Could the discovery of the first Indian Ocean microplate hint at when the Himalayas was actually formed?

A team of Australian and American scientists claimed to have found the first ancient Indian Ocean microplate, aiding them to identify the time of the initial collision of India and Eurasia – about 47 million years ago – that led to the formation of the 2,900-kilometer long Himalayan mountain range.

The team said that while there are a minimum of seven known Pacific Ocean microplates, their discovery was the first one in the Indian Ocean. Microplates are smaller tectonic plate fragments.

The team successfully solved the plate tectonic jigsaw through radar beam imaging from a satellite. The technology allowed them to pinpoint the age of the collision, the accuracy of which has led to decades-long debates among scientists.

The microplate was named Mammerickx microplate, after seafloor mapping pioneer Dr. Jacqueline Mammerickx.

According to the researchers, crustal stresses resulting from the collision led to the Antarctic Plate cracking a good distance from the collision zone, and then broke off a piece the size of Tasmania in Australia in a remote central Indian Ocean patch.

University of Sydney’s Dr. Kara Matthews, lead author of the study, pointed out that the age of the collision, deemed the largest continent one on Earth, had been controversial and earned estimates of 59 to 34 million years past.

“Knowing this age is particularly important for understanding the link between the growth of mountain belts and major climate change,” she explained.

Co-author professor Dietmar Müller said they added a totally new and independent observation on the conception of this collision. According to him, the collision must have introduced a significant change in India’s crustal stress field, which was why the plate fragmentation they mapped is akin to a smoking gun to pin down the age of collision.

At present, the ongoing tectonic collision happening between the two continents creates geological impacts building up along the Himalayas, leading to various earthquakes each year. The study findings illustrate the stresses of the Indian Plate when its northern section first collided with Eurasia.

Ocean basins have not been explored as extensively as remote lands, said co-author professor David Sandwell from the Scripps Institution of Oceanography. He disclosed that about 90 percent of the planet’s seafloor is unmapped, taking 200 ship-years to complete a deep ocean survey outside of continental shelves.

The research findings were published in the journal Earth and Planetary Science Letters.

ⓒ 2021 All rights reserved. Do not reproduce without permission.