Fort Payne Chert

Very light to light-olive-gray, thin to thick-bedded fine to coarse-grained bioclastic (abundant pelmatozoans) limestone containing abundant nodules, lenses and beds of light to dark-grey chert. Upper part of formation locally consists of light-bluish-gray laminated siltstone containing vugs lined or filled with quartz and scattered throughout the formation are interbeds of medium to greenish-gray shale, shaly limestone and siltstone. Commonly present below the Fort Payne is a light-olive-gray claystone or shale (Maury Formation) which is mapped with the Fort Payne. The apparent thickness of the Fort Payne in this province varies due to differnetial dissolution of carbonate in the formation.
State Alabama
Name Fort Payne Chert
Geologic age Mississippian
Lithologic constituents
Major
Sedimentary > Clastic > Siltstone (Bed)
Sedimentary > Carbonate > LimestoneVery light to light-olive-gray, thin to thick-bedded fine to coarse-grained bioclastic (abundant pelmatozoans) limestone.
Minor
Sedimentary > Clastic > Mudstone > Shale (Bed)
Sedimentary > Clastic > Mudstone > Claystone (Bed)Commonly present below the Fort Payne is a light-olive-gray claystone or shale (Maury Formation) which is mapped with the Fort Payne.
Sedimentary > Chemical > Chert (Bed)abundant nodules, lenses and beds of light to dark-grey chert.
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 Colbert - Lauderdale - Lawrence - Limestone - Madison