SEQUENCE STRATIGRAPHY AND BASIN DYNAMICS OF THE SOUTHEASTERN MARGIN OF THE YANGTZE PLATE IN SOUTH CHINA DURING THE LATE PROTEROZOIC TO EARLY PALAEOZOIC

The formation and evolution of the Yangtze Plate play an important role in the tectonic evolution of China paleocontinent.This paper tries to demonstrate the evolution of the Yangtze Plate during the Early Palaeozoic with the aid of the method of outcrop sequence stratigraphy and sedimentary basin analysis.In the study of the palaeogeography of the Yangtze Plate,the outcrop sequence stratigraphy has been developed,and this kind of new method provides a di-rect technigue to document the age and physical character of sequence boundaries and sea-level changes.In the first-order Cycle of the eustatic changes in South China,the main sea-level rise experienced two supercycles.In the Early Sinian,the melting of glaciers at two times led to the increase in volume of the sea water and in depth of the sea water column.resulting in the first main rise of the sea level.The second supercycle is represented by the first and second Early Cambrian sedimenntary sequences,indicating the maximum rate of the global sea-level rises and the accomplishment of the largest transgression in South China.There occurred a progressive fall of sea level after the middle Late Cambrian,and the Early Palaeozoic first-order sea-level variation cycle was terminated at the end of the Silurian period.