Fault Development and Tectonic Evolution in the Lishu Depression, Songliao Basin, NE China
作者机构:Sinopec Northeast Oil and Gas Company School of Geoscience China University of Petroleum (East China) CNOOC Research Institute Ltd.
出 版 物:《Journal of Earth Science》 (地球科学学刊)
年 卷 期:2023年
核心收录:
学科分类:081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程]
摘 要:The Lishu Depression, located in the southeastern region of the Songliao Basin, exhibits diverse fault types and complex tectonic evolution characteristics, however, the slipping direction and activity duration of strike-slip faults, as well as the overall tectonic evolution process remain unknown. This study applied a method for determining the slipping direction and activity duration of strike-slip faults, and reconstructed the tectonic evolution process of the Lishu Depression using balanced cross sections. The determination of the slipping direction of strike-slip faults was based on the analysis of the dislocation distance of a specific set of strata on two fault walls within the anticline zone, and the activity duration of strike-slip faults was defined by the sedimentary period of the strata cut by faults, and the variation characteristics of formation thickness. The slipping direction and activity duration of the strike-slip faults in the study area suggest that the depression experienced a left-lateral strike regime during the sedimentary periods of 135–131.8 and 124.5–112 Ma. However, during the sedimentary periods of the Yingcheng Formation (131.8–124.5 Ma), the region was influenced by a right-lateral strike background. The study area experienced a continuous process of extension from 145.6 to 124.5 Ma, and compression commenced from the depositional period of the Nenjiang Formation (88.5 Ma), as shown by negative values of the extension rate. The findings of this study hold significant theoretical implications for the identification of the slipping direction and distance of strike-slip faults within comparable depressions. Moreover, these results have practical implications for further hydrocarbon exploration in the Lishu Depression.