Siwalik Hills - AbsoluteAstronomy.com

The Sivalik hills is a mountain range of the outer Himalayas

Himalayas

The Himalaya Range or Himalaya Mountains Sanskrit: Devanagari: हिमालय, literally "abode of snow"), usually called the Himalayas or Himalaya for short, is a mountain range in Asia, separating the Indian subcontinent from the Tibetan Plateau...

also known as Manak Parbat in ancient times. Shivalik literally means 'tresses of Shiva

Shiva

Shiva is a major Hindu deity, and is the destroyer god or transformer among the Trimurti, the Hindu Trinity of the primary aspects of the divine. God Shiva is a yogi who has notice of everything that happens in the world and is the main aspect of life. Yet one with great power lives a life of a...

’. This range is about 2400 km (1,491.3 mi) long enclosing an area that starts almost from the Indus

Indus River

The Indus River is a major river which flows through Pakistan. It also has courses through China and India.Originating in the Tibetan plateau of western China in the vicinity of Lake Mansarovar in Tibet Autonomous Region, the river runs a course through the Ladakh district of Jammu and Kashmir and...

and ends close to the Brahmaputra, with a gap of about 90 kilometres (55.9 mi) between the Teesta

Teesta River

River Teesta or Tista is said to be the lifeline of the Indian state of Sikkim, flowing for almost the entire length of the state and carving out verdant Himalayan temperate and tropical river valleys. The emerald-coloured river then forms the border between Sikkim and West Bengal before joining...

and Raidak

Raidak River

The Raidak River is a tributary of the Brahmaputra River, and a trans-boundary river, flows through Bhutan, India and Bangladesh.-Bhutan:...

rivers in Assam

Assam

Assam , also, rarely, Assam Valley and formerly the Assam Province , is a northeastern state of India and is one of the most culturally and geographically distinct regions of the country...

. The width of the Shivalik hills varies from 10 to 50 km (6.2 to 31.1 mi), their average elevation is 1500 to 2000 m (4,921.3 to 6,561.7 ft).

Other spelling variations used include Shivalik and Siwalik, originating from the Hindi and Nepali

Nepali language

Nepali or Nepalese is a language in the Indo-Aryan branch of the Indo-European language family.It is the official language and de facto lingua franca of Nepal and is also spoken in Bhutan, parts of India and parts of Myanmar...

word 'shiwālik parvat' शिवालिक पर्वत. Other names include Churia hills , Chure hills , and Margalla hills.

Geology

The Sivalik hills are the southernmost and geologically youngest east-west mountain chain of the Himalayas. The Siwaliks have many sub-ranges. They extend from Sikkim

Sikkim

Sikkim is a landlocked Indian state nestled in the Himalayan mountains...

westward through Nepal

Nepal

Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...

and Uttarakhand

Uttarakhand

Uttarakhand , formerly Uttaranchal, is a state in the northern part of India. It is often referred to as the Land of Gods due to the many holy Hindu temples and cities found throughout the state, some of which are among Hinduism's most spiritual and auspicious places of pilgrimage and worship...

, continuing into Jammu

Jammu

Jammu , also known as Duggar, is one of the three administrative divisions within Jammu and Kashmir, the northernmost state in India.Jammu city is the largest city in Jammu and the winter capital of Jammu and Kashmir...

, Kashmir

Kashmir

Kashmir is the northwestern region of the Indian subcontinent. Until the mid-19th century, the term Kashmir geographically denoted only the valley between the Great Himalayas and the Pir Panjal mountain range...

and POK, and are cut through at wide intervals by large rivers flowing south from the Himalayas. Smaller rivers without sources in the high Himalayas are more likely to detour around sub-ranges. Southern slopes have networks of small rills and channels, giving rise to ephemeral streams during the monsoon

Monsoon

Monsoon is traditionally defined as a seasonal reversing wind accompanied by corresponding changes in precipitation, but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea...

and into the post-monsoon season until groundwater supplies are depleted.

