The southern margin of the Junggar Basin is in the circum-Tibetan Plateau Basin and range system. Subjected to the long distance transfer of the tectonic extrusion by the uplift of the Tibetan Plateau since Cenozoic era, the structural deformation is very complex and the seismic imaging is poor, which lead to controversial understanding of the structural deformation characteristic and the mechanics. Moreover, there is few research on the lateral variation between the anticlines and the longitudinal structural transition from the orogenic belt to the basin. Based on the latest wide-line seismic data, the authors study the middle-deep structure characteristic of the Huomatu anticline belt in the central margin of the southern Junggar Basin by the fault-bend fold theory, and illustrate the lateral variation by the comparative analysis of the characteristics and the deformation strength. The process of structural evolution and the longitudinal transition are elaborated by the balanced section and structural forward approaches on the basis of the model building and the fine explanation. There are low-amplitude fault-bend folds in the deep zone and the compound structural triangle wedge, associated with secondary fold-adjusted fault and small back-thrust faults, in the middle zone of the Huomatu anticline belt. The shallow zone develops fault-propagation folds. The lateral transition relation is characterized by similar structural patterns and waxing and waning structural degree. For the longitudinal transition, low amplitude tectonic deformations developed and expanded toward the basin center by structural compression between the Jurassic and Miocene period, and compound structural triangle wedge and pop-up structure formed in the strong compression in the Pliocene Epoch. Subsequently, fault-propagation folds accommodated in the shallow and the piedmont thrust belt was pushed to the surface and denuded.
Zhou Xiaojun Wang Xu Chen Wei Yu Yangli Meng Lifeng. Structural deformation and transition relations of the deep structure in the central margin of the southern Junggar Basin[J]. Chinese Journal of Geology, 2020, 55(2): 339-351.