THE HIMALAYAS

THE HIMALAYA DESCRIPTION ITS ORIGIN AND ALL PASSES IN HIMALAYA WITH VERY INTERESTING MAPS & CONCISE ,CAN BE EASILY REVISED.

THE HIMALAYAS

consist of four lithotectonic mountain ranges, namely 

(i) the Trans-Himalaya or the Tethys Himalaya,

 (ii) the Greater Himalaya,

 (iii) the Lesser Himalaya, and

 {iv) lhe Shiwalik orthe Outer Himalaya.

extend from the eastern boundary of Pakistan to the border of Myanmar for about 2500 km with a varying width of about 500 km in the west and about 320 km in the east.
lie to the north of the Ganga-Brahmaputra Plains and are separated from the plains by the Himalayan Front Fault (HFF).
Include parts of Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Nepal, Sikkim, Bhutan and Arunachal Pradesh.
Their offshoots run in a north-south direction along the India-Myanmar boundary through Nagaland, Manipur, and Mizoram.
Origin of the Himalayas
The origin of the Himalayas has been a point of contention among the geologists and geomorphologists.
It is a complex mountain system having rocks from the Pre-Cambrian and Eocene periods. Mostly formed of sedimentary and metamorphic rocks, it has been subjected to intense folding and faulting. 

The main theories about the origin of the Himalaya are as under:
(i) The Geosynclinal Origin
main supporters Argand, Kober and Suess.
led to the formation of a long Tethys Sea between the Lauratian Shield (Angaraland) of the north and the Gondwanaland of the south.

This sea was occupying the region of Himalayas during the Mesozoic Era (l80 m years ago).
At the end of the Palaeozoic and beginning of the Mesozoic Eras, the Tethys almost girdled the whole Earth running from Europe in the west to China in the east Eroded material from the two land masses (Eurasian Shield -Angaraland and Gondwanaland) was deposited in the Tethys Sea and assumed considerable thickness due to the sinking nature of the sea bed.

During the Cretaceous Period, the bed of the sea started rising which led to the folding of three successive ranges of the Himalayas.

The first upheaval led to the formation of the Greater Himalayas during the Eocene Period (about 65 m years back). Similarly, the second upheaval took place during the Miocene Period (about 45 million years back) resulting in the formation of the Lesser Himalayas, and the third upheaval
started in the Pliocene period (about 1.4 million years back) resulting in the formation of the Shiwaliks or the Outer Himalayas.

(ii) The Plate Tectonic Origin of the Himalayas
The theory of Plate Tectonics was put forward by WJ Morgan of Princeton University in 1967.
based on the concept of 'Sea-Floor Spreading' advocated by H. H. Hess.
about 70 or 65 million years ago there was an extensive geosyncline, called the Tethys, in place of the Himalayas.
About 60-30 million years ago the Indian plate came very close to the Asian plate and started subducting under the Asian plate.

caused lateral compression due to which the sediments of the Tethys were squeezed and folded into three parallel ranges of the Himalayas.

estimated that this convergence has caused a crustal shortening of about 500 km in the Himalayan region and is compensated by sea floor spreading along the oceanic ridge in the Indian ocean region.
Since the northward movement of the Indian plate is still continuing, the height of the Himalayan peaks is increasing.

The Indian Plate is moving northward and the center of rotation is constantly changing.
The continent-to-continent collision between the Indian and the Asiatic plates started around 65 million years ago and caused the Himalayas to rise from the Tethys geosyncline.

Thus, the first major phase of uplift in the Himalayas occurred around 65 million years ago.
This orogenic movement elevated the central axis of ancient crystalline and meta-sedimentary rocks which have been intruded by large masses of granite.

believed that the first major phase of uplift initially produced the Ladakh and Zaskar ranges of the Trans-Himalayas before the formation of the Great Himalayas.

Hence, it is to be realized that except the Kashmir part of the Himalayas, the Himalayan ranges have not developed from a geosyncline and are made up of elements formerly connected to the marginal parts of the Indian shield.

During the main Himalayan orogeny, this continuous geosynclinal sedimentation led to the underthrusting of the Indian shield against the Tibetan Massif which buckled down the geosynclinals deposits, resulting in the outflow of a large amounl of ultrabasic rocks known as ophiolites.

