Half an Everton pothole

This entire valley was under water as the Wisconsin glacier melted - water rushed through, and where depressions were present in the limestone bed sometimes harder rocks would be swirled around by the turbulence causing these potholes as the harder rock eroded the softer limestone. Some of the potholes here and in Rockwood are a few metres in diameter - others smaller. Some are quite deep. The side of this one was sheared off and you can see the structure and the layered nature of the limestone.

Everton, Ontario