• Northeastern Arizona is part of the Colorado Plateau Physiographic province. The Colorado Plateau is characterized by flat-lying, relatively undisturbed, largely marine sedimentary rocks of Paleozoic and Mesozoic age that are covered by Tertiary to recent volcanic flows near Flagstaff and Springerville. Permian strata truncate Cambrian, Devonian, Mississippian, Pennsylvanian and Proterozoic rocks along the margins of the Defiance Uplift. Maximum submergence of the Defiance uplift may have occurred during the Mississippian, but the Mississippian rocks were subsequently eroded back, probably by renewed, slow emergence of the uplift in
    Pennsylvanian through Permian Time.


  • As much as 2,000 feet of Permian strata were eventually deposited on the Proterozoic Basement rocks of the Defiance uplift. All past production of helium and current oil, gas and CO2 are from rock formations of Paleozoic age in the Plateau Province. The major tectonic features in Northeastern Arizona include the Defiance and Kaibab uplifts in the northern part of the area. The Black Mesa Basin is situated between the Kaibab and Defiance Uplifts. The Holbrook Basin is located between the Defiance Uplift
    to the north and the Mogollon Slope to the south. A prominent escarpment known as the Mogollon Rim defines much of the southern edge of the Plateau Province.