Mountain formation

Mountain formation occurs due to a variety of geological processes associated with large-scale movements of the Earth's crust (tectonic plates).

[1] Folding, faulting, volcanic activity, igneous intrusion and metamorphism can all be parts of the orogenic process of mountain building.

[3] From the late 18th century until its replacement by plate tectonics in the 1960s, geosyncline theory was used to explain much mountain-building.

[5][clarification needed] There are five main types of mountains: volcanic, fold, plateau, fault-block, and dome.

[10][11] A shield volcano has a gently sloping cone because of the low viscosity of the emitted material, primarily basalt.

An example is the Sierra Nevada range, where delamination created a block 650 km long and 80 km wide that consists of many individual portions tipped gently west, with east facing slips rising abruptly to produce the highest mountain front in the continental United States.

Although originally attributed to a melting of subducted oceanic crust, recent evidence belies this connection.

Thrust and reverse fault movement are an important component of mountain formation.
Illustration of mountains that developed on a fold that thrusted.
Annotated view includes Ushkovsky , Tolbachik , Bezymianny , Zimina , and Udina stratovolcanoes of Kamchatka , Russia. Oblique view taken on November 12, 2013, from ISS. [ 7 ]
Stratovolcanoes associated with a subduction zone (left) and a spreading ridge volcano (right). A hotspot volcano is center. [ 8 ]
The Dome of Vitosha mountain next to Sofia
Zard-Kuh , a fold mountain in the central Zagros range of Iran.
Fault-block mountain of the tilted type. [ 16 ]
Sierra Nevada Mountains (formed by delamination) as seen from the International Space Station .