A COLLAGE OF 1:24,000 DIGITAL GEOLOGIC MAPS (CARRVILLE, NOTASULGA AND LOACHAPOKA QUADRANGLES) ALONG THE PIEDMONT-COASTAL PLAIN ONLAP OF ALABAMA

Three digital geologic maps, from west to east, the 1:24,000 Carrville, Notasulga, and Loachapoka Quadrangles, east-central Alabama, are presented. The area underlying the quadrangles straddles the boundary between the Appalachian Piedmont (Inner Piedmont and Pine Mountain [PMT] terranes) and Gulf Coastal Plain (Upper Cretaceous Tuscaloosa Group) physiographic provinces. The Geological Survey of Alabama and its Geologic Mapping Advisory Committee has placed a high geologic mapping priority for this area due to rapid growth along the I-85 corridor and Auburn also is one of the fastest growing cities in Alabama. Detailed geologic mapping is needed for planning and development and for ground- and surface-water protection studies as required by the Alabama Department of Environmental Management. Mapping also helps to delineate high-silica quartzite and granite bodies that, due to the area's occurrence along the fall line, are the most southern sources of crystalline rock available for aggregate stone for a large part of the southeastern U.S. Basic research objectives are to better characterize: 1) basement and cover evolution within the PMT; 2) suspect Appalachian terranes; and 3) major fault zones separating the terranes (i.e., Brevard zone, Stonewall line, and Towaliga). Research goals are to gain a better understanding of how the Laurentian margin evolved and subsequently was dismembered and reassembled during the Appalachian orogeny, which has broader implications for the growth of continents, Laurentian-Gondwanan plate interactions, and supercontinent cycles. The computer generated maps were developed by scanning the topographic quads and hand-drawn overlays of station localities, structural/fabric data, contacts, and structural traces using an IDEAL® FSC 8010, 85 cm wide, color scanner at Auburn University. The scanned images were imported into a standard PC using Corel Designer 9.0® software. The topographic base map was digitally overlayed and geological information was digitized using a Wacom® touchscreen monitor and pen. The digitized map and various layers were printed directly from Corel Designer 9.0® or exported as a Windows® metafile (.wmf) into other drawing software packages and printed on an HP Designjet 5000 plotter in the Department of Geology and Geography, Auburn University.