The Himalaya and humans are both Cenozoic creatures. The Cenozoic (literally 'new life') is the latest era in Earth's history, encompassing the past 65 million years. By human standards, this is a long period of time, but by the Earth's scale of 'deep time,' it represents merely 1.5 percent of Earth's age (4500 million years). About 65 million years ago, the Mesozoic ('middle life') Era or the Age of Reptiles ended with the extinction of dinosaurs and many other species, and the Cenozoic or the Age of Mammals began.
What is more is that the Himalaya is the youngest mountain on Earth, and geologically speaking, it is still active and still rising to the sky. There are many active faults and numerous earthquakes (some big and many small) in the Himalayan region. Likewise, humans are also the youngest species on Earth, and they are still rising to their human potential, intellectual peaks, and spiritual sky. Just as the rise of the Himalaya has been accompanied by earthquakes and landslides, so has been the development in human's communities associated with changes, crises and challenges.
The Himalaya, the youngest mountain on Earth, did not come into existence all of a sudden. It has taken tens of millions of years for these mountains to form. When the Mesozoic Era began about 245 million years ago, India together with Africa, South America, Australia, and Antarctica were parts of a super-continent in the southern hemisphere called Gondwana. (It was named after the Gond tribes in central India, in whose land the evidence for the existence of the former super-continent was first discovered in the mid-nineteenth century by British geologists working in the Geological Survey of India in Calcutta.)
A vast sea, which geologists have named the Tethys (after the wife of Oceanus in Greek mythology) lay between Gondwana and Eurasia. Gondwana was subsequently split into several major tectonic plates. Gondwana was Mother of four continents (Antarctica, South America, Australia, and Africa) and one subcontinent (India); she was also Mother of the three oceans (the South Atlantic, the Antarctic, and the Indian Oceans) that separate these continents.
The Indian continental plate separated from Gondwana about 120 million years ago, and as it drifted northward, the Tethys ocean became small and smaller because it began subducting beneath the margin of Asia. Ocean-floor rocks (mainly basalt) are heavier than continental rocks (mainly granite); so when they are pushed together, the oceanic floor subducts beneath the continental margin. And in so doing, a magmatic arc made up of volcanic and granitic rocks is produced on the continental margin from the melting and upward rise of the subducting oceanic crust (as it happens today along Indonesia, Japan, and the Andes). This was also the case with the subduction of the Tethys. The volcanic and granitic rocks in Kohistan (in northern Pakistan), Ladakh (in India) and all along southern Tibet (from Kailas through Lhasa to Mishimi hills at the easternmost boundary of the Himalaya) are products of the Tethys subduction. These rocks were formed between 120-40 million years ago. This magmatic range is known as the Trans-Himalaya — a term coined by Alexander Cunningham in his book Ladak (1854). The Trans-Himalaya was extensively explored by the 'Pundits' of the Indian Survey during the 1860s-1890s and by the Swedish geographer Sven Hedin, author of the three-volume book, Trans-Himalaya (1909-1912).
About 50 million years ago, the Tethys ocean completely disappeared, and the Indian continental plate crashed into Asia. 'Suture zone' is the line where two continental plates collide and join each other. The Indus-Tsangpo Suture Zone marks the tectonic boundary of the collision between India and Asia. It was so named by the Swiss geologist Augusto Gansser in the Geology of the Himalaya (1964) because the upper river courses of the Indus and the Tsangpo (Brahmaputra) flow along this suture zone. In the Indus-Tsangpo Suture Zone, we find the remnants of the Tethys oceanic rocks — both volcanic rocks of the oceanic floor and deep-sea sediments of the Tethys. These rocks were not destroyed by subduction but were preserved by uplift along thrust faults. After the collision, the speed of the Indian plate decreased remarkably from 15 to 5 centimeters a year. Nonetheless, India still pushed further north, and as a result, the Earth's crust between India and Asia deformed (by faulting and folding) and uplifted, and the Himalayan mountains began to take shape.
Major faults running through the entire length of the Himalaya (about 2400 km from northwest to northeast) have divided the Himalayan chain into several longitudinal zones. These zones include (from north to south) the Tethys (Tibetan) Himalaya, the High Himalaya, the Lesser (Lower) Himalaya, and the Sub-Himalaya (Siwalik Range).
