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Question 1

India’s geological divisions

Answer 1

Based on the different geological structure and formations, India is divided into three geological divisions, as follows:
Š The Peninsular Block
Š The Himalayan and other Peninsular mountains
Š Indo-Ganga-Brahmaputra plains

Question 2

The north eastern part of the peninsular block is separated from the main block by

Answer 2

The north eastern part of the block is separated from the main block by the Malda Fault in West Bengal in Chota Nagpur Plateau

Question 3

The rift valleys of Narmada, Mahanadi, Tapi and Satpura block mountains are examples of?

Answer 3

• Peninsular block is formed by ancient gneisses and granites and has been a rigid mass of block standing since the Cambrian period except for the western part, where a part of it is submerged beneath the sea
  • The block was a part of Indo-Australian plate
  • During tectonic activity, vertical movements resulted in faulting. The rift valleys of Narmada, Mahanadi, Tapi and Satpura block mountains are examples.

Question 4

Peninsula consists mostly of relics and residuals like ?

Answer 4

Peninsula consists mostly of relics and residuals like Aravali ranges, Nallamala hills, Javadi hills, Veliconda hills, Palkonda range and Mahendragiri hills.

Question 5

The east flowing rivers like ____, _____ and _____ form delta in Bay of Bengal.

Answer 5

Many rivers flow through this Peninsular block. The east flowing rivers like Mahanadi, Krishna and Godavari form delta in Bay of Bengal.

Question 6

The west flowing rivers are?

Answer 6

Sabarmati, Mahi, Narmada, Tapi - they have no deltas

Question 7

The west flowing rivers do not form any delta because?

Answer 7

The west flowing rivers like Narmada, Tapi etc do not form any delta because:
Š- The slope of the Western Ghats is steep and that is the reason that these rivers have a rapid flow. Due to this, the rivers carry their silt into deep sea.

-Š There is very less silt deposition. At the same time, the Narmada and Tapti rivers flow via the rift valleys and while doing so the eroded material carried by them gets deposited in the fractures of the fault zones. Thus, they don’t form deltas.
Š
- Moreover, the tides are also one reason that the rivers of western side don’t form deltas. The west flowing rivers form estuaries instead.

Question 8

Examples of erosional features of Western Ghats?

Answer 8

The rivers of Western Ghats too form spectacular gorges and V-shaped valleys which are the result of the vertical erosional activities of peninsular rivers like Krishna, Ghataprabha, Tungabhadra, Periyar etc. Many waterfalls like Dudhsagar, Sivasamudram, Jog falls are the resultant erosional features of Western Ghats.

Question 9

Indo-Ganga-Brahmaputra Plains came into being ?

Answer 9

This flood-plain came into being about 64 million years ago when it originally was a geo-synclinal depression.

The depression reached maximum development during the third phase of the Himalayan mountain formation

The plain was the result of sediments brought and filled by Himalayan and Peninsular region

Question 10

What are Geosynclines?

Answer 10

The ‘Geosynclines’ are major structural and sedimentational units of the earth’s crust.

They are elongated trough-like depressions submerged beneath the sea water.

These basins become filled with great thickness of sediments and along with the accumulation of pile of sediments; there occurs progressive subsidence of the basin floor resulting into plain formation at a much later geological stage.

Question 11

Soil in the plains and their depths

Answer 11

These plains are mostly formed of alluvial deposits and therefore are extremely fertile and the depth of deposits vary between 1000-2000m

Question 12

India - Physiography division

Answer 12

• India is divided into 6 physiographic divisions:

Š The Northern and the North Eastern Mountains
Š The Northern Plains
Š The Peninsular Plateau
Š The Indian Desert
Š The Coastal Plains
Š The Islands

Question 13

The Himalayan Mountain System is formed due to thee

Answer 13

They are formed by the tectonic collision of the Indian Plate with the Eurasian Plate.

Question 14

Length and width of The Himalayan Mountain System

Answer 14

The Himalayan Mountain System forms an arc over the Indian subcontinent, which covers a distance of about 2,400 Km in length with varying width from 400 Km in Kashmir to 160 Km in Arunachal Pradesh

Question 15

How do The Himalayan Mountain System act as a barrier?

Answer 15

These mountains act as a physical barrier between Central and East Asian countries and India and protect the Indian subcontinent from the icy cold winds of Central Asia.

They act as climatic, drainage and cultural divide

Question 16

The northern mountain system is divided into?

