THE EARLY PRECAMBRIAN CRUSTAL EVOLUTION OF CHINA

The Archaean continental crust in China originated from dispersed nucl ei under the influence of whirl tectonics 2.5 Ga ago. From the beginni ng of the early Proterozoic, the crustal evolution process was control led by the plate tectonics. A. tectonic regime of coexisting mobile be lts of different characteristics and rigid blocks emerged. The diversi ty of tectonic setting and structures marked the beginning of a new ep och of crustal evolution. The north China protoplatform, the Tarim pro toplatform and the Yangtze protoplatform are considered to have separa ted from each other by least at the end of Archaean, based on the earl y Proterozoic accretion zones developed between them. Cathaysia gradua lly moved closer to the Yangtze protoplatform in the early Proterozoic . The nearly north-south primary structural trend of the early Protero zoic formations in the northern margin of the modern north China platf orm indicates that the north China protoplatform had been connected wi th the Siberian craton during and before early Proterozoic times. Copy right (C) 1996 Published by Elsevier Science Ltd