Future Potential for metal Resources From Black Shales: Ni, Mo, Zn, Cu, U, V, Ag, Au, PGE CODES University of Tasmania
Slide 9.2 Oxidized Vs Reduced Basins OXIDIZED Basins produce stratiform Cu-Co, Zn-Pb and U REDUCED Basins produce Au-As, P, Ba and metalliferous black shales (Ni, Mo, Zn, Cu, U, PGE)
Slide 9.3 Pyritic Black Shales are King! Sources of Ni, Mo, As, Zn, Cu, Co, U, V, Ag, Au, PGE
Some Significant Metalliferous Black Shales Slide 9.4 -Mo-Se U-Ni-Mo-V (Sweden) -Zn Zn-Mo-Ni (Russia) V-As-Mo-Se-Ni-Ag-Zn-Au (Nevada) V-Ag-Cr-Se (South China) Ni-Mo-Zn-Au-PGE (South China)
Slide 9.5 Some Approximate Grades size ppm ppm ppm Comment Talvivaara Finland 1.1 billion t 1300 Cu 4900 Zn 2200 Ni 3% of world Ni resource Alum Shale Sweden >1.0 billion t 160 U 300 Mo 2500 V Approx figures Mo-Ni South China 1600km X 2-15 cm 1-4% Ni 2-7% Mo 600 V Plus Se, U, As Au, Pt Nevada NCT 70km 3 X 2-15 m 235 Ni 120 Mo 2200 V 2000 Zn, plus Se, Au, Ag, As Nick Deposit Canada ~ 400 km 3 X 10-40 cm 5% Ni 0.7% Zn 3000 V Plus Au, PGE, Se, As, Mo, Re
Ni ppm Zn ppm Slide 9.6 Organic Carbon Content Varies from 0.2 to 25% organic carbon 1000 Low metamorphic grade examples are oil shales Metal content is commonly related to organic carbon content V and Mo are good proxies for organic carbon 10 4 ALS_CD13-mudst 1000 RMF black mudstone RMF grey siltstone RMF carbonate 100 100 10 10 1 1 10 100 1000 10 4 V ppm 1 1 10 100 1000 10 4 V ppm
Talvivaara: Finland Slide 9.7 Palaeo Proterozoic
Slide 9.8 Talvivaara - Finland Discover in 1982 by Geol. Survey of Finland Palaeoproterozoic black shales (schists) in Archean gneiss terrain 20-100m thick pyrite-pyrrhotite carbonaceous schist Identified over strike length of >200km Resource grade of 0.13% Cu, 0.49% Zn, 0. 22% Ni, 102 ppm Mo, 630 ppm V and 7% organic C Mining commenced in 2008 Metals extracted by bioheapleach methods
Slide 9.9 Alum Shale Sweden
Slide 9.10 Alum Shale - Sweden Cambrian to Lower Ordovician Organic-rich pyritic shale unit 20 to 60 m thick within black shales over 200m thick Previously mined for alum, oil and uranium One of world largest resources of uranium 1.05 billion pounds of U 3 O 8 defined at the Viken Project, grading 170 ppm U Other metal contents are around 300 ppm Mo, 2500 ppm V, 380 ppm Ni
Southern China Lower Cambrian Black Shale Series Slide 9.11
Slide 9.12 Southern China Lower Cambrian black shales and oil shales Various stratabound deposits of Ni-Mo, barite, phosphate, uranium and vanadium within the black shale series Thin massive sulfide Ni-Mo ores average ~4% Mo and ~2% Ni Other metals: ~2% Zn, ~800 ppm V, 2400 ppm Se, 250 ppm U plus minor PGE Intermittent occurences over 1600km strike length
Slide 9.13 Yukon - Nick
Slide 9.14 Stratigraphic Column Hulbert et al. (1992)
Slide 9.15 Richardson-Ogilvie Mts: Yukon Nick deposit discovered in 1981 Devonian black shale basin 10-40 cm thick massive sulfide layer Identified over strike length of 400km Best grades of 7% Ni, 2.3% Zn, 0.33% Mo, 0.57% Se, 2400 ppm V and minor PGE
Slide 9.16 Genetic Theories Meteorite impact ejector (Goodfellow, 2009) Metal Exhalation along basin margin faults (Coveney et al., 1992) Absorption from seawater onto organic matter under extreme euxinic conditions (Lehmann et al., 2007)
Absorption from Seawater Slide 9.17 Lehmann et al., (2007)
Continental Margin Anoxic-Euxinic Basin Slide 9.18 metal input: fluvial detritus Redox sensitive trace elements trapped in organic muds OX: Mo 5+, Ni 2+ As 3+, V 4+, Au 3+ Detrital clays + adsorbed Au Mo4+ Ni RED: + As 3-, V 3+, Au + ORGANOMETALLIC COMPLEXES: Mo, As, V, Ni, Au DIAGENETIC PYRITE
Slide 9.19 Stage 1: During Diagenesis
Metals Move from OM into Diagenetic Pyrite Slide 9.20
