Structural deformation of the Northern Monocline belt in the Kuqa depression and implications for the Cenozoic uplift history of the South Tianshan Mountains

Abstract

The Northern Monocline zone is adjacent to the South Tianshan Mountains. Under continuous compression induced by the uplift of the South Tianshan Mountains in the late Cenozoic, structural deformation in the Northern Monocline zone is quite different from the layered contractional deformation in the whole Kuqa depression. Based on the latest three-dimensional seismic data, the structural deformation in the Northern Monocline zone is analyzed, and the typical seismic profile is restored to analyze the tectonic evolution. The results show that the salt structure is weakly developed in the Northern Monocline belt. The deformations in the supra-salt, salt and subsalt layers are relatively consistent, and only slight layered contraction is present locally in the western part. Structural deformation in the Northern Monocline belt is mainly controlled by the thickness of the original salt deposit, the uplift and tilting degree of the basement and subsalt layers, and the strong compressional stress from the South Tianshan Mountains. The restoration of the growth strata and tectonic evolution of the Northern Monocline area shows that the uplift of the South Tianshan Mountains began during the deposition of the Jidike Formation, has gradually increased since the Neogene and is at its peak at present.