The origins of the Himalayas have been debated by a number of academics. O.H.K. Spate, D.N. Wadia, M.S. Krishnan, S. Burrard, E.H. Pasco, G.E. Pligrim, de Terra, T.T. Paterson, T. Hagen, Auden, A. Heim and A. Gansser, Wagner, and a slew of others are prominent among them. There is almost universal agreement that the Himalayan Mountains arose from a vast geosyncline known as the Tethys Sea, and that the uplift occurred in stages. Divergent viewpoints have been stated, however, on the process and timing of elevation, as well as the forces responsible for such massive uplift. The following is the consensus that has formed from many researchers' perspectives:

The layout of continents and oceans 120 million years ago was significantly different from what it is today. Pangaea was a supercontinent that existed at the time. Laurasia or Angaraland was the name given to the northern half of the continent, which included what is now North America and Eurasia (Europe and Asia). South America, Africa, South India, Australia, and Antarctica were all part of Pangaea's southern hemisphere. Gondwanaland was the name given to this landmass. The Tethys Sea, which ran between Laurasia and Gondwanaland, was a long, narrow, and shallow sea. Rivers carried sediments from these landmasses and deposited them on the seabed. Because of the southerly movement of Angaraland or the northward movement of Gondwanaland, these sediments were subjected to intense compression. The majority of experts believe that the northward movement of Gondwanaland caused compression in the sediments at the Tethys Sea's floor. Whether Angaraland went south, Gondwanaland moved north, or both moved towards one other, the net result was the same: the Tethys Sea sediment was squeezed and crushed, and a series of folds formed one after the other, giving birth to the world's tallest relief features - the Himalayas. The maximal push offered at two extremities of the Indian Peninsula during its northward drift is ascribed to the Himalayas' curving shape, which is convex to the south. The Aravalis in the northwest and the Assam ranges in the northeast did it, functioning as two extended arms pushing out the extremities while the core section sank, giving the Himalayas an arcuate shape. According to recent studies, India is moving north at a rate of roughly 5 cm per year, colliding with the rest of Asia and bending the Himalayas between Angaraland and Gondwanaland.

It's vital to remember that the Himalayas are made up of at least three separate ranges that run more or less parallel to one another. As a result, the Himalayas are thought to have arisen in three phases from the Himalayan Geosyncline, i.e. the Tethys Sea, one after the other. The Great Himalayas were formed about 120 million years ago, marking the start of the first phase. The development of the Great Himalayas, according to some geologists, was completed some 70 million years ago. The Middle Himalayas were formed about 25 to 30 million years ago, in the second phase. The Shiwaliks were produced during the latter stages of the Himalayan orogeny, between two and twenty million years ago.

The diastrophic motions that helped construct the Himalayas began in the late Cretaceous and lasted through the Eocene, Middle Miocene, Pliocene to the lower Pliocene, and then into the upper Pleistocene to sub-Recent eras. There is evidence that the Himalayan uplift process is not yet complete, and that they are continuously rising. The Himalayas are still rising, according to the heights measured at several locations using trigonometrical methods. The average elevation of the Himalayas was 2,440 m above sea level around a million years ago, according to Godwin Austen's estimations, and has now increased to 3,050 m. The Mahabharat range is still undergoing significant uplift. The evidence that the Himalayas are continuing rising is as follows:

• Some of the Shiwalik hills' fossil deposits can also be found on the Tibetan plateau. It suggests that the Tibet plateau's past climate was comparable to that of the Shiwalik hills, and that the plateau's elevation was nearly identical to that of the current Shiwalik hills, and that the plateau has since risen to its current elevation.
• The fact that earth quakes occur often in the Himalayan region indicates that the Himalayas have not yet reached isostatic equilibrium and are continuously rising.
• The Himalayan Rivers are still in their youthful stage and have been rejuvenated in recent times. This is another proof of rising trend in the Himalayas. Terraces found at the valley sides suggest rejuvenation of the valley region due to uplift.

100 metres above the current water level are visible, indicating that the water level was significantly higher until recently. Only in the event of an area might this be accomplished. The Himalayas are currently rising at a pace of 5 to 10 centimetres per year.

