PECULIARITIES OF DISTRIBUTION AND A MODEL FOR THE MECHANISM OF FRACTIONATION OF PLATINUM GROUP METALS IN SULFIDE NICKEL ORES OF THE ELAN-TYPE DEPOSITS. PAPER 2. GEOLOGIC AND GENETIC NATURE OF ORE-MAGMATIC SYSTEM OF THE YELAN TYPE AND FRACTIONATION MECHANISM IN PGM ORES
The geologic and genetic nature of ore-magmatic system (OMS) and the role of crustal contamination in the evolution of the magmatic melt are considered. The criteria for recognition of the nature of contaminated intrusions with a high degree of productivity for non-ferrous ores, noble and other metals are given. A theoretically and experimentally grounded model for sulfide platinoid-copper-nickel ores and fractionation of platinum metals in a prolonged formation of the OMS of the Yelan type is proposed.