A geologic map shows the distribution, composition, and age of the rocks and sediments in a specific geographic area. "Geologic maps are the single most important and valuable tool we have for understanding and living with the Earth around us.
Their usefulness is so broad that geologic maps are the most requested scientific product produced by state and federal geological surveys" (Meeting Challenges with Geologic Maps an American Geological Institute Environmental Awareness Series).
Because geologic maps contain such a wealth of information, they are used to solve diverse land-use problems, such as finding, developing, and preserving mineral, energy, and water resources; reducing losses from natural hazards, including earthquakes, volcanoes, landslides, and other ground failures; evaluating and planning for land management and environmental protection; mitigating the effects of coastal and stream erosion; locating waste repositories, highways, pipelines; and planning for basic Earth science research.
National Geologic Map Database (NGMDB)
The NGMDB is the primary source for geologic map information of the United States and is organized into four searchable parts:
- Geoscience Map Catalog
- Access to geologic maps and other information and data developed under the FEDMAP, STATEMAP, and EDMAP components of the NCGMP. Links to other organizations' data and information on general geology, natural hazards, earth resources, geophysics, geochemistry, geochronology, stratigraphy, paleontology, and marine geology.
- Geologic Names
- Lexicon of lithologic and geochronologic rock units used in geologic maps and scientific reports. Includes unit names recognized by the USGS Geologic Names Committee.
- New Mapping
- Information about geologic mapping currently being conducted by FEDMAP, STATEMAP, and EDMAP.
Geologic Map Database
Meeting Challenges with Geologic Maps
(8.1 Mb Adobe® PDF)
To create, manage, and publish natural science data and information effectively, both data producers and users agree that it is essential to adhere to widely-accepted standards.
Three mechanisms promote the development and coordination of widely-accepted standards for geologic maps and mapping data:
- National Geologic Mapping Act of 1992: Stipulates that standards be developed to support the National Geologic Map Database (NGMDB);
- Federal Geographic Data Committee (FGDC), through its Geologic Data Subcommittee: Responsible for development of standards to support geologic data management at the Federal level;
- Association of American State Geologists (AASG): Formed the Digital Geologic Mapping Committee to work with the NGMDB and the FGDC to develop standards applicable to the State Geological Surveys as well.
The NGMDB Project Chief also serves as Chair of the FGDC Geologic Data Subcommittee and as principal liaison to the AASG Digital Geologic Mapping Committee. Thus, the NGMDB Project Chief coordinates a standards development effort by the Nation's major data producers.
Detailed information relating to geologic mapping-related standards:
- Background Information on Standards Development
- A summary of current and historical standards development activities.
- Standards and Guidelines
- Links to standards documents and related topics, including:
- Geologic map symbolization
- Geologic map data models
- Map publication guidelines
- Digital mapping techniques