The controls on the structural styles in the Wuyitage area, southwestern Tarim Basin: Insights from discrete-element numerical simulation

[Objective] The collision and ongoing convergence between the Indian and the Eurasian plates led to the uplift and expansion of the Tibetan Plateau and the formation of a mountain-basin system rich in oil and gas resources. Fold-and-thrust belts, as an important structural unit for accommodating compressive shortening, has always been a hot and challenging topic in structural geology research due to its complex structural styles and deformation evolution history. This paper focuses on the Wuyitage area in the foothill belts of the southwestern Tarim Basin by integrating the differences in structural styles, detachment layers, and paleo - uplift distribution demonstrated by previous investigations. [Methods] Through the application of the discrete-element numerical simulation method, the coupled process between the basin and the mountain under the combined action of multiple factors is explored. [Results] The results show that the thrust belt in the study area exhibits significant structural segmentation, and its geometries are governed by regional detachment layers, such as the Paleogene gypsum - salt layer. The thickness disparity of the detachment layer directly influences the fault slip efficiency and deformation intensity. When the detachment layer is thicker, the detachment effect is strengthened, the decoupling between the upper and lower strata becomes more pronounced, and it is more conducive to the propagation of thrust structures towards the hinterland. When the detachment layer is thinner, the detachment effect is weaker, and faulting is more prone to occur along the pre - existing basement faults. The presence of the Ulagen and other paleo - uplifts have also played a dominant role in the development of thrust faults by reconstructing the regional stress field and the mechanical properties of the strata. [Significance] This study reveals the main controlling mechanism of the differential structural deformation styles in the Wuyitage area in front of the southern Tarim Basin, providing an important basis for better understanding the coordinated evolution of basins and ranges and its potential resources and environmental effects in the study area.