Evolution of the Upper Crustal Deformation in Subduction Zones

Abstract

The uplift and evolution of a noncollisional orogen developed along a subduction zone, such as the Andean system, is a direct consequence of the interrelation between plate tectonic stresses and erosion. Tectonic stresses are related to the convergence velocity and thermal state, among other causes. In this paper, a new model designed to investigate the evolution of the topography and the upper crustal deformation of noncollisional orogens in a subduction zone produced by the oceanic crust being subducted is presented. The mechanical behavior of the crust was modeled by means of finite elements methods to solve Stokes equations for a strain-rate-dependent viscoplastic rheology. The model takes into account erosion effects using interface-tracking methods to assign fictitious properties to nonmaterial elements.