The Himalayas [This Dynamic Earth, USGS] The Himalayas: Two continents collide Among the most dramatic and visible creations of plate-tectonic forces are the lofty Himalayas, which stretch 2,900 km along the border between India and Tibet. This immense mountain range began to form between 40 and 50 million years ago, when two large landmasses, India and Eurasia, driven by plate movement, collided. Because both these continental landmasses have about the same rock density, one plate could not be subducted under the other. The pressure of the impinging plates could only be relieved by thrusting skyward, contorting the collision zone, and forming the jagged Himalayan peaks. About 225 million years ago, India was a large island still situated off the Australian coast, and a vast ocean (called Tethys Sea) separated India from the Asian continent. When Pangaea broke apart about 200 million years ago, India began to forge northward. By studying the history -- and ultimately the closing-- of the Tethys, scientists have reconstructed India's northward journey.

About 80 million years ago, India was located roughly 6,400 km south of the Asian continent, moving northward at a rate of about 9 m a century. When India rammed into Asia about 40 to 50 million years ago, its northward advance slowed by about half. The collision and associated decrease in the rate of plate movement are interpreted to mark the beginning of the rapid uplift of the Himalayas. Artist's conception of the 6,000-km-plus northward journey of the "India" landmass (Indian Plate) before its collision with Asia (Eurasian Plate). Solid lines indicate present-day continents in the Indian Ocean region, but no geologic data exist to determine the exact size and shape of the tectonic plates before their present-day configurations. The dashed outlines for the "India" landmass are given for visual reference only, to show the inferred approximate locations of its interior part in the geologic past. The "India" landmass was once situated well south of the Equator, but its northern margins began to collide against the southward-moving Eurasian Plate about 40 to 50 million years ago (see text).

The Himalayas and the Tibetan Plateau to the north have risen very rapidly. In just 50 million years, peaks such as Mt. Everest have risen to heights of more than 9 km. The impinging of the two landmasses has yet to end. The Himalayas continue to rise more than 1 cm a year -- a growth rate of 10 km in a million years! If that is so, why aren't the Himalayas even higher? Scientists believe that the Eurasian Plate may now be stretching out rather than thrusting up, and such stretching would result in some subsidence due to gravity. Sunset view of towering, snow-capped Mt. Everest, from the village of Lobuche (Solu-khumbu), Nepal. (Photograph by Gimmy Park Li.) Fifty kilometers north of Lhasa (the capital of Tibet), scientists found layers of pink sandstone containing grains of magnetic minerals (magnetite) that have recorded the pattern of the Earth's flip-flopping magnetic field. These sandstones also contain plant and animal fossils that were deposited when the Tethys Sea periodically flooded the region.

The study of these fossils has revealed not only their geologic age but also the type of environment and climate in which they formed. For example, such studies indicate that the fossils lived under a relatively mild, wet environment about 105 million years ago, when Tibet was closer to the equator. Today, Tibet's climate is much more arid, reflecting the region's uplift and northward shift of nearly 2,000 km. Fossils found in the sandstone layers offer dramatic evidence of the climate change in the Tibetan region due to plate movement over the past 100 million years. At present, the movement of India continues to put enormous pressure on the Asian continent, and Tibet in turn presses on the landmass to the north that is hemming it in. The net effect of plate-tectonics forces acting on this geologically complicated region is to squeeze parts of Asia eastward toward the Pacific Ocean. One serious consequence of these processes is a deadly "domino" effect: tremendous stresses build up within the Earth's crust, which are relieved periodically by earthquakes along the numerous faults that scar the landscape.

Some of the world's most destructive earthquakes in history are related to continuing tectonic processes that began some 50 million years ago when the Indian and Eurasian continents first met. The Himalayas | Tectonic Motion: Making the Himalayas | Nature | PBS Tectonic Motion: Making the Himalayas February 11, 2011 The Himalayas are a prime example of how tectonic plate motion can manipulate the earth in extraordinary ways. These colliding plates resulted in the formation of the highest mountain range on the planet. By the Power of My Convections Our continents are carried by a series of tectonic plates located in the earth’s lithosphere. These plates collide with and separate from each other at different rates determined by a process known as convection. Directly below the lithosphere is the inner mantle known as the aesthenosphere. Convection currents are generated in the earth’s inner mantle as molten rock forms from the radioactive decay of elements. As hot gas and liquid is produced it moves upward, displacing the cooler and denser gas and liquid.

