Characteristics Of Sequence And Sedimentary Of The Paleogene First Member Of Shahejie Todongying Formation Of Wen’an Slope Area Of Baxian Depression

Based on the theory of sequence stratigraphy and sedimentology, this paper aims to study sequencestratigraphy and sedimentary system inShahejie 1 Member to Dongying Formation inWenan SlopeofBaxian Depression,which comprehensively uses various data such as 3D seismic data,cores and well logging data.The target layer of the study area is divided into five3rd order sequence. Among them, Shahejie 1 Member is divided into SQ10、SQ11.Dongying Formation is divided into SQ12、SQ13、SQ14.Three kinds of sequence boundaries are identified, which are regional unconformity surface, syndeposit erosion surface and toplap/conversion interface.Three kinds of depositional system can be identified in middle shallow layer of Wenan Slope.They are lacustrine facies, braided river delta and river flood plain.Lacustrine facies and braided river delta facies are in Shahejie 1 Member.Lacustrine facies develops shore shallow lake sub facies,develops beach bar and lake mud microfacies.Braided river delta develops delta plain and delta front sub facies,mainly develops branch channel and crevasse splay microfacies.River flood plain mainly develops meandering river sub facies in Dongying Formation,and identifies point bar, bed retention, crevasse splay, floodplain sedimentation microfacies.Combined with the structure, heavy mineral analysis and clastic rock characteristics analysis,weknow clearly the two main source areas of Wen’an slope, which are south of Changfengzheng and north of Zuogezhuang.