天津地区地壳物性界面的计算及深部构造特征

利用天津地区重力及航磁资料，对不同深度上密度界面、磁化率等进行了反演计算。结果显示,本地区平均深度约6.5 km的密度界面与新生代底部的起伏基本一致。由此认为本区新生代以来地壳发育过程比较连续且稳定，西南部地区曾经有较明显的火成岩活动。结合该地区航磁异常的分层计算与对比，认为本地区的地壳结构受渤海湾裂谷盆地的对“倾牌组式构造”所控制，该地区西北部存在有北东向展布的深大断裂，其深部延展与本区大部分已确认的断裂深部延展方向基本一致且朝向东南。其活动性值得重视。

The Calculation and Study of Petrophysical Property Interfaces and Their Deep Structural Feature in Tianjin Area

The density and magnetic interfaces have been gained from the calculation based on gravity and magnetic data in Tianjin area.The result show that the interface,whose average depth is about(6.5 km) deep under earth's surface,is coincident with the relief of Cenozoic era surface in this area.So the viewpoint is taken shape that the strata have been formed steady and continuously since beginning of the Cenozonic era;There has been the activity of igneous rock obviously in south by west of the area.Combining the analysis and study on magnetic interface,the authors think that the crust structure here is controlled by "a pile up slopes poker face to face",which is a accepted as the growth model of Bohai gulf basin widely;There is a deep-major fault along northeast in west of the area.Its extension in deep is to southeastward which coincides in most of the faults in this area.More attention should pay to the activity of this fault.