As this convection process happens, those circulations push the lithosphere’s plates (and the seven continents that sit on top of them), slowly shifting the globe’s landscape over time. The direction and rate of movement is totally dependent on what kinds of convection currents are at work below. Making the Himalayas: 250 Million Years in 250 words Once, all the world’s landmass was connected, forming one super-continent known as Pangea. Approximately 200 million years ago, tectonic forces broke apart this giant continent into pieces, eventually forming the continents we know today. As convection currents worked independently on the plates associated with these new continental pieces, the plates and their respective continents began to drift across the globe to their present-day geographical locations. Eighty million years ago, India was approximately 6400 km (3968 miles) south of the Eurasian plate. Separating the two was the Tethys Sea. The Indo-Australian tectonic plate – containing the continent of Australia, the Indian subcontinent, and surrounding ocean – was pushed northward by the convection currents generated in the inner mantle.

For millions of years, India made its way across the sea toward the Eurasian plate. As India approached Asia, around 40 million years ago, the Tethys Sea began to shrink and its seabed slowly pushed upwards. The Tethys Sea disappeared completely around 20 million years ago and sediments rising from its seabed formed a mountain range. When India and Tibet collided, instead of descending with the plate, the relatively light sedimentary and metamorphic rock that makes up the subcontinent of India pushed against Tibet, forcing it upwards, and created a massive mountain fold. The Himalayas. This process hasn’t stopped. The Indo-Australian plate is still moving toward Eurasia, still pushing Tibet upwards. The Himalayas continue to rise by an average of 2 cm each year. The highest mountains are only getting higher. More from The Himalayas (6) Where are the Himalayas? | Mountain range in Asia | Himalayan Footsteps Home / Destinations / Where are the Himalayas? Where are the Himalayas? ‹ › Where are the Himalayas?

The Himalayas (or Himalaya) refers to the great mountain range of Asia; sprawling east to west from Afghanistan through Pakistan to India into Nepal, Tibet through Bhutan and ending in Burma. The most easily available access to the best of the Himalayas is in Northern India , Nepal , Tibet , and Bhutan . The Himalayas are home to many of the world’s highest mountains; Everest, K2, Kangchenjunga and Nanda Devi. Size Matters Even though the Himalayas are not the longest mountain range (that title belongs to the Andes), they do have the distinction of being the youngest and therefore, due to less time weathering, the highest mountain range in the world with over 30 peaks higher than 7315 metres/24000 feet. The tallest peak is Mount Everest , known locally in Nepal as Sagarmatha and in Tibet as Chomolungma. Everest is the tallest mountain on earth from sea level at 8848 metres/29028 feet. Still Growing The range began to form between 40 and 50 million years ago, when two large landmasses, India and Eurasia, driven by plate movement, collided.

At present, the movement of India continues to put enormous pressure on the Asian continent, and Tibet in turn presses on the landmass to the north that is hemming it in as a result the Himalayas continue to rise more than 1cm a year. (source: Click here for more about The Himalayas “People ask me, ‘What is the use of climbing Mount Everest?’ and my answer must at once be, ‘It is of no use…oh, we may learn a little about the behaviour of the human body at high altitudes, and possibly medical men may turn our observation to some account for the purposes of aviation. But otherwise nothing will come of it. If you cannot understand that there is something in man which responds to the challenge of this mountain and goes out to meet it, that the struggle is the struggle of life itself upward and forever upward, then you won’t see why we go. What we get from this adventure is just sheer joy. And joy is, after all, the end of life. We do not live to eat and make money. We eat and make money to be able to live.

