Geochemical and isotope-geochemical characteristics of the process of formation of platinum-metals mineralization in the layered massif Lukkulaisvaara (Karelia, Russia)

Semenov V. S., Semenov S. V., Savatenkov V. M., Dech V. N., GIebovitsky V. A.

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2017. V. 146. N 2. P. 18-45

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Language: Russian

Abstract

Study of the layered Lukkulaisvaara massif (in Olangskaya group of intrusions in the North Karelia) has shown the important role of supplementary phases of magmatic intrusions for the forming of platinum group metals (PGM) mineralization. Injection and crystallization of new portions of magma are connected with the formation of depression structures inside the intrusion, and they are somehow similar to structures of the «pot-hole» type. There is a return to high-temperature olivine-bearing cumulative associations in the basic part of the intrusion section. Formation of the PGM mineralization was accompanied by crystallization of secondary minerals in the wide range of temperature and pressure. For the insightful investigation of all these questions, the geochemical study had been carried out at the «Nadezhda» area and it provided new data on distribution of isotopes (Rb-Sr, Pb-Pb, Sm-Nd) in rocks of the massif.

Key words: gabbro-norites, Lukkulaisvaara massif, Karelia, PGM mineralization, post-magmatic alterations, geochemical characteristics, isotopic data (Rb-Sr, Pb-Pb, Sm-Nd).