Types of Plateaus

Plateau is an elevated tract of relatively flat land, usually limited on at least one side by a steep slope falling abruptly to  lower land. It may also be delimited in places by abrupt slopes rising to residual mountains or mountain ranges, as in the Tibetan plateau, where it occurs as an intermontane plateau. The term is also used to refer to a structural surface such as Meseta of Spain, in which case it is a tectonic plateau. It is also used to describe extensive lava flows (lava plateau). The surfaces of plateaus may be plain-like in quality, very flat, rolling or hilly, or they may be so dissected by streams and glaciers that it is difficult to recognize their original plateau characteristics.

Diastrophic Plateaus

Diastrophism is the large-scale deformation of the earth’s crust which produces continents, ocean basins and mountain ranges, etc. All the highest plateaus of the earth are the direct products of diastrophism. Since their uplifts they have been modified by various agents of erosion and in many cases by volcanism and minor earth movements. For convenience they may be classified as:

Intermontane Plateau

Intermontane Plateaus include the highest, largest and in many respects most complex plateaus of the world. Their surfaces show an extraordinary variety of topographic features.

Border Plateaus

Many plateaus border mountain ranges and owe their present position to the same uplifts that raised the mountains. Piedmont plateau is an excellent example of border plateaus. This plateau is a strip of land that stands between tile Atlantic coastal plains and the Appalachian Mountains. Its eastern side is marked by a more or less definite fall-line where the gradient of the rivers is steepest. On the west it terminates against the mountains of the Blue Ridge. Plateau of Colorado is also an example of the border plateau. It is bounded on the northeast by the Rocky Mountains and on the southwest by the Basin and Range Province.

Domed Plateaus

The plateau of Ozark (U.S.A.) is a good example of domed plateau. Ozark plateau was uplifted by folding and faulting into a broad dome some 65,000 sq km (40,000 square miles) in area during the Appalachian Revolution which occurred at the close of the Paleozoic Era.

Volcanic Plateaus

Volcanoes also form several varieties of plateaus. The largest are built by the lava flow. Smaller, degraded plateaus are formed by the resistant lava caps that protect the land from erosion and maintain its high elevation after the surrounding land has been worn away.

Erosional Plateaus

Such plateaus are formed particularly in semiarid regions where streams have cut away portions of high lands.