The formation of Himalayas, the higest mountain range in the world, was due to a smashing of India and Eurasia 47 million years ago, said a team of international scientists who discovered the first oceanic microplate in the Indian Ocean.
There are at least seven microplates in the Pacific Ocean but this is the first ancient Indian Ocean microplate that scientists have discovered now based on radar beam images from an orbiting satellite. They worked on further putting together the tectonic jigsaw puzzle and arrived at the age when the collision took place.
The scientists discovered that crustal stresses caused by the initial collision cracked the Antarctic Plate and removed a fragment in a remote patch of the central Indian Ocean. The ancient Indian microplate has been named the MammerickxMicroplate, after Jacqueline Mammerickx, a pioneer in seafloor mapping.
The authors include Dietmar Muller and Kara Matthews from the University of Sydney and David Sandwell from the Scripps Institution of Oceanography. The MammerickxMicroplate follows a rotating pattern of grooves and hills that turn the topography of the ocean floor into a jagged landscape. These “abyssal hills” cause a sudden increase in crustal stress, and led to formation of the Himalayan Mountain Range 47 million years ago, researchers said.
The tectonic collision is still ongoing causing numerous earthquakes in the region every year, they explained. Indian tectonic plate was travelling northwards at speeds of 15 cm a year, which is maximum, they pointed out.
“The age of the largest continental collision on Earth has long been controversial, with age-estimates ranging from at least 59 to 34 million years ago,” said Prof. Matthews. The finding has been published in the journal Earth and Planetary Science Letters.