KENTUCKY GEOLOGICAL SURVEY GEOLOGIC MAP DATABASE

The Kentucky Geological Survey (KGS) is nearing the completion of a project to digitize all 707 of the 7.5-minute geologic quadrangle maps that cover the state of Kentucky; they were published cooperatively with the U.S. Geological Survey between 1960 and 1978. This conversion process, partially funded by the Federal Statemap program, has resulted in GIS data sets, as well as new published geologic maps. Much remains to be done to implement a widely accessible spatial database of geologic information.

A centralized geologic map database is needed at KGS for at least two reasons. The first is to provide an analytical tool for geologists, in which the map data are used as a base for examining other spatial information, such as oil and gas data, water quality data, or limestone analyses. The second reason is to support creation of derivative map products that communicate geo-logic issues to nontraditional users. This latter use requires extending the geologic unit descriptions beyond what are normally found on the geologic map.

The initial design for this extended database is consistent with the conceptual modeling of geologic information provided by the North American Data Model effort (geology.usgs.gov/dm/steering/teams/design/). Three separate tables are being devel-oped to characterize geologic rock units. The first stores basic stratigraphic information about the units and their relationships to other units. The second stores data about the properties of rock units, mainly related to lithology. The last table deals with be-haviors of rock units in the context of applied geology or geotechnical engineering. An example would be guidance for con-structing septic systems, or estimating karst potential.

Kentucky geologic map databases were used for a National Geologic Map Database (NGMDB) prototype project to dem-onstrate analytical capabilities of a distributed map database (ncgmp.usgs.gov/ngmdbproject/reports/). Collaboration with the NGMDB project provides a national perspective to creating a state database, and also facilitates future information exchange among map databases by establishing standards in design and data format.