CENOZOIC PLUME IN THE UPPER AMUR AREA

Abstract

In the Russian Upper Amur Area and adjacent regions of southern Yakutia, Archean and Proterozoic metamorphic complexes intruded by Jurassic Stanovoi granitoids are most widespread. Cenozoic formations represented by low-depth volcanosedimentary deposits within overlying basins compose less than 10% of the area of this region. According to the conclusions of most researchers, the origin and modern geodynamics of Cenozoic structures are related here with the eastern extension of the Baikal rift system, which predetermines the linear (sublatitudinal) character of Cenozoic deformations of the crust and upper mantle in the Upper Amur area. New data obtained by the authors during the study of the spatial distributions of tectonosphere density heterogeneities up to depths of 100 km indicate that the deep structures of the Aldan Shield and adjacent Stanovoi fold–thrust system sharply differ from structures of the Baikal–Vitim superterrane and Baikal rift system and that they are characterized by a completely different concentric-zonal type of Cenozoic geodynamic activity.