Thursday, March 13, 2008

The Himalayans

The Himalayan mountain range, created by the collision of India with Asia, which began 50 million years ago.
The Himalayans is an ideal laboratory for understanding the response of continental lithosphere to plate tectonic forces while new ocean crust is constantly being created at mid-ocean ridges; old crust must either be destroyed or reduced at the same rate (or else the planet would be continually expanding and increasing in volume). The plates, therefore, emerging along mid-ocean ridges, sliding over the athenosphere, and grinding past other plates along transform faults, are almost all headed on a collision course. When two continents carried on converging plates ram into each other, they crumple and fold under the enormous pressure, creating great mountain ranges. The highest mountain range in the world, the snow-capped Himalayas, is an example of a continent-to-continent collision. This immense mountain range began to form when two large landmasses, India and Eurasia, driven by tectonic plate movement, collided. Because both landmasses have about the same rock density, one plate could not be subducted under the other.
Thrusting skyward could only relieve the pressure of the colliding plates. The folding, bending, and twisting of the collision zone formed the jagged Himalayan peaks. This string of towering peaks is still being thrust up as India, embedded in the Indo-Australian Plate, continues to crunch relentlessly into Tibet, on the southern edge of the Eurasian Plate.
About 220 million years ago, India was an island situated off the Australian coast, and separated from the Asian continent by a vast ocean called the Tethys Sea. When Pangaea broke apart about 200 million years ago, India began to move northward. Scientists have been able to reconstruct India's northward journey. When India rammed into Asia about 50 million years ago, its northward advance slowed. The collision and decrease in the rate of plate movement mark the beginning of the Himalayan uplift.
Now you have learned how the Himalayan Mountains were formed.

4 comments:

student08 said...

Good word choice.....it makes your paragraph sound more believable. it sounds more official. AH4

Anonymous said...

Its sounded very scientific. Therer were alot of numbers which made it sound very precise. JK1

Anonymous said...

It was very professional sounding. i thought it was great.
ak2

Anonymous said...

Great job! You obviously researched a lot.

NV2