June 2016 Newsletter:

Bedrock Geology of North Carolina

In many parts of the Piedmont of North Carolina, there is an interesting pattern of streams, lakes and rivers that seems to go against conventional Newtonian wisdom. Many of these drainage features go from the southwest to the northeast, which is 90 degrees away from the fastest path to the ocean. The answer to this paradox is best revealed by looking at a topographic relief map of our state and noting that in the western part of the state the Blue Ridge Mountains and associated landforms are oriented in the southwest to northeast direction as well.

And why is this so? Blame Africa! Starting approximately 450 million years ago there was a series of collisions of two major continental plates, the African Plate from the southeast and the North American Plate from the northwest. The collisions caused buckling, thrust faults, and deep fractures into the older bedrock along a northeast-southwest trend.