Chattanooga Shale and Frog Mountain Sandstone undifferentiated

(In areas mapped as Dcfm one or both units may be locally absent) - Chattanooga Shale -- Brownish-black organic shale containing light to dark-gray sandstone and rare limestone interbeds near the base. Frog Mountain Sandstone -- light to dark-gray sandstone with thin dark-gray shale interbeds, light-gray to black dolomudstone, glauconitic limestone, and fossiliferous chert locally in lower part.
State Alabama
Name Chattanooga Shale and Frog Mountain Sandstone undifferentiated
Geologic age Devonian
Lithologic constituents
Major
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Mudstone > Shale (Bed)Brownish-black organic shale
Minor
Sedimentary > Carbonate > Limestone (Bed)Chattanooga Shale -- rare limestone interbeds near the base; Frog Mountain Sandstone -- glauconitic limestone
Incidental
Sedimentary > Chemical > Chert (Bed)fossiliferous chert
Sedimentary > Carbonate > Dolostone (Bed)light-gray to black dolomudstone
References

Szabo, M.W., Osborne, E.W., Copeland, C.W. Jr., and Neathery, T.L., 1988, Geologic Map of Alabama, Geological Survey of Alabama Special Map 220, scale 1:250,000.

NGMDB product
Counties Tuscaloosa