南沙海域区域地质构造

REGIONAL GEOLOGIC TECTONICS OF THE NANSHA SEA AREA

以多年来在南沙海域的海洋地质—地球物理综合考察所取得的资料为基础 ,分析研究了区内的地球物理场特征、深部地壳结构、基底性质、断裂构造等 ,其中断裂构造划分出正断裂、逆冲断裂和走滑断裂 3个系统 ,区域上划分出 3大块体和 6个地块。叠置在不同地壳类型和基底之上或不同构造部位的 13个主要的大中型新生代盆地 ,具有沉积厚度大、盆地类型多、规模大的特点 ,是多种盆地原型的叠覆盆地 ,也是油气资源富集的重要场所。

Based on data from years comprehensive marine geological—geophysical investigations made in the Nansha sea area,the regional geophysical field features,deep structures of the crust,basement natures and faulting tectonics are analyzed and studied,and of the faulting tectonics,normal fault,obduction fault and strike slip fault systems can be found and there are 3 large regional massifs and 6 blocks.The 13 main Cenozoic sedimentary basins on large or intermediate scale,superimposed on crust of different types and basements and in different tectonic locations,are characterized by large sediment thickness,multiple types and large sizes,made up of several primary basins and serving as very important places for oil and gas accumulations.