1. Plate Tectonics:

Plate tectonics is the most modern and widely accepted theory that provides the most satisfactory solutions to complex and perplexing problems about the genesis of continents and oceans, mountain development, earthquake occurrence, and volcano eruptions. Harry Hess (1960), R.S. Dietz (Global Tectonics 1961), W.J. Morgan, and Le Pichon are credited with introducing this theory (Sea Floor Spreading and Continental Drift, 1968). Plate tectonics is a global dynamics theory in which the lithosphere is thought to be divided into a series of independent plates that move in response to upper mantle convection. A plate is a 100-kilometer-thick slice of lithosphere that floats on the underlying asthenosphere and moves independently of other plates. It consists of the rigid upper mantle, as well as oceanic and continental crust. The plates' edges are hotbeds of geological activity, including sea-floor spreading, volcanic eruptions, earthquakes, crustal deformation, mountain development, and continental drift. Plate borders are classified as (a) constructive, (b) destructive, and (c) conservative.

1. Constructive boundaries represented zones of ‘diverging margins’. In this case two plates move away from each other.
2. Destructive boundaries are also known as ‘converging margins’. In this case, two plates move towards each other, converge and in the process one plate overrides the other. The overridden plate is subducted and goes under the asthenosphere and is lost or consumed.
3. Destructive boundaries are also known as ‘converging margins’. In this case, two plates move towards each other, converge and in the process one plate overrides the other. The overridden plate is subducted and goes under the asthenosphere and is lost or consumed.

It is at the converging plate boundary that folded mountains such as the Himalayas form. The denser plate is subducted beneath the lighter plate when two convergent plates made up of continental crusts clash. The lateral compression that results squeezes and folds the sediments deposited on each side of the continental plate borders, as well as the sediments of the geosynclines that lie between them.

The Himalayas are the result of this activity on the convergence zone of the Asiatic and Indian plates in the north and south, respectively. The Indian plate began to move towards the Asian plate around 70 million years ago, and the Tethys Sea began to contract as the Indian and Asian plates moved closer to each other. Because the Indian plate is denser than the Asian plate, the former began to subduct beneath the latter, creating lateral compression of the marine sediment on the Tethys bed. According to geologists, the material was folded in three periods, resulting in three major Himalayan ranges. Although the process of the Indian plate migrating towards the Asian plate and the development of the Himalayan ranges was mostly accomplished some 10 million years ago, it is thought that the Indian plate is continuously moving northwards and the Himalayas are still rising. In the preceding paragraphs, evidence of a rise in the Himalayas was already mentioned.

According to recent studies, the Himalayan region has experienced a crustal shortening of around 500 kilometres due to the convergence of the Indian and Asian plates. The sea floor spreading along the Indian Ocean's oceanic ridge has compensated for this shortening. The height of the Himalayan mountains is increasing with the passage of time as the Indian plate continues to shift northward. The Indian plate is still advancing northward at a rate of around 5 centimetres each year, according to estimates. As a result of this movement, a new fracture has emerged on the Shiwalik hills' outer edges, separating them from the Ganga Plain. According to geologists, a new mountain chain will grow in the Ganga basin, pushing the region's rivers to migrate south. This obviously shows that the Himalayan upheaval is not yet complete and will continue for some time to come.

 

 

 

 

 

 

 

 

 

 

Physiographical Division of the Himalayas:

Geographers generally tend to divide the Himalayas on geographical, regional and geological bases. Geographically the entire Himalayan region can be divided into:

(1) The Himalayan Ranges; (2) The Trans- Himalayas and (3) The Eastern Hills

1. The Himalayan Ranges:

The Himalayas are made up of a number of mountain ranges that are more or less parallel or converging. Deep valleys separate these mountain ranges. The Himalayan, like all juvenile fold mountains, has a heavily dissected "ridge-and-valley-topography." The valleys of Kashmir and the Karewas, Kangra and Kulu valleys in Himachal Pradesh; the Dun valley; the Bhagirathi valley (near Gangotri) and the Mandakini valley (near Kedarnath) in Uttarakhand; and the Kathmandu valley in Nepal are the most notable valleys in the Himalayan region. Individual ranges have a strong slope to the south but a much milder slope to the north. The Himalayas rise abruptly from the plains of Bengal and Oudh in the eastern part, reaching considerable heights within a short distance from the foot of the mountains. As a result, the peaks of Kanchenjunga and Everest are only a few kilometres away from the plains and can be seen plainly from there. The western Himalayas, on the other hand, climb gradually from the plains through a series of ranges. Their snow-capped peaks are 150 to 200 kilometres from the plains. The Himalayan mountains are mostly found in India, Nepal, and Bhutan, but the northern slopes are partly in Tibet, while the western extremity is found in Pakistan, Afghanistan, and Central Asia. The Himalayas are made up of at least three parallel ranges that go from the Indo-Gangetic plain to the Tibet plateau.

