive sulphide base
••4. Epithermal Au deposits4. Epithermal Au deposits
Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf
Beloura TankBooth
WonawintaWonawintaWonawintaWonawintaWonawintaWonawintaWonawintaWonawintaWonawinta
Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia GoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfields
May DayMay DayMay DayMay DayMay DayMay DayMay DayMay DayMay Day
Rooker y Fault
Sandy Creek Fault
Gilm
ore l inamentW
agga
- Nym
agee
Stru
cture
Woonarra F
Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf Winduck Shelf
Beloura TankBooth
WonawintaWonawintaWonawintaWonawintaWonawintaWonawintaWonawintaWonawintaWonawinta
Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia Gilgunnia GoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfieldsGoldfields
May DayMay DayMay DayMay DayMay DayMay DayMay DayMay DayMay Day
Rooker y Fault
Sandy Creek Fault
Gilm
ore l inamentW
agga
- Nym
agee
Stru
cture
Woonarra F ••5. Massive sulphide base 5. Massive sulphide base
•• metals deposits metals deposits --Irish typeIrish type
••6. Carbonate hosted base 6. Carbonate hosted base ••metal deposits metal deposits -- MVT typeMVT type
M lM lM lM lM lM l
Kilparney
Mountain dam
Blue Mountain
Mineral HillMineral HillMineral HillMineral HillMineral HillMineral HillMineral HillMineral HillMineral Hill
Tallebung MineTallebung MineTallebung MineTallebung MineTallebung MineTallebung MineTallebung MineTallebung MineTallebung Mine
Mt HopeMt HopeMt HopeMt HopeMt HopeMt HopeMt HopeMt HopeMt Hope
Mt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineWagga TankWagga TankWagga TankWagga TankWagga TankWagga TankWagga TankWagga TankWagga Tank
Fault M lM lM lM lM lM l
Kilparney
Mountain dam
Blue Mountain
Mineral HillMineral HillMineral HillMineral HillMineral HillMineral HillMineral HillMineral HillMineral Hill
Tallebung MineTallebung MineTallebung MineTallebung MineTallebung MineTallebung MineTallebung MineTallebung MineTallebung Mine
Mt HopeMt HopeMt HopeMt HopeMt HopeMt HopeMt HopeMt HopeMt Hope
Mt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineMt Allen MineWagga TankWagga TankWagga TankWagga TankWagga TankWagga TankWagga TankWagga TankWagga Tank
Fault
••7. Quartz vein hosted 7. Quartz vein hosted ••gold depositsgold deposits
Melrose Melrose Melrose Melrose Melrose Melrose Melrose Melrose Melrose TroughTroughTroughTroughTroughTroughTroughTroughTrough
Rast Rast Rast Rast Rast Rast Rast Rast Rast TroughTroughTroughTroughTroughTroughTroughTroughTroughMount Hope Mount Hope Mount Hope Mount Hope Mount Hope Mount Hope Mount Hope Mount Hope Mount Hope
Trough Trough Trough Trough Trough Trough Trough Trough Trough Walters Walters Walters Walters Walters Walters Walters Walters Walters Range Range Range Range Range Range Range Range Range Shelf Shelf Shelf Shelf Shelf Shelf Shelf Shelf Shelf0km 50km
Melrose Melrose Melrose Melrose Melrose Melrose Melrose Melrose Melrose TroughTroughTroughTroughTroughTroughTroughTroughTrough
Rast Rast Rast Rast Rast Rast Rast Rast Rast TroughTroughTroughTroughTroughTroughTroughTroughTroughMount Hope Mount Hope Mount Hope Mount Hope Mount Hope Mount Hope Mount Hope Mount Hope Mount Hope
Trough Trough Trough Trough Trough Trough Trough Trough Trough Walters Walters Walters Walters Walters Walters Walters Walters Walters Range Range Range Range Range Range Range Range Range Shelf Shelf Shelf Shelf Shelf Shelf Shelf Shelf Shelf0km 50km