That is what life means and what life is for.” ― George Mallory, Climbing Everest Geology ~ Geology and Major Structures of the Himalayas The closing and subduction of the Tethyan Ocean, located between India and Asia during the Paleozoic, followed by collision of continents produced the structures and lithologies we see today in the Himalayas. Consequently, the mountains and surrounding regions are characterized by astounding complexity,represented by a variety of deformed and collision-produced lithologies and representing several phases of tectonic and deformational events. The Himalayas can be divided into six primary lithotectonic zones that occur in parallel belts. These zones consist of the Trans-Himalayan batholith, Indus-Tsangpo suture zone, Tethyan(Tibetan) Himalaya, Higher(Greater) Himalaya, Lesser(Lower) Himalaya, and Sub-Himalaya. Tectonic environments within these zones also vary. The emense collision of plates at 45 million years gave rise to an island-arc margin in the western Himalayas and an Andean-type margin in central-to-eastern Himalayan regions (Windley 1995).

Trans-Himalayan Batholith The Trans-Himalaya zone is a linear plutonic complex. It is partly covered by forearc rocks and continental molasse sedimentary rocks. These assemblages are derived from uplift of magmatic rocks and their subsequent erosion. The igneous complex consists of I-type lithologies, including gabbros,diorites, and granites. Formation of the complex is thought to have occured in several phases, between 110 and 40 million years. Partial melting of a subducting NeoTethyan slab beneath the Asian plate is thought to have resulted in these magmas (Sorkhabi 1999). This zone varies in a west-east direction. To the west, plutons were emplaced into an area, called the Kohistan-Ladakh region, and represent an island arc environement. Contrastly, eastern igneous rocks represent an Andean-type environment(Windley 1995). Western Trans-Himalaya An island arc formed on the northern side of the NeoThethys and became trapped in between Asia and India. This allowed for two stages of deformation.

The first consisted of collision of the arc with Eurasia, followed by collision with India, as the Tethys began to subduct under Asia (Windley 1995). The area is dominated by granodiorites and tonalite composed of a quartz+K-spar+biotite+hornblende+ sphene mineral assemblage. U-Pb in monazite and allunite dated the granitic rocks at 60.7 plus or minus 0.04 million years. Late stage bodies of pegmatite and leucogranitic dikes are also present. Pre-collision phases, consisting of felsic intrusions, have been dated by U-Pb in zircon techniques and record a date of 101 plus or minus 2 million years (Searle 1991). Eastern Trans-Himalaya The Kangdese sub-alkaline batholith extends along the north side of the Indus-Tsangpo Suture and represents the Andean style tectonic environment.

Rock types in this zone include slates, phyllites,schists, gneisses, amphibolites, and migmatites of Ordovician-Cretaceous age (Windley 1995). Indus-Tsangpo Suture Zone The Indus-Tsangpo Suture Zone (ITZS) defines the areas of collision between the Indian plate and the Kohistan-Ladakh arc in the western Himalayas and the Tibetan Lhasa block in the east (Windley 1995). It also marks the zone along which the Tethys Ocean was consumed by subduction processes. The ITSZ can be traced for more than 2000km (Searle 1991) between these regions and host a variety of rock types that tell us quite a bit about the orogen. Complete successions of ophiolites occur, some containing diamonds as well, suggesting high pressures during subduction and rapid extrusion along the suture zone. Glaucophane schists also occur in narrow belts along the ITSZ in Pakistan. Olistoliths occur in northwestern India and consist of reef and and continental slope sediments in abyssal tubidite deposits.

Mafic to felsic lavas as well as cherts, serpentinites, and dunites are also observed. Limestones and red sandstones are associated with Tethys Ocean sediments and found in the Ladakh region (Windley 1995). Such a wide variety of rock types along the ITSZ further indicates that the collision of plate boundaries was a complex one, effecting many terraines in many ways. Their one commonality is that this great structure separates Asian lithosphere from the Indian plate. Tethyan(Tibetan) Himalaya The Tethyan Himalayas are located to the south of the ITSZ. They consist of thick, 10-17km, marine sediments that were deposited on the continental shelf and slope of the Indian continent. This occured as India was drifting but still in the southern hemisphere (Verma 1997). Sediments are largely unmetamorphosed, which has made for excellent preservation of fossils and occur in synclinorium-type basins. Some however, have experienced greenschist facies deformation (Windley 1995). Fossils occur in this east-west zone within strata that are very clearly known.

