Литосфера (Aug 2015)
The age position of gold-sulfide mineralization in the metahyperbasites of the Sysert’ metamorphic complex in the Middle Urals
Abstract
The massive and disseminated gold-copper-cobalt sulfide ores (Karasya Gora deposit) are restricted to the body of metahyperbasites of anthophyllite and tremolite-anthophyllite composition. In the history of evolution of the Sysert’ metamorphic complex anthophyllite rocks are associated with processes of a granitization and appeared twice: during the Paleozoic regional silica-acid metasomatism, synchronous with a plagiogranitization, and during a local Late Paleozoic silica-acid metasomatism, synchronous with potassium granite magmatism. The age 294-306 Ma of the formation of the gold-sulfide ores in anthophyllite rocks is established using the U-Pb method of chemical dating of uraninite crystals and are shown (average value 300 ± 3 Ma). The obtained value of uraninite’s age indicates that the fluid produced at the regressive stage of a plagiogranitization which finished the process of the silica-acid metasomatism of the ultramafic rocks, participated in the gold-sulfide ore formation.
