It extends into Rajasthan on the west and has a kind of outlier in the Assam plateau in the east, and is bordered by the Sahyadris (Western Ghats) in the west and Eastern Ghats on the east; and has slope from west to east. Covering an area of about 16 lakh sq.km. The peninsular uplands forms the largest physiographic division of India.
The Peninsular Plateau of India was a part of Gondwanaland hundreds of million years ago. The rocks that make up the plateau match those of Africa not only in the age and type, but also in the layer sequence in which they occur.
It is the part of earth’s outer shell that is composed in great part, of generally horizontal rock beds that stand upon a firm and immovable foundation and that has for a number of years remained so impressive amidst all the cataclysm and revolutions that have again and again changed the face of the earth.
It is, thus, the oldest part of India and one of the stable land masses of the world, which have not undergone much disturbance except in a few places where marine transgressions have been made. The whole terrain is made up of several large or small plateaus, with undulating surfaces, with broad rounded summits seldom rising above 600 metres.
Hard rocks have withstood the forces of denudation. However, gentle gradients have been produced by prolonged weathering and erosion and hence, the low hills are either the remains of the old mountain systems (as in the case of the Aravalli hills) or the harder parts of the plateau itself which have withstood erosion (as in the case of the Western Ghats). In some parts there have been volcanic eruptions, which have covered vast areas in the north-west Deccan with a thick mantle of volcanic magma.
The configuration and drainage of the peninsula have been influenced by fracturing and tilting of the massif. The fault in which Narmada river flows divides the plateau into two unequal parts; the smaller one in the north being known as the Central Highlands (comprising the Aravalli ranges, east Rajasthan upland, Madhya Pradesh plateau and Bundelkhand upland stretching over about one-sixth of the total area of India); the bigger one in the south being known as the Deccan Plateau (comprising the Satpuras Western and Eastern Ghats, and a large number of plateaus-spread over about 70,000 sq.kms.)
The northern part is tilted towards north and its drainage is towards north, i.e., towards the Ganga valley, chiefly by way of the rivers Chambal, Sone, Kali, Sindh, Parvati, Damodar, Ken Betwa, and others. The southern part has been tilted east with bold heights to the west.
The Mahanadi the Godavari, the Krishna, the Cauvery and the Pennar all flow towards the east and fall into the Bay of Bengal. Narmada and Tapti are the only two large rivers which flow westward and fall into the Arabian Sea. The general elevation of the central Highlands ranges between 700 – 1000 m above the mean sea level.
It is made of hard igneous and metamorphic rocks. The Narmada Tapi divides this great plateau into the Malwa Plateau and the Deccan Plateau.