Geological interpretations from the Paterson AEM survey

Ian C. Roach

With contributions from: A.J. Whitaker, M.T. Costelloe & N.C. Williams

Onshore Energy and Minerals Division, Geoscience Australia GPO Box 378, Canberra ACT 2601

Geological interpretations from the Paterson AEM survey Introduction

1. Surface geomorphology and geology: 1. Topography-relief-palaeodrainage; 2. Geological provinces, cover geology; 3. Bedrock/cover relationship. 2. Airborne geophysics: 1. Gravity; 2. Aeromagnetics. 3. AEM data validation: 1. Geological and Geophysical data compilation. 4. AEM: the big-picture: 1. Surface conductivity; 2. Depth slices; 3. Detail of large objects – Anketell & Throssell shelfs, Rudall Complex, palaeodrainage systems; 4. Depth-to map. 5. Mineral Deposits.

Geological interpretations from the Paterson AEM survey BedrockBedrock--covercover

Precambrian bedrock vs. Phanerozoic cover:

85% cover

Difficult to explore!

1m surface geology bedrock cover

Geological interpretations from the Paterson AEM survey TopographyTopography

Total relief ca. 400 m

Easy area to fly AEM Lake Waukarlycarly

WOODIE WOODIE NIFTY !( !( TELFER !(

KINTYRE !( Percival Lakes

0150 00Kilometers Geological interpretations from the Paterson AEM survey PaleodrainagePaleodrainage MRVBF6 image, SRTM DEM

Surface relief hints at Palaeodrainage systems. Many interpretations with Similar themes

WOODIE WOODIE NIFTY !( !( TELFER !(

!( Major mines Wallal Palaeovalley KINTYRE van de Graaf !( Fishe r - Permian Percival Palaeovalley Oakover River AEM interp Beard Commander

01Geological50 interpretations00Kilometers from the Paterson AEM survey GeologicalGeological ProvincesProvinces Geological Provinces Canning Basin Paleozoic-Mesozoic Canning Basin Neoproterozoic Officer Basin

Yeneena Basin - Lamil Group Yeneena Basin - Isdell Formation

Yeneena Basin Yeneena Basin - Throssell Range Group Granite WOODIE WOODIE NIFTY !( !( TELFER Paleo- Mesoproterozoic Pilbara !( Lamil Rudall Complex - Connaughton Terane Craton Group Rudall Complex Rudall Complex - Tabletop Terane Throssell Rudall Complex - Talbot Terrane Range Rudall River Archean KINTY RE Group !( National Park Sylvania Dome Fortescue Basin

Pilbara Craton Collier Basin Talbot Hamersley Basin Rudall Complex Connaughton Tabletop

0150 00Kilometers Geological interpretations from the PatersonOfficer AEM survey Basin SolidSolid GeologyGeology Callawa Formation

Frezier Sandstone

Permian-Mesozoic solid geology Kslg - Lake George Formation Anketell Poole Ksbs - Broome Sandstone Formation Sandstone Formation Ksak - Anketell Sandstone Ksfr - Frezier Sandstone Kspa - Parda Formation WOODIE WOODIE NIFTY !( !( TELFER !( Kscr - Cronin Sandstone Interpreting AEM Jksc - Callawa Formation requires more Pslt - Triwhite Sandstone sophisticated knowledge Psno - Noonkanbah Formation of surface and near- Pspo - Poole Formation surface geology like this Psp - Paterson Formation KINTYRE Paterson new Permian-Mesozoic !( Paterson Formation Psg - Grant Group solid geology map Formation Triwhite Sandstone

Compilation by A.J. Whitaker

0150 00Kilometers Geological interpretations from the Paterson AEM survey InduratedIndurated regolithregolith

Interpreting AEM requires more sophisticated knowledge of surface and near- surface geology like this new indurated regolith map

WOODIE WOODIE NIFTY !( !( TELFER !(

Compilation by A.J. Whitaker KINTYRE A.J. Whitaker !(

Cenozoic materials Czik - Calcrete Czk - Calcrete Czl - Fe-duricrust Czlra - Fe-duricrust/colluvium

0 50 100 Kilometers 01Geological50 interpretations00Kilometers from the Paterson AEM survey WOODIE WOODIE NIFTY !( !( TELFER !(

Ternary radiometrics tells us about what occurs at the surface, and serfuace KINTYRE process, but what lies !( underneath?

