南海南部海域构造地貌

TECTONIC LANDFORM IN THE SOUTH OF THE SOUTH CHINA SEA

构造地貌是指由新构造运动直接形成的一种动态的、积极活跃的地貌类型。南海南部海域新构造运动强烈,类型众多,它们是控制海底构造地貌形成和发育的主要内动力因素。根据地质地球物理资料,对该区区域构造沉降、海底扩张、断裂作用、褶皱作用和火山活动等新构造运动类型及其形成的构造地貌进行了分析。区域构造沉降形成规模较大的构造台地、深水阶地和陆坡盆地等;海底扩张形成西南海盆、中央海盆及其内部的众多构造地貌类型;断裂作用形成断层崖、断阶、海底谷、断块山、断陷盆地等;褶皱作用形成山地和挤压构造盆地;火山作用形成海山、海丘。

Tectonic landform is a dynamic geomorphological type, which is directly controlled by neotectonic movement. The study to tectonic landform is an analysis using integrated methods of geomorphology, geodynamics and structural geology. Neotectonic movement had great intensity and numerous types in the south of the South China Sea,and such primary internal force controlled form and evolution of seabed tectonic landform. The authors analyze the types of neotectonic movement such as tectonic subsidence,seafloor spreading,faulting,folding,volcanic activity,and tectonic landforms.Tectonic subsidence formed large-scale tectonic mesa,deep water terrace and continental slope basin etc. Seafloor spreading formed the Southwest subbasin and the Central basin of the South China Sea and many tectonic landform types within these basins. Faulting formed fault cliff,fault terrace,seabed fault valley,block mountain and graben basin etc. Folding formed mountain and extrusion tectonic basin. Volcanic activity formed seamount and sea hill.