The large variety of size and distribution of fauna suggest that life was flourishing in this area before the orogen. Such success in biological diversity is accounted for by the relatively stationary position of the Tehthyan Zone between mid-Proterozoic and Eocene time. Episodic formation of land barriers enabled life to grow and diversify (Sorkhabi 1999). Higher(Greater) Himalayas The Higher Himalayas are also known as the Central Crystalline zone, comprised of ductily deformed metamorphic rocks and mark the axis of orogenic uplift. Mica schist, quartzite, paragneiss, migmatite, and leucogranite bodies characterize this uppermost Himalayan zone. They represent a multiphase deformation event, the first being Barrovian type, or normal geothermal gradient conditions. There was then a shift to Buchan-type metamorphism, low pressure and high temperature conditions, with temperatures greatly exceeding normal gradient temperatures(Sorkhabi 1999). Local retrograde events have also been noted. Analyses show that peak orogenic temperatures and pressures were 475-825 degrees Celsius and 500-800 megapascals.

Corresponding minerals assemblages are dominated by biotite to sillmanite, representing greenschist to amphibolite facies deformation. Deformation seems to have occured in a north to south direction and is associated with the Main Central Thrust Fault (MCT), which brings the higher Himalayas on top of the lower Himalayas (Sorkhabi 1999). Initially, it was thought that approximately 350km of shortening had occured in the Greater Himalayan sequence of rocks. However, through studies by DeCelles etal. (1998), a major thrust fault within the zone was discovered. As a result, it is now estimated that between 600 and 650km of shortening occured here. There was also a question of provenance for Great Himalayan rocks. Previous work suggested that lower Indian crust comprised this area. New interpretations of rocks there indicate that the higher Himalayas are actually made of supercrustal rock. This idea states that upper crustal material of India accreted northward onto the Asian continent and that crustal material was origanlly an appendage of India that was, itself, accreted to India during Paleozoic time.

This study implies that India probably had significantly more continental crust than previously thought, much more crust to be shortened in the formation of the Greater Himalayas. Lesser(Lower) Himalayas The Lesser Himalayan zone is bounded the Main Central Thrust(MCT) in the north and Main Boundary Thrust(MBT) to the south. Unlike the higher Himalayas, the lessers only experienced up to greenschist facies metamorphism. The rock types present here are also different. They are primarily sedimentary rocks from the Indian platform. Rock units here also show a series of anticlines and synclines that are in many cases quite sheared. Fossils have been documented in this zone, but they do not occur at the same frequency as Tehtyan zone fossils. Main Central Fault (MCT) This thrust fault was first described by Heim and Gansser (1939) when they noted a contact between terrigenous carbonate rocks and thick overlying metamorphic rocks, mica schists and gneiss (Sinha 1987). The Main Central fault marks the boundary between the higher and lesser Himalayan mountains.

It is a longitudinal thrust fault, and in many places is marked by a several kilometer thick zone of deformed rocks with varying degrees of shearing and imbrication (Sorkhabi 1999). Mylonitization and retrograde metamorphic assemblages also occur here. The MCT is the actual suture between Gondwanaland (India) and the Proto-Tehtys microcontinent to the north (Spikantia 1987). Movement along the fault has brought crystalline rock from the Higher Himalayan zone on top of Lesser Paleozoic sediments in the form of klippen in synclines (Windley 1995). These units are called the Outer Crystallines, as noted above on the map. Outer crystalline rocks, garnet and kyanite-bearing, were exposed by slip along the MCT followed by uplift and erosion of 10km of overlying rock (Molnar 1986). Sub-Himalaya This foreland zone consists of clastic sediments that were produced by the uplift and subsequent erosion of the Himalayas and deposited by rivers.

These rocks have been folded and faulted to produce the Siwalik Hills that are at the foot of the great mountains. Sub-Himalayan rocks have been overthrust by the Lesser Himalayas along the Main Boundary Thrust Fault. This steep thrust flattens with depth, dveloped during the Pliocene time and has been shown as active through the Pliestocene (Ni 1984). In turn, the Sub-Himalayas are bounded by a thrust fault to the south and are forced over sediments on the Indian plate. This fault system is called the Himalayan Frontal thrust (Sorkhabi 1999). Another view of Himalyan zones is the following schematic cross section modeled after DeCelles (1998). It not only shows geological divisions within the mountain belt, but also structures and geologic relationships between rock types and structures. It is effective in showing relative motion along faults. Earlham College - Geology 211 - Himalayas The Orogeny of the Himalayan Mountains Introduction The Himalayan Mountains are some of the most beautiful features of nature and are today home to many different groups of people.