These ophiolites are seen as exotic blocks on the Ladakh and Zaskar Ranges of the Trans-Himalayas.
The end effect of the buckling of the geosyncline was not only the crustaline thrust effect on Ladakh and Zaskar leading to their rise as ranges, but also the creation of the sharp tectonic line of the Indus suture along which large geosynclinal areas disappeared.

The intermontane basins in the Indus suture zone of Ladakh continued to receive molasses sedimentation in this period.

The second major uplift which took place around 45 million years ago, caused the rapid uplift of the southern mountain front of the Lesser Himalayas, giving rise to the extremely rugged and youthful Pir-Panjal, Dhauladhar, Karol, and Mahabharat Ranges abruptly and steeply.

The Greater Himalayas and the Lesser Himalayas are separated by the Main Central Thrust (MCT).
These spurs of the Lesser Himalayas again formed, in their tum, the intermontane basins of Kashmir, the Karol-basin, Dun Valley (Uttrakhand) and the Kathmandu Valley of Nepal.

The foredeep which was formed further away received the thick sequence of terrestrial sediments called Shiwaliks from the middle-Miocene to the middle-Pleistocene periods, covering a span ofabout 1.4 million years.

The Lesser Himalayas and the Sbiwaliks are separated from each other by the Main Boundary Thrust {MBT).

The 5000 metres thick Shiwaliks dominated by boulder and conglomerate, reflect the progressive uplift of the Himalayas from which they have been derived as a result of the third major phase of uplift.

The Shiwaliks are separated from the Northern Plains of India by the Himalayan Front Fault or HFF
The Shiwaliks form the normal jura type of structures with wider basin-like synclines alternating with steep, often faulted, asymmetric anticlines.

At present, the Himalayan Front Fault (HFF) is quite active recording frequent tremors and earthquakes .

Physiographic Dhrislons of the Himalayas

For a systematic study of the physiography and relief, the Himalayas may be divided into the following four divisions from north to south:
1. The Trans-Himalayas
2. The Greater Himalayas
3. The Lesser Himalayas
4. The Shiwaliks or the Outer Himalayas.

1. The Trans-Himalayas about 40 km wide.
contain the Tethys sediments.
The rocks of this region contain fossils bearing marine sediments which are underlain by 'Tertiary granite'.
partly metamorphosed sediments and constitutes the core of the Himalayan axis.
a great accumulation of debris in the valleys of defeated streams which could not maintain their southerly course across the rising barrier of the Himalayas.

2. The Greater Himalayas
rise abruptly like a wall north of the Lesser Himalayas.
The Main Central Thrust separates the Greater Himalayas from the Lesser Himalayas.
about 25 km wide with an average height above 5000 metres.
Almost all the lofty peaks of the Himalayas lie in this zone.
composed of crystalline, igneous or metamorphic rocks (granite, schists, and geneiss).
The basal complex of the Himalayas is Archaean.
At places, due to heavy thrust, older rocks are found overlying the newer rocks.
almost a contiguous range.
very few gaps mainly provided by the antecedent rivers.
receive less rainfall as compared to the Lesser Himalayas and the Shiwaliks.
Physical weathering is pronounced.
Erosion is, however less effective over the Greater Himalayas as compared to the Lesser Himalayas.
Being lofty, they have very little forest area..

3. The Lesser Himalayas
about 80 km with an average height of 1300-5000 m.
consists, generally, of unfossiliferous sediments or metamorphosed crystalline.
main rocks are slate, limestone and quartzites.
Along the southern margin of the Lesser Himalayas lies the autochthonous belt of highly compressed Upper Palaeozoic to Eocene rocks, often containing volcanic material.
Examples of autochthonous belts are found between Murree and Panjal thrust in Kashmir, Giri thrusts in the Shimla region and Karol and Main Boundary Thrust (MBT) in Garhwal region.
extensive erosion due to heavy rainfall, deforestation and urbanisation.

