Shiwalik 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.
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.
Dehra Dun in Uttarakhand is the best example
Potli Kothri, Chumbi, Kyarda, Chaukhamba, Udhampur, and Kotli are other important duns.
Middle or Lesser Himalaya or Himachal
In between the Shiwaliks in the south and the Greater Himalayas in the north.
Runs almost parallel to both the ranges.
It is 60-80 km wide and about 2400 km in length.
Elevations vary from 3,500 to 4,500 m
Many peaks are more than 5,050 m above sea level and are snow-covered throughout the year.
Lower Himalayas have steep, bare southern slopes and more gentle, forest covered northern slopes.
In Uttarakhand, the Middle Himalayas are marked by the Mussoorie and the Nag Tibba ranges.
Mahabharat Lekh, in southern Nepal, is a continuation of the Mussoorie Range
East of the Kosi River, the Sapt Kosi, Sikkim, Bhutan, Miri, Abor, and Mishmi hills represent Middle Himalaya
Middle Himalayan ranges are more friendly to human contact
Important ranges of Lesser Himalayas
Pir Panjal – J&K
Dhaola Dhar – Himachal Pradesh
Mussoorie and Nag Tiba – Uttarakhand
Mahabharat Lekh – Nepal
Between Pir Panjal and Zaskar Range lies the valley of Kashmir
The synclinal basin of the valley is floored with alluvial, lacustrine [lake deposits], fluvial [river action] and glacial deposits
Jehlum River meanders through these deposits and cuts a deep gorge in Pir Panjal through which it drains
In Himachal Pradesh, Kangra Valley (strike valley) extends from the foot of Dhaola Dhar Range to the south of Beas
Kulu Valley in the upper course of the Ravi is a transverse valley.
Great Himalayas (Himadri)
Also known as Inner Himalaya, Central Himalaya or Himadri.
The average elevation of 6,100 m and an average width of about 25 km
It is mainly formed of the central crystallines (granites and gneisses) overlain by metamorphosed sediments [limestone]
Folds in this range are asymmetrical with steep south slope and gentle north slope giving hogback topography
Terminates at the syntaxial bends, one in the Nanga Parbat in the north-west and the other in the Namcha Barwa in the north-east.
This mountain range boasts of the tallest peaks of the world, most of which remain under perpetual snow
Regional name of Mount Everest
Sagarmatha – Nepal
Chomlungma – China (Tibet)
Highest picks are
Everest – 8848 m – Nepal
K2 (Godwin Austen) – 8611 m – Karakoram range – PoK
Kangchenjunga – 8586 – India
Lhotse – 8516 m – Nepal
Makalu – 8485 m – Nepal
Mount Everest was first located by George Everest, Surveyor General of India in 1841
The Trans Himalayas
Himalayan ranges immediately north of the Great Himalayan range.
Also called the Tibetan Himalaya because most of it lies in Tibet.
Zaskar, Ladakh, Kailas and Karakoram are the main ranges.
It stretches for a distance of about 1,000 km in the east-west direction.
The average elevation is 3000 m above mean sea level.
The average width of this region is 40 km at the extremities and about 225 km in the central part.
Nanga Parbat (8126 m) is an important range which is in The Zaskar Range.
Kailas Range (Gangdise in Chinese) in western Tibet is an offshoot of the Ladakh Range. The highest peak is Mount Kailas (6714 m). River Indus originates from the northern slopes of the Kailas range.
Northern most range of the Trans-Himalaya in India is Karakoram Range also known as the Krishnagiri
Karakoram Range extends eastwards from the Pamir for about 800 km.
K2 (8,611 m)[Godwin Austen or Qogir] is the second highest peak in the world and the highest peak in the Indian Union.
The Ladakh Plateau lies to the north-east of the Karakoram Range. It has been dissected into a number of plains and mountains [Soda Plains, Aksai Chin, Lingzi Tang, Depsang Plains, and Chang Chenmo]
West to East Division of the Himalayas
Darjeeling or Sikkim Himalaya
Purvanchal or Eastern Hills
Kashmir Himalayas are also famous for Karewa formations and those are famous for the cultivation of saffron, apple, peach, almond etc.
‘Karewas’ in the Kashmiri language refers to the lake deposits, found in the flat-topped terraces of the Kashmir valley and on the flanks of the Pir Panjal range
In Ladakh region, Kashmir Himalaya is characterized by the cold desert condition
Stretching over Himachal Pradesh
The beautiful and highly productive valleys of Kangra, Kullu, Manali, Lahul, and Spiti lie in Himachal Pradesh
These valleys are well known for orchards and scenic beauty.
Shimla, Daihousie, Chamba, Dharaiushala, Kullu-Manali are the important hill stations of this region.
It lie between the Satluj and the Kali rivers
Its highest peak is Nanda Devi (7817 m)
Other important peaks are Kamet (7756 m), Trisul (7140 m), Badrinath (7138), Kedarnath (6940 m) Dunagiri (7066 m), Gangotri (6615 m) are important.