The mountains span the countries of India, Nepal, Pakistan, and Tibet in South Asia and are the location of the tallest mountains in the world. The Himalayan Mountains, however, have not always been the natural wonder that they are today. 100 Million years ago, in fact, the whole Indian sub-continent, sans Himalayas, was its own island. Farming the slopes of the Himalayas, Nepal How the Himalayas Formed The present-day continental formations on the world are, geologically speaking, relatively recent formations. 250 Million years ago, the continents were part of one giant super-continent, called Pangea. Due to plate tectonics, the crustal plates of the earth moving independently, pushing and pulling into one another and creating constant geologic activity, the continent of Pangea was ripped apart. The new continents slowly spread around the world creating the continents and oceans that we know today. As a part of this ripping apart, the Indian plate broke off from the bottom of Pangea and began to move northward, toward the larger Eurasian plate. India charged across the ocean at a rate of 10 – 15 cm/ year, an unusually fast rate for crustal plates.

Over the next several million years, the movement of the Indian plate slowly closed the Tethys ocean that had separated India from Eurasia. Approximately 55 million years ago, the Indian plate was heading steadily for the Eurasian plate, and approximatley ten million years ago crashed into it (see diagrams at right). The oceanic crust portion of the plate broke off, and, due to a greater density, was subducted underneath Eurasia and incorporated back into the mantle. The continental crust portion of the plate, however, is less dense. Therefore, it would not easily subduct beneath the greater plate. As a result, the two continents continued crashing into each other, with neither able to sink below the other. This collision is what created the Himalayan Mountain belt. The continental crust here is buckling and piling on top of each other to create the largest mountains on the world today. The Himalayan orogeny took between 40 and 60 million years, and is still continuing. The crust beneath the Himalayan Mountains is between 60 and 780 km thick. This is nearly twice as thick as continental crust over the rest of the world. This thick crust forms what is termed a ‘crustal root’.

This root protrudes downward into the mantle and is important for mountains because the buoyancy of the root allows the mountains to achieve their height. Sunrise in the Himalayas - View from Poone Hill, Nepal The Future of the Himalayas The Indian plate is continuing to crash into the continent of Asia. This is happening at an average rate of 2 cm/year, or 2 meters in the next century. The result of this continuing geologic change is periodic earthquakes in the Himalayas from accumulated energy from collision and the continuing growth of the mountains. It is unlikely, however, that the mountains will rise much farther. At present, the peak of Mount Everest, the tallest mountain in the world, is 29,029 feet (8,848 m) above sea level. Although the collision between India and Asia is continuing, erosive forces are also working on the mountain and wearing down the peaks. In addition, as the mountains continue to rise, their massive weight bears down on the crustal root and the rock that is buried in the crust. As this rock as pressed down into the mantle, it begins to melt and flow slowly, and can be squeezed out to the side, causing the mountain to collapse lower.

Global Positioning Systems (GPS) have been important to the geologic research involving plate tectonics and the India-Eurasia collision. It is GPS data that tell us how quickly the geologic change is happening. Using this data, several theorists have put forth that in the next 10 million years, India will plow forward another 150 - 200 km, roughly the width of the country of Nepal. This means that in 10 million years, Nepal as we now know it may no longer exist due to the powerful geologic forces of our earth. Several scientists also believe that the Himalayan region is due for some very powerful earthquakes to relieve the stress created by collision on the Himalayan arc. It is believed that a large earthquake in this region poses a serious threat for over 50 million people. Mt. Dhaulagiri (above), Mt. Everest (above, right) Mt. Kanchenjunga (above), Mt. Machhapuchhre (above, right) To see more pictures from my trek through the Himalayan Mountains, click here .

