Polychronic sources and isotopic age of the volcanogenic complex (Arvarench Unit) of the Imandra-Varzuga structure, Kola Peninsula

From the middle of the twentieth century, many problems of stratigraphy and correlation of volcanogenic sedimentary sections of the Paleoproterozoic intracratonic riftogen Imandra-Varzug structure (IVS), the largest on the Fennoscandinavian Shield, have been studied using traditional lithological and stratigraphic methods on the basis of signs such as the general composition and facies control of rocks, cyclic recurrence of lithogenesis, and regularities of the evolution of mineral and geochemical composition of volcanogenic sedimentary complexes. This paper contains new geochemical and isotopic data for volcanogenic complexes of the Arvarench Unit of the IVS, which allowed us to attribute them to the Paleoproterozoic Suma subhorizon and reveal multi-age crustal and mantle sources of primary melts.