Structural characteristics of northern margin of Kuqa depression, Tarim basin

Structural characteristics of northern margin of Kuqa depression, Tarim basin. Geological Bulletin of China, 2012, 31(9):1510-1519Abstract: The transition zone between Kuqa depression and South Tianshan uplift located in northern Tarim basin has complex structural system. This area is the key to understand the relationship between mountains and basins. Based on the newly-obtained 2D，3D seismic and drilling data，the authors studied the basin structure，structural styles and deformations in various segments. Some conclusions have been reached:①The transition belt between Kuqa depression and southern Tianshan uplift can be divided into five belts and three districts from north to south and four layers in vertical direction. The Kelasu belt can be divided into three deformation zones, i.e., high angle basement involvement zone, low angle basement involvement zone and cover rock decollement zone. ②The transition belt mainly formed three styles of structures, namely contraction structural style, salt structural style and strike-slip style. ③Kelasu belt can be divided into six segments form east to west with each segment having its own deformation style. ④The present structure feature was mainly formed in Late Cenozoic. The structural evolution stage can be divided into four stages, i.e., Late Permian-Triassic paleo foreland basin, Jurassic-Cretaceous depressive basin, Paleogene-Miocene weak contraction flexure basin and Pliocene-Quaternary intra-continent foreland basin. Pre-existent structure, salt flow and various thrusting nappes constituted main factors responsible for differential deformation.