Pictures not referenced via links to original website were taken by Marissa Pine, December, 2001 Author: Marissa Pine The Himalaya Mountains, Mount Everest and the Gobi Desert are on which continent? | Poll Everywhere That's an interesting question! Looks like a Poll Everywhere user asked an audience that very same question. You can crowdsource answers, too! We'll walk you through the steps to turn this question into a live poll. After that, you can ask any crowd, anywhere, anytime. Much more fun than asking Google. The Himalaya Mountains, Mount Everest and the Gobi Desert are on which continent? Poll responses are kept private Europe Asia North America Ask your audience a question with the Poll Everywhere app Step 2 Audience answers in real time using mobile phones, Twitter, or web browsers Step 3 See your response live on the web or in a PowerPoint presentation Still have questions? Is Poll Everywhere free? Yes! Free plans for K12 and Higher Ed educators include 40 responses per question, and the free business plan allows 25 responses per question. Paid plans allow more responses per question, along with premium features like moderation, post-event reporting, and a custom URL for your audience response page. Is this legit?

Yup. We invented this live text/web polling bonanza back in 2007. Now over 60% of the Fortune 500 and 100,000 educators use Poll Everywhere to engage everyone. We process millions of audience responses every month. The Geological Society Northward migration of India 225 million years ago (Ma) India was a large island situated off the Australian coast and separated from Asia by the Tethys Ocean. The supercontinent Pangea began to break up 200 Ma and India started a northward drift towards Asia. 80 Ma India was 6,400 km south of the Asian continent but moving towards it at a rate of between 9 and 16 cm per year. At this time Tethys Ocean floor would have been subducting northwards beneath Asia and the plate margin would have been a Convergent oceanic-continental one just like the Andes today. Between 40 and 20 Ma the rate of northward drift slowed as the two continental plates collided and the former Tethys Ocean closed. Neither continental plate could be subducted due to their low density/buoyancy.

This caused the continental crust to thicken due to folding and faulting by compressional forces. The continental crust here is twice the average thickness at around 75 km. The thickening of the continental crust marked the end of volcanic activity in the region as any magma moving upwards would solidify before it could reach the surface. The Himalayas are still rising by more than 1 cm per year as India continues to move northwards into Asia, which explains the occurrence of shallow focus earthquakes in the region today. However the forces of weathering and erosion are lowering the Himalayas at about the same rate. The Himalayas and Tibetan plateau trend east-west and extend for 2,900 km, reaching the maximum elevation of 8,848 metres (Mount Everest). Image: from This Dynamic Earth, by Kious and Tilling. Courtesy of the US Geological Survey. Geology of the Himalayan Mountains Geology of the Himalayan Mountains The collision between the Indian subcontinent and Eurasian continent, which started in Paleogene time and continues today, produced the Himalayas and Tibetan Plateau, spectacular modern examples of the effects of plate tectonics.

Tibetan Plateau itself is a collage of microplates or continental fragments that were successively added to the Eurasian plate during the Paleozoic and Mesozoic eras. Paleomagnetic analysis indicates that these older microplates were in the southern hemisphere during the Paleozoic era. Each older fragment, like the larger Indian Plate, made a long northward journey as the intervening ocean was subducted, and was accreted to the Eurasian continent. The resulting sutures are marked by scattered occurrences of ophiolite, ocean floor material that was caught up between the crustal blocks during accretion. The collision that produced the Himalayas was only the latest, albeit climactic, episode in this long series of collisions. The Indian plate continues to move northward relative to Asia about 5 cm per year. Given the great magnitudes of the blocks of the Earth's crust involved this is a remarkable rate, about twice the speed at which your fingernails grow. This movement caused the rocks along the leading edge of the Indian plate to deform and fracture. Immense slices of Indian crust were pushed southward and stacked up to produce the Himalayan orogen (above figure).

Several distinct sequences of rock are recognized in the Himalayas, separated from one another and rocks of the Indian plate by northward-dipping fault zones. It is these zones that accommodated the huge amounts of crustal shortening as the rock sequences were slid one over another. From north to south, these rock packages and fault zones are the Tibetan Sedimentary Sequence (blue), South Tibetan Detachment Zone (Detachment Fault), Greater Himalayan Sequence (red and pink), Main Central Thrust (MCT) and Maha Bharat Thrust (MT), Lesser Himalayan Sequence (light blue), Main Boundary Thrust (MBT) and Main Frontal Thrust (MFT), and Gangetic Basin of the Indian subcontinent (yellow). NASA's on-line geomorphology book describes the Himalayas and Tibetan Plateau and the associated geology of Afghanistan, Pakistan, western India . Project INDEPTH, which has done seismic profiling across Tibet and the Himalaya, has an interesting, but technical, web page with some great pictures at: . Readings Allegre et al., 1984, Structure and evolution of the Himalaya-Tibet orogenic belt: Nature, v. 307, p. 17-22.

