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Gondwana Breakup

June 5, 2008

A new explanation for how the ancient supercontinent of Gondwana broke into the continents of the southern hemisphere.


Breaking up a supercontinent…I’m Bob Hirshon and this is Science Update.

The continents of the southern hemisphere once formed a vast supercontinent called Gondwana. But about 183 million years ago, it began to split apart. Scientists once thought it broke into many small, independently moving pieces that migrated haphazardly across the southern oceans before reaching their current locations. But to structural geologists Matthias Konig and Graeme Eagles, these chaotic trajectories just didn’t make sense. Eagles explains.

GRAEME EAGLES (Univeristy of London):
This view of Gondwana was quite unusual in terms of the patterns of plate tectonics that we’ve observed from more recent times in the oceans.

So they created a new computer model of the ocean floor. It suggests that the supercontinent originally split into just two pieces. Millions of years later, smaller plates began to break off one-by-one, forming the landmasses of the southern hemisphere. I’m Bob Hirshon, for AAAS, the science society.