PLATEAUS A plateau is an elevated area generally in contrast to the nearby areas. It has a large area on its top unlike a mountain and has an extensively even or undulating surface. The rocks of the plateaus are layered with sandstones, shales and limestones.
According to their mode of formation and their physical appearance, plateaus may be grouped into the following types:
1. Tectonic Plateaus These are formed by earth movements which cause uplift, and are normally of a considerable size, and fairly uniform altitude. They are also called continental plateaus. Their heights vary from 600-1,500 metres. Plateaus of Brazil, South Africa, West Australia, Chhota Nagpur and Shillong are examples of continental plateaus.
2. Intermontane Plateaus When plateaus are enclosed by fold mountains, they are known as intermontane plateaus, e.g., Tibetan Plateau (between the Himalayas and the Kunlun), Bolivian Plateau (between two ranges of the Andes), etc.
3. Piedmont Plateaus Situated at the foot of a mountain, piedmont plateaus are bounded on the opposite side by a plain or an ocean. The plateau of Malwa in India, those of Patagonia in Argentina and the Appalachian in the USA are some of the examples of piedmont plateaus. These are also called the plateaus of denudation because areas which were formerly high have now been reduced in elevation by various agents of erosion.