Chapter 2 – Structure and Physiography

What is the geological structure of India?
India’s geological structure includes ancient Archaean rocks, folded mountains, sedimentary basins, and volcanic formations. The Peninsular Plateau is one of the oldest landmasses on Earth.

What are the major physiographic divisions of India?
India has six major divisions: The Northern Mountains, Northern Plains, Peninsular Plateau, Indian Desert, Coastal Plains, and Islands.

What is the Peninsular Plateau?
A stable landmass made of hard crystalline rocks, the Peninsular Plateau is the oldest part of India. It is rich in minerals and has a rugged terrain.

What are the characteristics of the Himalayas?
The Himalayas are young fold mountains formed by tectonic collisions. They are high, geologically active, and divided into three parallel ranges: Himadri, Himachal, and Shiwalik.

What is the Indo-Gangetic Plain?
A large alluvial plain formed by the Indus, Ganga, and Brahmaputra rivers. It is flat, fertile, and densely populated, stretching across northern India.

What is the significance of the Northern Plains?
They support intensive agriculture due to fertile soil, abundant water, and flat terrain. These plains are also important for transportation and settlement.

What is the Indian Desert?
Also known as the Thar Desert, it lies in western Rajasthan. It receives very low rainfall, has sandy soil, and extreme temperatures.

What are coastal plains?
Narrow strips of land along the Arabian Sea and Bay of Bengal. The Western Coastal Plain is narrower and the Eastern Coastal Plain is broader.

What are the features of the Eastern Coastal Plain?
It is wide, has deltas of major rivers like Mahanadi, Godavari, and Krishna, and supports dense agriculture and settlements.

What are the features of the Western Coastal Plain?
It is narrow and uneven, with features like estuaries, backwaters, and lagoons. It includes Konkan, Kanara, and Malabar coasts.

What are the Lakshadweep Islands?
A group of coral islands in the Arabian Sea. They are flat and small, formed by atolls and reefs, and have fragile ecosystems.

What are the Andaman and Nicobar Islands?
Volcanic islands located in the Bay of Bengal. They are forested, mountainous, and have strategic and ecological importance.

How were the Himalayas formed?
They were formed by the collision of the Indian Plate with the Eurasian Plate, causing the crust to fold and uplift into mountains.

What is the significance of the Deccan Plateau?
It is rich in minerals, supports agriculture and plateau farming, and contains important rivers like Godavari and Krishna.

What is the Malwa Plateau?
Located in central India, this volcanic plateau is between the Aravalli and Vindhya ranges and is known for black soil.

What is the Chotanagpur Plateau?
Located in eastern India, it’s a storehouse of minerals like coal, iron, and mica. It is highly dissected by rivers and hills.

What is the Western Ghats?
A mountain range running parallel to the western coast. It is a UNESCO World Heritage Site and a biodiversity hotspot.

What are the Eastern Ghats?
Discontinuous hills along the eastern coast. They are older, more eroded than the Western Ghats, and intersected by rivers.

What is the Purvanchal Hills?
An extension of the Himalayas in the northeast. Includes hills like Patkai, Naga, and Mizo Hills. They are rich in forest and cultural diversity.

What is the Vindhya Range?
A range of hills in central India that separates the Indo-Gangetic plain from the Deccan Plateau.

What is the Satpura Range?
Lies south of the Vindhyas and runs east-west in central India. It acts as a watershed between the Narmada and Tapi rivers.

What is the Aravalli Range?
One of the oldest fold mountains, located in western India. It extends from Gujarat to Delhi and has rich mineral deposits.

What is the significance of river valleys in India?
They provide fertile land, support agriculture, settlement, and act as cradles of civilization. Major valleys include Ganga, Brahmaputra, and Indus.

What are block mountains?
Formed by faulting and uplift of land blocks. Examples include the Vindhya and Satpura ranges in central India.

What is the Shillong Plateau?
Located in Meghalaya, it is an uplifted part of the Peninsular block and is separated from the main plateau by faults.

What are lagoons and backwaters?
Lagoons are shallow water bodies separated from the sea by sandbars. Backwaters are water channels formed by the sea along the coast, especially in Kerala.

What is the Bhabar region?
A narrow belt of coarse alluvium at the Himalayan foothills where rivers disappear into porous soil before re-emerging in the Terai.

What is the Terai region?
A marshy, water-logged region south of Bhabar, formed by rivers re-emerging. It has fertile soil and supports dense forests and agriculture.

What is the difference between Eastern and Western Ghats?
Western Ghats are continuous, higher, and more fertile, while Eastern Ghats are fragmented, lower, and more eroded by rivers.

How does India’s physiography affect its diversity?
It results in a range of climates, soil types, vegetation, and resources, shaping India’s cultural, agricultural, and economic diversity.