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

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 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.