WASHINGTON: An international team of scientists has discovered the first oceanic microplate in the Indian Ocean — identifying when the initial collision between India and Eurasia occurred leading to the birth of the Himalayas.
The team of Australian and US scientists believe the collision occurred 47 million years ago when India and Eurasia initially smashed into each other.
Although there are at least seven microplates known in the Pacific Ocean, this is the first ancient Indian Ocean microplate to be discovered.
“The age of the largest continental collision on Earth has long been controversial. Knowing this age is particularly important for understanding the link between the growth of mountain belts and major climate change,” said lead author Dr Kara Matthews from University of Sydney’s school of geosciences.
Radar beam images from an orbiting satellite have helped put together pieces of this plate tectonic jigsaw and pinpointed the age for the collision, whose precise date has divided scientists for decades.
The new research shows that 50 million years ago, India was travelling northwards at speeds of some 15 centimetres a year – close to the plate tectonic speed limit.
Soon after, it slammed into Eurasia crustal stresses along the mid-ocean ridge between India and Antarctica intensified to breaking point.
The crustal stresses caused by the initial collision cracked the Antarctic Plate far away from the collisional zone and broke off a fragment the size of Australia’s Tasmania in a remote patch of the central Indian Ocean.