•Modified from David (2010)
Cobar Superbasin is worldclass mineral province
b b i i i lTinderra granite
Coonar
Gilm
••NN ELURAELURA
• Cobar Superbasin pre‐mining metal inventory:
– >2.2 Mt Cu = US$18b$
Bucka
roon F
ault
Roo
rra Fau lt
more Lineam
ent
GREAT COBARGREAT COBAR
PERSERVERANCEPERSERVERANCE
CSACSA
McKINNONSMcKINNONS
MT BOPPYMT BOPPYNEW OCCIDENTALNEW OCCIDENTALPEAKPEAK
PIPELINEPIPELINE
– >7 Moz Au = US$12b– >4.7 Mt Zn = US$9.5b– >2.8 Mt Pb = US$5.5b
145 M A US$4 5bokery Fault
Structure
WindnokShelf
PERSERVERANCEPERSERVERANCE
WONAWINTAWONAWINTANYMAGEENYMAGEE
PIPELINEPIPELINE
HERAHERA
– >145 Moz Ag = US$4.5b– Total = US$50b
Thule granite
Shel
f
Nymagee-Wagga Stru
Canbelego‐Mineral Hill Rift Zone
MAY DAYMAY DAY
MT HOPE MINEMT HOPE MINE
WAGGA TANKWAGGA TANK
MALLEE BULLMALLEE BULLAg
Au
MUNDOEMUNDOE
AuAgPb
Erimeran granite
Mt Hop
e Tro
ugh
Walt
ers
Rang
es S
hR
ast T
roug
h
ZoneMT HOPE MINEMT HOPE MINE
C
ZnCu
Zn
Cobar Basin Architecture Cobar Basin Architecture Courtesy Courtesy VladVlad DavidDavid
Cu
11
Host sequence• Local stratigraphy correlates to
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5 PitF Anticline approximate
Geol boundary accurate
Geol boundary approx
Marker beds
Qs - soil
si - silcrete
fe - ironstone, ferruginous siltstone
qb - quartz blow
Daus - orange-yellow silty sandstone and siltstone
Das - well sorted quartz-rich sandstone
Dal - turbiditic quartz-rich sandstone and siltstone
Dauv - quartz-rich crystal tuff
Daut - vitric tuff or silicified claystone
Daul - silicified crinoidal limestone
Dauf - olive green fossiliferous sandstone and mudstone, local rip up clasts
• Local stratigraphy correlates to the Shume Formation and overlying Upper Amphitheatre Group.
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» Shaft
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Fault approximate
!! !! Quartz reef
M Syncline accurate
M Syncline approximate
GF RC holes
RAB holesG
p• The sequence at Mallee Bull
has been folded and faulted.• A broad anticlinorium is
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• A broad anticlinorium is interpreted. The western margin comprises thinly bedded turbidites (mudstone
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(to sandstone) with minor volcaniclastic units.
• On the eastern margin shallow
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gmarine sandstones are glauconitic and contain dismembered trilobites
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• On surface, significant historic gold workings are scattered with shafts
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Metres
• Mallee Bull fm (inf )Host sequence• Mallee Bull fm (inf.) comprises well bedded turbidites dominantly of mudstones and siltstones
• Lower portions have• Lower portions have distinct volcanic detritus and scattered li t litholistoliths
• The basal unit is a volcaniclastic/epiclastic/ psequence of felsicvolcanics (SRV)Hi hl i bl i• Highly variable in texture, fabric and width
• The top of the ShumeHost sequence• The top of the ShumeFm is a marker unit (Keep It Dark sandstone). Forms raised rounded massive outcropsp
• Supermature massive quartz sandstone
• Beneath this interval is the 4 Mile facies (inf.) hosting mineralisationg
• This unit passes into coarser facies turbiditesf h Sh Fof the Shume Fm.
