V. A. STEPANOV

PLATINUM-COPPER-NICKEL PROVINCES OF THE NORTH-ASIAN CRATON

The results of isotope dating of alkaline-ultramafic polyphase massifs and carbonatites, and related rare-metal mineralization by pyrochlore U-Pb SIMS SHRIMP II method developing within CIR VSEGEI are presented. Some challenges of this dating method and interpretation approaches are discussed on the example of Paleozoic alkaline-ultramafic Kovdor massif (North Karelia) pyrochlore collections.

Keywords: pyrochlore, U-Pb local dating, SHRIMP II, Kovdor massif, rare-metal mineralization, isotope-geochemical characteristics, alkaline-ulramafic massif, carbonatites