Characteristics and Types of Sedimentary Facies of Paleogene-Neogene in the Middle Segment of the Southern Margin of Junggar Basin

In the middle segment of the southern margin of Junggar basin,according to available data of outcrops observation,core description,electrofacies,depositional setting,climatic condition and structural feature,four types of sedimentary facies are identified,which include the alluvial facies,braided river facies,braided-delta facies and lacustrine facies.Their lithologic features,sedimentary structures and vertical evolution sequences are analyzed in detail.And take the E1-2z1 of Well An-5 for example,elaborated the main types of sedimentary facies in the study area,which is sediment of frontal braid river delta and shore-shallow lacustrine,and illustrated the main cause of sedimentary origin during the evolutionary process of sedimentation.