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GEOGRAPHY Chapter 2: Physical Features of India
(1) PHYSICAL FEATURES OF INDIA 02 Physical Features of India We find various types of landform features in India because its geographical extent is very vast. While the eastern part of our country is uneven, rugged, and hilly, the Ganga– Brahmaputra region has vast stretches of plain lands. Formation of the Land Forms • Several factors such as the presence of different types of rocks, geological formations, weathering, erosion and deposition have influenced and affected the land features of India. • Geologists have forwarded various theories regarding the formation of the physical features of the Earth. • One of the most probable theories is the ‘Theory of Plate Tectonics’. This theory postulates that the crust of the Earth has been formed out of seven major and some minor plates. • The movement of the plates beneath the surface of the Earth creates tension, resulting in folding, faulting and volcanic activities. • Plate movements are broadly categorised into three different types. When the plates come towards each other, they form convergent boundaries. When the plates move away from each other, they form divergent boundaries. Transform boundaries are formed when the plates horizontally move past each other. • All these movements of the plates have gradually changed the size and the position of the continents over millions of years.
(2) PHYSICAL FEATURES OF INDIA 02 • The peninsular part of India, the oldest landmass, was part of the Gondwanaland. Previously, the Gondwanaland included Africa, South America, Australia, Antarctica, and India. It was one single landmass. • Because of the impact of convectional currents, the crust was split into many pieces. The Indo–Australian plate got separated from the Gondwanaland and drifted towards the north. • As it drifted towards the north, it collided with the Eurasian plate. As a result of this collision, the sedimentary rocks which were settled in the large-scale depression in the Earth’s crust called Tethys were folded and formed the mountain system of western Asia and the Himalayas. • The upliftment of the mountains out of the Tethys Sea and the sinking of the northern part of the peninsular plateau led to the formation of a large basin. • When the rivers flowed from the mountains in the north to the peninsular plateau in the south, the depression was filled because of depositional activities of the rivers. This led to the formation of the northern plains of India which gradually became rich in alluvial
(3) PHYSICAL FEATURES OF INDIA 02 deposits. • While the peninsular plateau of India composed of igneous and metamorphic rocks is one of the ancient landmasses on the surface of the Earth, the Himalayan Mountains are young fold mountains. They have high peaks, deep valleys with fast-flowing rivers. Major Physiographical Divisions of India The major physiographical divisions of India are a. The Himalayan Mountains b. The Northern Plains c. The Peninsular Plateau d. The Indian Desert e. The Coastal Plains f. The Islands The Himalayan Mountains The Himalayan Mountains are young fold mountains which run in the west to east direction. They run over about 2,400 km. • The width of the mountains varies from 2,400km in Kashmir to 150km in Arunachal Pradesh. • The Himalayas are divided into three parallel ranges. They are