Paper No. 24
Presentation Time: 8:00 AM-12:00 PM
GEOLOGIC MAP OF THE TAYLORSVILLE QUADRANGLE, SOUTHEASTERN FORELAND, TALLADEGA BELT, AND EASTERN BLUE RIDGE, GEORGIA
A geologic map of the Taylorsville, Georgia quadrangle was compiled using AutoCAD Map 2000i® software with support from the U.S.G.S. Educational Mapping Program. The quadrangle, located in northwest Georgia, contains rocks of the easternmost foreland fold and thrust belt, the Talladega belt, and part of the eastern Blue Ridge. These sequences are bordered by two major thrusts, with the TalladegaCartersville fault at the base of the Talladega belt and the Allatoona fault at the base of the eastern Blue Ridge. Rocks of the fold and thrust belt are contained within an open, southwest-plunging syncline which is decapitated by the TalladegaCartersville fault, and cored by the Mississippian Fort Payne Chert, a thin section of Early to Middle Devonian Frog Mountain Sandstone (?), and the Middle Ordovician Rockmart Slate. Each of these units is unconformity-bounded below. The unconformity at the base of the Rockmart cuts across the Lower Ordovician Newalla Limestone down into the lower Knox Group, and lies across both limbs of an earlier, very open, southwest-plunging syncline, which must be related to mild Ordovician deformation. Post-Rockmart, pre-Frog Mountain/Fort Payne deformation is not apparent, as the latter two units lie concordantly atop the Rockmart. The Talladega sequence is >4 km thick and consists of a monotonous section of biotite-grade sericite phyllite rhythmically interbedded with medium-to-fine grained feldspathic metawacke, probably equivalent to the Silurian (?)Devonian Lay Dam Formation in Alabama. The eastern Blue Ridge consists of an accreted terrane containing the Ordovician Pumpkinvine Creek Amphibolite, Galts Ferry Gneiss, and Canton Schist. This mapping project successfully demonstrates the effective use of AutoCAD Map 2000i® software, and the several advantages of such software beyond those of manual map drafting. With such software, maps may be drafted and compiled with greater precision, can offer hyperlink capability (i.e. rock descriptions, petrography, digital field photos, etc.), and may be stored and exchanged as electronic files.