南沙海区及邻区构造演化动力学的若干问题  

SOME REMARKS ON THE TECTONIC EVOLUTION OF NANSHA AND ITS ADJACENT REGIONS IN SOUTHERN SOUTH CHINA SEA

作　　者：周蒂[1] 吴世敏[1] 陈汉宗[1] 

机构地区：[1]中国科学院边缘海地质重点实验室,中国科学院南海海洋研究所,广东广州510301

出　　处：《大地构造与成矿学》2005年第3期339-345,共7页Geotectonica et Metallogenia

基　　金："十五"科研院所社会公益研究专项项目(编号2001DIA50041);国家重点基础发展规划课题(G2000046702);中国科学院重要方向项目(KZCX2-SW-117)资助.

摘　　要：通过南沙海区地球物理资料及围区地质地球物理资料的对比分析,指出南沙海域及邻区中新生代经历晚三叠世碰撞缝合事件及巽他陆块的形成,晚白垩世板块运动重大变格及东亚陆缘的大规模裂谷作用,始新世板块运动重大变革及古南海的消亡,中新世变革事件及南海今日面貌的奠基等四个重要演化阶段。并提出“东亚陆缘超级剪切”动力学模式来概括南沙海区及邻区这新生代构造演化:在特提斯构造域西段(印度部分)、东段(澳大利亚部分)及西太平洋构造域这三大体系的竞争和联合的影响下,东亚陆缘岩石圈交替承受“左行压扭”和“右行张扭”超级剪切应力场的作用,导致南海等边缘海的张开或关闭,以及周边地块的裂离、拼合。After analyzing the geological and geophysical data about Nansha and its adjacent regions, the authors point out that there exist four key evolutionary stages, i. e. , the unification of Sundaland in Late Triassic, the rifting of the eastern margin of Asia in Late Cretaceous, the subduction of proto - South China Sea during Eocene,and the opening of South China Sea in Late Oligocene. A megashear model was proposed to interprete the Cenozoic evolutionary dynamics of Nansha and its adjacent areas. The interaction between the two large convergent zones,the Tethys and the Circum -Pacific, resulted in the convergent forces competing and combining with one another.This shearing was characterized by alternative sinistral transcompression and dextral transtension. The variation in stress field led to the opening and closing of the South China Sea and the splitting, moving and colliding of its adjacent blocks.

关 键 词：南沙海区 构造 动力学 演化 

分 类 号：P541[天文地球—构造地质学]