Indian geography Notes
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THE NORTHERN AND NORTHEASTERN MOUNTAINS
The Himalayas, geologically young and structurally fold mountains stretch over the northern borders of India. These mountain ranges run in a west-east direction from the Indus to the Brahmaputra. The Himalayas represent the loftiest and one of the most rugged mountain barriers of the world. They form an arc, which covers a distance of about 2,400 Km. Their width varies from 400 Km in Kashmir to 150 Km in Arunachal Pradesh. The altitudinal variations are greater in the eastern half than those in the western half. The Himalaya consists of three parallel ranges in its longitudinal extent. A number of valleys lie between these ranges.
The northern most range is known as the Great or Inner Himalayas or the ‘Himadri’.
It is the most continuous range consisting of the loftiest peaks with an average height of 6,000 metres. It contains all the prominent Himalayan peaks.
FORMATION OF HIMALAYAS
225 million years ago (Ma) India was a large island situated off the Australian coast and separated from Asia by the Tethys Ocean.
● The supercontinent Pangea began to break up 200 Ma and India started a northward drift towards Asia.
● 80 Ma India was 6,400 km south of the Asian continent but moving towards it at a rate of between 9 and 16 cm per year.
● At this time Tethys Ocean floor would have been subducting northwards beneath Asia and the plate margin would have been a Convergent oceaniccontinental one just like the Andes today.
● From about 50-40 Ma the rate of northward drift of the Indian continental plate slowed to around 4-6 cm per year.
● This slowdown is interpreted to mark the beginning of the collision between the Eurasian and Indian continental plates, the closing of the former Tethys Ocean, and the initiation of Himalayan uplift.
● The Eurasian plate was partly crumpled and buckled up above the Indian plate but due to their low density/high buoyancy neither continental plate could be subducted.
● This caused the continental crust to thicken due to folding and faulting by compressional forces pushing up the Himalaya and the Tibetan Plateau
225 million years ago (Ma) India was a large island situated off the Australian coast and separated from Asia by the Tethys Ocean.
● The supercontinent Pangea began to break up 200 Ma and India started a northward drift towards Asia.
● 80 Ma India was 6,400 km south of the Asian continent but moving towards it at a rate of between 9 and 16 cm per year.
● At this time Tethys Ocean floor would have been subducting northwards beneath Asia and the plate margin would have been a Convergent oceaniccontinental one just like the Andes today.
● From about 50-40 Ma the rate of northward drift of the Indian continental plate slowed to around 4-6 cm per year.
● This slowdown is interpreted to mark the beginning of the collision between the Eurasian and Indian continental plates, the closing of the former Tethys Ocean, and the initiation of Himalayan uplift.
● The Eurasian plate was partly crumpled and buckled up above the Indian plate but due to their low density/high buoyancy neither continental plate could be subducted.
● This caused the continental crust to thicken due to folding and faulting by compressional forces pushing up the Himalaya and the Tibetan Plateau
● The Himalayas are still rising by more than 1 cm per year as India continues to move northwards into Asia, which explains the occurrence of shallow focus earthquakes in the region today.
CHARACTERISTIC FEATURES
● The Himalayas form an arcuate curve convex to the south.
● This curved shape of the Himalayas is created due to the maximum push offered at the two ends on the Indian peninsula during its northward drift.
● In the north-west, it was done by Aravalis and in the Northeast by the Assam ranges.
Syntaxial Bends of the Himalayas
● Himalayas extend in the east-west direction from the Indus gorge in the west to the Brahmaputra gorge in the east and take sharp southward bends at these gorges. These bends are called syntaxial bends of the Himalayas.
● The western syntaxial bend occurs near the Nanga Parbat.
● The eastern syntaxial bend occurs near the Namche Barwa
CHARACTERISTIC FEATURES
● The Himalayas form an arcuate curve convex to the south.
● This curved shape of the Himalayas is created due to the maximum push offered at the two ends on the Indian peninsula during its northward drift.
