The Peninsular Plateau – Structure and Physiography of India
The Peninsular plateau features the most varied geography in the world, being made up of rolling, dissected tablelands forming a network of steep-sided valleys.
Delhi ridge in the northwest, (extension of Aravalis), the Rajmahal hills in the east, Gir range in the west and the Cardamom hills in the south constitute the outer extent of the Peninsular plateau. However, an extension of this is also seen in the northeast, in the form of Shillong and Karbi- Anglong plateau.
This is one of the oldest and the most stable landmass of India. The general elevation of the plateau is from the west to the east, which is also proved by the pattern of the flow of rivers.
Some of the important physiographic features of this region are tors, block mountains, rift valleys, spurs, bare rocky structures, series of hummocky hills and wall-like quartzite dykes offering natural sites for water storage.
The western and northwestern part of the plateau has an emphatic presence of black soil. The northwestern part of the plateau has a complex relief of ravines and gorges.
The ravines of Chambal, Bhind and Morena are some of the well-known examples. On the basis of the prominent relief features, the Peninsular plateau can be divided into three broad groups:
- The Deccan Plateau
- The Central Highlands
- The North-eastern Plateau.
The Deccan Plateau
The Deccan Plateau extends over Southern, Central and parts of North western regions of India. Bear in mind that Deccan is usually referred to as a specific region in Maharashtra. And also refer to it as an area or plateau meaning the same thing although not entirely the same area because it refers to the mountain ranges which are known as Western Ghats. But no matter how you look at it the Deccan Plateau is one of the most sought after tourist destinations in India.
Western Ghats are comparatively higher in elevation and more continuous than the Eastern Ghats. Their average elevation is about 1,500 m with the height increasing from north to south. Anaimudi (2,695 m), the highest peak of Peninsular plateau is located on the Anaimalai hills of the Western Ghats followed by Dodabetta (2,637 m) on the Nilgiri hills.
Most of the Peninsular Rivers have their origin in the Western Ghats. Eastern Ghats comprising the discontinuous and low hills are highly eroded by the rivers such as the Mahanadi, the Godavari, the Krishna, the Kaveri, etc.
Some of the important ranges include the Javadi hills, the Palconda range, the Nallamala hills, the Mahendragiri hills, etc. The Eastern and the Western Ghats meet each other at the Nilgiri hills.
The Central Highlands
They are bounded to the west by the Aravali range. The Satpura range is formed by a series of scarped plateaus on the south, generally at an elevation varying between 600-900 m above the mean sea level.
This forms the northernmost boundary of the Deccan plateau. It is a classic example of the relict mountains which are highly denuded and form discontinuous ranges.
The extension of the peninsular plateau can be seen as far as Jaisalmer in the West, where it has been covered by the longitudinal sand ridges and crescent-shaped sand dunes called barchans.
The North-eastern Plateau
One interesting curiosity of the Indian landform is the existence of a large plateau – an extension of the main Peninsular plateau – between the Himalayas and the north-eastern hill ranges generally known as the North-Eastern Plateau.
Later, this depression got filled up by the deposition activity of the numerous rivers. Today, the Meghalaya and Karbi Anglong plateau stand detached from the main Peninsular Block.
The Meghalaya plateau is further sub-divided into three: (i) The Garo Hills; (ii) The Khasi Hills; (iii) The Jaintia Hills, named after the tribal groups inhabiting this region.
An extension of this is also seen in the Karbi Anglong hills of Assam. Similar to the Chotanagpur plateau, the Meghalaya plateau is also rich in mineral resources like coal, iron ore, sillimanite, limestone and uranium.