VECTOR-GIS GEOLOGIC MAPS FROM ALONG THE FALL LINE IN EAST-CENTRAL ALABAMA

Geologic maps are fundamental tools used in interpreting geologic relationships for a host of academic, governmental, socio-economic, and industrial stockholders. By converting existing geologic maps from paper format to GIS vector format, most any type of geologic information can be easily incorporated, readily accessed and updated, georeferenced, and queried using a variety of GIS analytical techniques. We present methods and procedures used to produce seamless digital geologic maps for five adjacent (‘stitched’) 1:24000 scale geologic quadrangle maps (from west to east, Tallassee, Carrville, Notasulga, Loachapoka, and Auburn quads) of southernmost Appalachian Piedmont terranes from east-central Alabama. These maps straddle the boundary with sedimentary rocks of the Gulf Coastal Plain (i.e., the fall line) and reflect the geology of the southernmost exposed eastern Blue Ridge, Inner Piedmont, and Pine Mountain terranes. Our project aims to develop a practical method for the production, and digitization of geologic maps that are compatible with those used by the Geological Survey of Alabama and the USGS. The procedure requires that existing PDF files of geologic maps be digitized in a heads up manner creating feature classes contained within a personal geodatabase.