NONTRADITIONAL GOLD-PLATINUM DEPOSITS IN EAST SIBERIA

The authors have revealed a commercially important platinum mineraliza tion (0.1-7.3 ppm Pt) in the gold-bearing metasomatites and ores of th e Sukhoi Log, Zun-Kholba, and Irokindinskoe deposits in East Siberia. At the Sukhoi Log deposit native platinum, Pt3Cu; Pt3Fe; Pt, Fe; Pt-3( Cu,Fe), (Pd,Ag)(n),(Te,Bi)(m), PtS in accretion with pyrite, galenite, and sphalerite have been found. These gold ores should be considered complex gold-platinum and referred to gold-platinum-sulfide-telluride- listwanite (Sukhoi Log) and gold-platinum-quartz-sulfide-beresite (Zun -Kholba, Irokindinskoe) formations of hydrothermal-metasomatic genesis . The deposits are located in Late Proterozoic - Paleozoic rifting str uctures on the areas of active paleodiapirism development. Such nontra ditional objects are characterized by step accumulation of Au, Pt, Pd, Ph, and Os in ore-localizing fault-fold structures, in zones of fract ure, mylonization, and hydrothermal metasomatism among carbonaceous, t errigenous, and terrigenous-volcanogenic rock masses of the upper rift ing parts of terrigenous synclines and ophiolitic belts.