1. Exploration and Development Research Institute of PetroChina Jilin Oilfield Company, Songyuan 138000, Jilin, China; 

Through systematic analysis of drill core, logging and other data from Changling fault depression, combined with the detailed interpretation of 3D seismic data in the whole area, the lithofacies and paleogeography of the study area during the fault depression period were restored. Four lithofacies types such as lakes, braided river deltas, fan deltas, and volcanoes have been identified, and nine subfacies and several microfacies have been fur? ther subdivided. At the same time, based on the analysis of the structural evolution of Changling fault depression, the sedimentary evolution process and filling characteristics during the fault depression period are deeply studied. The research results show that the overall fault depression period of the study area can be divided into initial fault depression, rapid fault depression, and fault depression shrinkage periods. The internal part can further identify the local uplift at the end of Huoshiling Formation and Shahezi Formation, as well as the structural inversion at the end of Yingcheng Formation. The six structural stages mentioned above are corresponding to the initial filling stage of the fault depression (Huoshiling Formation), the initial denudation and leveling stage of the fault depression (the end of Huoshiling Formation), the filling stage of the rapid fault depression period (Shahezi Formation), the com?pression and denudation stage of the rapid fault depression period (the end of Shahezi Formation), the filling stage of the fault depression shrinkage period (Yingcheng Formation) and the compression and denudation stage of the fault depression shrinkage period (the end of Yingcheng Formation), respectively.