GEOLOGIC MAPPING IN EAST TENNESSEE BY THE TENNESSEE DIVISION OF GEOLOGY: A PROGRESS REPORT

Over the past two years, the Tennessee Division of Geology (TDG) completed mapping the geology of the Cave Creek, Philadelphia, Sweetwater, Sullivan Gardens, and Leesburg quadrangles in East Tennessee. These areas were chosen based on population growth trends and environmental issues, but they also included some interesting foreland fold-thrust belt geology. The work was partially funded by the U.S. Geological Survey StateMap Program.

The Cave Creek, Leesburg, and Sullivan Gardens geologic maps were compiled on a personal computer using ESRI's ArcView© Geographic Information System (GIS) software. Stratigraphic columns and cross sections were drawn using Adobe Illustrator© graphics software. These are the first geologic maps that TDG has produced in GIS-format starting from raw field data. We did not use GPS technology for these mapping projects, but now have the GPS equipment when needed. We did use a number of free software extensions to help us deal with the structured framework of the ArcView program and to improve its versatility for creating geologic maps. One of the difficulties in making the transition from manually drafted to digitally produced geologic maps is implementing new publication standards involving aspects such as database structure and graphic styles.

The Division of Geology is behind other state surveys in the development of GIS-based geologic maps, but is building upon the lessons learned by them. Our goal is to produce a standardized digital geologic map that is available to the public in various formats (paper, CD, internet downloads). At this time, however, the lack of staff support (personnel and expertise) and continued updates in computer hardware and software hamper our ability to develop a streamlined process from field data collection to a digital map product.