Basin and range are the uniform tectonic system which are closely linked in temporal and spatial development and formation mechanisms. Formation of the Late Triassic Paleo-Tethys orogenic belt in the Tibetan Plateau had a significant impact on the southern margin of the Tarim Basin. This orogenic event caused an intense thrust deformation in the front region of western Kunlun Mountains. The paleo-geomorphy formed by this thrust deformation had played an important role in controlling the Late Jurassic-Cretaceous deposition. Meanwhile, it also determined the distribution of oil and gas in this area. Based on a detailed field survey of Mesozoic strata in the outcrops of the western Kunlun Mountains, and combined with the analysis of drilling data and the detailed interpretation of high quality seismic profiles, this paper studies the characteristics of Late Triassic paleo-structure and the sedimentary filling process of Jurassic-Cretaceous in the piedmont of western Kunlun Mountains, in order to reveal the Late Triassic paleo-structure and its control of deposition. A Late Triassic foreland fold and thrust belt is found in front region of western Kunlun Mountains where basement involvement structure developed in the root and imbricated structure developed in the front zone respectively, and the position of frontier fault of the Triassic foreland fold and thrust belt is near the frontier fault of Cenozoic fold and thrust belt. Controlled by these thrust faults, the Paleozoic strata formed a series of anticline uplifts with steep north rim and gentle south rim. Triassic paleo-geomorphy showed lower from south to north in general due to the intense uplift of the Tethys orogenic belt. Affected by surface weathering and erosion, the paleo-uplifts in the core of anticline had the shape with steep north slope and gentle south slope, but the depressions related to the fracture zone usually had the shape with gentle north slope and steep south slope, and such paleo-geomorphy feature is the basic geomorphological framework before the deposition of Jurassic sequence. During the Early Jurassic, four half graben rifts developed in the piedmont of western Kunlun Mountains due to post-orogeny rifting extension where the basin controlling fault developed on the side of Tethys orogenic belt. Interior of rift depression, the paleo-geomorphy was higher from south to north, and the Jurassic sequence was onlap deposition to the north slope. The paleo-geographical framework which was the superimposition composed of paleo-geomorphy caused by the Late Triassic deformation and the Early Jurassic rifts controlled the deposition of Jurassic-Early Cretaceous, until Late Cretaceous.
Chen Yangui Wu Hongxiang Zhang Liang Cheng Xiaogan Chen Cai Zhang Yuqing Ren Ping Zhang Fengqi Chen Hanlin. Characteristics of the Late Triassic paleo-structure in the mountain front region of western Kunlun and its control of Jurassic-Cretaceous deposition[J]. Chinese Journal of Geology, 2018, 53(4): 1405-1418.