Division of Sedimentary Facies and Sequence Stratigraphy of Jurassic Sangonghe Formation in the Center of Junggar Basin

There existed an argument on sandstone genetic types and division of sequence stratigraphy of Jurassic Sangonghe Formation in the center of Junggar Basin.Deposition of Jurassic Sangonghe Formation was formed by shore-shallow lacustrine from the sedimentary facies.By analyzing outcrop sections,cores,logging data and fabric features of facies succession,it was considered that the 2nd member of Sangonghe Formation was formed by braided stream deposition.Based on the study,sequence stratigraphic principles and identifying result of different sequence boundaries are studied,Jurassic Sangonghe Formation is divided into five third-order sequences and sandbodies of the 2nd member of Jurassic Sangonghe Formation are distributed in low system from SQ2~SQ4,which belongs to channel eroding and filling systems during later stage of LST.