Slide 9.21 Metals Re-organise During Diagenesis V 3+, Mo 4+, Ni +, Au 0, Zn 2+, Se 2+, S 2+, U 4+ Metals are partially to completely released from organic matter into new diagenetic mineral phases V Zn Ni Mo S, Se Au U V-illite sphalerite pyrite Native Au bitumen
Metalliferous Carbonaceous Mudstone/Siltstone Slide 9.22 Pyrobitumen V: 1,740 ppm Ag: 2.4 ppm Ni: 290 ppm Mo: 690 ppm U: 425 ppm Au: 4.6 ppm Diagenetic pyrite V: 202 ppm Ag: 216 ppm Ni: 940 ppm Mo: 905 ppm U: 1.2 ppm Au: 0.35 ppm
Slide 9.23 Marine black shales are concentrated during Ocean Anoxic Events (OAEs) Strauss (2006)
Slide 9.24 North American Margin: Cambrian to Devonian Nick Basin Ni-Mo-Zn Carlin District Groves et al (2005)
Slope and Basin Facies (after Cook et al., 2005) Slide 9.25 Metalliferous shale Devonian Silurian Ordovician Cambrian
North Carlin Trend Slide 9.26 Upper Mud Member: metalliferous black shale Same age as the Nick Ni-Mo-Zn horizon in Yukon
Slide 9.27 22000 20000 CODES / AMIRA P923: Drill holes logged and sampled at Goldstrike 1 km Meikle Bootstrap 3000 ft GA-65c 18000 Tara Griffin 16000 14000 CD-13c Clydesdale GA-54c Golden April BSC-168c Barrel 12000 10000 DPC-67 8000-3000 0 3000 6000 9000 12000 15000
Metalliferous Organic-Rich Unit in Upper Mud Enriched in V, Ag, Mo, Se, Ni, As, Zn, Au first recognised by Emsbo et al (1999) Slide 9.28 Modified from Furley ( 2001)
Upper Mud Member Enriched in V, Ag, Mo, Se, Ni, As, Zn, Au Slide 9.29
Sample 224 - Upper Mud Member Slide 9.30
Diagenetic Pyrite Analysis Slide 9.31 Diagenetic Pyrite ppm V: 2170 Ni: 8950 Cu: 12,590 Mo: 2670 Se: 3990 Au: 72.4 As: 3900
Slide 9.32 Stratiform Au-Ni-Mo-Se-V in Upper Mud Modified from Furley ( 2001)
feet feet feet BSC 168c - west of Screamer V score = V+Mo+Se+Ni+Zn CD-13cV2.kg 7:58:48 AM 1/7/09 CD-13cV2.kg 7:58:48 AM 1/7/09 Slide 9.33 Barrick Geochem 2:28:48 PM 8/7/09 feet 30 70 110 150 190 230 270 310 350 390 430 470 510 550 590 630 670 710 750 790 830 RCF UM RC2 RC1 PP2 feet 70 150 230 310 390 470 550 630 710 790 RCF UM 10 90 170 250 330 410 490 570 650 730 810 SSD 0 1000 2000 3000 4000 5000 V+Mo+Se+Ni+Zn ppm SSD 0 0.5 1 1.5 2 2.5 3 Ag ppm 0 0.5 1 1.5 2 2.5 3 Au ppm
Slide 9.34 Organic-rich diagenetic pyrite Horizons; enriched in Se, Zn, Ni, Mo, V, Ag +/- Au related to sedimentary cycles RC2 RC1 PP2 Upper Mud PP1 Planar Laminated PP base of Wispy? RM1 RM2 RM1
Se ppm Zn ppm Zn ppm Ni ppm Ag ppm VAMSNAZ Relations in WR Slide 9.35 1000 10 100 10 4 1 ALS_CD13-mudst 10 1000 1 1 10 100 1000 10 4 V ppm 10 RMF black mudstone RMF grey siltstone RMF carbonate 0.1 0.01 1 10 100 1000 10 4 ALS_CD13-mudst V ppm 10 4 100 1000 RMF black mudstone RMF grey siltstone RMF carbonate 1 10 100 10 0.1 1 10 100 1000 10 4 V ppm 1 1 1 10 100 1000 10 4 1 10 100 1000 10 4 V ppm V ppm
Slide 9.36 RMF VAMSNAZ LA-ICPMS Map
Diagenetic Pyrite Layers; Enriched in Ag, Au, Se and Ni Slide 9.37
Slide 9.38 Also Contain Te, Mo, Hg, Pt
Epigenetic Carlin Gold Overprints Metalliferous Shale Slide 9.39
Slide 9.40 This is a Very Common Feature of Carlin and Orogenic Au Deposits Metalliferous black shale
Kapai Slate is a metalliferous black shale which may play a similar role in the Goldfields Kapai Slate (The green leader?)
Slide 9.42 Take Home Message(s) Metalliferous black shales are developed from Archean to Jurassic Related to periods of widespread ocean anoxia Potential economic metals are Ni, Zn, Cu, Mo, U, Au and PGEs Stratifom or stratabound ores can be regionally extensive, low grade but billions of tonnes These thin metalliferous shale horizons can be the focus for later hydrothermal gold overprinting and concentration (e.g. North Carlin Trend)
Where to Explore in Australia for Metalliferous Shales Slide 9.43