ABSTRACT

Numerical simulations of continental collision can show how deformation and surface erosion interact to shape mountain belts. The high strains involved in mountain building and the discontinuous velocity boundary conditions of collisional orogens suggest the use of a non-continuum numerical technique for this purpose. In this study the distinct element method is used for the first time to investigate collisional orogeny. The two-dimensional experimental setup includes the first-order controlling features of the kinematics and the surface morphology of mountain belts. These are (1) the asymmetric kinematic boundary conditions for the continental crust of the upper and lower plate, (2) flexural isostatic compensation of crustal thickening and (3) surface denudation. The experiments show how different patterns of surface denudation modify the distribution of strain, particle paths, and exhumation patterns.