ObjectivesKnowing about India’s Relief, Major Physiographic Units and Structure. To understand the major landforms

features and the underlying geological structure, Their

association with different rocks and minerals as well as nature of

soil types.

Facts that Matter1.India is a large landmass formed during different

geological periods by processes such as Weathering, Erosion and deposition have also influenced her relief.

2.According to the Theory of Plate tectonics, the crust or the upper part of the earth has been formed out of seven major

and some minor plates. 3.These plate movements are of Three types – convergent boundary, Divergent Boundary and transform Boundary.

4.The oldest landmass was a part of the Gondawana land which includes India, Australia, South Africa, South America

and Antarctica as one single landmass.

Facts that Matters5. The physiographical Divisions of India

a)The Himalayasb)The Northern Plainsc)The peninsular Plateaud)The Indian Deserte)The Coastal Plainsf)The Islands

Facts That Mattersa)The Himalayas stretch over the northern borders of India.

-The northern most range is called ‘Himadri’.-The Southern range is called ‘Himachal’.

-The Outermost Range is called ‘Shiwaliks’. b)It is formed by interplay of 3 Major river system- The Indus,

The Ganga and Brahmaputra.-Its divided into three sectors. The Punjab Plains formed by

Indus and its tributaries. Large Part of this plain lies in Pakistan. The Ganga plain extends between Ganga and Teesta river.

Facts That Matter-The Northern Plain also have diverse relief Features.

According to this, This plain can be divided into four Regions-The river after descending from the mountains deposit

pebbles in a narrow belt lying parallel to the slopes of the shiwaliks. It is known as Bhabhar.

-South of the belt, the streams and Rivers re-emerged and create a wet swampy and marshy region known as Terai.-The Largest Part of the Northern Plain is formed of older

Alluvium and known as Bhangar.-The newer Younger deposits of fold Plains are Called Khadar.

Facts That mattersc) The Peninsular Plateau is a tableland composed of the old crystalline, igneous and metamorphic rocks. It's a part of the

oldest landmass on the surface of earth. It has broad and shallow valleys and rounded hills.The Plateau consists of two

main divisions: 1. Central Highlands 2. Deccan Plateau.d) The Indian desert lies towards the western margins of the Aravali Hills. It is undulating sandy plain covered with sand dunes. This region receives very low rainfall below 150mm

per year.

Facts That Matterse)The coastal Plain extended in the form of a strip along the Bay of Bengal on the east and the Arabian sea on the west.

- The western coast, sandwiched between the Western Ghats

and the Arabian Sea, is a narrow plain. It consists of three sections.

- The northern part of the coast is called the Konkan(Mumbai-Goa)

- the central stretch is called the Kannad Plain

- the southern stretch is referred to as the Malabar coast.- Lake Chilika is an important feature along the eastern coast.

Facts That Mattersf) -The Lakshadweep Islands group lying close to the Malabar

coast of Kerala.This groups of islands is composed of small coral islands . Earlier they were known as Laccadive,Minicoy and Amindive.In 1973 these were named as Lakshadweep.

- It covers small area of 32 sq.km. Kavaratti island is the administrative head- quarters of Lakshadweep.

- The elongated chain of islands located in the Bay of Bengal extending from north to south.

-These are Andaman and Nicobar islands. They are bigger in size and are more numerous and scattered.

- The entire group of islands is divided in to two broad categories- The Andaman in the north and the Nicobar in the

south .-These island groups are of great starategic importance for the

country.

One word Answers1.What is the northernmost range of the Himalayas Known as?Ans : Himadari2.In which country is Dhaulagiri located?Ans : Nepal3.Which two rivers demarcate the Nepal Himalayas?Ans : Kali and Tista4.Where are Kailash and Mansarovar Located?Ans : Tibet5.Which is The Highest peak of Eastern Ghats?Ans : Mahendragiri6.What type of soil is found in Peninsular plateau?Ans : Black Soil7. Where is the Chilka Lake located?Ans : Orrisa

Question AnswersQuestion.2: Answer the following questions briefly:

(i) What are tectonic plates?(ii) Which continents of today were parts of the Gondwana land?

(iii) What is bhabar?(iv) Name the three major divisions of the Himalayas from north to south.

(v) Which plateau lies between the Aravali and the Vindhyan ranges?(vi) Name the island group of India having coral origin.

Answer:(i) Due to internal heat of the earth, the currents of the semi-molten rocks

begin to move towards the crust and tear it apart dividing it into large fragments called lithospheric or tectonic plates. There are seven such major

plates namely, South America, North America, Pacific, Indo–Australian, Eurasian, African and Antarctic.

(ii) Gondwana land is the name given to the hypothetical ‘super-continent’ located in Southern hemisphere. Gondwana Land included South America,

part of Africa (south Africa including Madagascar), part of Asia (India, Arabia, Malaya), Australia and Antarctica, prior to its break-up under the forces

causing continental-drift. (iii) The ‘Bhabar’ is that narrow belt of the plain which is covered with

pebbles and lies along the foothills of the Shiwaliks from the Indus to the Teesta. This belt is laid down by numerous streams descending down the hills.

(iv) The three major divisions of the Himalayas from north to south are –(a) The northernmost range which is known as the great Himalayas or

Inner Himalayas or the Himadri.(b) The range lying to the south of the Himadri which is known as Himachal

or the lesser Himalaya.(c) The outermost range of the Himalayas which is known as the Shiwaliks.

Theses are the foothill ranges and represent the southernmost division of the Himalayas.

(v) Malwa plateau or Central Highland(vi) Lakshdweep.

Question.3: Distinguish between(i) Converging and diverging tectonic plates.

(ii) Bhangar and Khadar

Answer:(i) The internal heat of the earth makes the molten rocks to rush towards

the surface of the earth and drive the crust into large fragments known as “Tectonic Plates”. These plates are drifting oven the mantle of the earth. As a result when the two or more plates are pushed towards each other they are called ‘Converging Plates’. On the other hand if they are moving away

from each other, they are called ‘Diverging Plates’.(ii) According to the age of the soils of the Northern Plain they have been differentiated by two names: (a) Bhangar and (b) Khadar. The difference

between these two are mentioned below –(a) Bhangar - These are the older alluvium or old soil and form the largest

part of the Northern Plains. They lie above the flood plains of the rivers and present a terrace like structure. It often contains Kankar nodulesmade of

calcareous deposits.(b) Khadar - The newer and younger deposits of the flood plains are

known as ‘Khadar’. So, these are the new alluvium or new soil and are very fertile. Thus, Khadar is ideal for intensive agriculture.