庙西凹陷构造特征

Structural characteristics of Miaoxi Sag

庙西凹陷位于渤中坳陷东南部,由北洼、东洼、南洼3个次级构造单元组成。地震构造解释和断裂系统分析表明:庙西凹陷北洼和东洼分别由2个箕状断陷构成,南洼北部为地堑构造,南洼南部为箕状断陷;各次洼受到郯庐断裂带的影响不同,北洼、东洼受到伸展构造系统的影响,南洼则明显受到郯庐断裂带的改造。3个次洼内部的伸展断裂受深层走滑断裂所诱发,构成走滑构造系统的一部分,浅层受张家口—蓬莱断裂带改造。

Miaoxi Sag is located in the southeast of Bohai Bay, and it is made up by the North subsag, the East subsag and the South subsag. The seismic interpretation and fracture analysis show that the North subsag and East subsag is respectively constituted by two dustpan-shaped fault depression, it is graben structure in the north of South subsag, and dustpan-shaped fauh depression in the south. The influences of Tan-Lu fault zone on each suhsag are different. The North subsag and East subsag are influenced by extended tectonic system, and the South subsag is influenced by Tan-Lu fault. The extended faults in the thine subsags are caused by the strike-slip faults, constituting a part of strike-slip tectonic system, and the shallow faults are transformed by Zhangjiakou-Penglai fauh zone.