Discrete Element Modelling of Fault Nucleation and Propagation in Collision Zones
Since the advent of plate tectonics, modelling the deformation of continents (particularly the nucleation, growth and interaction of large faults) has been plagued by drastic shortcomings. Dynamic scaling is difficult or impossible with analogue models, while numerical models yield results that are difficult or impossible to compare with long-term geological evidence.
We use the YADE discrete element (DEM) code to produce a suite of 3D continental collision models. These 3D DEM models produce two large strike-slip faults that extrude and rotate coherent blocks. Together with strike‐slip movement, large-scale thrust faults generate the step‐by‐step growth, from south to north, of a plateau. The fault deformation and plateau generation are in general agreement with observations of the Red River and Altyn Tagh mega‐faults and the rise of the Tibet‐Qinghai plateau.
Codes are developed and tested by trying to reproduce the results of simple 2D experiments performed with analogue models using sand or plasticine. In the future we will try to apply the adapted codes and methods to the real earth, with plausible boundary conditions, ultimately including gravity and 3D deformation. The final goal is to simulate the evolution of large-scale faulting in Asia during the last 50 million years.
- Earth Observatory of Singapore