Interim geologic map of the Santa Clara quadrangle, Washington County, Utah (OFR-339)

By: G. C. Willis and J. M. Higgins

The Santa Clara quadrangle is in the St. George basin of southwestern Utah and is popular for its scenery of vivid red sandstone contrasting with black basalt lava flows. It is on a structural block bounded by the down-to-the-west Grand Wash-Reef Reservoir-Gunlock fault system to the west and the Hurricane fault zone to the east. Strata in the quadrangle dip about five degrees northeastward and are cut by a few minor faults. The upper three members of the Lower Triassic Moenkopi Formation, the middle red, Shnabkaib, and upper red, are the oldest exposed rocks in the quadrangle. They are unconformably overlain by the Shinarump Conglomerate and Petrified Forest Members of the Upper Triassic Chinle Formation. A Lower Jurassic section consists of the Dinosaur Canyon, Whitmore Point, and Springdale Sandstone Members of the Moenave Formation, lower and upper members of the Kayenta Formation, and the Navajo Sandstone.

This Open-File release makes information available to the public during the review and production period necessary for a formal UGS publication. This map may be incomplete, and inconsistencies, errors, and omissions have not been resolved. While the document is in the review process, it may not conform to UGS standards; therefore it may be premature for an individual or group to take actions based on its contents.

Other Information:
Published: 1996
Pages: 87 p.
Plates: 2 pl.
Scale: 1:24,000
Location: Washington County
Media Type: Paper Map