Structural controls on the primary distribution of mafic-ultramafic intrusions containing Ni-Cu-Co- (PGE) sulfide mineralization Peter1 C Lightfoot and Dawn Evans-Lamswood, Vale Base Metals Process Controls on Formation of Nickel Sulfides Tetonic Setting Crustal Architecture Craton Margin 7 Crust 6 Basalt Lavas 5 2 Sub-Continental 4 Lithospheric Mantle Disseminated Sulphide Strike-slip Upper Crustal fault zone 2 Sediments 3 Mantle Mid-Crustal 1 Metamorphic Rocks Sulphide-rich Begg et al (2011) Plume Layers 30 - 40 km 2 Key Process Controls 7 Syn-tectonic and post-tectonic modification 6 Sulphide segregation 5 Sulphide saturation and metal endowment Deep Crustal Granites and Gneisses 4 Emplacement 1 3 Fractionation and contamination After: Lightfoot (2007) and Naldrett (2010) 2 Ascent of magma 2 Generate ultramafic magma from metal 1 endowed source Extensional spaces in transform fault systems act as “magma highways” from mantle to surface and control many small differentiated intrusions with nickel sulfide deposits Magma Conduits Kinematics : dextral strike-slip fault zone right-stepping left-stepping extensional contractional bend bend oblique oblique normal fault thrust View Along Plane of Stike-Slip Shear Zone Plan View Magma Conduits (pipes, dykes, chambers) at different crustral levels Surface PLAN A - Pipe Configuration Chamber Conduit PLAN A PLAN B - Dyke Configuration Chamber PLAN B Dyke Rigid PLAN C? PLAN C - Chamber Chamber Ductile Crust Melt Accumulation Melting Mantle 3 Heat Source Key Points To Take Away • Widespread importance of strike-slip structures on emplacement of small differentiated intrusions with transported sulphide: Vertical champagne glass-shaped chonoliths (e.g. Huangshan, Huangshandong, Jingbulake, Limahe, Hong Qi Ling…) Accumulations within sub-horizontal chonoliths (e.g. Noril’sk- Talnakh, Karatungk, Nkomati, Babel-Nebo…) • A common model for nickel sulfide formation in the roots of large igneous provinces in craton-margin structures • Case studies of Chinese deposits, Norli’sk and Voisey’s Bay • Chamber geometry, ore distribution, and transport of magmatic sulfide controlled by dilational space created in a right-lateral fault zone 4 Distribution and scale of Ni sulfide deposits in China 80°E90°E 100°E 110°E 120°E 130°E Huangshan, 50°N Jingbulake Huangshandong Central Asian Orogenic Belt Hongqiling Kalatongke Central Orogenic Belt North China Craton Yangtze Craton Tarim Craton 40°N Cathaysian Block Himalayan Orogen Xiarihamu Jinchuan Large >1000kt Ni Yangliuping Medium >100-1000kt Ni 30°N Limahe Small >10-100kt Ni Qingquanshan Jinbaosan Baimazhai 20°N Ban Phuc 1000 Km 5 Distribution of nickel deposits in Western China Border Mesozoic-Cenozoic Basins Cover Nickel Sulfide Deposit Mesozoic fold-thrust belt Faults (strike-slip with thrusting) Paleozoic Town / City Karatungk Precambrian Underlain by Shield After: Mao et al. (2008), Cunningham (2007) Junggar Basin 45°N Urumqi Mongolia Hami Hami Basin Jingbulake Hulu Tula’ergen Huangshandong Korla Huangshan Pobei 40°N Tarim Xinjiang Basin Gansu Xiarihamu Jinchuan Qinghai Lashuisha 85°E 90°E 95°E 100°E 6 Restraining bends and pull-apart basins along the Gobi-Tien Shan fault system in Eastern Xinjiang, China Aj