东海陆架盆地伸展率和压缩率及构造跃迁

东海陆架盆地位于欧亚板块的东南缘和西太平洋活动大陆边缘,本文选取了东海陆架盆地主要凹陷的17条地震剖面,采用平衡剖面技术,计算了主要凹陷新生代不同演化阶段的伸展率和压缩率。分析表明,东海陆架盆地构造演化总体由西向东跃迁。晚白垩世至晚古新世东海陆架盆地裂陷中心在西部坳陷带,始新世东迁至东部坳陷带,上新世东迁至东海陆架盆地东侧的冲绳海槽盆地。古新世中后期东海陆架盆地西部坳陷带北侧昆山凹陷反转;中新世东部坳陷带的西湖凹陷反转。东海陆架盆地西部坳陷带与东部坳陷带构造演化不同,证明了东海陆架盆地的东西分带。西部坳陷带北部的长江坳陷和南部的台北坳陷构造演化不同,东部坳陷带北部的西湖凹陷和南部的钓北凹陷构造演化不同,证明了东海陆架盆地的南北分块。

Extensional and compressive ratios from East China Sea shelf basin and their structural jumping

The East China Sea shelf basin lies in the southeast margin of the Eurasian plate and the edge of the western Pacific plate.This paper selects 17 balanced cross sections from principal Sags in the East China Sea shelf basin.The amount of extensional and compressive ratios from principal sags in Cenozoic have been obtained by means of the technique of balanced cross sections.Extensional and compressive ratios analyzing showed that the tectonic evolution jumped from west to east in the East China Sea shelf basin.The center of rifting expansion was in the western zone from Late Cretaceous to Late Paleocene,which jumped to eastern zone in the Eocene and to the Okinawa trough basin in the Pliocene.The north of the western zone reversed in the middle and Late Paleocene,and Xihu sag of eastern zone reversed in Miocene.The difference of the east depression belt and the west depression belt in structural evolution proved that the East China Sea shelf basin is east and west sub zone.The difference of Changjiang depression in the north of the west depression belt and Diaobei depression in the south in structural evolution and the difference of Xihu sag in the north of the east depression belt and Taibei depression in the south in structural evolution proved that the East China Sea shelf basin is north and south sub zone.