Ternary Radiometrics Red: K Green: Th Blue: U

0150 00Kilometers Geological interpretations from the Paterson AEM survey GravityGravity

Gravity can be used to interpret large scale Anketell density contrasts that Waukarlycarly Shelf Embayment may be related to different rock types

Throssell Range Group Canning Basin Rudall Complex Lamil Group Rudall Complex WOODIE WOODIE NIFTY !( !( TELFER !( Pilbara Craton

KINTYRE !(

Rudall Complex

0150 00Kilometers Geological interpretations from the Paterson AEM survey Officer Basin 1VD1VD magneticsmagnetics

Anketell Waukarlycarly Shelf Embayment

Throssell Range Canning Basin Group Lamil Group

WOODIE WOODIE NIFTY !( !( TELFER !(

KINTYRE !(

Aeromagnetics can tell us Aeromagnetics can tell us Rudall Complex the depth to magnetic basement and give us another view of sub- surface rock types

0150 00Kilometers Geological interpretations from the Paterson AEM survey HowHow dodo wewe validatevalidate this?this?

WOODIE WOODIE NIFTY !( !( TELFER !( AEM can tell us about the lateral continuation of surface and sub-surface materials and can be interpreted for geology. How do we validate this? KINTYRE !(

0150 00Kilometers Geological interpretations from the Paterson AEM survey Geological validation

• Drill holes: a publicly-available drill hole compilation (Roach, 2009); • Solid geology: a compilation by Czarnota et al. (2009); • Surface geology: the 1:1 000 000 scale Surface Geology of Western Australia (Stewart, 2008); • 1:250 000 and 1:100 000 geological maps; • Magnetics: GA Magnetic Map of Australia; • Gravity: GA Gravity map of Australia; • Radiometrics: GA Radiometric Map of Australia (Minty et al., 2009); • Conductivity logs

All GAGeological data interpretations are fromavailable the Paterson AEM on survey-line at: www.ga.gov.au/minerals DrillingDrilling

• 4,300+ logged drill holes. • Released as GA Record and database Roach (2009).

Geological interpretations from the Paterson AEM survey Drill holes vs AEM conductivity sections

300

200

100

0 m ASL 5 km

-100

-200

Geological interpretations from the Paterson AEM survey GA LEI section geological interpretation

• Line 30820, ca. 8 km north of Nifty Cu mine. • Interpretation after Bagas (2002), Lamil 1:100,000 geology sheet.

W E

Geological interpretations from the Paterson AEM survey Large-scale geological interpretations

• Interpretations mostly from gridded data: – GA LEI Depth Slices: • Created by draping gridded inversion conductivity values over an elevation model; • Represent a conductivity ‘skin’ at a certain depth from topographic surface. – GA LEI Elevation Slices: • Removes terrain; • Represent a conductivity ‘level’ from datum. • Grids have data under the DOI removed.

Geological interpretations from the Paterson AEM survey Mapping palaeosurfaces- Conductivity anomaly contours

• Created using gridded GA LEI data and drill holes. • Assumes conductivity anomaly follows broad sub-Permian unconformity – DOI permitting: • Only drawn in areas where Permian and younger fill is conductive. • Able to visualise large palaeotopographic features and some unconformities.

Geological interpretations from the Paterson AEM survey Depth slices show subsurface conductivity features, Can these be used to map conductivity GA LEI Depth slices surfaces?