To the south of the Indus-Tsangpo Suture Zone lies the Tethys Himalaya, which is made up of sedimentary rocks (limestone, shale, and sandstone) deposited on the continental shelf of the Tethys. This zone is also called the Tibetan Himalaya because most of its rocks are exposed in southernmost parts of Tibet. In Pakistan, the Tethys rocks are rarely found because they have been either eroded away or changed (under high temperatures and pressures) into metamorphic rocks. In India, the Tethys rocks are found in Kashmir, Zanskar, Spiti, Chamba, and northern Kumaun. The Tethys rocks are also found all along the northern margin of Nepal (especially in the Annapurna area), Sikkim and Bhutan.
The Tethys sedimentary rocks range in age from the Cambrian through the Eocene periods (from 550 to 50 million years ago). They are abundant in fossils of marine animals; therefore, they provide important information about the evolution of life. One of the most popular Tethys fossils is that of ammonite. The ammonites had coiled shells and came in various sizes (from one centimeter to over one meter). They were free-floating animals in the shallow parts of the Tethys ocean and became extinct (together with the dinosaurs) about 65 million years ago. The Himalayan peoples call the ammonite fossils Shaligrams. Mountain climbers and trekkers can find them in the high mountains, and tourists can purchase them in the low land urban markets. They are much revered by religious people in the Himalaya. Some pilgrims wear the ammonite fossils as amulets, and after passing a high pass, they place the fossils on roadside rocks, thus confusing geologists who find them. For geologists the ammonite fossils are the witnesses of a great ancient ocean, out of which the Himalaya grew. The Tethys wrote her biography in the rocks and fossils, and the story of the Tethys is not only a prologue to the story of the Himalaya but also a record of changes in the life, climate, and geography of our planet during the Paleozoic ('old life') and Mesozoic ('middle life') Eras.
The Himalaya emerged from the ruins of the Tethys. A deep sea gave way to a high mountain. The Tethys closed as an ocean but nothing in nature is terminated for good. Nature is in a flux. The rocks at the bottom of the Tethys ocean now occupy the highest peaks of the Himalaya — on Mt. Everest (Chomulungma), on Nanda Devi, and others. Even the granite peaks of the High Himalaya devoid of the Tethys sediments (such as Manaslu in Nepal and Badrinath in India) were once covered by these sediments but they have been gradually eroded away. It is in the Earth's scheme that not even the Himalaya should last forever. Once erosion exceeds tectonic uplift, mountains wither away — albeit slowly. In the case of the Himalaya, however, this is not going to happen in the near future because the push of the Indian plate will provide the uplifting force for these mountains for millions of years to come: The Himalayan mountains are still young.
Although the Himalayan mountains are young, the rocks forming these mountains are not. We have already seen that the continental shelf rocks of the Tethys date back to the beginning of Cambrian period — almost 550 million years ago. But there are still much older rocks in the Himalaya — the rocks underneath the Tethys shelf rocks are of Pre-Cambrian age. These rocks are now found in the High Himalaya and Lesser Himalaya. Geologists have determined the ages of these granite and granite gneiss rocks by the radioactive dating techniques and have found that they were formed in three major stages — the oldest about 2000 million years ago, some about 1000 million years ago and the others about 500 million years ago. Rocks of similar type (granite and granite gneiss) and of similar ages are also found in peninsular India. The Himalaya is indeed the northern continental margin of India that has deformed (by faulting and folding) and uplifted by tectonic forces. Moreover, the ages 2000, 1000, and 500 million years ago also mark the times of major mountain-building events in a large part of Earth, including India. In other words, the Himalaya is the latest reincarnation of ancient mountains.
