Title

Е.N. LEPEKHINA, А.V. ANTONOV, B.V. BELYATSKY, N.V. RODIONOV, N.G. BEREZHNAYA, S.S. SHEVCHENKO, S.A. SERGEEV (VSEGEI)

Some features of U­-Pb SHRIMP dating of pyrochlore from alkaline-­ultramafic polyphase Kovdor massif (North Karelia): isotope-­geochemical characteristics of the evolution of pyrochlore-­group mineral composition

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.