Description/Abstract Topography on the Earth’s surface reflects the structure and dynamics of its interior. In mountain belts, high elevations are usually attributed to the presence of anomalously thick crust. For the Central Andes of South America, lithospheric shortening has generated a 50-70 km thick crust and the ~4 km high Altiplano-Puna plateau. Shortening should have also thickened the underlying mantle lithosphere. However, geophysical studies show that the mantle lithosphere is anomalously thin below much of this region. This talk will present computer models that address how mantle lithosphere can be removed below a mountain belt. The models demonstrate that removal is accompanied by crustal deformation, magmatism and significant vertical deflections of the Earth's surface. Such models may explain localized transient basins that are found throughout the Central Andes.