SOME PROPOSED REVISIONS ON THE STRUCTURE AND STRATIGRAPHY OF THE CONASUGA GROUP IN THE EASTERN VALLEY AND RIDGE OF GEORGIA

Geologic mapping along the boundary between Bartow and Gordon Counties, Georgia (Fairmount and White East 7-1/2 minute quadrangles) indicates that the structure and formational assignments within the Conasauga Group require revision. Two new thrust faults are recognized; here termed the Highway 411 Fault, and the Slate Mine Road Fault. Between the Cartersville-Great Smoky Fault and the Highway 411 Fault, the Rutledge Formation (mixed dolomite and limestone) is overlain by the Rogersville Shale. Between the Highway 411 Fault and the Slate Mine Road Fault, the Maryville Limestone (no dolomite recognized) is overlain by the Nolichucky Shale. The Nolichucky Shale also extends several miles west of the Slate Mine Road Fault. Dips are very shallow except near thrust fault boundaries.

Cressler (1974) mapped lithologies within the Conasauga Group in this area, but did not make formational assignments. We are in basic agreement with his mapped lithologic units; but recognition of the two thrust faults requires a substantially different interpretation of a geologic section through the area.

Assuming there is stacking of the thrust sheets, and considering that both the shales and limestones in this area are carbonaceous, there is potential for natural gas discovery either within the eastern portion of the Valley and Ridge, within the stacked sequence, or to the east of the Cartersville-Great Smoky fault where these units likely extend in the subsurface beneath the Blue Ridge and possibly the Piedmont.