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Mountains and Plateaus

Mountains

  • Part of land > 900 mts height
  • With slope ~ 25 – 30*
  • Mainly of four type viz.

 

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

 

Fold Mountains

  • Formed by folding of geosyncline sediments under compressible tectonic forces
  • For Ex. Himalaya, Alps, Rockies, Andes, Alapchhian, Ural, Aravalis
  • Since the rock strata have been elevated to great heights, Fold Mountains are also called mountains of elevation
  • Are closely associated with volcanic activities
  • Contains many active volcanoes, especially in circum Pacific fold mountain system
  • Are rich in mineral resources such as Tin, Copper, Gold & Petroleum

Fold Mountains

 

Block Mountains

  • Formed due to faults caused by tension or compression forces which lengthen or shorten earth’s crust
  • It causes a section of it to subside or rise above the surrounding level
  • For Ex. Vosges (France), Black Forest (Germany)
  • Faulting results in formation of Block Mountains & their counterparts in rift valleys
  • In general, large scale Block Mountains & rift valleys are due to tension rather than compression

Block Mountains

 

Volcanic Mountains

  • Also known as mountains of accumulation
  • Formed due to accumulation of thick lava as a result of volcanic eruption
  • Common in circum pacific belt
  • For Ex. Fuji Yama (Japan), Mt. Popa (Myanmar), Mt. Mauna loa (Hawai), Mt. Mayon (Phillipines), Mt. Agung (Bali), Mt. Merapi (Sumatra) & Mt. Catopaxi (Euador)

Volcanic mountains

 

Residual / Dissected / Relict Mountains

  • Formed due to waning of previously existing elevated regions by erosion
  • For Ex. Nilgiris, Parshavnath, Hills of Peninsula India, Mt. Manodnock (USA)
  • Mountains evolved by denudation, where the general level of land have been lowered by agents of denudation; also known as mountains of denudation

Plateaus

  • An elevated area compared to its surroundings, having a large almost flat top area (Also known as tableland)
  • Like all highlands, Plateaus are also subjected to erosional processes, as a result their original characteristics are highly altered
  • According to their mode of formation & their physical appearance, plateaus may be divided into 3 types viz.

 

Tectonic Plateaus 

  • Formed by earth movements which causes uplift, of a considerable size with fairly uniform altitude
  • For ex. Deccan plateaus, Mesera plateau (tilted of central Iberia) & Harz plateau (Faulted of Germany)

 

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

 

Volcanic Plateau

  • Molten lava from the volcanic eruption may solidify to form successive sheets of basalatic lava, known as Lava plateau
  • For ex. Antrim Plateau of Northern island, NW part of Deccan Plateau & Columbia Snake Plateau (Biggest one)

 

Dissect Plateaus

  • Formed due to continuous weathering & erosion by running water, wind & ice
  • High plateaus worn down & their surface becomes irregular
  • For Ex. Scottish Highland

 

Generally Plateaus have rich mineral resources & have been actively mined for ex.

  • African plateau yields gold, diamonds, copper, Manganese & Chromium.
  • Brazilian plateau yields iron & Manganese
  • Deccan Plateau Yields Manganese, Iron & Coal
  • Western Australian plateau yields Gold & Iron
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  1. Ecoliterature and the Global Economy by Professor …

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