NPR : News

Filed Under:

Scientists May Have Uncovered Ancient Microcontinent

The remains of a small continent have been hiding right under our noses for the past 85 million years or so.

That's according to a new study published Sunday in the journal Nature Geoscience. Scientists looked at lava sands from beaches on Mauritius to determine when and where the material might have originated.

Their conclusion? The lava sands, containing particles called zircon xenocrysts, came from a Precambrian microcontinent dubbed "Mauritia" that was sandwiched between the land masses that today make up Madagascar and India. It was all part of a supercontinent known as Rodinia that existed between 2 billion and 85 million years ago. (Not to be confused with the better known and slightly more contemporary supercontinent Pangaea).

Mauritia was a sliver of land that broke apart and disappeared under the sea as the Rodinia ripped itself apart as part of the process of plate tectonics, scientists believe.

The BBC quotes the study's lead author, Trond Torsvik, as saying the sand his team examined dates to a 9-million-year-old eruption near the modern-day islands of Marion and Reunion that spewed much older material.

"We found zircons that we extracted from the beach sands, and these are something you typically find in a continental crust. They are very old in age," said Torsvik of the University of Oslo in Norway.

Torsvik believes pieces of Mauritia have been interred under 6 miles of surface and spread over a swath of the Indian Ocean, according to the BBC.

"However, a small part could have survived.

" 'At the moment the Seychelles is a piece of granite, or continental crust, which is sitting practically in the middle of the Indian Ocean,' explained Prof Torsvik.

" 'But once upon a time, it was sitting north of Madagascar. And what we are saying is that maybe this was much bigger, and there are many of these continental fragments that are spread around in the ocean.' "

Copyright 2013 NPR. To see more, visit http://www.npr.org/.

NPR

Poetry Behind Bars: The Lines That Save Lives — Sometimes Literally

Words Unlocked, a poetry contest for juveniles in corrections, has drawn more than 1,000 entries. Its judge, Jimmy Santiago Baca, says it was a poetry book that helped him survive his own prison term.
NPR

When It Came To Food, Neanderthals Weren't Exactly Picky Eaters

During the Ice Age, it seems Neanderthals tended to chow down on whatever was most readily available. Early humans, on the other hand, maintained a consistent diet regardless of environmental changes.
NPR

Trump And Cruz Campaign At California GOP Convention

The remaining Republican presidential candidates have been making their case at the party's state convention. Capital Public Radio's Ben Adler explains the divisions on display among Republicans.
NPR

'The Guardian' Launches New Series Examining Online Abuse

A video was released this week where female sports journalists were read abusive online comments to their face. It's an issue that reaches far beyond that group, and The Guardian is taking it on in a series called "The Web We Want." NPR's Audie Cornish speaks with series editor Becky Gardiner and writer Nesrine Malik, who receives a lot of online abuse.

Leave a Comment

Help keep the conversation civil. Please refer to our Terms of Use and Code of Conduct before posting your comments.