Antarctica was connected to North America 1.1 billion years ago

The strongest evidence yet found has revealed that parts of North America and Antarctica were connected 1.1 billion years ago, long before the supercontinent Pangaea formed.

“I can go to the Franklin Mountains in West Texas and stand next to what was once part of Coats Land in Antarctica,” said Staci Loewy, a geochemist at California State University, Bakersfield, who led the study.

Loewy and her colleagues discovered that rocks collected from both locations have the exact same composition of lead isotopes.

Earlier analyses showed the rocks to be the exact same age and have the same chemical and geologic properties.

The work strengthens support for the so-called SWEAT hypothesis, which posits that ancestral North America and East Antarctica were joined in an earlier supercontinent called Rodinia.

In latest study, Loewy, Ian Dalziel, research professor at The University of Texas at Austin, Richard Hanson of Texas Christian University and colleagues from several overseas institutions, found that rocks barely peeking through the ice in Coats Land, a remote part of the Antarctic continent south of the Atlantic Ocean basin, reflect a former continuation of the North American rift system.

The study was published online in the September issue of the journal Geology.