Geological interpretations from the Paterson AEM survey WOODIE WOODIE NIFTY WOODIE WOODIE NIFTY !( !( TELFER !( !( TELFER !( !(

KINTY RE KINTY RE !( !(

0150 00Kilometers 0150 00Kilometers

Conductivity formlines m ASL Depth slice -100 0 information are used 20 40 here to develop a 60 80 100 model of the 120 140 Palaeozoic- 160 180 200 Proterozoic 220 240 unconformity surface WOODIE WOODIE NIFTY WOODIE WOODIE NIFTY unconformity surface !( !( TELFER 250 !( !( TELFER !( 260 !( in the Paterson region 280 300 310 320 340 360 KINTYRE KINTYRE !( 380 !( 400

Geological interpretations from the Paterson AEM survey 0150 00Kilometers 0150 00Kilometers WOODIE WOODIE NIFTY !( !( TELFER !(

KINTYRE The Palaeozoic- !( Proterozoic unconformity surface, shown here, is the pre-Permian palaeotopography

0150 00Kilometers Geological interpretations from the Paterson AEM survey W a u k a r Depth slice with large- lyly A c n scale geological features a k Canning r e l e annotated ly tete Basin annotated T h E llll h SS r m o h s b s a e s ll e y ff llll m

S e n h t Broadhurst e t Formation lflf

WOODIE WOODIE NIFTY Canning !( !( TELFER !( Palaeovalley Fortescue/ Pilbara

Coolbro Disappointment Sandstone KINTYRE !( Palaeovalley Permian palaeovalleys Rudall Complex Rudall Complex

0150 00Kilometers Geological interpretations from the Paterson AEM survey W a u k a r lyly A c n a k Canning r e l e ly tete Basin T h E llll h SS r m Palaeotopographic model o h s b s a e with large-scale s ll e y ff llll m geological features

S e h n annotated h t annotated Broadhurst e t Formation lflf WOODIE WOODIE NIFTY !( !( TELFER !( Canning Palaeovalley Fortescue/ Pilbara

KINTYRE Coolbro !( Disappointment Sandstone Palaeovalley Permian palaeovalleys Rudall Complex Rudall

0150 00Kilometers Complex Geological interpretations from the Paterson AEM survey 3D3D perspectiveperspective viewsviews

Geological interpretations from the Paterson AEM survey PatersonPaterson SouthSouth

Canning Basin Rudall Mesozoic & Permian Complex Sediments on-lap outcrop Rudall Complex

Disappointment Palaeovalley system

Rudall Complex Under cover N

Geological interpretationsm from ASL the Paterson160 AEM survey 200 240 280 320 DisappointmentDisappointment PalaeovalleyPalaeovalley

AEM interp van de Graaf Fisher - Permian Disappointment Percival Palaeovalley Palaeovalley Beard Flow direction

Previously unmapped tributary 0212.5 5Kilometers Geological interpretations from the Paterson AEM survey PatersonPaterson NorthNorth Kintyre

Nifty Woodie Woodie N Canning Telfer Palaeovalley Thr os s el W l S a he au l ka f rly ca rl ly Em ba ym en Canning Anketell Shelf t Basin

Geological interpretations from the Paterson AEM survey CanningCanning PalaeovalleyPalaeovalley

?

Flow direction

AEM interp

TELFERTELFER !(

0210 0Kilometers Geological interpretations from the Paterson AEM survey InterpretedInterpreted PaleozoicPaleozoic-- ProterozoicProterozoic unconformityunconformity

WOODIE WOODIE NIFTY !( !( TELFER Height of unconformity !( above sea level

KINTY RE !(

0150 00Kilometers Geological interpretations from the Paterson AEM survey InterpretedInterpreted covercover thicknessthickness

Depth to unconformity WOODIE WOODIE NIFTY !( !( TELFER !( metres High : 292.081

KINTY RE Low : -31.3929 !(

0150 00Kilometers Geological interpretations from the Paterson AEM survey A large proportion of the region remains under- explored. AEM data can

