Magmatic NiCuPGECr Deposits Distribution of Magmatic Sulphide Deposits
Magmatic Ni-Cu-PGE-Cr Deposits
Distribution of Magmatic Sulphide Deposits Norilsk Sudbury Bushveld
Magmatic Sulphide Ore (Pyrrhotite and subordinate pentlandite (Fe, Ni)8 S 9)
Ni Grades and Tonnages
Cu Grades and Tonnages
PGE Grades and Tonnages
Geology of the Sudbury Complex
Evidence of Meteorite Impact Onaping fallback breccia Shatter cones Granophyre - impact melt
Meteorite Impact Origin of the Sudbury Complex Sudbury Stratigraphy Airborne debris Onaping Impact Stratigraphy Ejecta Breccia Melt Sulphide concentrations Onaping formation Partial melting Sublayer Onaping formation Sudbury Irruptive Sublayer
Sudbury Footwall-Type Deposit
Sudbury Ni-Cu Ores Inclusion Ore Pyrrhotite-chalcopyrite and peridotite inclusions Chalcopyrite Pyrrhotite Pentlandite Massive Ore Pyrrhotite Pentlandite (Fe, Ni)9 S 8
The Billiard Ball Model of Magmatic Sulphide Textures (Naldrett, 1969)
Fraser and Strathcona Mines Cross-Section
Footwall Ores Chalcopyrite sill with alteration halo cuts off mafic dyke. High PGE into host gneiss Pyrrhotite- and chalcopyrite-dominated veins in footwall gneiss
Oxygen/Sulphur Fugacity and Fe. O Controls on Sulphur solubility in Silicate Melts 1300 o. C 975 o. C Sulphur dissolves H 2 S at low f. O 2 and as SO 2 at high f. O 2
Wt. % Metal in Silicate Liquid Metal partitioning between Sulphide and Silicate Melts Wt. % Metal in Sulphide Liquid
The Norilsk Ni-Cu Deposit
A Model for the Norilsk Deposit Magma saturates in sulphide due to decrease in f. O 2 Flood basalts Gabbro sill Sulphide Coal-bearing sediments Evaporites Limestones Gabbroic magma Limestones Coal-bearing sediments Limestones Magma dissolves high concentration of sulphur Limestones Evaporites
Bushveld Igneous Complex
Bushveld Stratigraphy Merensky Reef Gabbroic anorthosite Critical Zone Chromitite Anorthosite Lower Zone Pyroxenite Harzburgite
Controls on the Formation of Chromitite Layers Assimilation of silica-rich sediments Magma mixing
Merensky Reef Chromite Anorthosite Merensky Reef Pyrrhotite + PGE minerals
The Role of Convection, Crystal Settling and Repeated Magma Injection in the Bushveld
A Model for the Emplacement of the Bushveld Complex
- Slides: 24
