| The deformation of the Iranian plateau subject to the convergence of the Arabian shield and Eurasian plate, is studied by the "thin viscous sheet" numerical model. The lithosphere is approximated by a thin layer having a uniform initial thickness, and the flow of material is assumed to be governed by a power law rheology. The solutions are calculated for velocity fields, crustal thickness distributions, stress and strain rate fields, and topography variations. The effects of the physical parameters (rheology, density etc.) are investigated through two non-dimensional parameters: n, the power law exponent in the constitutive relation between stress and strain rate, and Argand number Ar, which is a measure of the relative importance of the buoyancy force to the viscous force. The lack of deformation in central Iran and the southern Caspian block, is considered, by including lateral heterogeneities in the rheology of the lithosphere. The results show that heterogeneous models with non-Newtonian materials for n greater than 3 and $rm1 |
