DIGITAL GEOLOGIC MAP/DATABASE VIA GRAPHIC-ONLY SOFTWARE: DYING METHOD OR VALID OPTION FOR THE FUTURE?

The production of digital geologic maps by both geologic surveys and private consultants has recently favored the use of GIS software (ARCview, ARC info, AutoCAD, etc.) over graphics-only software (Adobe Illustrator, Corel Draw, etc.). The Structural Geology and Tectonics Research Group at the University of Tennessee currently employs both methods providing us with a broad perspective and better knowledge of the advantages and disadvantages of each. The graphics-only method is beneficial due to both the availability of off-the-shelf graphics software and ease of use in the production of printable maps and graphic databases. The use of graphics software allows graduate students, with or without extensive computer experience, to create digital geologic maps while actively pursuing field-based research. Also, these maps are easily transformed into final printable maps for publication and distribution upon completion of research. These criteria are easily met, with the production of high-quality maps, by the use of graphics-only software. On the other hand, we favor GIS methods where large amounts of data have to be spatially analyzed or transformed. The ability to query geographically referenced databases for specific kinds of information, the possibility of creating new data sets from existing ones, and the need to export geologic data to specialized geologic software are the main reasons to favor GIS methods. The major disadvantages are a steep learning curve, time-consuming data input, and extra steps in the final presentation stage. In the near future, integration with GPS systems will eliminate the need for digitizing data. We have developed a number of highly customized techniques to bridge the gap between these two methods, but the difference in the scope of each approach prevents us from developing a more comprehensive solution. In conclusion, graphic-only software is preferred if the primary intention is to produce high-quality, easily reproducible, geologic maps while GIS is essential if a complex georeferenced database is needed for current and future data analysis.