中文摘要：

本文综合利用广州海洋地质调查局历年来在中国南海西沙海域采集的重、磁、震资料,结合前人研究成果.采用了场源边缘识别、磁性体顶面埋深欧拉反演以及重、磁、震剖面联合反演等技术.针对西沙海槽盆地岩浆岩分布、重大断裂、深部构造等进行了综合研究.研究结果表明,盆地内岩浆岩主要形成于印支期和燕山期,大部分分布于盆地断阶带上;识别出了NE向和EW向两组断裂.二者分别从北部和中部横贯盆地;盆地磁性基底埋深在6.0~12.6km之间。整体上呈＂中部深、南北浅＂的特征;西沙海槽盆地的莫霍面埋深在19~26 km之间,呈现出＂南北深中部浅＂的拉张裂谷特征.本文研究获取了西沙海槽盆地的基础地质构造特征.可深化盆地地质构造背景的认识,为该盆地下一步的油气工作提供基础研究资料.

英文摘要：

Based on 2D multi-channel seismic data interpretation and previous research results, the paper mainly study on distribution of magmatie rocks and major faults, deep seated structure of XISHA Trough Basin, using edge detecting techniques of potential field＇s sources, Euler anti-convolution for the depth of magmatic rock＇ s top surface and profile comprehensive inversion of gravity-magnetic-seismic data, which collected by Guangzhou Marine Geological Survey. The results show that the Indosinian-Yanshanian magmatic rock mainly distribute in the step-fauh zone in XlSHA Trough Basin, there are NE and EW fault systems across the entire basin, the magnetic floor＇s depth is 6. 0 - 12. 6 km with characteristic of higher in North-South and Lower in Middle, the Moho surface＇s depth is 19. 0 - 26. 0 km with tensile rupture rift＇ s characteristic of Deeper in North-South and Lower in Middle. A series of results, including distribution of magmatic rocks and major faults, magnetic floor＇s depth, Moho surface＇ s depth, will supply more knowledge on geological structures of XISHA Trough Basin and detailed basement geology data for the coming Oil and Gas Exploration.