Sedimentary evolution characteristics and the main controlling factors of 2nd and 3rd members of Shahejie Formation in downthrown side of Shicun Fault in Dongying sag
Based on well logging,drilling,seismic interpretation and other data,the sedimentary evolution characteristics and the main controlling factors of the 2nd and 3rd members of Paleogene Shahejie Formation in downthrown side of Shicun Fault in Dongying sag were researched. The result shows that the sedimentary facies of the 3rd member of Shahejie Formation includes delta plain subfacies,delta front subfacies,shore-shallow lake subfacies and beach-bar subfacies. The southeastern Guangrao Salient and the southwestern Luxi Uplift were the two major provenances in this depositional period. The braided delta front subfacies,delta front subfacies,shore-shallow lake subfacies and beach-bar subfacies were identified in the 2nd member of Shahejie Formation. The braided delta front subfacies developed in the eastern zone of the study area,which was affected by the source supply of Guangrao Salient. The delta front subfacies originated from Luxi Uplift developed in the southern zone dominantly. The sedimentary filling process was from retrogradation to progradation during the deposition of the 3rd member and the 2nd member of Shahejie Formation. The development and evolution of sedimentary facies were mainly affected and controlled by fault movement,supply intensity of provenances and paleoclimate.