Gangotri, Milam, and Pindar are the main glaciers of Uttarakhand.
Mussorrie. Nainital. Ranikhet. Almora. and Bageshwar are hill stations
It stretches from river Kali to river Tista for about 800 km
A major part of it lies in Nepal except the eastern part called Sikkim Himalaya and in the Darjeeling District of West Bengal. All the three ranges of himalayas are represented here.
The highest peaks of the world like Mt. Everest (8850 m) Kancheniunga (8598 m), Makalu (8.181 m) are situated in this part of the himalayas.
Lesser Himalaya is known as Mahabharat Lekh in this region.
This part of the Himalayas lies between the Tista river in the west and the Brahmaputra river in the east and stretches for a distance of about 720 km.
Also known as the Assam Himalayas, the Eastern Himalayas occupy mainly the areas of Arunachal Pradesh and Bhutan.
Arunachal Himalayas show a marked dominance of fluvial erosion due to heavy rainfall.
Purvanchal or Eastern Hills
Brahmaputra marks the eastern border of Himalayas. Beyond the Dihang gorge, the Himalayas bend sharply towards south and form Purvanchal
They run along the India-Myanmar Border extending from Arunachal Pradesh in the north to Mizoram in the south.
They are mostly composed of sandstones (Sedimentary rocks)
Hills are covered with dense forest
Purvanchal hills are convex to the west
These hills are composed of
Patkai Bum – Border between Arunachal Pradesh and Myanmar
Manipuri Hills – Border between Manipur and Myanmar
Extension of Purvanchal continues in Myanmar and Andaman & Nicobar Islands
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.
Himalayan ranges 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 where the Indus river has cut a deep gorge.
The eastern syntaxial bend occurs near the Namche Barwa.
Importance of Himalayan Region
Influence on Indian Climate
They intercept the summer monsoons coming from the Bay of Bengal and Arabian Sea causing precipitation in the entire Ganga Plains, North-Eastern Hills.
They direct the monsoon winds towards north-western India (Punjab, Haryana etc.. But these regions receive most of the rainfall due to Western Disturbances coming from the Mediterranean regions).
Protect northern-plains from the cold continental air masses of central Asia.
Himalayas influence the path of Sub-tropical Jet stream flowing in the region. They split the jet stream and this split jet stream plays an important role in bring monsoons to India.
Had there been no Himalayas, the whole of India would have been a desert and its winters would have been very severe.
The Himalayas are a natural defense barrier.
But the Chinese aggression on India in 1962 has reduced the defense significance of the Himalayas.
Source of Rivers
Rivers that feed nearly half a billion population of India originate in Himalayas.
The swift flowing rivers from Himalayas bring enormous amount of silt (alluvium) which constantly enrich the Ganaga and Bramhaputra plains.
Due to its natural topography and swift flowing perennial rivers, the Himalayan region offers several natural sites with great hydroelectric power generation potential.
Many hydroelectric power plants have already been constructed.
But all this comes at a great environmental costs.
The Himalayan host rich coniferous and evergreen forests. Lower levels have tropical evergreen forests and higher levels have Alpine vegetation (Coniferous).
The Himalayan forests provide fuel wood and a large variety of timber for industries.
Himalayan forests host wide variety of medicinal plants.
Several patches are covered with grass offering rich pastures for grazing animals.
Due to rugged and sloped terrain, the Himalayas are not potential agricultural sites.
Some slopes are terraced for cultivation. Rice is the main crop on the terraced slopes. The other crops are wheat, maize, potatoes, etc.
Tea is a unique crop which can be grown only on the Shiwalik hill slopes in the region.
Fruit cultivation is a major occupation. A wide variety of fruits such as apples, pears, grapes, mulberry, walnut, cherries, peaches, apricot, etc. are also grown in the Himalayan region.
Himalayan ranges have a large number of tourist spots.
The hilly areas in the Himalayas are not affected by hot winds like loo. Hence they offer cool and comfortable climate.
The increasing popularity of winter sports has increased the rush of tourists in winters.
Srinagar, Dalhousie, Dharamshala, Chamba, Shimla, Kulu, Manali, Mussoorie, Nainital, Ranikhet, Almora, Darjeeling, Mirik, Gangtok, etc. are important tourist centres in the Himalayas.
Himalayas host many Hindu and Buddist shrines.
Kailas, Amarnath, Badrinath, Kedarnath, Vaishnu Devi, Jwalaji, Uttarkashi, Gangotri, Yamunotri, etc. are important places of pilgrimage.
Mineral Resources in the Himalayas
Geosynclinal deposits in tertiary rocks are regions of potential coal and oil reserves.
Coal is found in Kashmir, Copper, lead, zinc, gold, silver, limestone, semi-precious and precious stones occur at some places in the Himalayas.
But the exploitation of these resources requires advanced technologies which are not yet available.
Also, disturbing such a fragile environment leads to more pain than gain (present hydroelectric power projects have already proved this).