Scientists find strong evidence of a long-lost continent
A glance at the Risk board (or an atlas, if you want to be slightly more academic) will tell you that there are seven continents, even if the icy poles are criminally overlooked in parlour games of world domination. But scientists have found pretty compelling evidence of one that’s no longer with us – and no, it’s not Atlantis. This one would have been around the Indian ocean, and evidence of it has been found hidden deep in volcanic rock discovered on Mauritius.The missing continent has been christened Mauritia, and suggestions of its existence were first posited by the University of Witwatersrand’s Lewis Ashwal back in 2013 when he discovered that the island’s sandy beaches contained fragments of zircon crystals, some 300 times older than the island itself. The geology community was sceptical, however, because new continents aren’t just accepted as fact willy-nilly. “There were many sceptics in the science community who criticised our suggestion because they felt that zircons on the beach sand could have been transported there by winds, or ocean currents, or birds, or vehicle tyres, or by people’s shoes,” Ashwal told Popular Science.
Those sceptics have a hard job discounting the latest discovery, though, which proved that there are ancient zircon crystals actually embedded within the island’s volcanic rock. What’s amazing about this is that while the island is a spritely nine million years old, the zircon crystals contained within it are two billion if they’re a day. Ashwal’s theory is that when the volcanic magma slipped out of the Earth’s mantle, it passed through the lost continent of Mauritia before erupting onto the Earth’s surface and creating Mauritius nine million years ago. The bits of zircon crystal from Mauritia were simply too tough to melt, thus becoming part of the island’s DNA.
“This exciting and unexpected result can only mean that there is a piece of ancient continent below the young volcanoes of Mauritius,” explained Ashwal.
Mauritia may once have encompassed the island of Madagascar, too. Ashwal compared the zircons uncovered on Mauritius to rocks in Africa and India, and found that the best match is Madagascar. Mauritia is likely a missing part of Gondwana – the supercontinent that broke up 200 million years ago to form the Earth as we know it today.
“Our work shows that continental break-up is more complex and messy than previously thought, and can result in continental fragments of various sizes, littering the ocean floor,” explained Ashwal.