The extensional dextral strike-slip duplex of JZ27-33 Block in Liaodong Bay

Abstract：Three main NNE-striking strike-slip faults are developed in JZ27-33 block of Liaodong Bay, i.e., Liaozhong 3 fault (or Liaozhong 1 fault), Liaozhong 2 fault and Liaodong 2 fault. These 3 faults assume en echelon distribution on the plane, with many secondary normal faults of strike-slipping nature developed between them. These normal faults strike NE or NEE and obliquely intersect main strike-slip faults, and the sharp angle between them indicates the corresponding stratigraphic moving direction on the plane. Negative flower structure is another important feature of the giant strike-slip faults. It is therefore concluded that the faults of the study area have characteristics of “duplex” on the plane and negative flower structure on the cross-section, and that the faults in JZ27-33 block of Liaodong Bay formed a typical “extensional dextral strike-slip duplex system”, with the main controlling factors composed of the dextral strike-slip and plane distribution of Tanlu fault, the multi-phase tectonic movement and the brittle sedimentary layers.