PRECIOUS METALS IN ROCKS AND ORES FROM INTRUSIVE COMPLEXES OF KOLA PENINSULA

摘要

Distribution of Pt, Pd, Rh, Ir, Ru, Os, Au and Ag was studied in rocks and ores of alkaline, ultramafic and mafic intrusive complexes developed in the north-eastern part of Baltic shield. These complexes belong to different formation types, are dated from 2.45 to 0.38 Ga and bear chromite, magnetite, ilmenite, titanomagnetite, magnetite-apatite-rare metals, copper-nickel sulfide and PGE mineralizations. Average Pd/Pt ratio makes 2.3 within unaltered rocks of all complexes, the Ru/Ir ratio making 2.3 is one and the same also. The main intrusive phases of all massifs have the similar character of precious metals ratios normalized to chondrites. But in sulfide and oxide ores these ratios are slightly differing. Oxide ores, during their formation, become enriched in iridium subgroup metals; the sulfide ores were enriched in all kinds of precious metals, but particularly in Au, Ag and palladium subgroup metals. Gold and silver are especially typical for sulfide-bearing carbonatites of the later stages in alkaline-ultramafic formation. Concentration rate, from rocks to ores, increases from 10 to 1000 within range from Os to Ag. In general, the studied complexes of Kola metallogenic province have the Ru-Pd specialization.