Ancient Micro-continent Found Lying Underneath Mauritius in Indian Ocean
Could there have been 8 continents all along and we are just finding out about it now? Scientists have discovered a hidden micro-continent that was sandwiched between southern India and Madagascar for several hundred million years and now lies at the bottom of the ocean underneath the island of Mauritius.
The research team from Norway, South Africa, Germany and the UK identified the ancient "micro-continent" after analyzing beach sands from the island of Mauritius and gravity measurements in the Indian Ocean region to reconstruct plate tectonics. The reconstruction showed that India's Lakshadweep islands and Mauritius were both once part of this micro-continent.
The scientists have named the micro-continent "Mauritia" and helps explain the origin of the Seychelles, which have "long been considered a geological peculiarity", the team reports in the journal Nature Geoscience.
The plate tectonics reconstruction suggests that Mauritia was tucked between southern India and Madagascar which about 750 million years ago lay between latitudes 30° North and 50° North.
"This is an unexpected discovery, never proposed before," Lewis Ashwal, a senior geologist and a study team member from the University of Witwatersrand in South Africa, told The Telegraph.
Professor Trond Torsvik, from the University of Oslo, Norway, said: "We found zircons that we extracted from the beach sands, and these are something you typically find in a continental crust. They are very old in age."
The zircon dated to between 1,970 and 600 million years ago, and the team concluded that they were remnants of ancient land that had been dragged up to the surface of the island during a volcanic eruption.
The study suggests that about 83 million years ago, soon after magmatic activity in the region, India along with Seychelles and some Mauritian continental fragments separated from Madagascar while Mauritius remained with Madagascar.
"We can't say when India precisely lost (connection with) Mauritia," Ashwal said. Scientists say tectonic and volcanic activity would have led to the submergence of Mauritia. "Undersea volcanoes lead to the spread of the ocean floor - this expanded the ocean that submerged Mauritia," said Mamilla Venkateshwarlu, a scientist at the NGRI, Hyderabad, who has been studying 1,100 million year old rocks in India to determine its position in the supercontinent Rodinia.