Lord Vishnu is believed to have become incarnate ten times. He descended to the earth in ten different forms (avatars) to preserve righteousness in the world. The Himalaya has done the same: Mountains reincarnate to preserve the planet's 'right environment' for life. This Vishnu-Himalaya parallelism has mythological beauty and richness. In Hindu mythology, Himavat is the personification of the Himalayan mountains. He is the father of Ganga, a heavenly river that flew from the toe of Vishnu, but which was brought down to the earth (by the prayers of the sage Bhagirath) to purify the ashes of the dead. To save the earth from the shock of Ganga's fall, Lord Shiva caught the river on his brow and the mat of his hair thus checked Ganga's flow in the Himalaya through seven streams — the Bhagirathi (Ganga proper) rising in Gangotri being one of them. The site where the Ganges enters the plains of northern India is called Haridwar (the gate of Hari or Shiva); in ancient times, people also called it Ganga-dwara (the gate of Ganga). Himavat's younger daughter is variously known as Uma, Himavati, Pravati or Devi, who is also the consort of Shiva. Nanda Devi is attributed to this goddess, while Mount Kailash is considered as Shiva's paradise and Shivling is thought to be Shiva's Lingam (stone phallus). Vishnu himself also has his foot in the Himalaya, close to the Ganges: Kedarnath and Badrinath are attributed to him in several myths. The peaks, valleys, rivers and rocks of the Himalaya have long been perceived as sacred landscape to its peoples, pilgrims, and scholars as well as to it climbers, surveyors and scientists.
The High Himalaya with peak elevations from 3000 m (in the south) to 8000 m (in the north) represents the "backbone" of the Himalaya that was once buried to the greatest depths and then uplifted to the greatest heights. The rocks of the High Himalaya are mostly metamorphic rocks such as gneiss and schist. These rocks were formed from the preexisting rocks (of the Indian continental crust) that were buried deeply and thus subjected to enormous temperatures and pressures. So much so that some of them were melted and became new granite rocks (called 'leuco-granite' or white granite). The metamorphism as well as the formation of the new granite rocks in the High Himalaya took place about 24-20 million years ago — some 25 years after the India-Asia continental collision. The granite rocks of the High Himalaya are all situated along the northern border of the High Himalaya and are in contact with the Tethys Himalayan zone. Most of the high peaks (over 7000 m) of the Himalaya contain this 'granite cores', so to speak. These granites can be easily identified in the field; they are white in colour (due to abundance of quartz and feldspar minerals) and also contain flakes of muscovite (white mica), biotite (black mica) and large crystals of black tourmaline.
The whole of the High Himalaya has been uplifted and moved southward on the back of a major fault called the Main Central Thrust (so named by Augusto Gansser in 1939). This fault marks the southern boundary of the High Himalaya and the northern boundary of the Lesser Himalaya. The rock types in the Lesser Himalaya are more varied, but they are largely sedimentary and metamorphic rocks of Pre- Cambrian age (older than 550 million years). Most of the hill resorts and forests of the Himalaya are situated in the Lesser Himalaya. The southern boundary of the Lesser Himalaya is marked by another major thrust fault — the Main Boundary Fault (named by the British geologist Henry Medlicott in 1864).
About 20 million years ago, as the High Himalaya began to rise, a basin was formed in front of the Himalaya — "the Himalayan foreland basin." And as the Ganga and her sisters fell on the High Himalaya, they eroded the Himalayan rocks and carried them into the basin. The basin was filled with mud, sand and gravel, which were consolidated over time to form mudstone, sandstone and conglomerate. The thick beds of boulder conglomerates occur on top of these sediments; they started shedding from the Himalaya from about 3 or 2 million years ago. These boulder beds indicate that by that time, the Himalayan mountain had become quite high and were close to its foreland basin (rivers deposit boulders close to the mountain).
About 700,000 years ago the Himalaya experienced another remarkable geological event: The Himalayan foreland basin partitioned into a northern and a southern part. The northern part uplifted along a new fault called the Himalayan Frontal Fault (by the Japanese geologist Nakata who studied this fault in 1972). This uplift has formed the Siwalik Range skirting the Lesser Himalaya. The southern part forms the Indus-Gangetic plains of northern India. These plains are covered by the contemporary sediments although all the older sediments that came from the Himalaya are also preserved beneath the recent sediments.
