Quaternary geology of the Scipio Valley area, Millard and Juab Counties, Utah (SS-79)

By: C. G. Oviatt Quaternary deposits and structures have been mapped at a scale of 1:62,500 in a 270-square-mile area of central Utah that includes Scipio Valley, Little Valley / Mills Valley, and Round Valley. Scipio Valley and adjacent valleys to the north and south occupy structural grabens along the eastern side of the Basin and Range physiographic province. Bedrock in the surrounding mountains varies in age from Precambrian to Miocene, and the area was strongly affected by both Sevier orogenic thrust faulting and late Cenozoic normal faulting. The area is in the transition zone between the Basin and Range and Colorado Plateaus physiographic provinces. The purpose of this report is to describe the surficial deposits of Quaternary and late Tertiary age in Round, Scipio, and Little Valleys. The map area encompasses about 270 square miles in parts of eight 7.5-minute topographic quadrangles (Fool Creek Peak, Mills, Williams Peak, Scipio North, Scipio Pass, Scipio South, Coffee