MESOZOIC GRANITOIDS OF THE UPPER AMUR REGION: NEW SR, ND, AND O ISOTOPIC COMPOSITION DATA

Abstract

First data on the Sr, Nd, and O isotopic compositions in Mesozoic granitoids of the upper Amur region and previous data on the Sr and Nd isotopic compositions available for different-age granitoids are discussed. The upper Amur region comprises a spacious territory located between the Siberian and North China platforms. Based on literature data, the region includes the following major structural units: Aldan–Stanovoi, Baikal–Vitim, and Amur superterranes, Mongol–Okhotsk Foldbelt, and Umlekan–Ogodzha volcanoplutonic belt that unites and overlaps structures of the Amur Superterrane and the Mongol–Okhotsk Foldbelt.