With some of the world’s tallest peaks, Asia’s “the abode of snow” region is a magnet for thrill seekers, worshipers, and scientists alike. The imposing 1,400-mile Himalayan mountain range that separates the plains of the Indian subcontinent from the Tibetan Plateau is the scene of an epic continent-continent collision that took place millions of years ago and changed the Earth, affecting its climate and weather patterns.
With some of the world’s tallest peaks, Asia’s “the abode of snow” region is a magnet for thrill seekers, worshipers, and scientists alike. The imposing 1,400-mile Himalayan mountain range that separates the plains of the Indian subcontinent from the Tibetan Plateau is the scene of an epic continent-continent collision that took place millions of years ago and changed the Earth, affecting its climate and weather patterns. The question of how the Indian and Eurasian tectonic plates collided, and the mountains came into existence, is one that scientists are still unfolding. Now, new research published in PNAS and led by MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS) confirms that it’s more complicated than previously thought.
“The Himalayas are the textbook example of a continent-continent collision and an excellent laboratory for studying mountain-building events and tectonics,” says EAPS graduate student Craig Martin, the paper’s lead author.
The story begins around 135 million years ago, when the Neotethys Ocean separated the tectonic plates of India and Eurasia by 4,000 miles. The common view of geologists is that the Neotethys Ocean plate began subducting into Earth’s mantle under Eurasia, on its southern border, pulling India north and the tectonic plates above it together to ultimately form the Himalayas in a single collision event around 55-50 million years ago. However, geologic evidence suggested that the high rate of subduction observed didn’t seem to quite fit this hypothesis, and model reconstructions place the continental plates thousands of kilometers apart at the time of this inferred collision. To account for the time delay and subduction strength required, MIT’s Oliver Jagoutz, associate professor of geology, and Leigh “Wiki” Royden, the Cecil and Ida Green Professor of Geology and Geophysics, proposed that because of the high speed, orientation, and location of the final continental collision, there needed to be another oceanic plate and subduction zone in the middle of the ocean, called the Kshiroda plate and the Trans-Tethyan subduction zone (TTSZ), which ran east to west. Additionally, EAPS geologists and others postulated that an arc of volcanic islands, like the Marianas, existed in between the two, called the Kohistan-Ladakh arc. Located near the equator, they took the brunt of the force from India before being squished between the two continental crusts.
Read more: Massachusetts Institute of Technology
