THE RB-SR GEOCHRONOLOGY AND ISOTOPIC GEOCHEMISTRY OF ORE-HOSTING ROCKS AND WALL-ROCK METASOMATITES OF THE MESOTHERMAL TALOVEIS GOLD DEPOSIT, WESTERN KARELIA

Abstract

Thus, Rb-Sr isotopic-geochemical investigations indicate the Paleoproterozoic (1.7 Ga) age of wall-rock metasomatites, beresite aureoles, and, presumably, mesothermal gold mineralization of the Taloveis deposit. The formation of gold-bearing quartz veins in the Archean and their subsequent reactivation in the Proterozoic are not confirmed, since neither geostructural nor petrographic data indicate the two-stage evolution of tectonic and hydrothermal-metasomatic processes usually observed in reworked Archean gold deposits. Paleoproterozoic endogenous activation and gold mineralization in the Karelian Block were probably related to the final stage of evolution of the Svecofennian collisional orogen, the crocodile-type structure of which was deciphered from seismic data 150 km west of the studied object.