New Continent Discovered

May 26, 2010 5:47 am
Filed Under: Editorial, News

Evidence of a drowned “microcontinent” has been found in sand grains from the beaches of a small Indian Ocean island, scientists say.

A well-known tourist destination, Mauritius (map) is located about 1,200 miles (2,000 kilometers) off the coast of Africa, east of Madagascar. Scientists think the tiny island formed some nine million years ago from cooling lava spewed by undersea volcanoes.

But recently, researchers have found sand grains on Mauritius that contain fragments of the mineral zircon that are far older than the island, between 660 million and about 2 billion years old.

In a new study, detailed in the current issue of the journal Nature Geoscience, scientists concluded that the older minerals once belonged to a now vanished landmass, tiny bits of which were dragged up to the surface during the formation of Mauritius. (Also see “World’s Oldest Rocks Suggest Early Earth Was Habitable.”)

“When lavas moved through continental material on the way towards the surface, they picked up a few rocks containing zircon,” study co-author Bjørn Jamtveit, a geologist at the University of Oslo in Norway, explained in an email.

Most of these rocks probably disintegrated and melted due to the high temperatures of the lavas, but some grains of zircons survived and were frozen into the lavas [during the eruption] and rolled down to form rocks on the Mauritian surface.”