Scientists have confirmed the existence of a “lost continent” under the Indian Ocean island of Mauritius that was left over by the breakup of the supercontinent, Gondwana, which started about 200 million years ago.
The piece of crust, which was subsequently covered by young lava during volcanic eruptions on the island, seems to be a tiny piece of ancient continent, which broke off from the island of Madagascar, when Africa, India, Australia and Antarctica split up and formed the Indian Ocean.
“We are studying the breakup process of the continents, in order to understand the geological history of the planet,” said Prof. Lewis Ashwal from University of the Witwatersrand in South Africa.
Also Read: She could be first female with ‘tree man’ syndrome
By studying the mineral, zircon, found in rocks spewed up by lava during volcanic eruptions, Prof. Ashwal and his colleagues have found that remnants of this mineral were far too old to belong on the island of Mauritius.
“Earth is made up of two parts — continents, which are old, and oceans, which are ‘young’. On the continents you find rocks that are over four billion years old, but you find nothing like that in the oceans, as this is where new rocks are formed,” said Prof. Ashwal.
“Mauritius is an island, and there is no rock older than nine million years old on the island. However, by studying the rocks on the island, we have found zircons that are as old as three billion years,” he said.
Zircons are minerals that occur mainly in granites from the continents. They contain trace amounts of uranium, thorium and lead, and due to the fact that they survive geological process very well, they contain a rich record of geological processes and can be dated extremely accurately.
“The fact that we have found zircons of this age proves that there are much older crustal materials under Mauritius that could only have originated from a continent,” said Prof. Ashwal.
“According to the new results, this breakup did not involve a simple splitting of the ancient super-continent of Gondwana, but rather, a complex splintering took place with fragments of continental crust of variable sizes left adrift within the evolving Indian Ocean basin,” Prof. Ashwal added.
Also Read: India beat England by 75 runs, clinch T20 series 2-1