Fold mountains:
Fold mountains are mountain ranges that are formed when two of the tectonic plates that make up the Earth's crust push together at their border. The extreme pressure forces the edges of the plates upwards into a series of folds. When plates collide or undergo subduction(that is – ride one over another), the plates tend to buckle and fold, forming mountains. Most of the major continental mountain ranges are associated with thrusting and folding or orogenesis. Examples are the Jura and the Zagros mountains.
The Earth has two different types of crust: continental crust and oceanic crust. Orogenic events can occur on both types of crust. The Himalaya Mountains are still growing as the Indian continental plate folds over the Eurasian continental plate. Orogeny can also involve oceanic plates. Beneath the microcontinent of Zealandia, the Pacific plate is being folded over the Australian plate. The result is New Zealand's Southern Alps.
The Appalachians were once taller than the Himalayas. The range stretches from Newfoundland in southeastern Canada down through the eastern United States to central Alabama. However, erosion has taken its toll on the Appalachians. Today, some of its higher peaks are less than a third of the height of Everest.
Fault-block mountain or Block mountains:
When a fault block is raised or tilted, block mountains can result. Higher blocks are called horsts and troughs are called graubens. A spreading apart of the surface causes tensional forces. When the tensional forces are strong enough to cause a plate to split apart, it does so such that a center block drops down relative to its flanking blocks.
These can be small or form extensive rift valley systems, such as the East African Rift zone. Death Valley in California is a smaller example.
Two types of block mountains are lifted and sloped. Lifted type block mountains have two steep sides exposing both sides scarps, leading to the horst and grauben terrain seen in northern Europe, including the Upper Rhine valley, a grauben between two horsts, the Vosges mountains (in France) and Black Forest (in Germany). Another grauben is the basin of the Narmada River in India, between the Vindhya and Satpura horsts.
Tilted type block mountains have one gently sloping side and one steep side with an exposed scarp, and are common in the Basin and Range region of the western United States.
Volcanic mountains:
Movements of tectonic plates create volcanoes along the plate boundaries, which erupt and form mountains. A volcanic arc system is a series of volcanoes that form near a subduction zone where the crust of a sinking oceanic plate melts.
Most volcanoes occur in a band encircling the Pacific Ocean (the Pacific Ring of Fire), and in another that extends from the Mediterranean across Asia to join the Pacific band in the Indonesian Archipelago.