[Skywise]

http://www.foxnews.com/science/2014/04/2...=obnetwork

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.

Full article at link.

Brian

[Island Chris]

Brian and all,

I think I read the science article a couple weeks ago in "GSA Today". There is a chunk of Africa under the part of Conanicut Island (Jamestown) Rhode Island where I live. They thought the rocks were about 300 million years-old and part of North America until they found Trilobites over 500 million years old similar to African trilobites in Beavertail State Park. There is a fault zone that separates North American and African rocks through the salt marsh next to the Newport Bridge less than 2 km north of us. About the largest earthquake in Rhode Island that I am aware of in the last few decades is only about M3.1. (I could check). But, the town considers earthquakes the 2nd biggest hazard after windstorms (hurricanes etc).

Unusually well done page on the tectonic history:

http://www.jamestown-ri.info/geological_history.htm

Chris