THE NATIONAL GEOLOGIC MAP DATABASE – YOUR LINK TO GEOSCIENCE INFORMATION

The USGS and the Association of American State Geologists (AASG) are mandated by Congress to provide a National Geologic Map Database (NGMDB) of standardized geoscience information that can be used to address societal issues and improve our base of scientific knowledge. This partnership serves to advance both the goal of building the NGMDB and the need for each geological survey to improve their ability to deliver map information to their users. Of real significance, this collaborative activity also involves the Geological Survey of Canada, universities, and the private sector.

Because of the mandate's broad scope, we use a phased, incremental approach to design the Database. This approach gives us the necessary time to build consensus and expertise among the Database designers in the State geological surveys and the USGS. Furthermore, it helps us to more effectively consider and respond to evolving technology and user needs.

We started by creating a Map Catalog containing bibliographic information on more than 54,000 geoscience map products and a geologic names lexicon (“GEOLEX”), and we are prototyping an Image Library of geologic maps in MrSID format and a National Paleontology database.

Working with other U.S. and Canadian agencies, we are developing standards for a conceptual data model, lithologic terminology, locational accuracy, and map symbology. These standards will provide the rules under which the online, vector-map database will be developed. We are designing the database through a series of prototypes, iteratively testing the standards and evolving our ideas on database design. All geological surveys in the U.S. will help build and manage this distributed database to effectively provide useful map data with common data formats and lithologic terminology.

The NGMDB also helps to advance the general state of knowledge and expertise in techniques for building digital geologic maps and databases, in part by organizing a series of annual Digital Mapping Techniques workshops. These informal meetings have significantly helped the geoscience community converge on more standardized approaches for digital mapping and GIS analysis. Information and links to the databases are available at http://ncgmp.usgs.gov/ngmdbproject/.