3D Discrete Element Simulation of Large-scale Faulting and Crustal Thickening in the India-Asia Collision Zone

Understanding the discontinuous nucleation, growth, and interaction of large faults within continental collision zones remains a challenge. Previous analog experiments simulating the India-Asia collision successfully modeled the development and kinematics of large strike-slip faults within the Eurasian plate. However, these 2D experiments were dynamically unscaled with gravity and did not allow the development of topographic relief. We use the YADE discrete element (DEM) code to alleviate these problems, producing a suite of 3D models. These 3D DEM models also involve the extrusion and rotation of coherent blocks by generating two large strike-slip faults. The location, size and offsets of these faults are consistent with those of the Red River and Altyn Tagh mega-faults. In addition, concurrently with strike-slip movement, the large scale deformation includes the successive formation, from South to North, of thrust faults that bound a growing plateau which may be considered analogous to the Tibet-Qinghai plateau. While based on very simplified boundary conditions and mechanical properties, such modeling results are therefore consistent with the topographic, tectonic and geological evolution of Eastern Asia in the last ~50 million years.