郯庐断裂带辽东湾段变形特征及展布规律

Deformation characteristics and distribution of Tan-Lu fault zone in Liaodong Bay Depression

牛成民 杨海风 郭涛 李伟 吴智平

Chengmin Niu Haifeng Yang Tao Guo Wei Li Zhiping Wu

基于最新的大连片三维地震处理资料，对辽东湾坳陷主走滑断裂进行了系统判识，进一步结合前人研究成果探讨了辽东湾坳陷郯庐断裂带的分支组成与展布规律。结果表明，辽东湾坳陷郯庐断裂带应发育3条（组）分支断裂，东支发育在辽东地区，为辽东1号断裂；中支发育在辽中地区，新生界断裂为辽中1号和辽中2号断裂，在深层两条断裂合并为一条主走滑断裂；西支位于在辽西地区西部斜坡位置，新生界断裂为辽西走滑断裂。3条（组）分支断层均切割至深部基底，并可到达莫霍面，在重力异常图上具有明显的体现。辽东湾坳陷3条（组）郯庐断裂带分支断层构造变形特征存在明显差异，与渤海海域渤中-渤东段、渤南段也存在显著差异，走滑程度的强弱、先存断层的复活、地层厚度与岩性特征，以及基底性质的差异是造成这种差异性的主要原因。

Based on the recent 3D seismic interpretation of the Liaodong Bay Depression， we systematically identify the main strike-slip faults， and further discuss the branches and distribution pattern of the Tan-Lu fault zone in the depression in combination with previous research achievements. The results show that there are three （group） branch faults in the Tan-Lu fault zone： the east branch is located in Liaodong area， labeled as No. 1 Liaodong fault； the middle branch is developed in Liaozhong area， including the Cenozoic branches of No.1 and No.2 Liaozhong faults， which have got merged into one major strike-slip fault in the deep layer； the west branch is located in the western slope of Liaoxi area， the Cenozoic Liaoxi strike-slip fault. The three （group） branch faults root in the deep basement and even the Mohorovicic discontinuity， as obviously manifested on the gravity anomaly. There are significant differences in the structural deformation characteristics of the three branch faults in the Liaodong Bay Depression， and they are also significantly different from the Bozhong-Bodong section and Bonan section of the Bohai Sea， mainly resulting from the extent of strike-slip， reactivity of previous faults， thickness and lithology of strata and the property of basement.

10.11743/ogg20220202