Southeastern Section–55th Annual Meeting (23–24 March 2006)

Paper No. 12
Presentation Time: 8:00 AM-12:00 PM

GEOLOGIC MAP OF THE BENEDICT AND FELTON QUADRANGLES OF NORTHWEST GEORGIA


HILTON, Deborah C., Department of Geological Sciences, Florida State Univ, Tallahassee, FL, 32306, dcdhilton@earthlink.net

A geologic map of the Benedict and Felton, Georgia quadrangles was created using AutoCAD Map 2000i software with support from the U.S.G.S. Educational Mapping Program. These quadrangles are located in northwest Georgia, in the easternmost foreland fold and thrust belt, and contain the following stratigraphy in descending order: Mississippian Floyd Shale and Fort Payne Chert, Devonian Frog Mountain Sandstone, Middle Ordovician Rockmart Slate, Lower Ordovician Newala-Lenoir Limestone, and Knox Group. These units are contained within a complex series of map-scale, northeast-southwest, doubly plunging, overturned, isoclinal folds that are obliquely decapitated by the overlying Talladega-Carterville fault. Units above the Newala-Lenoir are all unconformity bounded, but bounding unconformities cannot be demonstrated to be angular over the area of the mapped quads. For example, the Rockmart maintains a relatively uniform thickness of ~250 m. The polymict diamictite lithofacies of the Rockmart extends for ~26.5 km along strike from the Benedict quad northeastward into the Taylorsville quad, and is restricted to more southeastern exposures of the unit. The Rockmart, Frog Mountain (locally), Fort Payne, and Floyd are restricted to isoclinal synclines. Both the Rockmart and the Floyd contain the same generation of slaty cleavage that parallels the axial planes of these folds. The repetition of stratigraphy in the area has previously been interpreted as the result of fault imbrication rather than fold repetition as indicated here. This mapping project continues to demonstrate the effective use of AutoCAD Map 2000i software. Using such software, maps may be created with greater precision, offering hyperlink capability (i.e., rock descriptions, petrography, digital field photos), and may be stored and exchanged as electronic files.