Geologic maps use a combination of colors, lines, and symbols to depict the relative age, composition, and relationships among rocks and sediments at and near the earth’s surface.
See Geologic maps – what are you standing on? and Practical uses of geologic maps for more information.
7.5′ quadrangle maps cover 7.5 minutes of latitude by 7.5 minutes of longitude, or about 55 square miles in Utah, and are the standard series for detailed geologic mapping. In this series, one inch on the map represents 24,000 inches, or 2,000 feet, on the ground. 7.5′ Alphabetized List (7.5-minute quadrangle geologic maps listed by quadrangle name.)
30’x60′ quadrangle maps cover 30 minutes of latitude by 60 minutes of longitude, or about 1,760 square miles in Utah, and are the standard series for intermediate-scale geologic mapping. In this series, one inch on the map represents 100,000 inches, or 1.6 miles, on the ground.
1×2-degree quadrangle maps cover 1 degree of latitude by 2 degrees of longitude and are the standard series for intermediate-scale geologic mapping. In this series, one inch on the map represents 250,000 inches, or about 4 miles, on the ground.
Non-quadrangle maps are published at various scales and may cover part of one or more 7.5′, 30’x60′, or 1°x2° quadrangles. UGS Non-quadrangle Geologic Maps List
To obtain maps: Click on map area to view popup windows containing map information and links to purchase map, or to download a pdf map or a zip file with GIS data (if available). U.S. Geological Survey (USGS) maps are available at the National Geologic Map Database.