Jan 4, 2011 13:04 GMT  ·  By

The distant past held an entirely different continental configuration than the modern world does, experts say, and, as part of that setup, it could be that the eastern parts of Antarctica were connected to the southwestern portions of the United States.

It's no secret that the world's land masses were hundreds of millions of years ago connected into a single supercontinent. Over the ages, motions in the Earth's mantle pushed the tectonic plates apart from each other, until they reached the current configuration.

As part of such a setup, it may be that Antarctica was connected to the SW parts of the modern-day United States at one point, before migrating southwards. This theory is called SWEAT (Southwestern United States and East Antarctica).

It was recently investigated in detail by researchers at the University of Minnesota-Duluth, led by Department of Geological Sciences (DGC) expert John Goodge, and funded by a US National Science Foundation (NSF) grant.

The idea that the two may have been connected was proposed back in 2008, as Goodge and his team were conducting a sample-collecting study of the underlying continental crust of Antarctica.

“We were picking up boulders in the moraines that looked interesting. It was basically just a hodge-podge of material,” the expert says, quoted by Daily Galaxy. One of the rocks was however a bit peculiar, he adds.

The rare form of granite had “a particular type of coarse-grained texture,” Goodge explains, which is what prompted him and his team to conduct chemical and isotopic analysis of the sample.

Its composition was proven to be “very similar to a unique belt of igneous rocks in North America,” the expert explains.

“There is a long, linear belt of these igneous rocks that stretches across [the ancient land mass called] Laurentia. But 'bang' it stops, right there at the (western) margin where we knew that something rifted away,” the team says.

“It just ends right where that ancient rift margin is, and these rocks are basically not found in any other part of the world,” they add.

“This was first-rate work and a fascinating example of scientists at work putting together the pieces of a much larger puzzle,” explains the director of the division of Antarctic sciences at the NSF Office of Solar Programs, Scott Borg.

“Not only do the authors pull together a diverse array of data to address a long-standing question about the evolution of the Earth's crust during a critical time for biological evolution, but the research shows how the ideas surrounding the SWEAT hypothesis have developed over time,” he concludes.