Geological and genetic interpretation of the results of samarium-neodymium dating of minerals of gold-tungsten deposits of the Verkhne-Yenashima ore cluster (Yenisei Ridge, Siberia)

Abstract

Samarium-neodymium isotopic characteristics in minerals of gold-tungsten deposits of Olympiada, Olenye and greisen manifestation of tungsten Vysokoye-2 were studied. Isochron ages for mineralization of pre-mining quartz-wolframite-shelite, ore gold-shelite-sulfide, and post-mining fluorite-carbonate stages are 921.2 ± 7.5, 919 ± 93, and 915 ± 47 Ma, respectively. The e Nd (T) values in the minerals range from -1.3 in wolframite to -9.3 in scheelite 2 associated with gold, indicating their crustal nature. Model dating of T ( DM 2- st ) for minerals of pre-mining (1636-2053 Ma) and post-mining (1762-1806 Ma) stages correlates with the time of formation of granitogneiss domes in the region. The dating of T(VM 2- st ) for scheelite 2 (2250-2304 Ma) corresponds to the time of formation of tholeiite-basalt volcanics of the Indiglin complex, which can be considered as the primary source of gold. Gold mineralization in the interval 921-915 Ma resulted from remobilization of gold from the black shale strata and its redeposition during thermal-fluid impact during intrusion of granitoids of the Tartar-Ayakhta Complex at the 930-950 Ma.