南海中部西区新生代构造演化规律与盆地形成演化动力学机制探讨

Cenozoic tectonic evolution and dynamic mechanisms for the western part of the central South China Sea

本文以现代构造地质与地球动力学理论为指导,利用平衡剖面技术对南海中部西区进行了构造演化特征及演变史的恢复,制作了其上下构造层的构造纲要图,划分了南海中部西区新生代以来经历的三大构造演化阶段:(1)裂陷阶段;(2)坳陷阶段;(3)区域沉降。并指出了其动力学机制:始新世末,印度板块与欧亚板块发生碰撞产生的远距离效应以及渐新世西太平洋板块向东亚大陆边缘产生的俯冲效应是南海中部西区新生代构造演化的主要动力学机制。

Abundant petroleum resources reside in the South China Sea,an important target area for the offshore petroleum exploration in China and also one of the hotspots for the petroleum exploration in the world.In the light of the theories of modern tectonic geology and geodynamics and balanced cross section technique,the authors in this study contend that the western part of the central South China Sea has gone through three stages of tectonic evolution since the Cenozoic,including rifting,down-warping,and regional subsidence.The dynamic mechanisms contain the distal effects triggered by the Indian-Eurasian plate collision at the latest Eocene and the subduction effects of the Western Pacific plate toward the East Asian continental margin during the Oligocene.