by Grant C. Willis
This CD contains plot files of a geologic map of the Glen Canyon Dam area of southern Utah and northern Arizona (provided as two plates-east and west parts), and is one of several maps recently completed by the Utah Geological Survey that provide complete geologic map coverage of Lake Powell and Glen Canyon National Recreation Area. Glen Canyon Dam, completed in 1964, is anchored in Jurassic Navajo Sandstone, the oldest formation exposed in the map area. Jurassic and Cretaceous strata are cut by a few small faults and warped by broad shallow folds. Surficial deposits consist of extensive river and stream terrace gravel, eolian sand, and minor alluvium and talus. The map is based on new field mapping and aerial photograph interpretation and is provided as two plates in PDF format with a 12-page explanatory booklet that describes map units.
Open-File Report 607 $14.95