USGS National Geologic Map Database Collection

The National Geologic Map Database (NGMDB) is a Congressionally mandated national archive of geoscience maps, reports, and stratigraphic information. According to the Geologic Mapping Act, the U.S. Geological Survey and the Association of American State Geologists (AASG) shall cooperatively build this national archive, according to technical and scientific standards whose development is coordinated by the NGMDB. At present, the NGMDB consists of a comprehensive set of publication citations, stratigraphic nomenclature, downloadable content, unpublished source information, and guidance on standards development. The NGMDB contains information on more than 90,000 maps and related geoscience reports published from the early 1800s to the present day, by more than 630 agencies, universities, associations, and private companies.