DIGITAL GEOLOGIC MAP OF THE UNITED STATES.

The geologic map of the United States was published in 1974 by the U. S. Geological Survey. This major publication contains an enormous amount of information on the surficial geology of the United States. Many geologists have used this map as a research tool. Most have needed information from only specific parts of the map, and have manually extracted data from these areas. These data have then been combined with other geological information, much of which - especially that concerning minerals and energy - either is already in machine-readable computer files or is rapidly being converted to that form.