辽东湾地区重、磁异常特征及其区域构造分析

Gravity-magnetic anomalies of Liaodong Bay and their tectonic implications

辽东湾地区是沿郯庐断裂系发展的新生代裂谷盆地,其断裂展布、基底性质对区域构造研究具有重要意义。充分利用我国海洋区域地质调查项目获取的辽东湾地区最新船载重、磁数据,详细描述了重、磁异常特征及对比分析特征。在此基础上,结合前人对区域构造及岩石物性的研究成果,对区域构造进行了分析和解释,指出了辽东湾坳陷"东西分带"的构造格局及不同时期区域构造的差异,对研究区内主要断裂展布、岩浆岩分布进行了划分,探讨了辽东湾及其周缘海域新太古宙古陆壳基底的分布。

Liaodong Bay is a Cenozoic rift basin in the Bohai Sea developed along the Tanlu fault.The distribution of fault system and the characters of basement have played critical roles in the performance of regional tectonics.This paper is devoted to the gravity and magnetic anomalies in Liaodong Bay based on previous tectonic researches,petrophysical properties and the newly acquired gravity and magnetic data from the various basic marine geological survey programs in China.There we made detailed description and comparative analysis of gravity and magnetic anomalies.In addition,regional tectonics of the study area are analyzed and interpreted.It is clearly noticed that the tectonic pattern of"east-west zonation"in Liaodong Bay Depression the difference of regional tectonic patterns vary with time from place to place.Together with the changes in distribution of main faults and magmatic rocks,the distribution of the new Archean curst basement in Liaodong Bay and its adjacent seas are also discussed.