Chapter 7 - New Insights on the Origin of Ultramafic-Mafic Intrusions and Associated Ni-Cu-PGE Sulfide Deposits of the Noril’sk and Taimyr Provinces, Russia: Evidence From Radiogenic- and Stable-Isotope Data

Abstract

This study evaluates combined U-Pb, Hf-Nd-Sr-Os radiogenic and Cu-S stable isotope data for the ultramafic-mafic intrusions of the Noril’sk and Taimyr Provinces to provide new insights on the timing and sources of materials involved in the generation of variously mineralized lithologies and associated Ni-Cu-PGE sulfide ores. New isotopic-geochemical evidence indicates a complex geological history for the economic intrusions and associated Ni-Cu-PGE sulfide deposits. We propose that an extended period of concentration of the ore components in staging chambers was a key factor in the formation of economic Ni-Cu-PGE sulfide deposits. This requires a reevaluation of models for the origin of the Norilsk-type intrusions and their relationship to the Siberian flood basalts. A set of key geophysical and isotope-geochemical fingerprints is suggested to guide exploration for Ni-Cu-PGE sulfide ores.