Paleomagnetic analysis of eastern Tibet: implications for the collisional and amalgamation history of the Three Rivers Region, SW China

A comparative analysis of paleolatitudes and latitudinal displacements was undertaken for the South China, Simao, Baoshan, Shan-Thai, Indochina, Qiangtang, Lhasa and Himalayan blocks by using available paleomagnetic data to determine the collisional and amalgamation history of the main blocks in the Three Rivers region, western Yunnan. The results show that (1) the Simao Block is a South china-derived block; (2) the Baoshan and Shan-Thai blocks were Subjected to rapid northward drift during the period from Late Carboniferous to Late permian; (3) the Baoshan Block collided with the Simao Block in the Late Permian and continued to drift rapidly northwards. together with the South China and Shan-Thai blocks, until the Late Triassic; (4) the Paleo-Tethys separating the Baoshan and Simao blocks was possibly opened in the Early Silurian; (5) the Meso-Tethys ranged in age from Early Permian time to Early Cretaceous time. and reached its greatest width of about 42degrees latitude in the Late Triassic. (C) 2004 Elsevier Ltd. All rights reserved.