Local geology
• The lower stratigraphy is correlated to the ShumeFm
• Comprises poorly to well bedded
d t / ilt t dmudstone/siltstone and sandstone‐dominated turbidites
• The Shume Fm is divided informally on the basis of faciesfacies
• The uppermost portions of the Shume Fm hosts mineralisation (the 4 Mile facies)
Local geology
• Silver Ray volcanic member of the Mallee Bull Fm (Upper y ( ppAmphitheatre Group)
• Dominantly epiclastic, with clasts of coherent felsicvolcanics and aphanitic lithic material
O h li b h
Local geology
• On the western limb the stratigraphy dips steeply to the westMi li i b l h• Mineralisation occurs below the Keep It Dark sandstone in the Shume FmTh K I D k d i• The Keep It Dark sandstone is a persistent marker bed at the top of the Shume FmV l i l i k i h• Volcaniclastic rocks occur in the Mallee Bull Fm as olistoliths and the basal Silver Ray volcanics.R l i d t it l• Rare volcanic detritus also present in the 4 Mile faciesunderneath the Keep It Dark sandstonesandstone
Previous exploration
i d illi f l i l
EXPLORER YEARS METHODS COMMENTS
No prior drilling, surface exploration only
Mount Hope Minerals 1970-1973 Mapping, airborne magnetic-radiometric-EM survey
Modern style exploration but focus on outcropping or shallow targets
Union Corporation 1976-1978 Airborne and ground magnetics, mapping, auger geochem
Modern style exploration but focus on outcropping or shallow targets
Newmont 1984-1986 Geochemistry Focus on shallow or outcropping targets
Shell Minerals 1981-82 RAB/chip sampling Focus on shallow orShell Minerals 1981 82 RAB/chip sampling Focus on shallow or outcropping targets
Pasminco/Triako 2000-2009 Identification and modelling of magnetic
Modern exploration for Cobar-style deposits. No follow up on anomaly G5 – Malleeg
anomaliesy
Bull
Exploration by Peel
•Focus on historic 4 Mile gold field due to presence of G5 magnetic anomaly
Mallee Bull
Exploration by Peel
• VTEM survey with follow‐up fixed loop EM and downhole IP
• Detailed geological mappingDetailed geological mapping and previous exploration compilation
• 60 Rab, 27 RC and 9 diamond holes
• Drilling includes 60 RAB 27 RC• Drilling includes 60 RAB, 27 RC and 9 diamond holes
Geophysical surveys
A i id i /EM l id ifi d i h 4 Mil• A coincident magnetic/EM anomaly was identified in the 4 Mile area. Follow‐up fixed loop EM and downhole IP further defined this
Exploration by Peel Mining
•Thorough logging of core and chips, field Niton and ALS assaying of chips and core
•Integration of all data to produce drill sections
•3D modelling of geophysics and drill sections (in progress)
•Comprehensive deep drilling program and down hole•Geophysics planned
Mallee Bull Discovery
R lt t d t• Results to date– Mallee Bull Cobar‐style discovery better results to date include:
10m@ 9 01% Pb 11 00% Zn 41 g/t Ag 0 77 g/t Au 6 65m@ 3 10% Cu 34 g/t Ag 0 93 g/t Au10m @ 9.01% Pb, 11.00% Zn, 41 g/t Ag, 0.77 g/t Au 6.65m @ 3.10% Cu, 34 g/t Ag, 0.93 g/t Au
9.3m @ 1.20% Cu, 19 g/t Ag, 0.14 g/t Au 10m @ 1.70% Cu, 46 g/t Ag, 0.27 g/t Au
5m @ 2.40% Cu, 28 g/t Ag, 0.60 g/t Au 7m @ 2.32% Cu, 14 g/t Ag, 0.15 g/t Au
7m @ 1.31% Cu, 19 g/t Ag, 0.56 g/t Au 6m @ 2.01% Cu, 64 g/t Ag, 0.43 g/t Au
11m @ 2.71% Cu, 36 g/t Ag, 0.26 g/t Au 10m @ 2.66% Cu, 41 g/t Ag, 0.51 g/t Au
5m @ 2.14% Cu, 41 g/t Ag, 1.29 g/t Au 10m @ 2.22% Cu, 33 g/t Ag, 0.44 g/t Au