Bogd Bogda Shan Barkol Tagh Turpan Basin 200km Xinjiang After: Mann, (2007) Huangshandong Huangshan 15km Lightfoot, Evans-Lambswood, (2007) 7 Geology of the Huangshandong Intrusion and the location of Cu-Ni Sulfide mineralization A 162° 325° A’ A’ 200m 1km A Huangshandong 15km Gabbronorite Gabbro to olivine gabbro Faults Ni-Cu sulphide Gabbro Diorite Synform mineralization Diorite Antiform Boreholes Peridotite8 Country rocks Xinjiang: Hami Belt – shaft on Huangshandong Photograph: Peter Lightfoot, 2001 9 Xinjiang: Hami Belt – exploration under Chairman Mao’s 5 Year Plans Photograph: Peter Lightfoot, 2001 10 Geology of the Huangshan Intrusion and the location of Cu-Ni Sulfide mineralization Diorite A Gabbro Gabbronorite V Y Hornblende peridotite Z Peridotite Plan View Websterite Dunite 500 Disseminated Ni - Cu sulfide mineralization m Basalt and trachyte Conglomerate and sandstone X U Siltstone Limestone Fault X 50° Y 90° Z 0 U V B 0 C Huangshan Intrusion 500 Cross m 500 Section (m) Long Section View 500 11 View (m) Jingbulake Intrusions, Xinjiang Province Carboniferous Blueschist Jingbulake Carboniferous Greenschist Carboniferous Eclogite 40 km Early-Middle Paleozoic Granite Mafic Intrusion 42°40 N Marble Sulu Carboniferous Volcanic sedimentary rocks Proterozoic Complex Changawuzi 42°25 N Fault Yang et al., 2012 81°00 E 81°30 E 12 Karatungk #1,2 and 3 Intrusions, Xinjiang Province, China: North-facing long section #1 #2 #3 4036322824201612 4 3 11 19 27 35 43 51 59 63 71 79 87 95 103 111 0 500 (m) 0 500 m 1000 F9 Wang et al., 1991 Biotite-pyroxene diorite Biotite-hornblende norite and F4 Biotite-hornblende gabbronorite Karatungk Biotite-hornblende olivine F20 gabbronorite F18 Biotite-hornblende diabase gabbro F3 Disseminated sulphide F21 Heavy disseminated sulphide F7 Cu-rich massive sulphide Ni-rich massive sulphide 1000Km 13 F6 150 F5 m Karatungk #1,2 and 3 Intrusions, Xinjiang Province, China: West-facing long section #2 Deposit #3 Intrusion Country rock Olivine gabbronorite Gabbronorite Diorite Quartz monozonite Outline of mineralization Borehole trace Wang et al., 1991 14 200 m Location Map of the Jinchuan Intrusion, Proterozoic Longshushan Belt, Gansu Province, China After Song et al., 2008 39°00’ 10 km Cenozoic Cretaceous Devonian-Jurassic Paleozoic granite Cambrian-Silurian Shandan Zhangbutai Proterozoic mafic- ultramafic intrusion Qingshijing Proterozoic 38°40’ Fault Magmatic sulfide mineralization Jinchuan Intrusion Jinchuan Jinchuan 38° 20’ 1000 Km Yongchang 15 101°00’ 101°30’ 102°00’ 102°30’ Geological Map and Sections of the Jinchuan Intrusion 16 Tang Zongli (1993) Mine area #2 – no trace of sulfide or country rock xenoliths inside the intrusion at surface Photograph: Peter Lightfoot, 2000 17 Sequential Emplacement of Sulfide-bearing silicate melts Jinchuan Model 18 Hongqiling – Geology, Structure and Mineral Occurrences Hongqiling 1000 Km Hongqiling Jilin #1 Deposit Mesozoic sedimentary rocks Granitoid rocks Mafic-ultramafic Intrusions Jilin #7 Hulan Group Gneiss (younger) 05Deposit Hulan Group Gneiss (older) km Fault 19 After Zhou et al., 2000 Hongqiling: Jilin Province A B Gabbro Eastern Pyroxenite Intrusion 200 Eastern Olivine Pyroxenite Intrusion Disseminated sulfide 0 