PROVIDING KENTUCKY'S GEOLOGIC MAPS ON THE WEB

Having completed the digitization of all the 1:24,000-scale geologic maps for Kentucky, the Kentucky Geo-logical Survey is developing a Web site that will allow users to create a highly customized geologic map for any project area in the state and then view related information, including well information, geotechnical and hazards data, related publications, photographs and illustrations, and a variety of other descriptions about Kentucky geology. The digital compilation process included edgematching of adjoining maps to minimize discontinuities at the edges of quadrangles. All of the map data are stored in a seamless spatial database so that rendering of map units is uniform in all locations. Map legends are created dynamically to ensure a custom explanation for each map view.

Because geologic map information can be used for a wide variety of applications, many different styles of maps can be created. The standard base map is a hillshade topographic image with overlain topographic contours to give a three-dimensional effect, but other bases can be used. Derivative classifications of the geologic units, such as karst potential or primary lithology, can be selected as an alternative to traditional stratigraphic symbolization. Users can also turn off the geologic units to focus attention on faults, structure contours, or other similar themes.

Many users will want to compare geologic units to other kinds of map information. For example, sinkholes or quarry outlines can be superimposed on the map for analysis. Locations of a variety of point data, such as oil wells, water wells, coal measurements, sample locations, measured sections, and photographs, can also be added to the map. And data pertaining to those locations will be accessible through point- and area-based search tools.