Volcanic Mountains Formation and Characteristics

Characteristics: Volcanic mountains are an accumulation of materials which are ejected from the earth's crust. They are also referred to as mountains of accumulation. The materials are ejected through a hole called a vent or a pipe. The opening or mouth of the vent on the ground surface is called a crater. The materials ejected from the earth's crust include hot rocks, lava, ashes, dust, volcanic gases and liquid mud. The ejected materials gradually build up to form mountains which can be either conical or dome-like. For example, the Kilimanjaro, Mountain Kenya, Elgon and Cameroon in Africa; Fajiyama in Japan, Vesuvius in Italy and Cotopaxi in the Andes are roughly conical in shape while the basalt dome of Mouna Lao in Hawaii is an example of a dome-shaped volcanic mountain.

Mode of Formation of Volcanic Mountains

A volcanic mountain is formed through a volcanic eruption which is a forceful ejection of molten materials from the earth's crust. The ejected materials gradually build up to form a mountain. A volcanic mountain can be either violent or mild. A volcanic mountain may consist of alternating layers of ash and lava or mainly of lava. Volcanoes which consist of alternating layers of lava and ash are said to be composite, while those that are made up almost exclusively of lava are called lava cones.

There are two types of lava cones. Acid lava which is stiff and viscous has a gig silica content and flows slowly, while basic lava is more fluid and has more sodium, calcium and magnesium. It also flows more rapidly and travels much further before hardening than acid lava. This is the formation of volcanic mountains.