First Data on the Age of Early Paleozoic Granitoids from the Malyi Khingan Terrane of the Central Asian Fold Belt

摘要

The principal structure of the Central Asian fold belt is determined by the combination of many continental massifs and smaller fold belts of different ages [1]. In its eastern segment, the most typical examples of the massifs are the Bureya (Turan) and Malyi Khingan (Jiamusi) massifs, which represent the main element of the Bureya-Jiamusi superterrane [2, 3] (Fig. 1). The metamorphic complexes, which have been dated back to the Early Precambrian [4], are usually thought to form the "basement" of these terranes. Recent data show, however, that protoliths of metamorphic rocks were formed in the Late Proterozoic or Early Paleozoic, and superimposed structural-metamorphic transformations are related to the Paleozoic and Mesozoic, not Precambrian, stages in geological development of the Bureya-Jiamusi superterrane [5-7].