Answer 16

The northern mountain system is divided into three parts, called – The Himalayas, The trans-Himalayas and The Purvanchal Hills

Question 17

Classification of Himalayas?

Answer 17

1- The longitudinal division of Himalayas ( based on north-south alignment)

2- West to east division of Himalayas based on region and height of the mountains.

Question 18

longitudinal division on Himalayas?

Answer 18

There are three parallel ranges in the Himalayas (longitudinal division)

• Š Himadri or the Greater Himalayas (They are the inner most mountain ranges)
• Š Himachal or the Lesser Himalayas (they are the middle Himalayas)
• Š Shiwaliks or the Outer Himalayas

Question 19

Avg height and width of Himadri

Answer 19

Greater Himalayas or Himadri or Himagiri comprises all major mountain ranges of the Himalayas.

The average height of these mountains is 6000m and average width is around 120 – 190 km.

Question 20

Important peaks of Greater Himalayas or Himadri?

Answer 20

Mount Everest (8850m) – the highest peak in the world, Mt. Kanchenjunga (8586m), Mt. Makalu (8481m), Mt. Dhaulagiri (8172m) are some of the important peaks of this mountain range.

Other prominent Ranges include Kamet, Nanga Parbat and Annapurna.

Question 21

Rivers originating from Himadri

Answer 21

The Ganga and the Yamuna, two rivers originate from this Himalaya.

Question 22

Average height of Himachal or lesser Himalayas

Answer 22

The average height of these mountains are 3700 – 4500m and average width is 50 km.

Question 23

Areas included in Himachal are?

Answer 23

Areas included are Nepal, Bhutan, Kashmir, Indian states of Himachal, Uttarakhand, and Sikkim.

Question 24

Important ranges of Himachal?

They are famous for?

Answer 24

Pirpanjal, Nag Tibba, Dhauladhar, Mahabharat are some of the important ranges.

• The Middle Himalayas are famous for their valleys like Kulu, Kashmir, Kangra etc.
• Most popular hill stations are in these mountains like Shimla, Ranikhet, Darjeeling, Nainital etc

Question 25

Ancient name of outer Himalayas is

Answer 25

The ancient name of this range was | ‘Upgiri’.

Question 26

The Outer Himalayas makes almost a continuous chain of

Answer 26

The Outer Himalayas makes almost a continuous chain of more than 2400 km from the Indus gorge in the northwest to the Brahmaputra in Assam

Question 27

Height and width of Shiwaliks

Answer 27

The width of Shiwaliks is 10 – 15 km and the height seldom exceeds 1300 m.

Question 28

longitudinal valleys between the Shiwaliks and Himachal?

Answer 28

There exist many longitudinal valleys between the Shiwaliks and Himachal, running parallel to the mountains and are called ‘Duns’, like Dehradun, Kotli Dun, Patli Dun.

Question 29

Explain the formation of duns or duars?

Answer 29

Shivalik Hills were formed by the accumulation of conglomerates (sand, stone, silt, gravel, debris etc). These conglomerates, in the initial stages of deposition, obstructed the courses of the rivers draining from the higher reaches of the Himalayas and formed temporary lakes. With the passage of time, these temporary lakes accumulated more and more conglomerates. The conglomerates were well settled at the bottom of the lakes. When the rivers were able to cut their courses through the lakes filled with conglomerate deposits, the lakes were drained away leaving behind plains called ‘duns’ or ‘doons’ in the west and ‘duars’ in the east.

Question 30

West to east division of Himalayas based on region and height of the mountains.

Answer 30

On the basis of regions, from west to east, three regions have been demarcated by the presence of river valleys. 1. Western Himalayas Kashmir and Himachal Himalayas Kumaon or Central Himalayas 2. Central Himalayas Nepal Himalayas Sikkim and Darjeeling Himalayas 3. Eastern Himalayas Assam and Arunachal Himalayas

Question 31

On the basis of relief, alignment of ranges and similar geomorphological features, the Himalayas are divided into?

