Plateaus, Classification of Plateaus, Economic Significance of Plateaus Part-2

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Plateaus

Plateau has a large elevated area on its top unlike a mountain and has nearly even surface. Very often rivers or streams cut out deep valleys and gorges in plateau regions.

A plateau however remains much higher above the sea level from the nearby areas. Though plateaus are normally 600 metres above the sea level, there are plateaus of Tibet and Bolivia which are more than 3600 metres above sea level. The plateaus cover about 18% of the earth’s surface.

Classification of Plateaus

On the basis of their geographical location and structure of rocks, the plateaus can be classified as:

Intermontane Plateau: The plateau which are bordering the fold mountain range or are partly or fully enclosed within them are called the intermontane plateaus. Vertical movements raise these extensive landforms of nearly horizontal rocks to thousands of metres above the sea level. For example, the extensive and over 4500 metres high plateau of Tibet. It is surrounded by folded mountains like Himalaya, Karakoram, Kunlun, and Tien Shah on its two sides. The plateau of Colorado is over 1 km high into which rivers have cut the Grand Canyon and a series of gorges. Other examples include the plateau of Mexico, Bolivia, and Iran.

Piedmont Plateau: The plateaus that are situated at the foot of the mountains and are bounded on other sides by a plain or an ocean are called piedmont plateau. The plateau of Malwa in India, and the plateau of Patagonia situated between the Atlantic Coastal Plain and the Appalachian Mountain in U.S.A are such examples. These are also called the plateaus of denudation.

Continental Plateau: These are formed either by an extensive continental uplift or by the spread of horizontal basic lava sheets completely covering the original topography to a great depth. The volcanic lava covered the plateau of Maharashtra in India, the Snake River Plateau in northwest USA. These are also called the plateau of accumulation.

These plateaus, cover a vast area like the Great Indian Plateau and those of Arabia, Spain, Greenland, Africa, and Australia. They may be tilted on one side without any disturbance in the horizontal nature of the underlying rock strata as in the case of Great Indian plateau.

Different Types of Plateau

Different Types of Plateau

Different Types of Plateau

Economic Significance of Plateaus

Due to continuous erosion of their surface, the prevalence of a patchy or the slow development of agriculture and building of roads are observed on the plateaus. Plateaus are extremely useful to mankind in the following ways:

Storehouse of Minerals: Most of the minerals in the world are found in the plateaus. The extraction of minerals is relatively easier on plateaus. We get gold from the Plateau of Western Australia; copper, diamonds, and gold from the Plateaus of Africa; and coal, iron, manganese, and mica from the Chota Nagpur Plateau in India.

Generation of Hydel-power: Rivers falling down the edges of plateaus form waterfalls. These waterfalls provide ideal sites for generation of hydel-power.

Cool Climate: The higher parts of the plateaus even in tropical and sub-tropical regions has cool climate.

Useful for Animal Rearing and Agriculture: Plateaus have large grassland areas suitable for animal rearing specially for sheep, goat, and cattle. They provide a variety of products such as wool, milk, meat and skin. The lava plateaus as compared to other types of plateau are richer in agriculture since their soil is very fertile.

Plains

A low-lying relatively flat or slightly rolling land surface with very gentle slope and minimum local relief is known as a plain. Plains occupy about 55% of the earth’s surface.

Most of the plains have been formed by deposition of sediments brought down by rivers. Besides rivers, some plains have also been formed by the action of wind, moving ice, and tectonic activity. Plains have an average height of less than 200 metres.

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