https://geologypics.com/wp-content/uploads/2017/04/geologic-time-pics-logo-300x115.png00Marli Millerhttps://geologypics.com/wp-content/uploads/2017/04/geologic-time-pics-logo-300x115.pngMarli Miller2017-04-30 20:30:012017-08-25 22:51:33Great Unconformity and Colorado River, Arizona