Chunk of Africa Found Underneath Southeastern US

Geoscientists have identified a chunk of Africa stuck onto the southeastern United States.

A long mysterious zone of unusual magnetism that stretches from Alabama through Georgia and offshore to the North Carolina coast appears to be the suture between ancient rocks that formed when parts of Africa and North America were pressed together 250 million years ago. If so, Africa could have left a lot more behind in the American southeast when the conjoined continents rifted apart and formed the Atlantic Ocean.

“There are some large faults in the magnetic data,” said geologist Robert Hatcher of the University of Tennessee in Knoxville, regarding what is called the Brunswick Magnetic Anomaly and other magnetic features in the region. “They have not been active for a very long time. They are strike-slip faults like the San Andreas today. But there’s also younger fall with opposite direction.”

The faults appear to be the remains of the collision and then messy divorce of Africa and North America.

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The big challenge in sorting out the history of the southeast U.S. is that there are intriguing magnetic signals, as well as gravimetric measurements, but there is not enough deep borehole studies or seismic data to confirm the faults and the proposed scenarios.

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