● In the north-west, it was done by Aravalis and in the Northeast by the Assam ranges.
Syntaxial Bends of the Himalayas
● Himalayas extend in the east-west direction from the Indus gorge in the west to the Brahmaputra gorge in the east and take sharp southward bends at these gorges. These bends are called syntaxial bends of the Himalayas.
● The western syntaxial bend occurs near the Nanga Parbat.
● The eastern syntaxial bend occurs near the Namche Barwa
DIVISION OF HIMALAYAS
Himalaya Mountain Range can be categorized into western, central and eastern Himalayas.
● Sometimes one more classification is added by including Tibetan Himalayas which include the
southern edge of Tibetan Plateau.
● Sometimes one more classification is added by including Tibetan Himalayas which include the
southern edge of Tibetan Plateau.
- Western Himalayas include the area of Jammu & Kashmir, Pir Panjal, Ladakh and Baltistan, and Gilit region.
- The central Himalayas extends from Jammu & Kashmir to Sikkim and includes the area of Himachal, Garhwal, Punjab, and Nepal.
- The Eastern Himalayas extend from Sikkim to Assam and include the part of the range running in Bhutan, Arunachal Pradesh and Assam.
The Himalaya Mountain Range can also be classified on the basis of height and they are as follow
1.The Greater Himalayan range, which includes:
● The Great Himalayas(Himadri)
● The Trans-Himalayan range
2.Lesser or Middle Himalayas (The Himanchal Range)
● Outer or Sub-Himalayas (The Siwalik Range)
1.The Greater Himalayan range, which includes:
● The Great Himalayas(Himadri)
● The Trans-Himalayan range
2.Lesser or Middle Himalayas (The Himanchal Range)
● Outer or Sub-Himalayas (The Siwalik Range)
The Himalayas are wider in the west than in the east The width varies from 400 km in Kashmir to 150 km in Arunachal Pradesh.
● The main reason behind this difference is that the compressive force was more in the east than in the west.That is why high mountain peaks like Mount Everest and Kanchenjunga are present in the Eastern Himalayas.
● The ranges are separated by deep valleys creating a highly dissected topography.
● The southern slopes of the Himalayas facing India are steeper and those facing the Tibetan side are generally gentler.
● It contains some of the largest glaciers in the world and count goes as high as 15000 glaciers including Gangotri and Yamunotri glaciers
● The ranges are separated by deep valleys creating a highly dissected topography.
● The southern slopes of the Himalayas facing India are steeper and those facing the Tibetan side are generally gentler.
● It contains some of the largest glaciers in the world and count goes as high as 15000 glaciers including Gangotri and Yamunotri glaciers
THE GREATER HIMALAYAN RANGE
The Trans-Himalayan range (Tibetan Himalaya) Rivers originating from Himalaya Mountain are perennial and they have water for almost every part of the year.
● Almost one-fifth of the world population depends on water from the Himalayan system.The Trans-Himalayan range (Tibetan Himalaya) Rivers originating from Himalaya Mountain are perennial and they have water for almost every part of the year.
● Himalayas Basin is drained by nearly 19 rivers and they can be grouped into three major river systems of Ganges, Indus, and Brahmaputra.
● Apart from rivers, the Himalayan range has a large number of freshwater lakes.
● Some important lakes include Tilicho, Pangong Tso, and Yamdrok Tso Lake.
Most of the part of this Himalayan range lies in the Tibet and hence also called Tibetan Himalaya. This range lies in immediate north of Himadri with main ranges of
1. Zaskar
1. It separate from the great Himalayan Range near 80o E longitudes and runs parallel to it.
2. The Nanga Parbat (8126 mt) is the culmination of Zaskar range in north-west but the adjoining Deosai Mountain may also be included in it.
