ON THE TECTONIC POSITION OF THE BAOSHAN REGION DURING THE LATE PALEOZOIC

The aim of this study is to discuss the tectonic position of Baoshan i n Yunnan Province, China, during the Late Paleozoic by comparison of t he sedimentary facies, fauna and palaeomagnetic data from the Baoshan region with those from the Yangtze region and southern Tibet. The sedi mentary facies change suggests that in the Late Palaeozoic the Baoshan region underwent a similar geological history to southern Tibet, but different from that of the Yangtze region. The rugose corals and brach iopods as well as vertebrates of Baoshan are different from those of t he Yangtze region during the Late Palaeozoic. An evident segregation s eems to exist between them. The Late Paleozoic fauna of Baoshan shows certain similarities to southern Tibet. The Devonian and Late Carbonif erous faunas, especially, are very similar to those in southern Tibet. This indicates that there was no evident segregation between them in the Late Palaeozoic. The palaeomagnetic data reveal that in the Late P alaeozoic the Yangtze region was close to the equator, while the Baosh an region and southern Tibet were situated in the middle latitudes. On the basis of the palaeontological, sedimentological and palaeomagneti c data, it is inferred that Baoshan and southern Tibet were situated i n the same continental margin, and both regions were far from the Yang tze region during the Late Paleozoic. The Baoshan region may be consid ered as a massif within the Gondwana tectonic domain which includes so uthern Tibet, while the Yangtze region was located in another tectonic domain-the South Asian domain, with a wide ocean, the Tethys between them. Copyright (C) 1996 Published by Elsevier Science Ltd