Abstract: The study of tectono stratigraphic sequence and basin evolution in Shawan Sag,Junggar Basin,is of great signi-ficance both to the understanding of the basin structure and the petroleum exploration in this area,and to a certain extent to the understanding of the tectonic evolution of the Central Asian Orogenic Belt.Seismic and well data were integrated to perform fine tracing of seismic events,and to analyze the truncation,overlapping and pinch-out within each sequence deposited since the Carboniferous in combination of correlation on well-tie profiles,and finally six major tectonic sequences were recognized according to the corresponding tectonic regime transformation processes.Additionally,the fine interpretation of tectonics was based on the theory of fault-related folds,and the tectonic evolution of Shawan Sag since the Late Carboni-ferous was discussed mainly according to the fine interpretation and the balanced cross-section technique.The results show that the formation and evolution of the Shawan Sag can be divided into seven stages,namely the Late Carboniferous extensional fault depression,the Early Permian extensional depression,the Middle-Permian-to-Late-Triassic foreland basin,the Jurassic intracontinental depression and transpressional basin,the Cretaceous-to-Paleogene intracontinental depression,and the Neogene-to-Quaternary intracontinental foreland basin.The evolution is mainly controlled by multi-stage activities of the peripheral boundary fault zones.The strong transpression of the Hongche fault belt to the west boundary of the sag during the middle of Late Hercynian movement(P₂),Late Indosinian movement(T₃),and Middle-to-Late Yan-shanian movement(J₂-E),is the most powerful factor affecting the tectonic evolution and associated stratigraphic development and distribution in the sag.

Key words: unconformity, tectono-stratigraphic sequence, basin evolution, Shawan Sag, Junggar Basin