Role of the Ruoergai Subblock in tectonic partitioning on the eastern margin of Tibet

The mechanisms of tectonic transfer and strain partitioning at the eastern termination of the Kunlun fault system, particularly the role of the relatively strong Ruoergai Subblock, remain unclear. In this work, we used the finite element method to determine how the Ruoergai Subblock affects regional deformation. The results show that the Ruoergai Subblock is moving to the east or northeast in a manner that differs from the motion of the Bayan Har Block in the eastward extrusion process and thus accounts for the formation and behavior of the Awancang and Longriba faults. In addition, strain partitioning on the eastern margin of the Tibetan Plateau is progressively transferring from the Awancang fault, Ruoergai Subblock, and Longriba fault to the Longmenshan thrust. In this study, a block-controlled pattern is proposed that accounts for the distribution and behavior of most of the faults on the northern and eastern margins of the Tibetan Plateau. Our study has played a certain reference role in the consideration of railway fracture resistance parameters in the area of the southern section of the Longmenshan fault and the Xianshuihe fault during construction of the Tibet Railway. •Influence of Subblock in the consideration of Tibet railway fracture resistance parameters.•Tectonic partitioning near the eastern margin of the Tibetan Plateau.•Influence of the Ruoergai Subblock's physical properties on tectonics.•Strong block control on fault formation and behavior.