Bow City impact crater

The Bow City Impact Crater is a probable meteorite impact crater located in southern Alberta, Canada.^[2][3] The 8-kilometre-wide (5.0 mi) crater was discovered in 2012 by Wei Xie of the University of Alberta. The crater is estimated to have formed approximately 70 million years ago. The crater is not directly visible from the surface, as it is buried under approximately a kilometer of overburden. Petrochemical seismic studies provided the first clues to the existence of the crater.

• http://en.wikipedia.org/wiki/Bow City impact crater