Geology
Definition of underthrust
verb (past and past participle underthrust)
[with object] force (a crustal plate or other body of rock) beneath another formation: the Farallon plate was being underthrust beneath the North American plate (as noun underthrusting)this sediment may be deformed by the underthrusting be forced underneath (another formation): plate X is underthrusting plate Y in a NE direction
noun
an instance of one crustal plate or other body of rock being forced underneath another: the westward underthrust of the Pacific Ocean plate
