δ18O RECORD FROM CONODONT APATITE ACROSS THE LOWER-MIDDLE ORDOVICIAN BOUNDARY ON THE YANGTZE PLATFORM (WESTERN HUBEI,SOUTH CHINA)

摘要

1 INTRODUCTIONSouth China was covered by an epeiric sea during the Early Ordovician with an extensive accumulation of carbonates on the Yangtze Platform northwest of the Jiangnan Slope and the Zhujiang Basin(Chen et al.,1995).Review papers by Cocks and Thorsvik(2002,2004)show a position of the South China plate as well as many other Asian terranes(e.g.Tarim,North China,Tibet.Indonesia)along the western margin of Gondwana in the eastern Rheic Ocean.However.because of the lack of palaeomagnetic data and controversal views interpreting the faunal compositions and the depositional environments,difierent models have been proposed.