General Information about Geologic Maps (text modified from USGS):
Geologic maps provide a fundamental scientific resource on which land-use, water-use, and resource-use decisions are based. Geologic maps record the distribution of rock materials at and near the land surface. They can be used to help identify and protect valuable resources, avoid risks from natural hazards, and make wise use of our land. Geologic maps have many different uses, including assessing ground-water quality and contamination risks; predicting landslide hazards; locating and characterizing energy and mineral resources; sighting waste repositories; making wise decisions regarding land management and land-use planning; and for general education. The value of geologic map information in public and private decision-making has been shown to reduce uncertainty and, by extension, potential costs for large and small construction projects.