利用重力梯度反演南海西南海盆深部构造  

GRAVITY GRADIENT INVERSION OF DEEP STRUCTURE IN THE SOUTHWEST SEA BASIN

作　　者：唐仁敏[1] 张健[1] 

机构地区：[1]中国科学院研究生院地球动力学重点实验室,北京100049

出　　处：《地质力学学报》2006年第1期49-54,共6页Journal of Geomechanics

基　　金：国家自然科学基金(40474031)资助

摘　　要：重力梯度异常反映的是重力异常的变化，其分辨率比重力异常高。重力梯度空间参量图能给出构造倾角和倾面的信息，结合重力梯度剖面和梯度空间参量图可以构建出地下构造的几何模型，进而对一些复杂构造进行解释。本文利用重力梯度异常对南海西南海盆进行了解释，得到大致以西南海盆北东向扩张轴为对称轴的穹隆状构造面。该构造面在西南海盆下6～15km处形成一个密度界面，此界面可能是西南海盆北西-南东向海底扩张期间地幔上隆所引起的。The gravity gradient anomaly reflects the change of gravity anomaly, and it has a higher resolution than gravity anomaly. The plot of gravity gradient space parameters can give diagnostic information of dip angles and planes. A geometric model of subsurface structure may be constructed by integrating a gravity gradient section with the gravity gradient space parameter plot, and furthermore some complex structures may be interpreted. The authors used gravity gradient anomalies to interpret the Southwest sea basin of the South China Sea and obtained the domal structure plane with the NE-trending spreading axis of the sea basin as the symmetric axis. This structure plane forms a density interface 6-15 km below the sea basin, which might be caused by mantle uplift during NW-SE-trending sea floor spreading of the Southwest sea basin.

关 键 词：重力梯度 密度界面 西南海盆 南海 

分 类 号：P631.1[天文地球—地质矿产勘探]