This project is a study of the effects of basement topo- graphy, rock creep, lithology and thermal structure on the development of thin-skinned mountain belts. Data from the com- pressional belts of Pakistan will be used to model these parameters. The belt is active, and many of the geodynamic modeling constraints are available. The work will involve refinement of existing analytical theories of thin-skinned mechanics, scale models and extensive application of finite element modeling to explore relations between complex geometries and rheologies in the development of mountain belts. Results should be applicable to many compressional orogens, particularly those involving salt detachments.