ADVANCES IN DESIGN OF THE NATIONAL GEOLOGIC MAP DATABASE

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. 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 State geological surveys and the USGS. Furthermore, it helps us to more effectively consider and respond to evolving technology and user needs. We began by creating: 1) a Geoscience Map Catalog, which contains bibliographic information on more than 70,000 products from nearly 350 publishers, and web links to these products; and 2) the U.S. Geologic Names Lexicon, a standard reference for the Nation's stratigraphic nomenclature that is being developed from previous lexicons and GNC index card files. The Map Catalog is supported by a growing inventory of online map images, in MrSID format. These databases are available at http://ngmdb.usgs.gov/. Because the NGMDB is a collaborative effort, each of our databases is built through the cooperation of all geological surveys in the U.S. It is, therefore, a tremendous challenge to design the most ambitious aspect of the NGMDB project -- an online, queryable database of geologic map information in vector and raster format that is served by our numerous project partners in a distributed environment. Working with other U.S. and Canadian agencies, we have developed standards for a map data model, lithologic terminology, locational accuracy, and map symbology. These standards are providing the framework for development of the distributed database. Recent progress in building the database includes a data-entry and database-management software tool with an accompanying suite of standard science terminologies, and an implementation of the database in ESRI Geodatabase format. Information can be found at http://ngmdb.usgs.gov/info.