The concept of indenter tectonics was first introduced by Molnar and Tapponnier in 1975, A
continent-continent collision can be visualized as a 'die-and-metal' model, with a rigid die (the 'indenter') moving into a softer, rigid-plastic metal (the 'host'). In a
tectonic setting, the terms 'rigid' and 'soft' refer to the strength of the
lithosphere. The strong lithosphere of the indenter remains relatively undeformed and its boundaries are preserved, while the host allows deformation by lateral movement of crust both along the contact with the indenter and within the host. The indenter block is too buoyant to subduct, so crustal accommodation is achieved by either shallow underthrusting and crustal thickening, or formation and later lateral displacement of several microplates. It is possible to have a combination of the two models. == Examples ==