Differential deformation of strike slip faults in the Liaodongwan Depression,offshore Bohai Bay Basin

As an important fault type in the Liaodongwan Depression,strike slip faults are components of the Tan-Lu fault zone,and they have exerted major influences on the structural framework and hydrocarbon accumulation in the depression.Based on detailed 3D seismic interpretation,this paper reveals the spatial distribution and segmented differential deformation characteristics of the strike slip faults in the Liaodongwan Depression. The strike slip faults mainly occur in the eastern and central Liaodongwan Depression,trend northeast as a whole,and have good continuity. They appear as flower structures on sectional view,while appear as strike slip duplex and imbricated structures on plane view. Comparison of deformation features of strike slip faults in different areas shows that the strike slip fault zone features in obvious segmented differential deformation. The strike slip faults can be divided into two segments,namely transpressional segment in the south and uplifting segment in the north. The uplifting segment can be subdivided into complex-uplifting,buried-uplifting and single-uplifting segments according to the shapes of the uplift. The development of the Liaodong uplift was mainly controlled by the transpressional movement of the strike slip faults,but the Liaoxi uplift with earlier initiation of uplifting was influenced by extensional stresses resulted from mantle uplifting.