Peninsular Plateau of India
The triangular shaped Peninsular Plateau of India extends from the south of Indo-Ganga Plain to the Cape Comorin (now Kanyakumari). This plateau is one of the oldest surfaces of the Earth and represents a segregated part of the old Gondwanaland.
The Aravalli range in the west and the Satpura, the Mahadeo and the Kaimur range in the south divide the Peninsular Plateau into two parts:
(i) The Central Indian Plateau in the north and (ii) The Deccan Plateau in the south of it. A brief account of them is given below:
Central Indian Plateau:
The Aravalli mountain, extending between Delhi and Ahmedabad (also Amdavad) , lies in the western flank of the plateau. Once a mighty fold mountain, it has been reduced now to a low one by denudation through hundreds of millions of years.
- In its southern part the Abu Hills contain its highest peak, the Guru Sikhar (1722 m).
- The Satpura and the Vindhya ranges are two noted ranges of the plateau.
- The Tapti and the Narmada flow through two rift valleys and the Satpuras (600-900 m) represent a block mountain formed in between these two rights.
- Dhupgarh (1350 m) is its highest peak.
- East of the Satpuras run the Mahadeo and the Maikala Range in succession.
- The arcuate Vindhya range extending from near the western boundary of Madhya Pradesh runs at first eastward and then northeastward.
- Manpur (881 m) is its highest peak.
The Deccan Plateau:
The Deccan Plateau is almost encircled by hills and mountains, viz. the Satpura, Mahadeo, Kaimur ranges on the north, the Western Ghat on the west and the Eastern Ghat on the east. The Deccan plateau forms a large portion of South India.
The Sahyadri or the Western Ghat rises steeply from the West Coastal Plain and descends gently eastward. Thalghat near Nasik and Bhorghat near Pune are two mountain gaps which connect Bombay (now Mumbai) and the West Coast to the rest of India by rail and road.
The Eastern Ghat or the Malayadri runs east of the Deccan Plateau parallel to the East coast. Eastern Ghats are not as continuous as Western Ghats and are much fragmented by river valleys. The features of Eastern ghats are given below:
- The highest point of Eastern Ghats is Mahendragiri (1680 m).
- The Eastern Ghats and the Western Ghats meet at the Nilgiri Hills in South Karnataka.
- Doddabetta (2637 m) is the highest peak of the Nilgiri mountains.
- South of the Nilgiri lies the Palghat Gap, which facilities easy communication between Kerala and the interior of India.
- The Anaimalai Range runs south of the Palght Gap. Its highest peak Anaimudi (2695 m) is also the highest in South India. The Anaimalai throws off two branches viz. the Palni Range in the north-east and the Cardamom or the Elumalai Range in the south.
The greater part of Maharashtra is lava plateau (volcanic plateau), called Deccan Trap. The plateau resulted from horizontal disposition of lava while in liquid state. The dissection of the plateau by rivers has given rise to flat topped hills or steps formed by differential erosion on soft ash and hard lava beds. Besides, Maharashtra, Deccan trap is spread over Madhya Pradesh and Gujarat. A large portion of Deccan Plateau consists of volcanic rocks (basalt). Several layers of volcanic eruptions that occurred for thousands of years resulted in the formation of Deccan Trap.
East of Maharashtra lies the Upper Mahanadi Basin or the Chhattisgarh Plain, to the north of which is the dissected Baghelkhand Plateau and to the south the mountainous Dandakaranya.
In the north-eastern part of the Deccan and to the west of lower Gangetic Plain extends the rectangular Chota Nagpur Plateau. The major central part of the plateau is constituted by the extensive Ranchi Plateau at an average height of about 700 m. The edge of the Ranchi Plateau is marked by several waterfalls of which Hundru, Jonha, Dasham and Hirni are especially noteworthy. South of the Ranchi Plateau is the high and rugged Garhjat Hills. The lava hills of Rajmahal marks the end of the Chota Nagpur Plateau on the north-east.
The Maharashtra Lava Plateau is flanked in the south-west by Karnataka Plateau and on the south-east by the Telangana Plateau.