3. Ladakh range is in the north of the Zaskar range which runs parallel to it.
2. Karakoram (northmost range)
1. It is also known as Krishnagiri which is situated in the northern most range of the Trans-Himalayan ranges.
2. Home of 3rd largest glacier in the world and greater glacier outside the polar regions.
3. It forms Frontier which China and Afghanistan.
4. K2 ( Godwin Austen) is the second highest peak in the world and highest in the Indian Territory lies here.
3. Ladakh
1. It lies to the north of the Leh,
2. It merges with the Kailash range in Tibet
1. Zaskar
1. It separate from the great Himalayan Range near 80o E longitudes and runs parallel to it.
2. The Nanga Parbat (8126 mt) is the culmination of Zaskar range in north-west but the adjoining Deosai Mountain may also be included in it.
3. Ladakh range is in the north of the Zaskar range which runs parallel to it.
2. Karakoram (northmost range)
1. It is also known as Krishnagiri which is situated in the northern most range of the Trans-Himalayan ranges.
2. Home of 3rd largest glacier in the world and greater glacier outside the polar regions.
3. It forms Frontier which China and Afghanistan.
4. K2 ( Godwin Austen) is the second highest peak in the world and highest in the Indian Territory lies here.
3. Ladakh
1. It lies to the north of the Leh,
2. It merges with the Kailash range in Tibet
Pamir Knot
● It is a unique geographical feature in the Pamir Mountains.
● It refers to the convergence of some of the world’s major mountain ranges, including the Tian Shan, Karakoram, Kunlun Shan, Hundukush and Pamir Systems.
● While a number of countries claim to be home to the Pamir knot, it is actually centred in the GornoBadakh-Shan autonomous region of eastern Tajikistan.
● It is a unique geographical feature in the Pamir Mountains.
● It refers to the convergence of some of the world’s major mountain ranges, including the Tian Shan, Karakoram, Kunlun Shan, Hundukush and Pamir Systems.
● While a number of countries claim to be home to the Pamir knot, it is actually centred in the GornoBadakh-Shan autonomous region of eastern Tajikistan.
The Great Himalayas (Himadri)
● The highest and the northern most range of the Himalayas.
● The most continuous range consisting of the loftiest peaks with an average height of 6,000 metres.
● It contains all the prominent Himalayan peaks.
● Terminate abruptly at the syntaxial bend.
● The folds of Great Himalayas are asymmetrical in nature. The core of this part of Himalayas is
composed of granite.
● The peaks are perennially covered with snow due to to the lofty heights (Hence Himadri).
● Almost all the prominent Himalayan peaks lies in this range like Mr Everest, Kanchenjunga, etc.
● Famous glaciers like the Gangotri and the Yamunotri lie here.
● Forests type → Needle leaved coniferous
● The highest and the northern most range of the Himalayas.
● The most continuous range consisting of the loftiest peaks with an average height of 6,000 metres.
● It contains all the prominent Himalayan peaks.
● Terminate abruptly at the syntaxial bend.
● The folds of Great Himalayas are asymmetrical in nature. The core of this part of Himalayas is
composed of granite.
● The peaks are perennially covered with snow due to to the lofty heights (Hence Himadri).
● Almost all the prominent Himalayan peaks lies in this range like Mr Everest, Kanchenjunga, etc.
● Famous glaciers like the Gangotri and the Yamunotri lie here.
● Forests type → Needle leaved coniferous
LESSER OR MIDDLE HIMALAYAS (THE HIMANCHAL RANGE)
● This range lies between the Shiwalik in the south and the Greater Himalayas in the north.
● Most rugged mountain system ranges mainly composed of highly compressed and altered rocks.
● The altitude varies between 3,700 and 4,500 metres and the average width is of 50 Km.
● It mainly consists of metamorphosed rocks.
● Gentle slopes of the eastern part of this range are covered with dense forests.
● The south facing slopes of this range are very steep and generally devoid of any vegetation.
● The north facing gentle slope of this range are covered by dense vegetation.
● Local names = Pir Panjal in Jammu and Kashmir; Dhauladhar in Himachal Pradesh.
