GEOLOGIC MAP ILLUSTRATING THE STRATIGRAPHY AND STRUCTURAL GEOLOGY OF THE BURNT HICKORY RIDGE, GEORGIA, 7.5-MINUTE QUADRANGLE

Geologic mapping of the Burnt Hickory Ridge, Georgia, 7.5-minute quadrangle by Thomas J. Crawford began in 1975 (Georgia Geologic Survey Open – File Report); Areal distribution of lithologies and structural interpretations have been modified by detailed fieldwork since 1975, with additions by Crawford, Kath, and Costello. Blue Ridge/Piedmont metamorphic rocks are shown as being thrust northward over north-south trending Cambrian and Ordovician rocks along the east-west trending Emerson-Talladega Fault. A sinuous fault trace and small windows exposing Ridge and Valley carbonate rocks emphasize the low angle of the Emerson-Talladega Fault on the Burnt Hickory Ridge quadrangle. The Allatoona Fault trends northeast across the middle of the quadrangle; and there are numerous other major faults to the southeast, with similar northeast trends.

Of particular significance on the Burnt Hickory Ridge quadrangle is a chloritic and calcareous schist-metagraywacke lithologic unit, consisting of: feldspar-quartz-muscovite schist and muscovite-quartz-feldspar metagraywacke, both of which are chloritic and calcareous, and contain thin well-layered quartzites. An abundance of quartz pods gives the rock a “rolling” texture, and the unit weathers brownish red to dark reddish brown. This distinctive lithologic unit extends across the Burnt Hickory Ridge quadrangle near the Emerson-Talladega Fault in broad open folds; and continues across the northwest corner of the Acworth quadrangle and to near the middle of the Allatoona Dam quadrangle, where it is in fault contact with the Corbin Metagranite, emphasizing the overriding relationship of the Emerson-Talladega Fault with the Great Smoky (Cartersville) Fault and the Allatoona Dam Fault.