The Himalayas
Say…
How did we form? Ok, we’ll give you a short blurb
First India, it kicked Gondwana to the curb
Then its drift across the ocean
Set our future birth in motion
When Asia’s coast it did encounter and perturb
TIMELINE
252 million BC
Mesozoic era starts
The Mesozoic era starts and the Paleozoic era ends
145 million BC
Cretaceous period starts
The Cretaceous period starts. This is the third, final, and longest period of the Mesozoic era. The Jurassic period ends.
Credits: Diorama by Masato Hattori
Map from the Deep Time Maps collection, courtesy of Colorado Plateau Geosystems, Inc.
120 - 100 million BC
India breaks away from Gondwana
Himalaya-formation,
marked as public domain,
more details on Wikimedia Commons
66 million BC
Cenozoic era starts
The Cenozoic era starts. This is the era in which we currently live. This is also the point at which the Mesozoic era ends.
Angiosperms are the dominant plants on land. Their reproductive structures are flowers. They produce fruit, which holds their seeds; and they reproduce by pollination.
66 million BC
Paleogene period starts
The Paleogene period starts. This is the first period of the Cenozoic era. This is also the point at which the Cretaceous period ends.
Credits: Diorama by Aldo Chiappe, courtesy of National Geographic
Map from the Deep Time Maps collection, courtesy of Colorado Plateau Geosystems, Inc.
50 - 40 million BC
Himalayas are formed
SAY MORE
Summary: How the Himalayas Formed
India kicks Gondwana to the curb: break from the supercontinent and drift across the ocean
About 110 million years ago, a large tectonic plate that India was sitting on broke off from a supercontinent called Gondwana. This Indian plate drifted across the ocean for about 50 million years and then crashed into another tectonic plate containing Asia.
Indian plate goes under Asian plate
Tectonic plates are made up of an underwater part (oceanic crust), and an above water part (continental crust). The landmass that we think of as the subcontinent India was actually just a part of a larger tectonic plate, the rest of which was under the ocean.
When the Indian plate crashed into the Asian plate, the oceanic crust of the Indian plate went under the Asian plate. As the Indian plate continued to move toward the Asian plate, its oceanic crust continued to disappear beneath Asia, bringing India’s continental crust closer and closer to Asia’s continental crust in a conveyor belt-like way.
Continental collision: India gets its chocolate in Asia’s peanut butter
Oceanic crust is very dense and prone to sinking. Continental crust is buoyant and will not sink much, it stays on top of the water.
Because the Indian plate’s continental crust would not go under the Asian plate like its oceanic crust did, when the Indian plate’s continental crust reached the Asian plate’s continental crust, the two continents collided. The Indian continent rammed directly into the Asian continent. This impact caused the earth between the two continents to become smashed together. Because the rocks in between the two continents had nowhere to go, they started bunching and folding. The rock started moving vertically because it had no more room to move horizontally.
This crumpling and bunching up of the continental crust raised the land and created what we now know as the Himalaya Mountains and the Tibetan Plateau.
India still moving, mountains still rising
India first crashed into Asia about 50 million years ago and has kept moving until the present day, although its speed was greatly reduced by the initial impact. The formation of the Himalayas occurred over the span of this 50 million year period as India continued to move further and further into Asia, plowing more and more earth into it; it was not an instantaneous event.
India is currently still moving into Asia and, subsequently, the area is still rising. Although the Himalayas rise about 1 cm per year, there seems to be a limit to how high mountains can grow. So some of the ongoing growth may be occurring in the form of the Himalayan mountains and the Tibetan Plateau getting wider rather than taller.
Tectonic Plates
The outer part of the Earth is like a cold hard shell. This shell is broken up into large pieces called plates.
The inner part of the Earth is hot. This heat allows the plates that sit on top of it to move around.
Plates have two types of Earth crust: oceanic and continental.
- Oceanic crust is very dense and prone to sinking.
- Continental crust is buoyant and will not sink for the most part.
Convergent Boundaries
As the plates move around on the Earth, they sometimes run into each other. The point at which two plates collide is called a convergent boundary.
Many significant geologic events occur at convergent boundaries, including mountain building, volcano formation, massive earthquakes, and the formation of ocean trenches and island arcs.
Subduction
When plates collide, one plate eventually slides under the other plate. This is called subduction. Subduction occurs at convergent boundaries (the point of collision of two plates).
Subduction results from a difference in density between the two plates that are colliding, i.e. – one plate is heavier than the other. The denser plate will subduct (go under) the less dense plate.
In the case of oceanic crust colliding with continental crust, the oceanic crust will always be subducted. In other words, the oceanic crust will always go under the continental crust.
Continental Collision
Continental crust is not very dense, it is buoyant. So when the continental crusts of two plates collide, neither one will sink under the other (neither plate is subducted). Instead, the continents bash into each other and the land gets squashed between them, forming mountains.
LEARN MORE
Video of a lecture and demonstration from a children’s science show.
Explains how the Himalayas and the Tibetan Plateau were formed. Also discusses plate tectonics, how triangulation works, and some history of how we arrived at the current prevailing scientific theories.
Video demonstrating the plate tectonics involved in mountain building using a sand model
Video about how India and Asia came to be fused together and the wide ranging effects of the merger
Researchers explain mystery of India’s rapid move toward Eurasia 80 million years ago
The speed at which India moved across the ocean toward Asia is considered to be extremely fast by geological standards.
Learn about subduction of tectonic plates
Learn about the geology of the Tibetan Plateau
Satellite image of snowpack in the Himalayas
Pictures of the Himalayas from the International Space Station
Composite photo of the Milky Way over the Himalaya mountains
Learn how the “Roof of the World” was formed
Subduction Introduction! Learn about amazing events in subduction zones
Extremely short overview of convergent plate boundaries from the U.S. National Park Service
Brief overview of convergent boundaries
Introduction to the different types of convergent plate boundaries and how they work
From deadly earthquakes to beautiful mountain ranges, convergent plate boundaries give rise to significant geological events
What happens when the continental crust of one tectonic plate collides with the continental crust of another tectonic plate
ALTERNATIVE VIEWS
Researchers find the Himalayan mountain range formed over a series of impacts, not a single event, as previously thought.
A fossil of an ancient palm tree is helping rewrite the history of the Tibetan Plateau
CONSPIRACY CORNER
Proven
There is a remote lake in the Himalayas containing hundreds of human skeletons of mysterious origin.
During a joint 1965 mission, the CIA and the Indian Intelligence Bureau lost plutonium cores in the Himalayas during a failed attempt to set up equipment to spy on China
Theory
An ape-like being similar to Bigfoot said to live in the Himalayan mountains
Some believe that devastating flooding of Indian villages is being caused by plutonium that was lost in the Himalayas in the 1960s. There is also fear about potential radioacitve pollution of the Ganges river.
