Ordovician System undivided in part (Includes Sequatchie Formation, Elkmont Formation, Leipers Limestone, Inman Formation, Nashville Group, and Stones River Group)

Sequatchie Formation -- grayish-red and yellowish-gray calcareous shale containing interbedded fossiliferous limestone. Elkmont Formation -- medium to dark-gray phosphatic limestone with interbeds of light to medium-gray and black shale. Leipers Limestone -- medium to dark-gray thin to medium-bedded fossiliferous limestone containing interbeds of argillaceous limestone. Inman Formation -- interbedded greenish-gray or moderate to dusky-red shale and light-gray peloidal limestone. Nashville Group undifferentiated -- medium to dark-gray argillaceous and fossiliferous limestone overlain by yellowish-gray laminated silty limestone. Stones River Group -- medium to dark-gray thick to thin-bedded limestone, argillaceous in part, locally very fossiliferous.
State Alabama
Name Ordovician System undivided in part (Includes Sequatchie Formation, Elkmont Formation, Leipers Limestone, Inman Formation, Nashville Group, and Stones River Group)
Geologic age Ordovician
Lithologic constituents
Major
Sedimentary > Carbonate > Limestone (Bed)Sequatchie Formation - interbedded fossiliferous limestone; Elkmont Formation - medium to dark-gray phosphatic limestone; Leipers Limestone - medium to dark-gray thin to medium-bedded fossiliferous limestone containing interbeds of argillaceous limestone; Inman Formation - light-gray peloidal limestone; Nashville Group undifferentiated - medium to dark-gray argillaceous and fossiliferous limestone overlain by yellowish-gray laminated silty limestone. Stones River Group -- medium to dark-gray thick to thin-bedded limestone, argillaceous in part, locally very fossiliferous.
Minor
Sedimentary > Clastic > Mudstone > Shale (Bed)Sequatchie Formation - grayish-red and yellowish-gray calcareous shale containing interbedded fossiliferous limestone; Elkmont Formation - medium to dark-gray phosphatic limestone; Leipers Limestone - medium to dark-gray thin to medium-bedded fossiliferous limestone containing interbeds of argillaceous limestone; Inman Formation - light-gray peloidal limestone; Nashville Group undifferentiated -- medium to dark-gray argillaceous and fossiliferous limestone overlain by yellowish-gray laminated silty limestone. Stones River Group -- medium to dark-gray thick to thin-bedded limestone, argillaceous in part, locally very fossiliferous.
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 Limestone - Madison