The fragment, called Mauritia, is thought to have previously been connected between what became India and Madagascar.
It's not often that new pieces of continents are found, which makes research just published in Nature Geoscience rather exciting. According to the authors, there's geological evidence of a microcontinent lying under the islands of Reunion and Mauritius in the Indian Ocean.
The fragment, called Mauritia, is thought to have previously been connected between what became India and Madagascar. As the former landmass, which included the Seychelles, split up and drifted apart, Mauritia split off on its own. Around 85 million years ago it sank under the Indian Ocean, and the same lava flows that produced islands like Mauritius masked its presence.
The multinational team behind the research studied the composition of sand on Mauritius. While the sand itself dated back to volcanic eruptions around 9 million years ago, they also found samples of the mineral zircon dating back to between 1970 million and 660 million years ago. The team argues that such zircon must have been dragged up to the surface by geologically recent lava flows, which suggests that Mauritia is indeed lying below the topmost crust in the region, perhaps just six miles down.