The Ganga plain extends between Ghaggar and Teesta rivers (Excluding these two rivers). It is spread over the states of North India (Haryana, Delhi, U.P, Bihar, partly Jharkhand) and West Bengal to its East.

Examples of variation in rocks.
(i) Some rocks are very hard such as marble (used for making Taj Mahal).
(ii) Some rocks are very soft such as soap stone (used in making talcum powder).
Examples of variation in soil.
(i) Alluvium soil is found in the Northern plains. It is very fertile soil.
(ii) Black soil is found in the Deccan Trap. It is useful for growing cotton.
Causes of these variations
(i) Most of these variations are caused due to differences in rock formations.

One of the most important physical divisions of India in the northern plain:
(i) The Himalayan and the Peninsular rivers have made up this vast undulating plain by depositing alluvial soil.
(ii) This plain is the result of the interplay of three major river systems. They are the Indus, the Ganga and the Brahmaputra and their tributaries.
(iii) The deposition of alluvium in a vast basin lying at the foot hills of the Himalayas over million of years, formed the most fertile plain in the world.
(iv) It is spread over an area of 7 lakh sq.km. The plain is about 2400km. long and 240 to 320 km. wide.It is the most densely populated physiographic division.
(v) With a rich soil cover combined with adequate water supply and favourable climate it is agriculturally the most productive part of the country.
(vi) This plain has been the centre of human settlements from ancient times.
(vii) Numerous large cities have evolved on the banks of the rivers.
(viii) Majuli is the largest inhabited riverine island.

(i) Corsls are small, short lived, sedentary marine animals with a calcareous horny skeleton.
(ii) These thrive in shallow, mud free and warm wastewater grow into large colonies called coral reefs.
(iii) They secrete calcium carbonate (hard rock like substance). The coral secretion and their skeletons form coral deposits in the form of reefs.
(iv) They are mainly of three types: barrier reef, fringing reefs and atolls.
(v) Atolls are circular or horse shoe shaped coral reefs.
Examples: The Great Barrier Reef of Australia; and Lakshadweep Islands.

1. The Indian desert lies towards the western margins of Aravali Hilla
2. It is also called Thar Desert, and extends to Sindh province of Pakistan.
3. It is an undulating sandy plain coverd with sand dunes.
4. It has very low rainfall, below 150 mm per year.
5. It has arid climate.
6. It has very less vegetation.
7. Streams appear during the rainy season, but they disappear into sand due to very less water.
8.Luni is only river in this region.
9. Brachans (crescent shaped dunes) cover larger areas. Longitudinal dunes become more prominent near the Indo-Pakistan boundary.

1. The Decan Plateau is a triangular landmass.
2. It lies to the south of the river Narmada
3. The Satpura ranges flank in broad base in the north while the Mahadev, the Kaimur hills and the Maikal range are its eastward extension.
4. The Deccan plateau is higher in the west and slopes gently eastwards.

Assam Himalayas

(i) Plate Tectonics. The scientific concept that explains the movements of the crust's plates is called plate tectonics.
(ii) According to the theory of plate tectonics the entire crust of the earth has been divided into seven major and some minor plates.

Barren Island, situated in the Andaman and Nicobar group of Island.

Bhabar.A narrow belt of pebbles on the foot of Shiwalik mountains, 8 to 16km in width is known as Bhabar.

Larger fragments of earth's crust are known as tectonic plates.

The Coastal Plains:
The Peninsular plateau is flanked by a stretch of narrow coastal strips running along the Arabian sea on the west, and the Bay of Bengal on the east.
(a) The western coast is located between the Western Ghats and the Arabian sea.
(i) It is a narrow plain.
(ii)  It consists of three sections.
1. The northern part of the coast is called the Konkan (Mumbai-Goa).
2. The central stretch is called the Kannad Plain.
3. The southern stretch is known as the Malabar Coast.
(iii) The western coast consists of estuaries and lagoons.
(iv) The coast is indented. It has many good natural harbours.
(b) The wide-levelled plain along the YJay of Bengal is called the Eastern Coastal Plain.
(i)  Its northern part is referred to as the Northern Circar.
(ii)  The southern part is known as the Coromandel Coast.
(iii) This plain is dominated by fewer lagoons and thick alluvial deposits in the deltaic tracks of the rivers flowing into the Bay of Bengal.
(iv) Large rivers such as the Mahanadi, the Godavari, the Krishna, and the Kaveri have formed extensive delta on this coast..
(v) Largest salt water lake in India, Lake Chilika lies in the state of  Odisha.