While driving in the Indo-Gangetic plains toward the Himalaya, the traveller first comes across the Siwalik Range, rising suddenly from the plains. These foothills were first studied by Captain Proby Cautley during the 1830s-1850s, when he engineered the construction of the Ganga Canal in order to get water out of the Ganges to irrigate the land lying between the Yamuna and Ganges rivers which frequently suffered from famine. As a result of the surveys and excavations made for the Ganga Canal, a great amount of sedimentary rocks and mammalian fossils were unearthed in the hills. Captain Cautley and his geologist colleague Hugh Falconer studied these rocks and their fossils, and gave the name of 'Siwalik' rocks to them because the important pilgrimage site, Haridwar, was situated on one of these hills.
The Siwalik rocks are quite rich in the fossils of mammals, because the ancient forests in the Himalayan foreland basin were a suitable habitat for many animals including the elephant, tiger, rhino, horse, buffalo, cow, pig, deer and monkey. How about our forest-dwelling human ancestors?
In the lower and middle parts of the Siwalik sediments, there are several ape-like fossils, notably Sivapithecus, Ramapithecus and Gigantopithecus.
Sivapithecus ('Ape of Siva') was described in 1910 by the British geologist Guy E. Pilgrim, and Ramapithecus ('Ape of Rama') was discovered in the early 1930s the American palaeon-tologist ('fossil scientist') G. Edward Lewis in the Potwar plateau (now in Pakistan). Both of these fossils have also been found in the other parts of the Siwalik hills including Kashmir and Nepal. The relationship between Sivapithecus and Ramapithecus has been debated for decades. Both of them had robust jaws, and thick-enamelled chewing teeth. This suggests that they ate hard plants and nuts. Whether Rampithecus was a variety of Sivapithecus (for example, its female form or a smaller variety) or they were two different genera has not been resolved yet although most scientists believe they were the same genus. Fossils of Sivapithecus-Ramapithecus have also been found in East Africa, Turkey, and China. During the 1960s and 1970s, it was widely believed that Ramapithecus was the ancestor to the early hominids that later appeared in East Africa. However, a detailed examination of the Sivapithecus face bones has shown that Sivapithecus-Ramapithecus was the ancestor to the line of the modern orang-utans (interestingly the word 'orangutan' in the Malay language means 'man of the wild').
The oldest fossil of Sivapithecus dates back to 17 million years ago in Africa. In the Siwalik sediments, the Sivapithecus-Ramapithecus fossils date from 15 to 8 million years ago. About 8 million years ago, Sivapithecus and Rampithecus were extinct probably because of environmental changes. They lived in tropical forests interspersed with broad rivers and tree savannahs. By 8 million years ago, the Himalaya and Tibet formed a high topography, the monsoon seasons began, and the climate became cooler and drier; therefore, the tropical forests shrank and grasslands expanded. The tree-dwelling apes were then in trouble.
Gigantopithecus ('Giant Ape'), however, could live on because it could move on ground and go to various places. Gigantopithecus became the ancestor of giant Asian apes (gorilla-like animals but taller and heavier) that lived until about half a million years ago in Asia. Indeed, Gigantopithecus was discovered (and named) in 1935 when the Dutch geologist Ralph von Koenigwald came across its large teeth in Hong Kong (Chinese) drugstores (they were sold as dragon teeth for medicinal purpose). It is possible that the tales and myths of Giants, which are found in Asia (from the biblical book of Genesis saying that, 'there were giants in the earth in those days,' to the Big Foot and Yeti tales of Nepal) were originated when our human ancestors encountered Gigantopithecus creatures.
The bipedal (two-legged) hominids emerged in East Africa about 4 million years ago, and the earliest of these (so far as scientists have discovered) was the genus Australopithecus ('Southern Ape'). Then came Homo habilis ('Handy Human'), which used stone tools. According to fossil evidence, Homo habilis lived between 2.5 and 1.6 million years ago. About 1.8 million years ago, Homo erectus ('Upright Human') appeared. It was this human that came out of Africa and spread to Eurasia. Their fossils have been discovered in China (Peking Man) and in Indonesia (Java Man). Homo erectus peoples used stones, discovered fire, and buried their dead. Although the fossils of Homo erectus have not been discovered in the Siwalik sediments, there are flake stones found in the sediments in the Narmada valley of peninsular India, the foothills of Kashmir (in India), the Jhelum valley and Soan valleys near Rawalpindi (in Pakistan). These sediments (mainly gravel) were deposited over the past one million years.