(A) The Shiwalik Range:

The Shiwalik, commonly known as the Outer Himalayas, is the Himalayan range's outermost range. It has a hogback appearance due to its steep southern slopes. The main features of this range include flat scarps, anticlinal crests, and synclinal valleys. This chain of hills, which runs almost parallel to the lesser Himalayas for a distance of about 2,400 km from the Potwar plateau to the Brahmaputra valley and overlooks the Great Plain, runs almost parallel to the lesser Himalayas for a distance of about 2,400 km from the Potwar plateau to the Brahmaputra valley. The Shiwaliks range in breadth from 50 kilometres in Himachal Pradesh to fewer than 15 kilometres in Arunachal Pradesh. Except for a break of 80-90 kilometres filled by the Tista River valley, it is a nearly uninterrupted series of low hills. The Tista and Raidak gorges have joined to produce a gap in the Shiwalik mountain that is 80-90 kilometres wide. The elevation ranges from 600 to 1500 metres. The Shiwaliks are made up of a thick layer of Miopleistocene sands, gravels, and conglomerates carried in by rivers flowing from the Himalayan upper peaks. Earth motions from the Middle Miocene to the lower Pliestocene eras folded, faulted, and indurated these rocks. The Shiwaliks were clearly developed last of all the ranges. In different parts of the country, the Shiwaliks are known by different names. In Jammu, they are known as Jammu Hills, whereas in Arunachal Pradesh, they are known as Dafla, Miri abor, and Mishmi Hills.

The Dhang Rang, Dundwa Range (Uttarakhand) and the Churia Ghat Hills of Nepal also form part of the Shiwalik range.

Because the Shiwalik Hills arose after the Himalayas, they hinder the flow of rivers draining from the Himalayas' upper peaks, resulting in the formation of temporary lakes. The debris carried by the rivers was deposited in these bodies of water. The lakes were drained away as the rivers carved their paths through the Shiwalik Range, creating plains known as 'duns' or 'doons' in the west and 'duars' in the east. The best example of such a plain is Dehra Dun in Uttarakhand, which is 75 kilometres long and 15-20 kilometres wide. Boulders and clay deposits cover the area. Other duns include Kotah, Patli Kothri, Chumbi, Kyarda, and Chaukhamba. The expansive gorgeous duns of Udhampur and Kotli in the Jammu hills are incredibly beautiful.

Thick woods dominate the eastern half of the Shiwalik range up to Nepal, although the forest cover thins out towards the west. In Punjab and Himachal Pradesh, the southern slopes of this range are nearly completely devoid of forest cover, and are heavily dissected by multiple seasonal streams known locally as Chos.

(B) The Middle or the Lesser Himalaya:

The Middle Himalaya runs virtually parallel to both the Shiwaliks and the Great Himalaya in the south and the Great Himalaya in the north. It is also known as the Himachal Pradesh or the Lower Himalaya. It features a complex system of mountains that are 60-80 km broad and varies in elevation from 3,500 to 4,500 metres above sea level. Locally linear longitudinal ranges have also formed, with steep, barren southern slopes and gentler, forested northern slopes, giving these ranges a hogback appearance, which is more evident here than in the Shiwalik. Many summits rise beyond 5,050 metres above sea level and are snow-covered all year. The Pir Panjal, Dhaola Dhar, Mussoorie range, Nag Tiba, and Mahabharat Lekh are among the notable ranges covered. In Kashmir, the Pir Panjal range is the longest and most important range. It stretches 300-400 kilometres from the Jhelum River to the upper Beas River, and is separated from the Zaskar Range by the Kashmir Valley. It reaches elevations of 5,000 metres or higher and is largely made up of volcanic materials. The Pir Panjal pass (3,480 m), Bidil (4,270 m), Golabghar pass (3,812 m), and Banihal pass are the most well-known passes in the Pir Panjal range (2,835 m). The Jammu-Srinagar highway and the Jammu-Baramula railway both travel via the Banihal pass. This range is traversed by the Kishanganga, Jhelum, and Chenab rivers. The Pir Panjal continues south-east of the Ravi as the Dhaola Dhar range, passing through Dalhousie, Dharmashala, and Shimla. This is the Middle Himalayas' southernmost range, with altitudes rarely exceeding 4,000 metres.

