The holiday islands of Reunion and Mauritius are all that remains of a small continent that’s been hidden under lava for millions of years. The land mass, dubbed Mauritia, detached about 60 million years ago while Madagascar and India drifted apart.
Such micro-continents in the oceans seem to occur more frequently than previously thought, says a new study in Nature Geoscience. Mantle plumes, giant bubbles of hot rock, rise from the deep mantle and soften tectonic plates from below, until they break apart at the hotspots.