Scientists have discovered a new micro-continent in the Indian Ocean, hidden by the islands of Reunion and Mauritius, in findings that have added a fresh chapter to the geological history of the Indian subcontinent.
The newly discovered continent, which scientists have called Mauritia, detached from the supercontinent Gondwanaland about 60 million years ago, around the time Madagascar and India also drifted away from what is present-day Africa. The findings were published on Sunday in the reputed journal Nature Geoscience.
Continental break-ups are often linked to the giant bubbles of hot rock that rise up from the mantle of the earth and soften tectonic plates from below, till these plates break at the hotspots. That’s how eastern Gondwana first broke about 170 million years ago, before further shattering into Madagascar, India, Australia and Antarctica, which then floated to their current locations.
The team of scientists – from Norway, Germany, Britain and South Africa – dated grains of sand from the beaches of Mauritius to conclude that plumes under the island played a key role in giving the Indian Ocean its current shape.
The plumes led to a rupture in the tectonic plates that separated Madagascar from India, creating the micro-continent. But because it was created through the rupture, and not by a clean separation from a larger landmass – unlike India or Australia – Mauritia – lies covered by lava just off the coast of Mauritius and Reunion, the French-controlled Indian Ocean island.
The discovery has added to growing evidence that the world’s ocean floors may be hiding several such micro-continents that if discovered and dated could help reveal the finer details of how and when present-day continents were born.