Answer 31

On the basis of relief, alignment of ranges and similar geomorphological features, the Himalayas are divided into the following subdivisions. * Kashmir or North-western Himalayas * Himachal and Uttaranchal Himalayas * Darjeeling and Sikkim Himalayas * Arunachal Himalayas * Eastern Hills and Mountains

Question 32

Kashmir and Himachal Himalayas : Location? Important ranges? Important passes? Valleys and lakes? Glaciers

Answer 32

The Himalayan region between Indus and Sutlej rivers Karakoram, Ladakh, Pir Panjal, Zanskar, and Dhaola Dhar are the main ranges of this section. Zojila, Rohtang, BaraLacha la and ShipkiLa are important passes. This area has the beautiful valleys of Kullu, Kangra and Lahaul and Spiti. It is also home to the beautiful Kashmir Valley and the Dal lake. Siachen and Baltoro glaciers are found in this region

Question 33

Kumaon or Central Himalayas: Important features

Answer 33

Himalayas between Satluj and Kali rivers, extensively in Uttarakhand. Nanda Devi, Kamet, Trishul are important peaks. Sources of sacred rivers like the Ganga and Yamuna Nainital, Sattal and Bhimtal are important lakes Valley of Flowers is also situated in this region This region is famous for the formation of Duns. Dehradun is the largest and the most famous dun in this region. Places of pilgrimage like Gangotri, Yamunotri, Kedarnath and Hemkund Sahib are situated in this region

Question 34

Nepal Himalayas Important features?

Answer 34

The area between Kali and Tista rivers * Tallest section of the Himalayas * Mainly in Nepal, this part comprises of all three ranges of Himalayas : Himadri, Himachal and Shiwaliks * Important peaks are Mount Everest, Kanchenjunga, Lhotse I, Makalu, Dhaula Giri and Annapurna * Kathmandu is a famous valley * The higher reaches of this region are inhabited by the Lepcha tribes.

Question 35

important features of Assam Himalayas?

Answer 35

The Himalayan part between Tista and Dihang rivers is called the Assam Himalayas. Darjeeling and Sikkim Himalayas are a part of this region. characterized by fast flowing rivers like Tista and deep valleys. This region has a mixed population of Nepalis, Bengalis and tribal population. This region has a moderate slope and the thick soil cover with very high organic content and well distributed rainfall throughout the year. Taking advantage of these physical conditions, the britishers introduced tea plantations in this region. characterized by the presence of ‘Duars’, which are the same as duns of West Himalayas. extreme east part of this region is called Arunachal Himalayas. Important peaks are Namcha Barwa and Kangtu. The Brahmaputra flows through this region along with many tributaries like Kameng, Subansiri, Dibang, Lohit and Dihang. extreme eastern parts have the maximum potential of hydro-electric power in the country. The Arunachal Himalayas have numerous ethnic tribal communities inhabiting this region like Monpa, Daffla, Mishmi, Abor, Nishi and Nagas. These communities practice shifting or Jhum cultivation. This region is extremely rich in biodiversity.

Question 36

important Mountain passes in Himalayas?

Answer 36

Banihal Pass: separates the Kashmir Valley in Jammu and Kashmir from the Outer Himalayas and plains to the south. Jelep La Pass: between India and Tibet in Sikkim. The pass connects Lhasa (Tibet) to India. Karakoram Pass: between India and China and is located in the Karakoram Range. Mana Pass: on the border between India and Tibet. located in Uttarakhand Nathu La Pass: It connects Sikkim with China’s Tibet Autonomous Region. This pass is of strategic importance in respect with Indo-China relations. Rohtang Pass: It connects the Kullu valley with Lahaul and Spiti valleys of Himachal Pradesh. Manali-Leh Highway, a part of NH 21, transverses Rohtang Pass. Shipki La Pass: India-Tibet border. The river Satluj enters India from Tibet through this pass. Zoji La Pass: in Kashmir, located on the Indian National Highway 1D between Srinagar and Leh

Question 37

What are Trans Himalayan Mountains?

Answer 37

- Himalayan Ranges immediately to the north of the Great Himalayan Range are called the Trans Himalayas. * It includes the mountain ranges of Karakoram, Zanskar, Ladakh and Kailash ranges. * It is also called the Tibet Himalayas because most of it lies in the Tibet region. * It stretches 1000km from east to west and average height is about 3000m.

Question 38

features of Karakoram range?

Answer 38

- India’s frontier with Afghanistan and China. northernmost range in the Trans-Himalayan Mountains. * The average width 120 – 140 km. Most peaks hardly ever fall below 5,500 m. Some of the peaks are more than 8,000 m above sea level. * K2 is the 2nd highest peak in the world & the highest in India. It is also known as Godwin Austen.

Question 39

Features of Ladakh Range?

Answer 39

* lies to the north of Leh. * The Ladakh Plateau lies to the north- east of the Karakoram Range. It is the highest plateau of Indian Union and has many plains like Soda plains and Aksai Chin. * This range merges with the Kailash range in Tibet.

