DISCRIMINATION OF SEDIMENTARY SYSTEM CHARACTERISTICS OF THE FOURTH MEMBER OF SHAHEJIE FORMATION IN DONGYING SAG, CHINA

摘要

The Dongying Sag is located in the southeastern part of the Jiyang Depression in the Bohai Basin. It is a braided fault-depression lake basin de-veloped in the Mesozoic and Cenozoic, and is an important oil and gas exploration area. The following results were obtained: the planar distribution characteristics of sedimentary facies and sedimentary systems in the Fourth member of Shahejie Formation in the study area were clarified; based on the analysis of the phase markers of the study area, alluvial fans and deltas were mainly developed on the southern slope of the Dongying Sag during the sedimentary period of the Fourth member of the Dongying Sag. The sedimentary facies types such as fan delta and beach dam; through the analysis of thickness and percentage of glutcnite, rock type and rock color, the distribution characteristics of sedimentary systems in the sub-sector of the Fourth member of Shahejie Formation arc obtained; Alluvial fan deposition, pure lower, pure upper section mainly develops shallow lake beach dam deposits.