PHYSIOGRAPHIC DIVISION OF INDIA

PHYSIOGRAPHIC DIVISION OF INDIA
India has a variety of physical features ranging from small islands to one of the highest peaks of the world. Physiographically, India can be divided into three major physiographic units-the mountain, the peninsular pla­teaus, and the plains. To these may be added the fourth, namely, the coasts and islands.
MOUNTAINS The Peninsular Mountains The moun­tains of peninsular India can be classified as follows:

The Western Ghats (The Sahyadri) About 1,600 km long and with an average elevation of 1,000-1,300 m, they run along the west coast from the south of the Tapti river valley to Kanyakumari. The Deccan Trap constitutes the northern portion of the Ghats. The southern part of the Ghats is composed of Archaean gneisses, schists and charnockites.

The Eastern Ghats These irregular hill ranges stretch from northern Orissa to the Nilgiris in Kerala and Tamil Nadu across coastal Andhra. They are mainly ranges of garnetiferous sillimanite gneisses or khondalite and charnockites. The highest peak is at 1,680 m in Vishakhapatnam district of Andhra Pradesh.
The meeting point of the Western and Eastern Ghats in the Nilgiri Hills has the highest point at Doda Betta peak.

The Vindhya Range Running from Sasaram (Bihar) in the east to Jobat (Gujarat) in the west, the Vindhya range separates northern India from the southern mainland. Mostly composed of sandstones and quartzites, it is lava­ridden in the west.

The Satpura Ra,zge Covered with lava, the range ex­tends from the Narmada valley in the north to the Tapti valley in the south. Its northern and southern borders are composed of sandstone, while the eastern section has Gondwana and Archaen gneisses. The average elevation is 1,030 m above sea level, with the highest point at Dhupgarh (1,350 m) near Pachmarhi (Madhya Pradesh).

The Aravallis M~de of the rocks of quartzites, gneisses and schists belonging to the Pre-Cambrian age, the Aravalli ranges constitute one of the most ancient fold mountain ranges of the world. Stretch­ing 800 km from the north-east to south-west of India, they separate the semi-desert and fertile regions of Rajasthan. The Gurusikhar peak (1,722 m) of the Abu Hills is the highest point of the range.