Potential Influences of Middle and Lower Crustal Flow on Landscape Evolution: Insights From the Himalayan-Tibetan Orogen

The Tibetan Plateau serves as a model for understanding the possible influence of middle and lower crustal flow on the geomorphic and tectonic evolution of continental plateau. This article presents the arguments in favor of a weak middle (and, in some areas, lower) crust beneath the plateau, and explores the development and features of popular models of the Himalayan-Tibetan orogenic system that incorporate lateral flow of this weak crust under the influence of gravity. Many long- and short-wavelength features of Tibetan and Himalayan landscapes are reasonably explained as a consequence of such flow.