We owe much of our knowledge of the Kashmir sediments and stone tools to the German geologist Helmut de Terra who studied them in the 1930s. The sediments in Kashmir are particularly interesting because they record a fascinating story of an ancient lake on the bank of which lived the Homo erectus generations, who also witnessed the uplift of the Himalaya and survived the ice ages. These Kashmir sediments, which have been uplifted along the Pir Panjal Range, are known as the 'Karewa' sediments (from the local Kashmiri word, Karewa, meaning terrace). They contain the lake deposits of Kashmir, the moraine (rock debris) of glaciers when they advanced during the ice ages, and the sands and gravels deposited by streams coming into the lake. Many of the paleolithic stone tools found here were made from the volcanic rocks and volcanic glasses (obsidian) commonly found in the Pir Panjal Range.
Homo erectus was the first humankind to come face to face with the Himalaya, to live under the shadow of these high mountains and to benefit from its waters, vegetation, and stones. The modern human species, Homo sapiens ('Wise Human'), evolved from Homo erectus about 200-300 thousand years ago. Some scientists believe that Homo sapiens first emerged in Africa and then spread to other continents (replacing the earlier Homo erectus populations). This is known as the Out of Africa hypothesis. Some other scientists believe that Homo sapiens gradually evolved from Homo erectus in various parts of the world. At present, this issue is hotly debated among the scientists studying the origin of humans. Whatever the future discoveries tell us, one thing is certain: The Himalayan region has been home to humans since time immemorial.
In the 1850s, when British railway builders were looking for ballast to construct the West India Railway (now in Pakistan), they were led by the locals to earth mounds packed with baked-earth bricks. Unaware of the mound's importance, the railway constructors dug up the earth mounds near Harappa and made a solid roadbed for the railway. It was not until the 1920s that archaeologists discovered that the mounds in Harappa and Mohenjo-daro were the remains of a sophisticated Indus Valley civilisation dating back to 5000 years or so. Later, the Indus (Sindhu) gave its name to the country of India. Two of the world's great religions — Hinduism and Buddhism — are deeply rooted in the Himalaya. Two of the world's great epics — the Mahabharat and the Ramayana — have their very setting in the Himalayan region. In the Mahabharat (II:27:3), where the journeys of the Pandavas and victories of Arjuna in the Garhwal Himalaya are described, we find, among interesting observations, the first geologic division of the Himalaya into 'inner mountains,' 'outer mountains,' and 'small mountains,' which probably correspond to the Higher-, Lesser and Sub-Himalaya as were named in the 19th century.
For millennia, the sediments shed from the Himalaya and deposited in the Indo-Gangetic plains have provided fertile fields for agricultural communities on a vast scale, and the Himalayan valleys and riverbanks have supported human settlements. And today, the Himalayan rivers fed by perpetual snow and monsoon rains provide fresh water for more than a billion people in south Asia, nearly one fifth of the world's population. The Himalaya is a water tower in the world, both in terms of water and soil resources, and cultural and spiritual resources.
The story of making the Himalaya (and humans) has not come to an end. As the Indian tectonic plate is moving northward at a rate of about five centimeters each year, the mountains of the High Himalaya are rising at a rate of five millimeters a year. So the uplift of the High Himalaya is about one-hundredth of the motion of Indian plate. This quantitatively unbalanced relationship between India's horizontal movement and the Himalaya's vertical uplift is interesting: It takes a great deal of horizontal movement to achieve a little bit of vertical uplift — on Earth as in human life. Our successes and achievements in life (a vertical uplift whether in our profession or in our spirit) are based on years of routine and disciplined work and a great deal of concentrated and continual effort. Even 'genius,' says Thomas Edison, 'is one percent inspiration and ninety-nine percent perspiration.'
When humans set their feet and eyes on the Himalaya, it is a romantic meeting between the Earth's youngest species and the youngest mountain. As the Himalayan mountains have developed on Earth, the evolution of humans has also been accompanied by the making of an inner Himalaya. Every human has a Himalaya within himself or herself. It is the peak of human potential and challenge as well as a place of silence and peace.
The geologic stories of how the Himalaya and humans overlap in a scientific and cultural setting.