The famed Kashmir valley runs for about 135 kilometres in a south-east to north-west direction between the Pir Panjal and the Zaskar Ranges of the major Himalayas. In the middle of the valley, it is around 40 kilometres wide. It has a total area of 4921 square kilometres and an average elevation of 1,585 metres above sea level. The origin of this valley is a point of contention among geographers and geologists. Wadia believes the Kashmir valley is a synclical basin bounded by the Pir Panjal to the north and the Himalayan slope, while de Terra believes it is a newly depressed intermont basin with indications of faulting. However, it is widely assumed that during the Pleistocene epoch, this basin was occupied by a lake. The Kashmir valley was formed when this was filled with sediment and raised. The Jhelum River meanders majestically through the synclinal basin of the valley, which is carpeted with a variety of alluvial deposits, including lacustrine, fluvial, and fluvioglacial, before entering the deep canyon it has cut through the Pir Panjal. Kangra Valley is located in Himachal Pradesh. It is a strike valley that stretches from the Dhaola Dhar Range's foothills to the south of Beas. The Kulu Valley, on the other hand, is a transverse valley in the Ravi's upper course.

The Mussoorie and Nag Tibba ranges represent the start of the Middle Himalayas to the east. The Mussoorie range, which stretches 120 kilometres from Mussoorie to Lansdowne, has an average elevation of 2,000-2,600 metres. The significant hill stations of Mussoorie, Nainital, Chakrata, and Ranikhet are located between 1,500 and 2000 metres above sea level. The Mahabharat Lekh is a continuation of the Mussoorie Range in southern Nepal. Its tops reach 3000 metres above sea level, while its average elevation ranges from 1,500 to 2,000 metres. The Kathmandu Valley, to the north, is a major feature of this region. The lower Himalayas are represented by the Sapt Kosi, Sikkim, Bhutan, Miri, Abor, and Mishmi hills east of the Sun Kosi River.

The Middle Himalayan ranges, on the whole, are less harsh and more welcoming to human contact. Shimla, Mussoorie, Ranikhet, Nanital, Almora, and Darjelling, among other Himalayan hill resorts, are all located here.

(C) The Great Himalaya:

Inner Himalaya, Central Himalaya, or Himadri are all names for this region. The Himalayan ranges' northernmost or innermost range is this one. This is the world's loftiest and most continuous mountain range, with an average elevation of 6,100 metres above sea level and a breadth of around 25 kilometres. It's around 150 kilometres from the northern edge of Northern India's plains. It is mostly made up of central crystalline (granites and gneisses) sediments that have been metamorphosed. This range has asymmetrical folds, with a sharp south slope and a mild north slope, resulting in 'hogback' morphology. This convex-to-the-south mountain arc suddenly ends at the Nanga Parbhat in the north-west and the Namcha Barwa in the north-east.

This mountain range has the world's tallest peaks, the most of which are always covered in snow. There are several summits that rise above 8,000 metres. Mount Everest, at 8,850 metres above sea level, is the tallest. Sagarmatha is its Nepalese name, which means "Goddess of the Sky." Chomlungma is the Tibetan name for it. This sky-touching mountain, located at 27⁰ 59^/ 6^// N latitude and 86⁰ 55^/ 46^// E longitude, was initially discovered in 1841 by Sir George Everest, the then Surveyor General of India, and was established as the world's highest peak by the Great Trigonometrical Survey of India in 1852. Mount Everest was given the name in 1865 as a homage to Sir George Everest.

It was previously known as peak XV. The Chinese, on the other hand, want the peak to be known as Qomolangma, which means "Mother of the World." Officials from the Qing dynasty, according to China, charted this mountain in 1717. Kanchenjunga, Lhotse, Makalu, Dhaulagiri, Manaslu, Cho Oyu, Nanga Parbat, Annapurna, Gosainthan, or Shisha Pangma are the other notable peaks in descending order of altitude. Nanda Devi, Kamet, Namcha Barwa, Gurla Mandhata, Badri Nath, Trishul, and others are among the major peaks between 7,100 and 8,000 metres in elevation.

Because the passes are often higher than 4,570 metres above sea level and snowbound for the majority of the year, this range is difficult to cross even through the passes. The main passes over the Great Himalaya include the Burzil pass and the Zoji La in Jammu and Kashmir, the Bara Lacha La and the Shipki La in Himachal Pradesh, the Thaga La, the Niti Pass, and the Lipu Lekh pass in Uttarakhand, and the Nathu La and the Jelep La in Sikkim. The Hindustan- Tibet Road crosses across the Shipki La on its way from Shimla to Gartok in Western Tibet. Jelep La is another key commercial route connecting Kalimpong (near Darjeeling) and Lhasa, Tibet (4,386 m).

