Geologic units in Lawrence county, Alabama

Bangor Limestone (Mississippian) at surface, covers 31 % of this area

Medium-gray bioclastic and oolitic limestone, containing interbeds of dusky-red and olive-green mudstone in the upper part.

Tuscumbia Limestone (Mississippian) at surface, covers 22 % of this area

Light-gray limestone, partly oolitic near top; fine to very coarse-grained bioclastic crinoidal limestone common; light-gray chert nodules and concretions are scattered throughout and are abundant locally. The apparent thickness of the formation in this province varies due to differential dissolution of the carbonate in the unit.

Hartselle Sandstone (Mississippian) at surface, covers 18 % of this area

Light-colored thick-bedded to massive quartzose sandstone, containing interbeds of dark-gray shale.

Pottsville Formation (lower part) (Pennsylvanian) at surface, covers 16 % of this area

Light-gray thick-bedded to massive pebbly quartzose sandstone, containing varying amounts of interbedded dark-gray shale, siltstone, and thin discontinuos coal. The Boyles Sandstone Member is a formally named unit in the lower part of the formation. Top of unit is mapped at the Black Creek coal.

Pride Mountain Formation (Mississippian) at surface, covers 6 % of this area

Medium to dark-gray shale, containing one to three units of a variable combination of sandstone and limestone in the lower part; locally contains rare interbeds of dusky-red and greenish-gray mudstone.

Parkwood Formation (Pennsylvanian-Mississippian) at surface, covers 4 % of this area

Interbedded medium to dark-gray shale and light to medium-gray sandstone; locally contains dusky-red and grayish-green mudstone, argillaceous limestone, and clayey coal.

Bangor Limestone (Mississippian) at surface, covers 2 % of this area

Medium-gray bioclastic and oolitic limestone, containing interbeds of dusky-red and olive-green mudstone in upper part.

Fort Payne Chert (Mississippian) at surface, covers 0.1 % of this area

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.

Pride Mountain Formation and Monteagle Limestone undifferentiated (Mississippian) at surface, covers < 0.1 % of this area

Light-gray oolitic limestone, argillaceous and in part bioclastic with interbeds of medium to dark-gray shale.