VI NCERT GEO GIST – MAJOR LANDFORMS OF THE EARTH

  • The landforms are a result of two processes. The first, or the internal process leads to the upliftment and sinking of the earth’s surface at several places. The second, or the external process is the continuous wearing down and rebuilding of the land surface.
  • The wearing away of the earth’s surface is called erosion. The surface is being lowered by the process of erosion and rebuilt by the process of deposition.
  • The different landforms can be broadly grouped as mountains, plateaus and plains depending on elevation and slope.
  • A hill is a land surface that rises higher than the surrounding area. Generally, a steep hill with an elevation of more than 600 meters is termed as a mountain.

Mountains:

  • A mountain is any natural elevation of the earth surface. The mountains may have a small summit and a broad base. The range is a line of mountains.
  • In some mountains, there are permanently frozen rivers of ice. They are called glaciers.
  • Examples are the Himalayan mountain ranges of Asia, the Alps of Europe and the Andes of South America.
  • The various types of mountains are fold mountains, block mountains and Volcanic mountains.
  • The Block mountains are created when large areas are broken and displace vertically. The uplifted blocks are called Horsts and the lowered blocks are called Graben.
  • The Volcanic mountains are formed due to the volcanic activity.

Plateaus:

  • A Plateau is an elevated flat land. It is a flat topped table land standing above the surrounding area. Example: Deccan Plateau of India.
  • Tibet Plateau is the highest plateau in the world with a height of 4,000 to 6,000 mts above the mean sea level.
  • And they are rich in minerals. Example: Chotanagpur plateau of India.
  • Generally the Plateaus are not continuous and are broken and hence there could be lot of waterfalls seen over plateaus. Example: Jog falls in Karnataka.

Plains:

  • These are large stretches of flat land and usually they are not greater than 200 mts above the mean sea level.
  • Most of the plains are formed by the eroded materials bring forth by the rivers. And hence they are very fertile. Example: Yangtze plains in China.
  • Construction of transport network is very easy and thus these plains are the very highly populated areas of the world.
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