DATABASE SCHEMA FOR NCGMP09—A PROPOSED STANDARD FORMAT FOR DIGITAL PUBLICATION OF GEOLOGIC MAPS
Documentation, example databases, and tools are online at http://ngmdb.usgs.gov/Info/standards/NCGMP09/. As a brief example of NCGMP09’s design, required tables include a GeologicMap feature dataset with (1) MapUnitPolygon and (2) ContactsAndFaults feature classes that are topologically linked; (3) a DescriptionOfMapUnits table that contains text description of units, along with age and symbolization information for the unit; (4) a StandardLithology table that specifies the lithologic composition of a map unit; (5) a Glossary table that defines terminology used in the database; and (6) a DataSources table that specifies provenance of items in the database on a feature-by-feature basis. Optional OverlayPolygon (e.g. alteration zones), ConcealedContactAndFault, and OtherLines (Dikes, veins, fold hinge surface traces) feature classes may be included to represent mapped features that do not participate in the map unit topology. Point feature classes may be included for point-located information (sample, strike and dip measurement, geochemical data); each data type is included in a separate point feature class with a standard collection of fields, along with fields specific to that data type. In the coming year we plan another round of revision and will write more tools to facilitate database creation. We solicit feedback on the database schema and collaboration in tool development.