中国东南大陆基底构造格局

中国东南边缘大陆基底年代学和构造发展程式是半个余世纪来纷争不已的重大基础地质问题。本文根据多种计时法所获年龄测定成果以及大量地质事实论证了“华夏古陆”,厘定其年代区间为(9—20)×10~2Ma,其间不整合面为1400Ma左右;华夏古陆与江南古陆在晋宁期发生对接碰撞,但向赣、湘、粤、桂方向开启,形成残洋盆地;自晋宁期—加里东期盆地沉积中心不断迁向南西,最终于广西运动、东吴运动关闭。华夏古陆在晋宁期后可能发生了漂移旋转运动。     

TECTONIC FRAMEWORK OF THE CONTINENTAL BASEMENT OF SOUTHEAST CHINA

The chronology and tectonic evolution model of the continental basement in southeast China margin is an important debatable geological subject. The Cathaysia is shown in this paper to be in accordance with many geological facts and also with the age data obtained by multi-dating method. Its age has been determined to range from 900 to 2000 Ma. The age of the unconformity plane in the Cathaysia is 1400 Ma. The collision and suture between the Jiangnan oldland and the Cathaysia took place during the early Jinning Period. Toward Jiangxi, Hunan, Guangdong and Guangxi, these two continents gradually opened to form a residual oceanic basin. The sedimentation centre of the basin continuously migrated southwestward from the Jinning through the Caledonian Period, and finally closed in the Guangxi Movement and Dongwu Movement. The drift-rotation of the Cathaysia after the Jinning Period has been inferred.