By: Hellmut Doelling, Paul A. Kuehne, and Douglas A. Sprinkel
The Ephraim quadrangle straddles the Wasatch monocline in Sanpete County in central Utah, with the Wasatch Plateau in the east half and Sanpete Valley in the west half. Bedrock units are mostly Tertiary in age and include (ascending) North Horn, Flagstaff, Colton, Green River, and Crazy Hollow Formations. Strata bend to more than 45Â¡ off of the Wasatch Plateau into Sanpete Valley. Normal faults form Shoulder graben and cut strata mostly parallel and subparallel to the Wasatch monocline. Landslides are common in the area due to weak layers in the North Horn, Flagstaff, and Colton Formations.
Also included are two plates-a geologic map at 1:24,000 scale with an explanation plate-and a 14-page booklet describing the geology of the quadrangle. The latest version of Adobe Reader is required to view the PDF files.
Includes GIS data