Orogenic Processes in Collisional Tectonics with Special Reference to the Himalayan Mountain Chain: A Review of Theoretical and Experimental Models

With advent of the plate tectonic theory geoscientists have taken a new turn in order to interpret the evolution of orogenic belts. As a consequence, a large volume of geodynamics models have emanated in recent times. In this paper we review some of the important models in context of the Himalayan-Tibetan system, which is believed to be the most spectacular collision-type orogenic belt. Studies on this system trend in diverse directions, covering surface topography to deep-crustal processes. Here we deal with theoretical and experimental models that address large-scale phenomena in orogens. Over the last two decades, geoscientists and geophysicists have extensively used wedge tectonic models to explain several tectonic processes in mountain chains, like sequential thrusting, folding and rock upliftments. The wedge models pivot principally on two considerations: 1) choice of boundary conditions and 2) rheology of the crust. In this review we classify the models into three rheological classes: Coulomb, plastic and viscous, and present the model results as a function of the boundary conditions.