天津静海—津南剖面地壳上地幔电性结构特征

ELECTRIC PROPERTY STRUCTURE OF THE CRUST AND UPPER MANTLE BENEATH JINGHAI-JINNAN PROFILE,TIANJIN

在天津市区南部的静海—津南一线布置了32个大地电磁测深点,剖面方位角92°,对采集的资料采用远参考与Robust技术进行了处理和解释。对该区的构造维数及构造方向做了分析,揭示了该剖面地壳上地幔电性结构特征,并进行了划分。成果显示:中下地壳存在双层低阻构造层,上地幔表现为中、高阻互层。在断裂带附近受构造活动影响,低阻高导构造层会发生上下错断与缺失。沧东、白塘口、天津断裂均是多组断层构成的断裂带,控制了双窑凸起、白塘口凹陷、板桥凹陷及静海斜坡带次级构造单元。

Tectonic of south Tianjin city is more complexity than other cities. Magnetotellurie （MT） data have been obtained at 32 sites along profile about 57.8 km from Jinghai - Jinnan areas, Tianjin, and got high resolution using the remote reference technique and 2 - D inversion method. The results show electric property structure of the crust and upper mantle clearly. The crust has two low resistivity and high - conductive, and the upper mantle has the character of normal or high resistivity together. Fault belts can make high - conductive of the crust and upper mantle up and do, sn. Cangdong, Baitangkou, Tianjin fault belts are made from some faults separately, which .control structures of Shuangyao convex, Baitangkan depression and Banqiao depression.