Tuesday, April 16, 2013

Ancient long-lost continent discovered under Mauritius

It’s not Atlantis, but a drowned continent has been discovered under Mauritius. The strip of continent, now at the bottom of the Indian Ocean, once connected Madagascar, Seychelles and India. As tectonic movement shifted the land masses apart, this land mass, now named Mauritia by researchers, was pushed to the bottom of the ocean, where it was broken apart by underwater volcanoes.

Evidence for this drowned, long-lost land comes from Mauritius where till date the oldest rocks collected on the island dated to about 8.9 million years ago, Yet grain-by-grain analyses of beach sand that says Bjørn Jamtveit, a geologist at the University of Oslo and his colleagues collected on the Mauritian coast revealed around 20 semi-preious zircons — tiny crystals of zirconium silicate that are resistant to erosion or chemical change — that were far older. The zircons had crystallized within granites or other igneous rocks at least 660 million years ago, says Jamtveit. One of these zircons was at least 1.97 billion years old.

Jamtveit and his colleagues suggest that rocks containing the travelling zircons originated in ancient fragments of continental crust located beneath Mauritius. They say that volcanic eruptions brought pieces of the crust to Earth’s surface, where the zircons eroded from their parent rocks to pepper the island’s sands. The team's work has been published in the journal Nature Geoscience.


Image: Prof.Trond H. Torsvik. University of Oslo

No comments:

Post a Comment