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Mineral Resources > Online Spatial Data > Geology > by state > Alabama Geology

Geologic units in Lawrence county, Alabama

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

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.

Lithology: limestone; chert; siltstone; shale; claystone

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

Parkwood Formation - 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.

Lithology: shale; sandstone; mudstone; limestone; clay or mud; mixed clastic/coal

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

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

Lithology: sandstone; shale

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

Pride Mountain Formation - 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.

Lithology: shale; limestone; sandstone; mudstone

Tuscumbia Limestone (Mississippian) at surface, covers 21 % of this area

Tuscumbia Limestone - 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.

Lithology: limestone; chert

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

Pottsville Formation (lower part) - 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.

Lithology: sandstone; shale; siltstone; coal

Bangor Limestone (Mississippian) at surface, covers 32 % of this area

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

Lithology: limestone; mudstone

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

Pride Mountain Formation and Monteagle Limestone undifferentiated - Light-gray oolitic limestone, argillaceous and in part bioclastic with interbeds of medium to dark-gray shale.

Lithology: limestone; shale