V.N. SMIRNOV, K.S. IVANOV, A.V. KOROVKO (IGG UB RAS)

Collision granodiorite-granite massifs in the eastern zone of the Middle Urals: U-Pb SIMS geochronology and tectonic settings

The U-Pb SIMS dating of zircons from two granodiorite-granite massifs (Starokrivchansky and Novokrivchansky), typical of the eastern margin of the Middle Urals, has shown that they had been forming in the period from 315 and 306 Ma ago. The analysis of the geological and geochronological data available proves that this stage of granitoid magmatism belongs to the collision period of the evolution of this region. The intrusion of dated massifs occurred synchronously with the formation of the Verkhisetsky granodiorite-granite complex, which is widespread in the open part of the Middle Urals that confirms the existence of a large episode of collisional granitoid magmatism, common for the eastern sector of the Urals and the basement of the adjacent part of the West Siberian Plate.
Keywords: granitoids, U-Pb SIMS dating, eastern margin of the Middle Urals, basement of the West Siberian Plate.