The Sivalik hills are chiefly composed of sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

and conglomerate rock formations, which are the solidified detritus of the great range in their rear, but often poorly consolidated. The remnant magnetization of siltstone

Siltstone

Siltstone is a sedimentary rock which has a grain size in the silt range, finer than sandstone and coarser than claystones.- Description :As its name implies, it is primarily composed of silt sized particles, defined as grains 1/16 - 1/256 mm or 4 to 8 on the Krumbein phi scale...

s and sandstones suggests a depositional age of 16-5.2 million years with Karnali River

Ghaghara River

Karnali or Ghaghara is a perennial trans-boundary river originating on the Tibetan Plateau near Lake Mansarovar. It cuts through the Himalayas in Nepal and joins the Sarda River at Brahmaghat in India. Together they form the Ghaghra River, a major left bank tributary of the Ganges. With a length of...

exposing the oldest part of the Siwalik Group in Nepal.

They are bounded on the south by a fault system called the Main Frontal Thrust, with steeper slopes on that side. Below this, the coarse alluvial Bhabhar

Bhabhar

Bhabhar is the region south of the Lower Himalayas and the Siwalik Hills It is the alluvial apron of sediments washed down from the Siwaliks along the northern edge of the Indo-Gangetic Plain.-Etymology:...

zone makes the transition to the nearly level plains. Rainfall, especially during the summer monsoon

Monsoon

, percolates into the bhabar, then is forced to the surface by finer alluvial layers below it in a zone of springs and marshes along the northern edge of the Terai

Terai

The Terai is a belt of marshy grasslands, savannas, and forests located south of the outer foothills of the Himalaya, the Siwalik Hills, and north of the Indo-Gangetic Plain of the Ganges, Brahmaputra and their tributaries. The Terai belongs to the Terai-Duar savanna and grasslands ecoregion...

or plains. This wet zone was heavily malaria

Malaria

Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...

l infested before DDT

DDT

DDT is one of the most well-known synthetic insecticides. It is a chemical with a long, unique, and controversial history....

was used to suppress mosquitoes. It was left forested by official decree by Nepal's Rana

Rana dynasty

The Rana dynasty ruled the Kingdom of Nepal from 1846 until 1953, reducing the Shah monarch to a figurehead and making Prime Minister and other government positions hereditary...

rulers as a defensive perimeter called Char Kose Jhadi (four kos forest, one kos equalling about three km or two miles). Upslope, the permeable geology together with temperatures routinely exceeding 40° Celsius throughout April and May only supports a low, sparse, drought-tolerant scrub forest.

North of the Siwalik belt the 1,500-3,000 meter Lesser Himalayas also known as the Mahabharat Range rises steeply along fault lines. In many places the two ranges are adjacent but in other places structural valleys 10–20 km wide separate them. These valleys are called Duns or Doons

Doon Valley

Doon Valley is a valley located in Sivalik Hills in Uttarakhand, India. It is the location of Dehradun, capital of Uttarakhand state.-Etmology:...

in India, which includes Dehradun, Patli Dun and Kothri Dun, both in Corbett National Park in Uttarakhand

Uttarakhand

, and also Pinjore Dun in Himachal Pradesh

Himachal Pradesh

Himachal Pradesh is a state in Northern India. It is spread over , and is bordered by the Indian states of Jammu and Kashmir on the north, Punjab on the west and south-west, Haryana and Uttar Pradesh on the south, Uttarakhand on the south-east and by the Tibet Autonomous Region on the east...

. In Nepal, these valleys are called Inner Terai
Inner Terai Valleys of Nepal
The Inner Terai Valleys or Bhitri tarai are various elongated valleys in Nepal situated between the Himalayan foothills, the 600–900 m high Siwalik or Churia Range and the 2,000-3,000 m high Mahabharat Range further north. Major examples are the Chitwan Valley southwest of Kathmandu and the...

and include Chitwan, Dang-Deukhuri and Surkhet

Surkhet

Surkhet is a district in the Bheri Zone of the Mid-Western Development Region of Nepal. Birendranagar is the administrative headquarter of Surkhet as well as the whole Mid-Western Development Region...