Bilham et al.., 1997, GPS measurements of present-day convergence across the Nepal Himalaya: Nature, v. 386, p. 61-64. Le Fort, 1996, Evolution of the Himalaya, in The Tectonics of Asia, Yin & Harrison (eds.), p. 95-109. Molnar, 1986, The geologic history and structure of the Himalaya: American Scientist, v. 74, p. 144-154. Searle et al., 1987, The closing of Tethys and the tectonics of the Himalaya: Geological Society of America Bulletin, v. 98, p. 678-701. Searle & Treloar, 1993, Himalayaan tectonics - an introduction: in Himalayan Tectonics, Treloar & Searle (eds.), p. 1-7. Schelling, 1992, The tectonostratigraphy and structure of the Eastern Nepal Himalaya: Tectonics, v. 11, p.

925-943. Tapponnier et al., 1986, On the mechanics of the collision between India and Asia, in Collision Tectonics, Coward & Ries (eds.): Geological Society Special Publication, no. 19, p. 115-157. The Himalayas: Two continents collide - WDRB Weather Blog WDRB Weather Blog 05/15/2015 The Himalayas: Two continents collide Among the most dramatic and visible creations of plate-tectonic forces are the lofty Himalayas, which stretch 2,900 km along the border between India and Tibet. This immense mountain range began to form between 40 and 50 million years ago, when two large landmasses, India and Eurasia, driven by plate movement, collided. Because both these continental landmasses have about the same rock density, one plate could not be subducted under the other. The pressure of the impinging plates could only be relieved by thrusting skyward, contorting the collision zone, and forming the jagged Himalayan peaks.

About 225 million years ago, India was a large island still situated off the Australian coast, and a vast ocean (called Tethys Sea) separated India from the Asian continent. When Pangaea broke apart about 200 million years ago, India began to forge northward. By studying the history -- and ultimately the closing-- of the Tethys, scientists have reconstructed India's northward journey. About 80 million years ago, India was located roughly 6,400 km south of the Asian continent, moving northward at a rate of about 9 m a century. When India rammed into Asia about 40 to 50 million years ago, its northward advance slowed by about half. The collision and associated decrease in the rate of plate movement are interpreted to mark the beginning of the rapid uplift of the Himalayas. The 6,000-km-plus journey of the India landmass (Indian Plate) before its collision with Asia (Eurasian Plate) about 40 to 50 million years ago (see text). India was once situated well south of the Equator, near the continent of Australia. The Himalayas and the Tibetan Plateau to the north have risen very rapidly.

In just 50 million years, peaks such as Mt. Everest have risen to heights of more than 9 km. The impinging of the two landmasses has yet to end. The Himalayas continue to rise more than 1 cm a year -- a growth rate of 10 km in a million years! If that is so, why aren't the Himalayas even higher? Scientists believe that the Eurasian Plate may now be stretching out rather than thrusting up, and such stretching would result in some subsidence due to gravity. Sunset view of towering, snow-capped Mt. Everest, from the village of Lobuche (Solu-khumbu), Nepal. (Photograph by Gimmy Park Li.) Fifty kilometers north of Lhasa (the capital of Tibet), scientists found layers of pink sandstone containing grains of magnetic minerals (magnetite) that have recorded the pattern of the Earth's flip-flopping magnetic field. These sandstones also contain plant and animal fossils that were deposited when the Tethys Sea periodically flooded the region. The study of these fossils has revealed not only their geologic age but also the type of environment and climate in which they formed.

For example, such studies indicate that the fossils lived under a relatively mild, wet environment about 105 million years ago, when Tibet was closer to the equator. Today, Tibet's climate is much more arid, reflecting the region's uplift and northward shift of nearly 2,000 km. Fossils found in the sandstone layers offer dramatic evidence of the climate change in the Tibetan region due to plate movement over the past 100 million years. At present, the movement of India continues to put enormous pressure on the Asian continent, and Tibet in turn presses on the landmass to the north that is hemming it in. The net effect of plate-tectonics forces acting on this geologically complicated region is to squeeze parts of Asia eastward toward the Pacific Ocean. One serious consequence of these processes is a deadly "domino" effect: tremendous stresses build up within the Earth's crust, which are relieved periodically by earthquakes along the numerous faults that scar the landscape. Some of the world's most destructive earthquakes in history are related to continuing tectonic processes that began some 50 million years ago when the Indian and Eurasian continents first met.

