S.I. TURCHENKO, T.L. TURCHENKO (IPGG RAS)

Features of metallogeny of Proterozoic intracratonic basins in the Fennoscandian and Canadian Shields

Intracratonic basins, which were widespread throughout the world in the history of the Earth’s evolution, are a specific type of tectonic structures in the Paleoproterozoic. They are also important riftogenic ore­bearing structures. The paper presents an attempt to correlate the evolution of intracratonic riftogenic basins in the Karelian Province, the Fennoscandian Shield (Onega and Kuolajarvi), with similar structures (Wollaston, Hurwitz, and Amer) in the Churchill Province, the Canadian Shield, for a period of 2.3 to 1.9 Ga. This period, particularly 2.1 to 2.0 Ga, is characterized by good correlation for black shale strata with Corg ranging from 2–5 to 10%, and in the Onega basin, up to the formation of shungite deposits. Although the correlation of these Paleoproterozoic deposits in terms of lithological features and age is quite possible, metallogenically, they are different. This is due to the greater degree of mafite­ultramate magmatism in the intracratonic structures of the Fennoscandian Shield with sulfide, PGE, and Ti­V mineralization, as compared to similar structures of the Canadian Shield, where Au­U mineralization is typical.
Keywords: correlation, intracratonic basins, Paleoproterozoic deposits, mineralization, Fennoscandian and Canadian Shields.