Study on Fault Characteristics of Lower Cretaceous in Lishu Fault Depression of Songliao Basin

Abstract As one of the most important geological structures, faults are widely developed in the crust, and the formation of faults is closely related to the regional stress field. The study of the fault characteristics can reflect the properties of the regional stress field in different periods. The regional stress field in Lishu fault depression, southeast uplift area of Songliao Basin is analyzed based on the statistical analysis and the study on the strike and length of the faults in different periods. The results illustrated that the Lishu fault depression went through three stages, the NW-SE extension in Huoshiling period, the left-lateral extrusion in Shahezi period, and the NW-SE extension in Yingcheng period, in which research the maximum value of regional stress field. With its special tectonic characteristics, Lishu fault depression reflects and records the tectonic regime and the main stages of innovation, transformation and evolution in geodynamic environment since the Mesozoic of northeast Asia tectonic domain.