扬子东南大陆边缘晚元古代—早古生代层序地层和盆地动力演化

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

摘要:

扬子板块早古生代的形成和演化对中国古大陆的板块构造演化有重大意义,本文试图通过用新发展起来的露头层序地层方法和沉积盆地演化分析来阐明其变化规律。

Abstract:

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.