Interim geologic map of the Vernal 30' x 60' quadrangle, Uintah and Duchesne Counties, Utah, and Moffat and Rio Blanco Counties, Colorado (OFR-506dm)

By: D. A. Sprinkel

The Vernal 30' x 60' quadrangle is located in the northeastern part of the Uinta Basin along the south flank of the Uinta Mountains. The quadrangle includes parts of Duchesne and Uintah Counties, Utah, and Moffat and Rio Blanco Counties, Colorado. Part of Dinosaur National Monument is in the northeast corner of the quadrangle on the Split and Blue Mountains sector of the Yampa Plateau.

The Uinta Basin is a rich storehouse of energy resources. Oil and gas production dominates resource exploitation in the quadrangle. Most of the oil and gas is produced from the Wasatch and Green River Formations; however, some oil production is from the Weber Sandstone and gas is produced from the Mesaverde Group. Gilsonite is mined within the quadrangle with the largest operation near Bonanza, Utah. Tar sand deposits are also mined in the quadrangle at Asphalt Ridge; additional tar sand deposits are located elsewhere along Asphalt Ridge, but they may not be developed because of poor quality or land ownership issues. Oil shale beds in the Green River Formation are a potentially significant resource that may be developed in the near future.

The Mississippian Madison Limestone is the oldest formation exposed in the quadrangle; it is visible at Split Mountain along the Green River. The Madison is overlain by other Paleozoic and Mesozoic rocks, with Mississippian through Cretaceous strata exposed in the northeast part of the Vernal 30' x 60' quadrangle. The remainder of the quadrangle contains exposures of Tertiary strata.

Other Information:
Published: 2007
Plates: 3 pl.
Scale: 1:100,000
Location: Duchesne County and Uintah County