Information Courtesy the United States Geologic Survey WDRB Meteorologist Jeremy Kappell The Himalayas | Himalayas Facts | Nature | PBS Himalayas Facts View The Himalayas in a larger map Name: Himalayas, Sanskrit for ‘abode of snow’ Geography: The Himalayas stretch across the northeastern portion of India. They cover approximately 1,500 mi (2,400 km) and pass through the nations of India, Pakistan, Afghanistan, China, Bhutan and Nepal. The Himalayan range is made up of three parallel ranges often referred to as the Greater Himalayas, the Lesser Himalayas, and the Outer Himalayas. Ecology: While intimidating mountains like Everest and 2K tend to dominate our perceptions of the region, the Himalayas are rich in biodiversity. Climates range from tropical at the base of the mountains to perennial snow and ice at the highest elevations. These complex and diverse eco-regions are interconnected: an ecological threat to one is ultimately a threat to many. Here are just a few examples of Himalayan ecology: Montane Grasslands and Shrublands: Western alpine shrubs and meadows can be found between 9,850 and 16,400 ft.

These areas tend to have cold winters and mild summers that allow for plant growth. Rhododendron plants cover the lower shrublands, while the alpine meadows, directly above, host a range of flora in the warmer months. Animals found in this region include the snow leopard, Himalayan tahr, musk deer, and pikas.Temperate Coniferous Forest: In the northeast, temperate sub-alpine conifer forests are found at elevations of 8,200 to 13,800 ft. Located in the inner valley area, these forests are protected from harsh monsoon conditions by surrounding mountain ranges. The dominant tree types are pine, hemlock, spruce, and fir. Animals found in this region include red pandas, takins, and musk deer. Temperate Broadleaf and Mixed Forests: Found in middle elevations of 6,600 to 9,800 ft. in the eastern region are broadleaf and coniferous forests. These forests receive almost 80 inches of annual rainfall, mostly during the monsoon season.

In addition to indigenous oaks and maples, plants like orchids, lichen, and ferns also grow in the area. A huge range of wildlife, including over 500 species of birds, are found here during the cooler seasons before they migrate to higher elevations to escape the hot summers. This is also the primary home for golden langur monkeys. Tropical and Sub-tropical Broadleaf Forests: Located at 1,650 to 3,300 ft. along a narrow strip of the outer Himalayan range are the Himalayan sub-tropical broadleaf forests. Here there is a wide range of plant life thanks to the areas varied topography, soil types, and rainfall levels. Forest types include subtropical dry evergreen, northern dry mixed deciduous forests, moist mixed deciduous forests, subtropical broadleaf forests, northern tropical semi-evergreen forests, and northern tropical wet evergreen forests. Wildlife includes many threatened species including tigers and Asian elephants. More than 340 different species of birds can be found in this region.

Highest peak: Mount Everest at 29,029 ft (8,848 m) is not only the highest peak in the Himalayas, but the highest peak on the entire planet. Other famous peaks include Karakora (K2), Kailash, Kanchenjunga, Nanga Parbat, Annapurna, and Manasklu. Rivers: The Himalayas are the source for the Indus, the Yangtze and the Ganga-Brahmaputra. All three are major river systems for the continent of Asia. The main rivers sourced in Himalayas are the Ganges, Indus, Yarlung, Yangtze, Yellow, Mekong, and Nujiang. Glaciers: The Himalayas are the third largest deposit of ice and snow in the world, after Antarctica and the Arctic. There are approximately 15,000 glaciers located throughout the range. At 48 miles (72 km) in length, the Himalayan Siachen glacier is the largest glacier outside the poles. Other notable glaciers located in the Himalayas include the Baltoro, Biafo, Nubra, and Hispur. Additional Facts:

Question: The Himalayas are on which continent?
Answer: Asia