● Most of the hill towns or resort towns are located in Himachal range for example Shimla, Mussoorie, Nainital, Darjeeling etc.
● This range lies between the Shiwalik in the south and the Greater Himalayas in the north.
● Most rugged mountain system ranges mainly composed of highly compressed and altered rocks.
● The altitude varies between 3,700 and 4,500 metres and the average width is of 50 Km.
● It mainly consists of metamorphosed rocks.
● Gentle slopes of the eastern part of this range are covered with dense forests.
● The south facing slopes of this range are very steep and generally devoid of any vegetation.
● The north facing gentle slope of this range are covered by dense vegetation.
● Local names = Pir Panjal in Jammu and Kashmir; Dhauladhar in Himachal Pradesh.
● Most of the hill towns or resort towns are located in Himachal range for example Shimla, Mussoorie, Nainital, Darjeeling etc.
All great valleys like Kashmir valley, Kangra valley, Kullu valley are present here.
● Forests type → Broad leaved evergreen
● Forests type → Broad leaved evergreen
OUTER OR SUB-HIMALAYAS (THE SIWALIK RANGE)
● The southernmost and outer most range of Himalayas which lies between the great plains and the Lesser Himalayas.
● It is also known as Manak Parbat in ancient times.
● They extend over a width of 10-50 Km and have an altitude varying between 900 and 1100 metres.
● These ranges are composed of unconsolidated sediments brought down by rivers from the main Himalayan ranges located farther north.
● These valleys are covered with thick gravel and alluvium.
● They are almost unbroken chain of low heels except for a gap of 80-90 km which is occupied by the valley of the Teesta river and Raidak river.
● Most of the Dun & Duars are located in this range
● Forests type → Deciduous type forests
● The southernmost and outer most range of Himalayas which lies between the great plains and the Lesser Himalayas.
● It is also known as Manak Parbat in ancient times.
● They extend over a width of 10-50 Km and have an altitude varying between 900 and 1100 metres.
● These ranges are composed of unconsolidated sediments brought down by rivers from the main Himalayan ranges located farther north.
● These valleys are covered with thick gravel and alluvium.
● They are almost unbroken chain of low heels except for a gap of 80-90 km which is occupied by the valley of the Teesta river and Raidak river.
● Most of the Dun & Duars are located in this range
● Forests type → Deciduous type forests
Duns
Duns are longitudinal valleys formed as a result of folding when Eurasian plate and Indian plate collided. They are formed between Lesser Himalayas and Shiwaliks. These valleys are deposited with coarse alluvium brought down by Himalayan rivers. These are known as Dun in the west and Duara in the East. Dehra Dun, Kotli Dun and Patli Dun are some of the well-known Duns.
Duns are longitudinal valleys formed as a result of folding when Eurasian plate and Indian plate collided. They are formed between Lesser Himalayas and Shiwaliks. These valleys are deposited with coarse alluvium brought down by Himalayan rivers. These are known as Dun in the west and Duara in the East. Dehra Dun, Kotli Dun and Patli Dun are some of the well-known Duns.
Chhos
The eastern part of Shiwalik range up to Nepal is covered with thick forests whereas forest cover becomes thin in the west. The southern slopes of Shiwalik range in Punjab and Himachal Pradesh are almost devoid of forest cover and directed by seasonal streams. Such areas are locally referred to as Chhos, typical manifestation seen in Hoshiarpur district of Punjab
The eastern part of Shiwalik range up to Nepal is covered with thick forests whereas forest cover becomes thin in the west. The southern slopes of Shiwalik range in Punjab and Himachal Pradesh are almost devoid of forest cover and directed by seasonal streams. Such areas are locally referred to as Chhos, typical manifestation seen in Hoshiarpur district of Punjab
| Name of Shiwaliks | Region |
| Jammu Region | Jammu Hills |
| Dafla, Miri, Abor and Mishmi Hills Arunachal Pradesh | |
| The Dhang Range, Dundwa Range Uttarakhand | |
| Churia Ghat Hills Nepal |