in olivine pyroxenite Western Intrusion Weakly mineralized -200 peridotite Western Amphibolite Intrusion Shaft (projected to -400 Gneiss Surface) Fault 250m 150m -600 Pit outline Plan View Section View A A’ C D Conglomerate Massive sulphide 200 A’ Disseminated and massive Sulphide in orthopyroxenite Number 7 100 Othopyroxenite and Deposit hybrid zone Schist 0 Marble Gneiss A -100 Outline of open pit Number 7 Faults and shear zones 100m Deposit 100m Unconformity -200 Plan 20View Section View (m) Intrusions controlled by structures beneath the ~260 Ma Emeishan Flood Basalt, SW China A Yangliuping Chengdu SICHUAN Panxi “Rift” Limahe Qingquanshan 1000km Kunming Yangtze craton YUNNAN Himalayan orogen Jinbaosan Emeishan flood basalt Underlain by many small intrusions Baimazhai Fault zone Nickel and PGE sulphide 200km deposits 21 Provincial boundary Geology of the Limahe and Qingquanshan Cu- Ni Sulfide Deposits (Sichuan Province) A A' B Plan C Section View (m) D Section View E Section View View o 70 1800 A A’ 1700 200m 50m 1600 50m Overburden Huili group quartzite Mined-out High grade massive sulfide Diorite and gabbro Huili group limestone Hekou formation Dissemintated sulfide Pyroxenite and peridotite Fault Gabbro Diabase Massive and disseminated Peridotite Fault Ni - Cu sulfide 22 Noril’sk Panoramic view from Bear’s Brook towards north Photograph: Peter Lightfoot, 2002 23 Distribution of Siberian Trap Basalts Kara Sea Siberian Trap basalt Basalt trap West Siberian basalts Sedimentary rocks West Siberian Economically mineralized Lowlands Noril’sk intrusions projected to surface Russia Isopach map thickness of Nadezhdinsky Formation Margin of basalts (in meters) Siberian Omsk Shield TALNAKH Novosibirsk KHARAELAKH INTRUSION INTRUSION Kazakhstan Mongolia www.largeigneousprovinces.org/LOM.html Samoedsky Tholeiitic basalts Picrictic basalts Kumginsky Alkalic and sub- Kharaelakhsky alkalic basalts Mokulaevsky Stratigraphic equivalent of Talnakh Type Intrusions Morongovsky Crustally- ~3500m Nd3 contaminated and Nadezhdinsky Ni-Cu-PGE-depleted 50km Nd2 basalts Nd1 Tuklonsky Khakhanchansky Stratigraphic equivalent of Low Talnakh Type Intrusions Gudchikhinsky Naldrett et al (1995) Syverminsky 24 Ivakinsky Stratigraphy of the Noril’sk Region Basalt Formation Period and Unit Thickness RockTypes Stratigraphic Position of Intrusion or Series (m) 80 - 140m Piv2 Ivakinsky suite Upper Permian Noril’sk - Intrusion Tungusskaya series 280 - 330 C-P22 Lower Permian Lower Middle Middle Carboniferous Talnakh Kalargonsky D kl 140 - 180 Intrusion Upper 3 formation Devonian Nakokhozsky 2-80 D3 nk formation D2 jk Yuktinsky formation 12 - 40 Middle Devonian D mt Manturovsky 110 - 210 Intrusion Talnakh 1-2 formation LowNoril Intrusion ’sk Low Razvedochninsky D rz 110 - 150 1 formation Kharaelakh Low Noril’sk 62 - 85 Intrusion D 1kr Kureysky formation Intrusion Lower Devonian D zb 110 - 140 1 Zubovsky formation Coal Limestone D1 hr Khrebtovsky formation 30 - 90 Conglomerate Dolomitic marl Sandstone Dolomite Yampakhtinsky D jm 50 - 100 Siltstone Anhydrite 1 formation Argillite Salt (NaCl) &
Details
-
File Typepdf
-
Upload Time-
-
Content LanguagesEnglish
-
Upload UserAnonymous/Not logged-in
-
File Pages42 Page
-
File Size-