Characteristics of structural deformation under Himalayan multi-periods movements in the Kuqa Depression

The Himalayan movement has a decisive impact on the geology and geomorphology of western China. The response of the structural deformation characteristics in Kuqa Depression to its multi−periods movement remains unsolved. Based on the interpretation of the seismic section of Kelasu structural belt in Kuqa Depression, by means of discrete element numerical simulation and structural physical simulation, this paper discusses the response characteristics and deformation evolution process of the structural deformation of Kelasu structural belt caused by multi−periods movements, vertical uplift and syntectonic sedimentation caused by Himalayan multi−periods movement under the background of compressive stress. The results show that the response of Kelasu structural belt to multi−periods movements is mainly reflected in controlling the propagation of detachment folds in the upper salt layer in the foreland direction, and the uplift intensity of folds at the compression end becomes weaker; The dip angle of the pre−spreading imbricate thrust fault system at the extrusion end of the lower salt layer changes regularly. The dip angle of the fault near the extrusion end is large, and the dip angle away from the extrusion end is small, but its thrust displacement is large. At the same time, syntectonic sedimentation controls the deformation range of detachment fold in the upper salt layer, and vertical uplift mainly controls the forward land propagation range of laminated tile thrust fault under salt. The study of tectonic deformation process shows that the multi−periods movement of Himalaya leads to the differential deformation of structural stratification in Kelasu structural belt. The deformation range of detachment folds in the upper salt layer is wider, and fold related faults are more developed. After the development of forward spreading imbricate thrust faults in the lower salt layer, the formation of recoil structures will be strengthened. The results reveal the influence of Himalayan multi−periods movement on the dynamic evolution process of Kelasu structural belt, and deepen the understanding of structural deformation mechanism and evolution process of Kelasu structural belt in the Kuqa Depression.