4. The Shiwaliks or Outer Himalayas/Sub-Himalayas extend from jammu Division of jammu and Kashmir State to Assam.
In width, Shiwaliks vary from 8 km in the east to 45 km in the west with an average elevation of about1300 m above sea level.
not a continuous range.
broader in the west and narrows down in the east.
Between the Shiwaliks and the Lesser Himalayas are longitudinal valleys called Doons/ Duns.
important Duns are Dehra Dun, Potli, Kothri, Kathmandu, Chumbi and Kyarda.
mainly composed of sandstones, sand rocks, clay, conglomerates and limstones, mostly belonging to the Upper Tertiary Period.
Longitudinal Divisions of the Himalayas
The Himalayas have also been divided by Sir S. Burrard into four divisions, namely (i) The Western Himalayas, (ii) The Kumaun Himalayas, {iii) The Nepal Himalayas, and (iv) The Assam Himalayas. Prof. S.P. Chatterjee (1973), divided the Himalayas into the following six transverse divisions:
1. The Kashmir Himalayas
2. The Himachal Himalayas
3. The Kumaun Himalayas
4. The Sikkim Himalayas
5. The Arunachal Himalayas
6. Purvanchal Himalayas

1. The Kashmir Himalayas about 350,000 sq km in the state of jammu and Kashmir, the range stretches about 700 km in length and 500 km in width.
With an average height of 3000 m, it has the largest number of glaciers in India.
The Ladakh region of the Kashmir Himalayas is characterised by cold desert conditions. Surrounded by the Greater Himalayas and the Lesser Himalayas is the Kashmir Valley.
a structural longitudinal 'Doon' (D.N. Wadia).
A special feature of the Vale of Kashmir is the Karewa (lacustrine) deposits consisting of silt, sand and clay.
These karewas are mainly devoted to the cultivation of saffron and have orchards of apple, peach, almond, walnut and apricot
characterised by high snow covered peaks, deep valleys, interlocked spurs and high mountain passes.
Pir-Panjal, Banihal (Jawahar Tunnel), ZojiLa, Pensi-La, Saser-La, Lanak-La, Jara-La, Taska-La, Chang-La, Umasi-La., and Qara-Tagh-La (Karakoram) are the important passes of the Kashmir Himalayas
The Himadri
Called the abode of gods, this section of the Himalayas has many snow capped peaks, such as Nanda Devi, Kamet and Trishul.

2. The Himachal Himalayas Stretching over Himachal Pradesh, it occupies an area of about 45,000 sq km.
All the three ranges (the Greater, the Lesser and the Outer Himalayas) are well represented in this region.
The northem slopes of the Himachal Himalayas are bare and show plains and lakes, while the southern slopes are rugged and forest clad.
Rohtang, Bara.-Lacha, lmis-La, and Shipki-La are the important passes which join Himachal Pradesh with Tibet (China).
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.
ShimIa, Dalhousie, Chamba, Kullu-Manali are the important hill stations of this region.

3. The Kumaun Himalayas lie between the Satluj and the Kali rivers, stretching to a length of 320 km and occupying an area of about 38,000 sq Jan.
Its highest peak is Nanda Devi (7817 m).
Among the other peaks Kamet (7756 m), Trisul (7140 m), Badrinath (7138), Kedarnath (6940 rn), Dunagiri (7066 m), jaonli or Shivling (6638 m), Gangotri {6615 m), and Bandarpunch (6320 m) are importanl Gangotri, Milam, and Pindar are the main glaciers of Uttarakhand.
The important hill stations include Mussorrie, Nainital, Ranikhet, Almora, and Bageshwar.
The Kumaun Himalayas are connected to Tibet by a number of passes namely, Muling-La (5669 m), Mana Pass, Niti Pass, (5068 m), Tun:Jun-La, Shalsal Pass, Balcha Dhu.ra. Kungrinbingri Pass, Lampiya Dhura, Mangsha Dhura, Marhi-La (4993 m), and Lipu Lekh.

4. The Central Himalayas stretches from river Kali to river Tista for about 800 km occupying an area of about 116,800 sq km.
A major part of it lies in Nepal except the extreme eastern part called Sikkim Himalayas and in the Darjeeling District of West Bengal.
All the three ranges of the Himalayas are represented here.
The highest peaks of the world like Mt. Everest (8850 m), Kanchenjunga (8598 m), Makalu (8481 m), Dhaulagiri (8168 m), Annapurna (8075 m), and Gosainath (8014 m) are situated in this part of the Himalayas.
has very few passes.
The passes of NathuLa and Jelep-La (4538 m in Sikkim) connect Gangtok (Sik.kim) with Lhasa {Tibet, China).
Kanchenjunga:
Situated on the border of Sikkim and Tibet,
the third highest mountain peak in the world.
It is 8,598 metres above sea level and remains snow covered throughout the year.
Some of the important rivers of India like Kosi and Tista have their origin in this mountain.