Fe give more accurate depth Fe Shale HM Fe FeFe Fe to target information Fe Fe Fe Cu Fe Au Cu Au Cu, Au, VAu, Cu Cu AuMn MnMn Cu, Pb Fl Mn Fe Cu Mn Pb, Zn, Ag Au, Cu, Ag Au Pb Cu MnMn Fe Mn Au Pb, Cu Mn Mn Gp Au Cr Mn Au Mn Zn, Pb, Ag Au Au Cu Salt Au Mn Mn Cu, Zn AuAu Pb Cu Zn Gvl Mn Mn Pb, Zn Gvl Gvl Au Fl Mn PbMn Zn, Cu Gvl Au Fl MnMn Pb Zn Au Fl Fl MnMn Mn Cu Sd Pb Zn GvlZn Fe Fl Au Zn, Pb, Ag AuAu Au Au Mn MnMn Gp Au Au Au Au Mn Cu, Pb, Zn Au BrtAu Cu Au Au MnMn Cu, Pb, Zn Cu, Pb, Zn Gvl Gvl Fe Cu AuAu Mn Au Depth to unconformity Au AuPb Mn Gvl Au Au W Au Mn Mn CuCu Gvl Au AuAu Au Ni WW Au Au Au CuAgAu MnMn Mn Cu Cu AuAu W WAu !( !( Au, AsCu, W Au Au, Cu, Zn, Pb Cu Zn W Au Mn MnMn Cu Au Au, Cu metres Au Pb Cu, Pb !( Au, Cu Cu Au Au Au Pb, Zn Cu, Au Au Cu Au Mn Mn Pb Au Au AuAu WAu MnMn Au, Cu AuAu AuAu Au Mn Mn Fe Cu AuAu Au Au MnMn Cu Cu Au Au High : 292.081 Au Au Cu MnMn Mn Gp Au AuAu Li Au AuAu Mn Au Au Au MnMn Fe Mn MnMn Zn, Pb Au, Cu, As Au Brl Fe Mn Mn Au Ta Mn MnW Mn Mn Br t Cu, Zn, Pb, Au Sn Brl Mn MnMn Mn Mn Mn Mn Mn Au Mn MnMn Mn Cu Cu, U, Co, Mn Au Cu Clcp Mn Mn Pb Mn Cu, Co K2SO4 Cu U, Pb, Zn, CuUU Low : -31.3929 Fe, MnCuCu MnMn U, Cu Cu Pb, Zn, Ag, Cu, U, Cd !(U Pb, Zn Cu Mn U, Cu, Pb Cor U, Au, Cu, Pb Jasp Cor Gp AuAu Cu Brt Au Cu PGE Fe Fe Mn Au Fe Au Fe Fe Brt, Sr, Mo, Ce Brt PGE U, Au, Pb Fe Fe Fe Mn Fe Fe Fe FeCu U, Zr Pb, Cu, Ce, LnO Fe Fe Fe Mn FeFe U, Au Fe , Mn Fe, Mn MnMn U, Pb, CuLnO, PbLnO, Pb Cu Mn Cu, Pb, As Mn, Fe U, Pb, Cu, Zn, Bi Au, Cu MnCu CuCu Fe, Mn Cu, Pb, Zn CuMn Brt Cu, Pb, ZnCu, Au Cu Cu, Au, Ni, PGEAu, Cu, Co Mn Cu Mn Dmd

0150 00Kilometers K2SO4, SaltGp Fe Fe Geological interpretations from the Paterson AEM survey K2SO4 FeFeFe Fe Fe FeFe Fe Fe Fe AEM Signatures of Mineral Deposits

• Finally, a quick look at how the AEM performed over some of the mineral deposits in the area.

Geological interpretations from the Paterson AEM survey Woodie Woodie plan & section

N

Geological interpretations from the Paterson AEM survey Permian or Tertiary valley fill Jeerinah Fm Woodie Woodie Mn deposits Woodie Woodie planPalaeokarst & withsection Mn ore

Permian Paterson Fm and/or Tertiary Oakover Fm

mASL

FL 30850

mASL FL 30860 Geological interpretations from the Paterson AEM survey Nifty plan & section

Resistive Broadhurst Fm Resistive Broadhurst Fm greywacke facies greywacke facies

Permian and Conductive Broadhurst Fm Permian (± Mesozoic) Quaternary cover Black shale facies and Quaternary cover

Geological interpretations from the Paterson AEM survey Telfer plan & section

Conductive unit in Permian and Quaternary cover Permian and Quaternary cover Telfer Member

Geological interpretations from the Paterson AEM survey Conclusion

• Regional AEM data give us: – A better understanding of paleotopography; – A better information on under-cover extent of mineralised rocks including 3-D disposition; – Reduced risk by providing more accurate depth to target information; – Much more information on landscape evolution for exploration models.

Geological interpretations from the Paterson AEM survey