By: Grant C. Willis and Hellmut H. Doelling
This interim geologic map of the Burrville 7.5' quadrangle in eastern Sevier and northernmost Piute Counties is part of a project to map the western half of the Salina 30' x 60' quadrangle. It is in the High Plateaus of central Utah with elevations from about 7000 feet (2100 m) in Grass and Plateau Valleys to over 11,000 feet (3300 m) on Fish Lake Plateau. Otter Creek flows southward through Plateau and Grass Valleys and is dammed to form Koosharem Reservoir. About 1200 feet (370 m) of Oligocene volcanic and volcaniclastic rocks derived from the Marysvale volcanic field to the southwest cover most of the quadrangle. They thin and thicken over paleo-topographic relief but generally thin northeastward. Many northeast- and northwest-trending normal faults, some probably active and capable of generating large earthquakes, create tilted benches and deep grabens. Valley grabens preserve young basin-fill deposits. Bedrock units are folded into a broad, poorly defined, west-facing monocline. Extensive surficial cover, including glacial deposits at high elevations, mantle most of the quadrangle.
Media Type: Paper Map