5. The Eastern Himalayas lie between the Tista and the Brahmaputra rivers, covering a distance of about 720 km with an area of 67,500 sq krn.
The Eastern Himalayas occupy the state of Arunachal Pradesh (India) and Bhutan.
the Himalayas rise very rapidly from the plains of Assam, and the foothills of Shiwaliks are very narrow.
The Eastern Himalaya include the Aka Hills, the Daphla Hills, Miri Hills, Abor Hills, Mishmi Hills, and Namcha Barwa.
has a number of mountain passes among which Bomdi-La, Tse-La, Dihang, Debang (Arunachal Pradesh) are the most important
In the Eastern Himalayas, due to heavy rainfall, fluvial erosion is quite pronounced.
On the southern border of Arunachal Pradesh, the Himalayas take a southerly turn and the ranges are arranged in a north-south direction.
Passing through the states of Arunachal Pradesh (Tirap Division} Nagaland, Manipur, Tripura, and Mizoram, the Himalayas are locally known as Purvachal.
The main hills of the Eastern Himalayas are Patkai-Bum (Arunachal Pradesh), NagaHills (Nagaland), Manipur Hills, Blue Mountains (Mizoram), Tripura Range, and Brail range.
On the border of Nagaland and Myanmar lies the Arakanyoma.
heavily forested.
Northern Myanmar is connected through Diphu, Hpungan, Chaukan, Pangsau, and Likhapani (Arunachal Pradesh).
Southwards, a pass joins Imphal (Manipur) with Mandalay (Myanmar).
The Purvanchal is joined by the Meghalaya Plateau in the west.
The extension of the Myanmar mountain chain continues southward up to Andaman and Nicobar Islands and even up to the Archipelago of Indonesia.
The Syntaxial Bends of the Himalayas
The general east-west trend of the Himalayas terminates suddenly at its western and eastern extremities and the ranges are sharply bent southward in deep knee-bend flextures which are called syntaxial bends.
The western syntaxial bend is near Nanga Prabat where the Indus has cut a deep gorge.
The geological formation here takes sharp hairpin bends as if they were bent round pivotal points obstructing them.
There is a similar hair-pin bend in Arunachal Pradesh where the mountains take a sharp bend from the eastern Lo southern direction after crossing the Brahmaputra river.
The tectonic strike also undergoes a deep k-nee-bend from an easterly to southerly trend.
Main Passes of Himalayas
Aghil Pass (Karakoram-Ladakh):
Situated to the north of K2 in the Karakoram at an elevation of about 5000 m above the sea level,
joins Ladakh with the Xinjiang (Sinkiang) Province of China.
remains closed during the winter season from November to the first week of May
Banihal Pass (Jawahar Tunnel):
Situated at an elevation of 2832 min the Pir-Panjal Range,
it joins Jammu with Srinagar.
The pass remains snow covered during the winter season.
The jawahar Tunnel{named after PanditJawaharlal Nehru), inaugurated in December 1956, was constructed for round-the-year surface transport.
Bara Lacha (Himachal Pradesh with Leh-Ladakh):
Situated in the state of jammu and Kashmir at an altitude of 5045 m.
It is on the National Highway connecting Manali and Leh.
Being a high mountain pass, it remains snow covered from November to mid-May.
Bomdi La (4331 m, Arunachal Pradesh):
Situated to the east of Bhutan in the Greater Himalayas in Arunachal Pradesh at an altitude of about 2600 m above sea level,
it connects Arunachal Pradesh with Lhasa, the capital of Tibet.
It remains closed in the winter season owing to snowfall and adverse weather.
Bunail Pass (Srinagar with Kishan-Ganga Valley):
Situated at an altitude of more than five thousand feet above sea level
this pass connects Ladakh with China.
Being snow covered during the winter season it remains closed for trade and transport.
Chang-La (Ladakh with Tibet):
Situated at an elevation of over 5270 m, it is a high mountain pass in the Greater Himalayas.
The road after Chang-Ia is extremely steep, leading to the small town of tangtse.
The pass has a temple dedicated to Chang-la Baba after whom the pass has been named.
Being snow-covered, it remains closed during the ·winter season.
Debsa Pass:
Situated at an elevation of 5270 m above sea level,
it is a high mountain pass in Greater Himalayas between the Kullu and Spiti districts of Himachal Pradesh.
This pass provides an easier and shorler alternative to lhe traditional Pin-Parbati Pass route between Kullu and Spiti.
Dihang Pass:
Situated in the state of Arunachal Pradesh at an elevation of about 4000 feet
this pass connects Arunachal Pradesh with Mandalay (Myanmar}.
Diphu Pass (Arunachal Pradesh with Mandalay in Myanmar):
Situated in the eastern part of Arunachal Pradesh,
provides an easy and shortest access to Mandalaya {Myanmar).