– Strike of mineralisation = >120m– Steeply dipping to the west and stratabound– Shallowest intercept to date = 150m below surface– Deepest intercept to date = 310m below surface– Mineralisation open in multiple directions, including down‐dip
Mallee Bull Discovery
• Mineralisation/geology characteristics– Broad alteration/mineralisation containing multiple intervals of massive sulphide and stringer mineralisation including chalcopyrite sphalerite galena pyrrhotiteand stringer mineralisation, including chalcopyrite, sphalerite, galena, pyrrhotite, arsenopyrite, pyrite
– Geology comprises package of structurally deformed turbidite sequence sediments (including volcaniclastics)
– Shoot‐like structure dipping west and plunging to south?– Favourable geological and structural position, sited on the “nose” of an anticline –a suitable high‐stress environment
– Multiple additional coincident geochem/magnetic anomalies– Large proximal magnetic anomaly to north (Butcher’s Dog) still unexplained– Mineralisation hosted within the Lower Amphitheatre Groupp p– Similarities to other Cobar‐style deposits such as CSA, Shuttleton and Nymagee‐Hera
“Cobar –style” deposits vs Mallee Bull Discovery
Attribute Mallee Bull
Polymetallic (Cu‐Ag‐Au‐Pb‐Zn)
Proximity to major structures y j(growth/transfer faults)
Shear‐hosted
Strong geophysical response g g p y p
Chlorite and silica alteration
Facies and rock competency contrasts p y
Moderate to high strain zone
Short strike length (<200m) g
Narrow widths (5‐20m)
Vertical continuity (>400m) ?
Generally occur as clustered/stacked lenses
?
Mallee Bull Discovery
• Deposit Drillcore comparison Mallee Bull (left) vs Nymagee (right)• Deposit Drillcore comparison – Mallee Bull (left) vs Nymagee (right)
Metal inventory and ore textures at Mallee Bull
• Cu, Zn, Pb, Ag, As, Sb, Bi, Au and Co• Ore mineralogy comprises chalcopyrite, pyrite, gy p py pypyrrhotite, sphalerite, galena, arsenopyrite, tetrahedrite, boulangerite (5PbS.2Sb2S3) and Pb, Sb, Bi sulphosalts,
i l tvery minor electrum• Complex timing relationships with early (diagenetic) pyrite later arsenopyrite pyrrhotite and pyrite thenpyrite, later arsenopyrite, pyrrhotite and pyrite, then later base metal sulphides and sulphosalts
• There are multiple generations of pyrite and pyrrhotitep g py py• Sphalerite and chalcopyrite show evidence of remobilisation
Mallee Bull mineralisation
•Cpy •Ga
•Asp•Po
•Sph
• Early formed arsenopyrite, brittly deformed, overprinted d ti ll l d b l h l it dand partially replaced by galena, chalcopyrite and
pyrrhotite
Ore textures• ReplacementReplacement textures, evidence of deformation of some sulphides
• Structural control along fractures and within veins
• Sulphides occupy i bmatrix between more
competent clastsN t di ti t• Note distinct green chlorite alteration
• Section from the top of the 4 Mile facies, note volcanic clasts
• Silicificationand black hloritechlorite development
• Sphalerite and galena precipitating in favourable sites including in and around the margins of clasts
Ore textures
• Early pyrite (diagenetic) with later anastomosing bands of sphalerite, pyrrhotite, lesser pyrite, galena and rare arsenopyrite
• Dark chlorite altered mudstone host. Fragments are ripped up into the massive sulphide horizon
Ore textures
• “elvan” type alteration (cf CSA)• Strongly siliceous clasts of mudstone• Strongly siliceous clasts of mudstone.• Matrix replacement by chalcopyrite, black chlorite,lesserpyrrhotite and sphalerite.
