A mountain formation starts when two tectonic plates collide. The colliding plates either subduct or uplift. Subduction means sliding of the oceanic crust below the continental crust. And uplift means upward movement of crust due to the movements of tectonic plates. Mountain formation started several million years ago when the continents were forming. During that time several collisions between the plates took place and several mountain ranges formed in every continent. Some of the significant formations are:
♦ Formation of the Himalayas: The Himalayas were formed by the collision of the Indo-Australian plate and the Eurasian plate.
♦ Formation of the Cascade mountain range: The Cascade mountain range (Mount St. Helens) is formed by the subduction of the oceanic crust of the
Juan de Fuca plate below the continental crust of the North American plate.