a traditional pass between India and Myanmar which remains open throughout the year for transportation and trade.
Imis La:
Situated at an elevation of over 4500 m,
this pass provides an easy access between Ladakh and Tibet (China).
It has a difficult terrain, steep slopes, and remains closed during the winter season.
Khardung La:
Situated at an elevation of more than six thousand m above sea level,
it is the highest motorable pass in the country.
The road, however, remains closed during the winter season.
Khunjerab Pass (Karakoram):
Situated at an altitude of more than five thousand feet in the Karakoram Mountains,
it is a traditional pass between Ladakh and the Sinkiang Province of China.
It remains snow covered during the winter season from November to mid-May.
Jelep La (4538 m):
Situated at an elevation of 4538 m above sea level,
this pass connects Sikkim with Lhasa.
It passes through the Chumbi Valley.
Lanak La:
Situated at an altitude of about five thousand metres in the Aksai-Chin (Ladakh),
it connects Ladakh with Lhasa.
The Chinese have constructed a road to connect the Xinjiang (Sinkiang) Province of China with Tibet.
Likhapani (Arunachal Pradesh):
Situated at an altitude of more than four thousand metres above sea level,
the Likhapani Pass joins Arunachal Pradesh with Myanmar.
For trade and transport, it remains open throughout the year.
Lipu Lakh (Uttarakhand):
Situated in the Pithoragarh District,
it connects Uttarakhand with Tibet
The pilgrims for Mansarovar Lake travel through this pass.
Landslides in the rainy season and avalanches in winter create great problems for movement and transportation.
Mana Pass:
Situated at an elevation of .5611 m above sea level in the Greater Himalayas,
it connects Uttarakhand with Tibet.
It remains snow covered for about six months during the winter season.
Mangsha Dhura Pass:
Situated at an elevation of more than five thousand metres in the district of Pithoragarh,
the Mangsha Dhura Pass connects Uttarakhand with Tibet.
The pilgrims for Mansarovar cross this pass. Landslides create great problems for tourists and pilgrims ..
Muling La (Uttarakhand):
Situated north of Gangotri,
this seasonal pass joins Uttarakhand with Tibet.
It remains snow covered during the winter season.
Nathu La (Sikkim):
Nathu La is located on the Indo-China border.
The pass, at 4310 m above sea leveL forms part of an offshoot of the ancient Silk Road.
one of the three trading border posts between India and China. After the 1962 war it was reopened in 2006 .
Niti Pass:
Situated at an altitude of 5068 m above sea level,
the Niti Pass joins Uttarakhand with Tibet
It remains snow covered during the winter season between November and mid-May.
Pangsan Pass (Arunachal Pardesh):
Situated at an elevation of more than four thousand metres above sea level,
this pass connects Arunachal Pradesh with Mandalaya (Myanmar).
Pensi La:
Situated in the Greater Himalayas at an elevation of more than five thousand metres above sea level to the east of Zoji La,
this pass connects the Valley of Kashmir with Kargil (Ladakh).
It remains snow covered from November to mid-May.
Pir-Panjal Pass:
The traditional pass from jammu to Srinagar, this pass lies on the Mughal Road.
After partition of the Subcontinent, the pass was closed down.
provides the shortest and easiest metalled road access from Jammu to the Valley of Kashmir.
Qara Tagh Pass:
Located in the Karakoram Mountains at an elevation of more than six thousand feet above sea level,
this pass was an offshoot of the Great Silk Road.
It remains snow covered during the winter season.
Rohtang Pass:
Located at an elevation of 3979 m above sea level,
this pass connects the Kullu, the Lahul and Spiti valleys of Himachal Pradesh.
It has excellent road access, constructed by the Border Road Organisation (BRO).
Traffic jams are common occurrences caused by the heavy movement of military vehicles, buses, taxis, trucks and goods carriers.
Shipki La:
Located at an altitude of more than 6000 m above sea level·
through the Satluj Gorge, the Shipki-La joins Himachal Pradesh with Tibet.
It remains snow covered during the winter season.
Thang La (Ladakh):
Located at an elevation of 5359 m above sea level, i
a mountain pass in Ladakh (J & K}.
the second highest motora'ble mountain pass in India after Khardung La.
Traills Pass:
Located at an elevation of 5212 m above sea level in the Pithoragarh and Bageshwar districts of Uttarakhand,
it is situated at the end of the Pindari Glacier and links Pindari Valley to Milam Valley.
Being steep and rugged, this pass is very difficult to cross.

