Upheavel dome

The Upheaval Dome is an enigmatic geological structure in San Juan County, Utah, United States, that has been variously interpreted as a meteorite impact structure or a salt dome. It is approximately 10 km in diameter and the crater is known to be less than 170 million years old (Jurassic or younger, but how much younger is not established.) The crater is clearly visible on the surface as light and dark brown concentric rings.