Age and Boundaries of the Olekma Magmatic Belt of the Selenga–Stanovoi Superterrane (Central Asian Mobile Belt)

Abstract

The Olekma magmatic belt of the Selenga–Stanovoi Superterrane within the Central Asian mobile belt is traced for a distance of more than 700 km. As a result of U–Pb geochronological studies, it was established that granitoids of the Olekma Complex have the Paleozoic age (355 ± 2 and 358 ± 2 Ma) in the eastern and central part of the belt, whereas consolidation of granitoids with a similar composition in the western segment occurred in the Early Mesozoic (237 ± 1 Ma). The formation of Mesozoic granitoids of the Olekma Complex occurred under the conditions of lithospheric extension, whereas Late Paleozoic granitoids were most likely formed during the collision of the Selenga–Stanovoi Superterrane and structures of the Baikal mountain area.