Characteristics and controlling effect of fault activity of Paleogene in Shinan area of Bozhong Depression on sedimentary facies

The detailed structural, stratigraphic and sedimentary interpretation of Paleogene in the studied area are carried out using three-dimensional seismic, drilling/logging data, etc. The characteristics and controlling effect of fault activity of Paleogene on sedimentary facies are analyzed. The results show that in Shinan area are developed the branch faults in the directions of close EW, NNE, EW from west to east. In the evolution of Paleogene sediments, the activity intensity of Shinan fault presents the trend of "weak-Enhancing-weakening-the strongest-weakening-the weakest". With the decreasing of fault activity rate, sedimentary facies are fan-delta or nearshore subaqueous fan, alluvial fan, meandering river delta, braided delta, beach bar and other facies.