Devonian-Missisippian undivided

Includes Fort Payne Chert, Chattanooga Shale in Dade Co.; Fort Payne Chert at top, Chattanooga Shale in middle and Armuchee Shale at bottom in all areas except Polk Co. and Dade Co.; Fort Payne Chert, and Armuchee Chert in Polk Co. CHATTANOOGA Shale (Dc)
State Georgia
Name Devonian-Missisippian undivided
Geologic age Devonian-Mississippian
Lithologic constituents
Major
Sedimentary > Chemical > Chert
Sedimentary > Clastic > Mudstone > Shale > Black-shale
Comments Ridge and Valley sedimentary rocks. Secondary unit descriptions from USGS Geologic Names lexicon (ref. GA003): The Fort Payne consists of limestones that are commonly cherty, biostromal, crinoidal, or siliceous. It also contains cherty dolostones and calcareous, cherty siltstones. Age is Early Mississippian. Named Chattanooga black shale. Thickness is 0 to 35 ft. In northwestern GA, underlain by the Rockwood formation and overlain by the Fort Payne chert. Armuchee chert described in northwestern GA as rusty, sandy, bedded chert, at places grading into ferruginous sandstone. Thickness 0 to 50 ft. Underlies Chattanooga shale and overlies Rockwood formation on north side of Coosa Valley, northwest of Coosa fault. Probably contemporary with Frog Mountain sandstone of Oriskany age, which is present only in the southwest corner of Rome quad.
References

Lawton, D.E., Moye, F.J., Murray, J.B., O'Connor, B.J., Penley, H.M., Sandrock, G.S., Marsalis, W.E., Friddell, M.S., Hetrick, J.H., Huddlestun, P.F., Hunter, R.E., Mann, W.R., Martin, B.F., Pickering, S.M., Schneeberger, F.J., and Wilson, J.D., 1976, Geologic Map of Georgia, Georgia Dept. of Natural Resources, Geologic and Water Resources Division, Georgia Geological Survey. Scale 1:500,000.

NGMDB product
Counties Catoosa - Chattooga - Dade - Floyd - Gordon - Walker - Whitfield