Pt-bearing Fedorovo-Pansky Layered Complex (Kola Peninsula): Sm-Nd geochronology and Nd-Sr characteristics

Abstract

Abstract Results of isotope-geochronological Sm-Nd studies of the Paleoproterozoic platiniferous Fedorovo-Pansky layered intrusive are presented. Implementation of a complex of isotope-geochemical methods (Sm-Nd, U-Pb, Rb-Sr) allowed a more reliable and precise study of the age, formation patterns, and conditions of ore substance localization in the major units of the complex, i.e., the Fedorova Tundra and Kievey deposits. Geological, mineralogical, and isotope-geochronological data combined facilitate the identification of three ore-magmatic systems within the Fedorovo-Pansky ore area: 1) early troctolite-gabbronorite (2526-2507 Ma); 2) major ore-bearing norite-gabbronorite-anorthosite (2502-2470 Ma); 3) anorthosite (2447 Ma). The main industrial PGE mineralization of the Fedorovo-Pansky ore area is related to the norite-gabbronorite-anorthosite ore-magmatic system with the age of 2500-2470 Ma. Analysis of Sm-Nd model ages for the Fedorova Tundra (2.9 - 3.4 Ma) and West-Pana (2.8 - 3.1 Ma) blocks of the complex indicated that the age range for the Fedorova Tundra intrusive chamber is inclined to more ancient ages, which is confirmed by geological observations of individual intrusive chambers of the complex blocks.