Pre-history

Sivapithecus
Sivapithecus
Sivapithecus is a genus of extinct primates. Fossil remains of animals now assigned to this genus, dated from 12.5 million to 8.5 million years old in the Miocene, have been found since the 19th century in the Siwalik Hills in what is now India, Nepal, and Pakistan...

(a kind of ape

Ape

Apes are Old World anthropoid mammals, more specifically a clade of tailless catarrhine primates, belonging to the biological superfamily Hominoidea. The apes are native to Africa and South-east Asia, although in relatively recent times humans have spread all over the world...

, formerly known as Ramapithecus) is among many fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

finds in the Siwalik region.

The Siwalik Hills are also among the richest fossil sites for large animals anywhere in Asia. The Hills had revealed that all kinds of animals lived there. They were early ancestors to the sloth bear

Sloth Bear

The sloth bear , also known as the labiated bear, is a nocturnal insectivorous species of bear found wild within the Indian subcontinent. The sloth bear evolved from ancestral brown bears during the Pleistocene and shares features found in insect-eating mammals through convergent evolution...

, Sivatherium

Sivatherium

Sivatherium ' is an extinct genus of giraffid that ranged throughout Africa to Southern Asia . The African species, S...

, an ancient giraffe, Colossochelys atlas, a giant tortoise amongst other creatures.

The remains of the Lower Paleolithic

Lower Paleolithic

The Lower Paleolithic is the earliest subdivision of the Paleolithic or Old Stone Age. It spans the time from around 2.5 million years ago when the first evidence of craft and use of stone tools by hominids appears in the current archaeological record, until around 300,000 years ago, spanning the...

(ca. 500,000 to 1250,000 BP) Soanian

Soanian

The Soanian is an archaeological culture of the Lower Paleolithic in the Siwalik region of the Indian subcontinent. Contemporary to the Acheulean, it is named after the Soan Valley in the Sivalik Hills, Pakistan. Soanian sites are found along the Sivalik region in present-day India, Nepal and...

culture have been found in the Siwalik region. Contemporary to the Acheulean

Acheulean

Acheulean is the name given to an archaeological industry of stone tool manufacture associated with early humans during the Lower Palaeolithic era across Africa and much of West Asia, South Asia and Europe. Acheulean tools are typically found with Homo erectus remains...

, the Soanian culture is named after the Soan Valley

Soan River

The Soan , Sawaan , Sawan or Sohan River is a river in Punjab, Pakistan.- Location and Geography :...

in the Siwalik Hills of Pakistan. The bearers of this culture were Homo erectus
Homo erectus
Homo erectus is an extinct species of hominid that lived from the end of the Pliocene epoch to the later Pleistocene, about . The species originated in Africa and spread as far as India, China and Java. There is still disagreement on the subject of the classification, ancestry, and progeny of H...

.

Demographics

Low population densities in the Siwalik and along the steep southern slopes of the Mahabharat Range, plus virulent malaria in the damp forests on their fringes create a cultural, linguistic and political buffer zone between dense populations in the plains

Indo-Gangetic plain

The northern Plains also known as the Indo - Gangetic Plain and The North Indian River Plain is a large and fertile plain encompassing most of northern and eastern India, the most populous parts of Pakistan, parts of southern Nepal and virtually all of Bangladesh...

to the south and the "hills" beyond the Mahabharat escarpment, isolating the two populations from each other and enabling different evolutionary paths with respect to language, race and culture.

In a few places local tribes such as Van Gujjars, or Gujjars have developed quasi-pastoral

Pastoral

The adjective pastoral refers to the lifestyle of pastoralists, such as shepherds herding livestock around open areas of land according to seasons and the changing availability of water and pasturage. It also refers to a genre in literature, art or music that depicts such shepherd life in an...

livestock

Livestock

Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...

-dependent or shifting agriculture strategies that support some population buildup, with significant environmental costs from deforestation

Deforestation

Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use....

and denudation

Denudation

In geology, denudation is the long-term sum of processes that cause the wearing away of the earth’s surface leading to a reduction in elevation and relief of landforms and landscapes...

Geology

Pre-history

Demographics

See also