Abstract:

The Tan-Lu fault belt is a regional deep fault belt.Geophysical data show that the main shift zone of the Tan-Lu fault goes roughly along the eastern margin of the Liaodong Bay depression.Several steep and near-vertical faults were developed along both sides of the Liaodong uplift in the eastern part of the Liaodong Bay depression.These faults cut all strata from the basement to the Neogene,and some of them even cut the Pleistocene and Holocene.In the southern part of the Liaodong uplift,the faults occur as a broom-like fault complex diverging to the south-west and converging to the north.In section,all the faults show features of normal fault displacement.In contrast,in the northern part of the Liaodong uplift,the faults occur as a feather fault complex diverging to the north-northwest and converging to the south.In section,some faults in the west show distinct characteristics of thrust fault displacement.Fault complex in the sedimentary cover of the basin near the Liaodong uplift reveals that,during the Cenozoic,the north-northeast-trending faults experienced obviously right-lateral slip activities.Sandbox simulation experiment indicates that the fault complexes along the northern and southern parts of the Liaodong uplift may be related to the Cenozoic right-lateral slip movement of the Tan-Lu fault.The differences in fault complex and movement may be related to changes of strikes of the main shift zone of the Tan-Lu fault.

Key words: strike-slip fault, fault complex, Cenozoic basin, Liaodong Bay, Tan-Lu fault zone