Mountains and Plateaus

by Devender

0 1308

Mountains and Plateaus

Mountains:

Mountains are part of the land having a height of over 900 meters and a slope of around 25 to 30*. There are mainly 4 types of mountains namely:

Fold Mountains
Block Mountains
Volcanic Mountains
Residual/Dissected/Relict Mountains

1 Fold Mountains:

These are formed by the folding of geosyncline sediments under compressible tectonic forces. Fold Mountains are also called mountains of elevation as the rock strata have been elevated to great heights.

These mountains are closely associated with volcanic activities
It contains a lot of active volcanoes especially in circum Pacific fold mountain system
These mountains are rich in minerals such as Tin, Copper, Gold & Petroleum

For example - Himalaya, Alps, Rockies, Andes, Alapchhian, Ural, Aravalis

2 Block Mountains:

These mountains are formed by faults that are caused by tension or compression forces that lengthen or shorten the earth's crust. It causes a section of it to subside or rise above the surrounding level.

This faulting results in the formation of Block Mountains & their counterparts in rift valleys
Tension is the cause behind the formation of these large scale black mountains and rift valleys, not compression

For example - Vosges (France), Black Forest (Germany)

3 Volcanic Mountains:

These mountains are also known as mountains of accumulation and are formed due to the accumulation of thick lava that came from volcanic eruptions.

These mountains are very common in the circum pacific belt

For example - Fuji Yama (Japan), Mt. Popa (Myanmar), Mt. Mauna loa (Hawai), Mt. Mayon (Philippines), Mt. Agung (Bali), Mt. Merapi (Sumatra) & Mt. Catopaxi (Ecuador)

4 Residual/Dissected/Relict Mountains:

These mountains are formed due to the waning of previously existing elevated regions by erosion. These are also known as the mountains of denudation as these are evolved by denudation where the general level of land got lowered due to agents of denudation.

For example - Nilgiris, Parshavnath, Hills of Peninsula India, Mt. Manodnock (USA)

Plateaus:

Plateaus are elevated areas compared to their surroundings that have a large almost flat top area. They are also known as tableland. Their original characteristics are highly altered as they are subjected to erosional processes.

The plateaus can be divided into 3 categories based on their mode of formation & their physical appearance which are:

Tectonic Plateaus
Volcanic Plateau
Dissect Plateaus

1 Tectonic Plateau:

These are formed by earth movements that cause uplift of considerable size with fairly uniform altitude.

For example - Deccan plateaus, Mesera plateau (tilted of central Iberia) & Harz plateau (Faulted of Germany)

When these plateaus are surrounded by mountains they are known as inter-montane plateaus. For example - Tibetian plateau, Bolivian Plateau
When the plateaus are surrounded by the sea or plains, they are known as Continental Plateaus. For example - Deccan plateau, Greenland plateau, South Africa plateau