Geologic Maps and Mapping
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Geologic maps constitute a fundamental and objective scientific foundation on which land-use, water-use, and resource-use decisions are based. A geologic map records the distribution of rock and soil materials at and near the land surface, and is the best science product to display the information that decision makers need to identify and protect valuable resources, avoid risks from natural hazards, and make wise use of our land. |
Detail from 1:24,000-scale geologic map from Bailey, E.H., Everhart, D. L., 1964, Geology and quicksilver deposits of the New Almaden district, Santa Clara County, California, U.S. Geological Survey Professional Paper 360, 206 p. |
USGS Geologist Wayne Premo collecting samples of Lower Proterozoic felsic gneiss (gray, layered rock) and amphibolite (black rock) in Clear Creek Canyon west of Denver, Colorado. Light-colored pegmatite dikes and sills cut the outcrop. |
Last modified 05-17-2005 12:55