The major geologic exposures in the Grand Canyon in Arizona, USA, range in age from the 2 billion year old Vishnu Schist layers at the bottom of the Inner Gorge to the 230 million year old layer on the Rim which is called what?
Kaibab Formation Kaibab formation Kaibab group Kaibab Limestone Kaibab limestone Kaibab Group Kaibab marble Kaibab Marble
kaibab formation kaibab limestone kaibab marble kaibab group
kaibab limestone
WikipediaEntity
Kaibab Limestone