• Some clasts contain fine trails of sulphides or disseminated grains
Ore textures
• Early sulphide minerals are deformed or show evidence of textural modification
• Arsenopyrite grains are fractured and later infilled by sphalerite, pyrrhotite, galena and chalcopyrite
• Early pyrite grains are also fractured and heavily included• Early pyrrhotite is completely recrystallised in some
ti I th it i l t i lsections. In others it is a late mineral• Galena grains are bent in some sections and show ductile deformationdeformation
Metal zonation
E l d b l i i id d h l (i• Early days, but a vague metal zonation is evident downhole (ievertically).
• The shallow intersections of sulphides are commonly pyrite‐The shallow intersections of sulphides are commonly pyritepyrrhotite, with minor sphalerite and galena. These are commonly massive and may exceed 2m in width
h i i d i d h l i i i b• Pyrrhotite is dominant downhole, pyrite is minor to absent at depth
• Downhole chalcopyrite is more abundant, with pyrrhotite andDownhole chalcopyrite is more abundant, with pyrrhotite and lesser pyrite, rarely massive, mostly in stringers and veins and fractures
• Arsenopyrite is a minor sulphide mineral throughout and unusually cited. It is more abundant in the lower mineralised zones
• Possible remobilisation of some sulphide minerals, in particular sphalerite and chalcopyrite, rarely galena
Hydrothermal alteration characteristics
• Characterised by locally intense chlorite alteration and silicificationG hl it lt ti f th h ti d t i• Green chlorite alteration of the hosting mudstones is intimately associated with sphalerite and chalcopyrite stringer zonesg
• Black chloritic alteration of the hosting sediments occurs in the uppermost sulphide zones with more abundant pyrite and pyrrhotite
• Carbonate veins are relatively early and typically t lli drecrystallised
• Gangue minerals proximal to sulphide horizons are coarser grained and commonly recrystallised (greencoarser grained and commonly recrystallised (green chlorite and quartz, in particular)
Timing relationships - preliminary
• Metamorphic conditions attained greenschist facies. Peak biotite grains replaced by chlorite and stilpnomelaneE l t lli d b t i h til l• Early recrystallised carbonate veins have stilpnomelaneselvedges
• Metamorphic biotite possibly replaced by hydrothermal• Metamorphic biotite possibly replaced by hydrothermal chlorite
• Sulphide formation is pre‐syn deformation and possibly p p y p ysyn‐post metamorphism (though overprinting by a later retrograde event is possible)
• Multiple generations of sulphide formation
Geochemistry of ore zones
• Matrix correlations of key metals in selected drillholeintersections reveal the following:
–Overall poor correlation between most metals except Zn/CdC l t d t l ll (0 7 0 8) i–Cu correlates moderately well (0.7‐0.8) in some intersections with Bi, Co, Sb
–Au/Ag generally well correlated, but not alwaysAu/Ag generally well correlated, but not always–As does not correlate well, except with gold, rarely–Zn/Pb generally correlate wellg y
• This data indicates the involvement of multiple fluid stages plus the effects of local remobilisation (particularly of Zn and Cu)
Summary
• Mallee Bull Cu‐Ag‐Au‐Pb‐Zn‐Co Discovery– 8km east of May Day Au‐Ag‐Pb‐Zn‐Cu deposit; adjacent to historic 4‐Mile goldfield– Coincident EM and magnetic geophysical anomaliesg g p y– Favourable geological position in volcaniclastic turbidite sequence age in the Lower Amphitheatre Group
– Favourable structural position located on “nose” of anticline; high strain environment f k ff d– Ease of access, 3 km off major road
– Perseverance required; several rounds of drilling necessary– High‐grade massive sulphides intercepted in July/August 2011– Complex multigeneration base metal deposit with significant Ag and Au– Complex multigeneration base metal deposit with significant Ag and Au– Mineralisation is pre‐syn deformation and possibly metamorphism– Deposit located near the Nymagee‐Wagga lineament– Similar to other Cobar‐style deposits such as Chesney, CSA and Shuttletony p y– Early stages of exploration and drilling
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