Useful notes on Empirical classification of plateau

The plateaux are classified as (1) Intermontane plateaux, (2) Mountain border plateaux, (3) Domed plateaux, (4) Volcanic plateau, and (5) Erosional plateau.

(1) Intermontane plateaux:

Intermontane plateaux include all the highest and the most complex plateaux on earth. Their surfaces are characterized by a large variety of topographic features. Plateau of Tibet, the plateaus of Bolivia and Peru, and the Mexican plateau are the typical examples of an intermontane plateau.

(2) Border plateaux:

This type of plateau was formed along with the adjacent mountains. The same uplift that raised the mountains was responsible for the formation of their bordering plateaux.

The Piedmont plateau, Plateau of the Colorado Front Range and the Colorado Plateau are excellent examples of a border plateau. All these plateaux are bounded on one or two sides by mountains.

The Grand Canyon is the outstanding feature of the Colorado plateau. There is a multitude of mesa and butte forms, especially in the neighbourhood of canyons.

(3) Domed Plateau:

Sometimes an extensive region is uplifted by tectonic forces in such a way that its central part is up-warped and the sides are rounded. Thus, endogenetic forces are responsible for the formation of domed plateau, so called because it resembles a dome.

The Ozark Plateau of Southern Missouri and northern Arkansas is a typical example of a domed plateau. This plateau is formed in one of the oldest land areas in U.S.A.

During the Appalachian Revolution the entire region was uplifted by folding and faulting into an extensive dome. This occurred at the close of Paleozoic Era. Remember that renewed uplifts have resulted into incomplete cycles of erosion.

(4) Volcanic Plateaux:

Volcanic plateaux are formed by the deposition of huge amount of lava flows. Volcanoes form several types of plateaux. Some plateaux are formed around the bases of volcanic mountains. In such cases lava flows down from central eruption.

Such plateaux are typical mixtures of fragmental materials, lava and mudflow ejected from the volcanoes. Such plateaux, however, are small and if they are not covered with resistant lava sheets, they do not have a long life.

They are degraded soon. Such a volcanic plateau surrounding Mount Mazama in Oregon is an excellent example.

The Deccan Traps form large size lava plateaux which are found in the states of Maharashtra (the largest Deccan lava plateau), Madhya Pradesh (Malwa Plateau) and Gujarat.

These lava plateaus together cover an area of about 5 lakh square kilometers. These plateaus are characterised by flat tops and terraced slopes.

There are volcanic plateaus in different countries like Ethiopia, Somalia (Africa), Columbia state in the U.S.A., Argentina, and Mexico etc.

(5) Erosional Plateaux:

Such erosional plateaux are formed in semi-arid regions. There streams have eroded away parts of the high plains leaving extensive, flat inter-valley highlands. The Colorado Piedmont Province in the U.S.A. has many such plateaux.

Besides the above mentioned plateau types, there are other minor types such as, dissected plateau, structural plateaus, desert plateaus and ice plateaus. Dissected plateau of India is exemplified by the Vindhyan Plateau with its east-west trending erosional scarps.

Structural plateaus are found in the Paris Basin in France, and are made of flat-lying resistant rocks. The Cherrapunji Plateau (Meghalaya) also belongs to this category.

It is characterised by the sedimentary beds lying horizontally. In Antarctica and Greenland several ice plateaus covered with ice-sheets are found. Ice plateaus have relatively flat upper surfaces and high elevation.