2. The Trans Himalayas:

The Trans Himalayas are the Himalayan ranges immediately north of the Great Himalayan range. Because the Tibetan Himalaya comprises the majority of the Himalayan ranges, it is also known as the Tibetan Himalaya. The primary ranges of the Trans Himalayan system include the Zaskar, Ladakh, Kailas, and Karakoram. It spans across around 1,000 kilometres east-west and has an average elevation of 3000 metres above sea level. The region's average breadth is 40 kilometres in the east and west, and around 225 kilometres in the middle.

Near 800E longitude, the Zaskar Range splits from the larger Himalayan Range and travels more or less parallel to it. In the north-west, the Nanga Parbat (8126 m) reaches its apex, but the neighbouring Deosai Mountain may also be included. The Ladakh Range is located north of the Zaskar Range and runs parallel to it. It stretches for around 300 kilometres and rises to an average elevation of 5800 metres above sea level. Only a few peaks in this range reach elevations of more than 6000 metres. Beyond the Indus, the Rakaposhi-Haramosh Ranges can be considered extensions of the Ladakh Range to the northwest. The Kailas Range (Gangdise in Chinese) is a branch of the Ladakh Range in western Tibet.

It has an average elevation of 5,500-6000 metres above sea level and a breadth of 30 kilometres. Mount Kailas is the highest point in the area (6714 m). The Indus River originates on the Kailas range's northern slopes. The Great Karakoram Range, also known as the Karishnagiri Range, is India's northernmost Trans Himalayan Range. It acts as a watershed between India and Turkistan, forming India's border with Afghanistan and China. It stretches for around 800 kilometres east of the Pamir. This range is 120-140 kilometres wide on average. It's a high-altitude range with peaks that rarely drop below 5,500 metres. Outside of the Polar Regions, it is the above of some of the world's largest glaciers.

Some of the summits reach altitudes of over 8,000 metres. K2 (8,611 m) is the world's second highest peak and the tallest peak in the Indian Union, rising magnificently in the shape of a cone. The British have given it the name Mt Godwin Austen, and the Chinese have given it the name Qogir. The Gasherbrum I or Hidden Peak (8,068 m), Broad Peak (8,047 m), and Gasherbrum II are the other peaks in the area that rise above 8,000 m above sea level (8,035 m). Another 19 peaks in Karakoram that cross the 7,600 m mark have yet to be identified.

The Karakoram Range is to the north-east of the Ladakh Plateau. It is the highest plateau in the Indian Union, with an average elevation of over 5,000 metres above sea level. It is divided into several plains and mountains, the most notable of which are the Soda Plains, Aksai Chin, Langzi Tang, Depsang Plains, and Chang Chenmo.

3. The Eastern hills or The Purvanchal:

The Himalayas abruptly turn southward after crossing the Dihang gorge, forming a series of comparatively low hills in the shape of a crescent with its convex side pointing west. Because they are in the eastern part of India, these hills are collectively known as the Purvanchal. They stretch from Arunachal Pradesh in the north to Mizoram in the south, along India's Myanmar border. These hill ranges differ significantly from the Himalaya in terms of relief and morphology, but they all stem from the same orogeny.

The Patkai Bum forms the international border between Arunachal Pradesh and Myanmar in the north. It is composed of solid sandstone and rises to a height of 2,000 to 3,000 metres. It connects with the Naga Hills after a short distance southwards, with Saramati (3,826 m) being the highest peak. The watershed between India and Myanmar is formed by the Patkai Bum and Naga Hills. To the west, the Kohima hills are made of sandstone slate and have a very rough topography. South of Naga Hills are the Manipur hills which are generally less than 2,500 metres in elevation. They are Manipur's and Myanmar's shared border. Naga Hills and Manipur Hills are separated by the Barail mountain. The Barail Range continues south into the Jaintia, Khasi, and Garo Hills, which are an eastward continuation of the Indian peninsular block divided by the Bengal Basin. The Mizo Hills (formerly known as the Lushai Hills) are located south of the Manipur Hills and have an elevation of less than 1,500 metres. The Blue Mountain (2,157 m) in the south is the highest peak. It is obvious that the elevation of the eastern hills decreases as we move from north to south. The rugged terrain, dense forests, and fast streams make these hill ranges feel foreboding, despite their low elevation.