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This roadcut perserves ripple marks that are now nearly two billion years old. Tilted during the Penokean Orogeny, these rocks are also some of the oldest redbeds (evidence of an atmosphere with free oxygen) in the world.
At Ableman's Gorge, a former quarry, 1.7 billion year old ripple marks form a vertical wall scores of feet high. Stop and think about what that means -- the sand that eventually became this rock was laid down at a time when the only living things on planet were unicellular. And the forces that can stand this up to vert...