| Summary: | The formation of the Songliao Basin was affected by multidirectional tectonic stress and various peripheral structural belts, and has a complicated geological structure and basin evolution process. The Lishu Fault Depression in the southern Songliao Basin has the characteristics of superimposed and complex evolution of multiple tectonic activities, and is a good window to reveal the impacts of the peripheral structural belts and basin tectonic-sedimentary response. Whether strike-slip tectonic activity controls the sedimentary process of the basin is an unsolved problem. Using three-dimensional seismic data to carry out detailed interpretation, combined with fault distance statistics, structural model analysis and other research methods, the extension activities of the Sangshutai and Qinjiatun faults in the Lishu Fault Depression during the Early Cretaceous were studied. The evolution process of the Sangshutai fault was controlled by the nearly east-west extensional tectonic stress. The initial scale of the fault was large, so the Sangshutai fault was less affected by the adjustment of the extension direction. The Qinjiatun fault was controlled by the NEE-SWW extension during the Early Cretaceous Huoshiling period, and by the NE-SW extension during the Early Cretaceous Shahezi period. The regional strike-slip activity in the Early Cretaceous extension in the Lishu Fault Depression caused a change in the extension direction.
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