Zoji La:
Located at an altitude of 3'850 m above sea level,
it joins Srinagar with Kargil and Leh. Because of heavy snowfall, it remains closed from December to mid-May.

The Border Road Organisation (B RO) has been trying to keep the road open for most part of the year.
Beacon Force of Border Road Organisation (BRO) is responsible for clearing and maintenance of the road during the winter season.
Recently, the Srinagar-Zoji-La Road has been declared a National · Highway (NH-l D) by the centre.
Gladers and Snowline
The lower limit of perpetual snow is known as 'snowline'.
The snowline in the Himalayas has different heights in different parts, depending on latitude, altitude, amount of precipitation, mouisture, slope and local topography.
There are about 15,000 glaciers in the Himalayas lying between the two syntaxial bends in the east and the west.
In the Assam Himalaya, the snowline is about 4400 metres, whereas in the Kashmir Himalayas it varies between 5100 to 5800 metres.
In the Kumaun Himalaya the snowline is about 5200 metres and about 5500 metres in the Karakoram.
On the Tibetan side, the altitude of the snowline is about 900 metres higher owing to great desiccation of the region and scarcity of moisture.
Thus, there is a direct relationship between the presence of moisture and the altitude of the snowline.
In general, more the moisture in the atmosphere, lower the altitude of the snowline and vice versa.
The main glaciers in the northern mountains are found in the Greater Himalayas and the Trans-Himalayan mountains (Karakoram, Ladakh and Zaskar).
The Lesser Himalayas have small glaciers, though traces of large glaciers are found in the Pir-Panjal and Dhauladhar ranges.
Most of the glaciers of the Lesser Himalayas are smaller in size, ranging from 3 to 5 km in length.
There are, however, some larger-sized glaciers also in Karakoram and the Greater Himalayas.
Some of the important glaciers are Siachen {75 km), Sasajni (68 km), Hispara (61 km), Biafo (60 krn), Baltora (58 km) (Karakoram mount.ams).
The Chogo Lungma Glacier (50 km) terminates at an altitude of 2070 m, the lowest recorded in the Himalayas.
In Uttrakhand, Gangotri, Milam and Pind.ari are the main glaciers. The glaciers of Karakoram are the remnants of the Pleistocene Age.
The diurnal rate of movement of these glaciers is between 8 to 15 em at the side and 20 to 30 em in the middle.
The glaciers of the Pir-Panjal are less numerous and smaller in size as compared to those of the Karakoram and the Greater Himalayan ranges.
The longest glacier of the Pir-Panjal is Sonapani glacier in the Chandra Valley of Lahul and Spiti region.
Its length is about 15 km at an altitude of about 4000 m near the Rohtang Pass.
The largest glacier in the NunKun peak is the Gangri Glacier which is about 13 km in length.
The glaciers of the Nanga Parbat Massif are small in size and are moving fast due to a steep slope.
The Chungphar, Rakhiot, Buzhi and Tashan are the other important glaciers of the Pir-Panjal Range.
The glaciers are not only the source of Himalayan rivers, but also maintain a regular supply of water in these rivers during off monsoon period.
The Himalayan glaciers are, however, receding.