Question 40

Features off Zanskar range?

Answer 40

- situated in Jammu and Kashmir. • The average height is about 6000 m. • This range separates Zanskar from Ladakh.

Question 41

Features of Kailash Mountain Range?

Answer 41

- one of the highest and most rugged parts. It is located in the southwestern part of the Tibet. • Mount Kailash is an important holy site for both Hindus and Buddhist. • It is the origin of the river Indus.

Question 42

Features of The Purvanchal Or Eastern Hills And Mountains?

Answer 42

* After crossing the Dihang gorge (Brahmaputra gorge) in Arunachal Pradesh, the Himalayas suddenly turn southward and form a series of comparatively low hills running in the shape of a crescent with its convex side pointing towards the west. * These hills are collectively called the Purvanchal because they are located in the eastern part of the country. It extends from Arunachal Pradesh in the north to Mizoram in the south and form boundary between India and Myanmar. * The Indo-Burma hill range is a part of the Arakan Yoma Suture zone that stretches south through Andaman – Nicobar island chain to Sunda. * The elevation of the Eastern Hills decreases from north to south and it is characterized by rough terrain, dense forests and swift streams. All these Ranges are generally 2,000m or less in height. * This region receives the most of monsoonal rainfall and therefore is covered with lush dense green forests. * Mawsynram, a village near Cherrapunji in Meghalaya is the wettest place on earth, receiving the highest annual rainfall. * These hills are inhabited by tribal groups who practice jhum cultivation.

Question 43

What are the hills of Purvanchal range?

Answer 43

* Mishmi hills – Contains the loftiest range of the Purvanchal. Dapha Bum is its highest peak. * Patkai Bum Range – It is the northernmost range forming the easternmost limit of the Great Himalaya Mountains, has synclinal structure and is made up of Tipam sandstone. * Naga Hills – It lies south to the Patkai Bum and Saramati (3826m) is its highest peak. Patkai Bum and Naga hills form the watershed between India and Myanmar. * Manipur Hills – It is south to Naga hills and form boundary between Manipur and Myanmar. Its central part is a large basin which appears to be bed of an old lake, a remnant of which occupies is known as Loktak Lake. The Barail Range separates Naga Hills from Manipur hills. * Mizo Hills (Lushai Hills) – It lies south to the Manipur hills and its highest point is the Blue Mountain (2157m) in the south. Mizoram is known as the Molassis basin which is made up of soft unconsolidated deposits.

Question 44

Significance of northern mountains?

Answer 44

• Physical barriers: separates India from central and East Asian countries. Accounts for the difference in climatic and weather patterns between Indian sub-continent from the rest of Asia. Natural frontier: protecting India from foreign invasions since early times. Climatic Influence: India is a monsoon land only because of the presence of Himalayas. also blocks the cold winter storms of East Asia from entering India. Himalayas splits the westerly jet streams into two branches and plays a significant role in bringing the monsoon. Source Region of Rivers: The Himalayas is the abundant reservoir of Great Indian rivers such as Ganga, Indus and Brahmaputra. Fertility of Soil: The Himalayan Rivers carry slits on their way down and deposit in the northern plain. (Alluvial soil) Hydro Electric Power Projects: The Himalayan valley with natural waterfalls offers the best location for construction of dams. Biodiversity and Vegetation: The forests provide fuel wood, medicinal plants and various raw materials that are needed for the forest based industries. Agriculture: major crop is rice. Crops like wheat, maize, potatoes, ginger, and tobacco are also cultivated. Tea is a unique crop which grows only on hill slopes. Many fruits such as apples, pears, peaches, mulberries, cherries along with citrus fruits are grown in the Himalayan region. Mineral Resources: Coal is found in Kashmir. Also minerals such as Copper, Cobalt, Nickel, Zinc, Lead, Antimony, Tungsten, Limestone, Gypsum and Magnetite are also present. Gold, Silver and other semi-precious and precious stones are also found Tourism: The beautiful landscapes on Himalayan mountain offer a great tourist spots. Hill stations such as Mussouri, Shimla, Kulu, Manali, Nainital, Chamba, Ranikhet, Almora, Darjeeling, Mirik, Gangtok etc Pilgrimage: Kedarnath, Badrinath, Vaishnodevi, Kailash, Amarnath, Tungnath, Uttarkashi, Gangotri, Yamunotri etc