EVOLUTION OF THE GEOLOGIC MAP
3-D geologic maps and visualizations provide geologists with new tools for explaining the distribution and character of subsurface sediments. This approach, however, requires more sophisticated software and data management strategies. While format and content standards are still evolving, publication options do allow delivery of 3-D content in different data formats which can be customized as needed. The ubiquitous nature of GIS technology and map data, has resulted in relatively easy accessibility to many base maps. In addition to geology, digital map publications can include map layers like elevation, DOQs, USGS topo map sheet layers and PLSS boundaries. These too can be offered in a range of formats. Data, reports, and documentation can be included, allowing full documentation to accompany data and maps. Photographs or raster graphical files can also be included, but care should be taken to ensure full image files are included with any lossy versions. Interactive 3-D map presentations are becoming feasible and can provide users with the ability to manipulate the maps and data to better understand the relevance of the map to specific applications. This is one area where technology is still advancing and frequently changing our publication options. These tools and publications are allowing geological surveys to examine the possibility of creative licensing options. This could allow the user to request custom map updates or customized visualizations over some period of time. Finally, custom applications allow web sites to be created that provide interactive use of all data, reports, and 2-D and 3-D maps. These sites would be costly to create and maintain, but would provide a high degree of user interaction with the data and could conceivably allow users to create their own interpretive map products.