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

Geologic units in Tishomingo county, Mississippi

Alluvial deposits (Quaternary) at surface, covers 0.1 % of this area

Alluvial Deposits - Sand, silt, clay, and gravel. In flood plain of Mississippi River more than 100 feet thick; in smaller streams generally less than 20 feet thick.

Lithology: sand; silt; clay or mud; gravel

Chester group (Mississippian) at surface, covers 4 % of this area

Chester group - Sandstone, shale, and limestone.

Lithology: sandstone; shale; limestone

Chester group (Mississippian) at surface, covers 6 % of this area

Chester group - Limestone, chert, and shale of Meramec, Osage, and Kinderhook age.

Lithology: limestone; chert; shale

Eutaw formation (Upper Cretaceous) at surface, covers 62 % of this area

Eutaw formation - More or less cross-bedded and thinly laminated glauconitic sand and clay; basal part includes the McShan formation, greenish-gray, micaceous, locally very glauconitic, very fine-grained sand and thin-bedded light-gray clay, small chert gravels may be present in basal beds, not recognized in northern Tishomingo County.

Lithology: sand; clay or mud; gravels

Eutaw Formation (Cretaceous) at surface, covers < 0.1 % of this area

Eutaw Formation - Light-greenish-gray to yellowish-gray cross-bedded, well-sorted, micaceous, fine to medium quartz sand that is fossiliferous and glauconitic in part and contains beds of greenish-gray micaceous, silty clay and medium-dark-gray carbonaceous clay. Light-gray glauconitic fossiliferous sand, thin beds of sandstone, and massive accumulations of fossil oyster shells occur locally in the upper part of the formation in western AL (Tombigbee Sand Member). In eastern AL thin to thick-bedded accumulations of the fossil oyster Ostrea cretacea Morton occur throughout much of the formation.

Lithology: sand; clay or mud; sandstone;

Eutaw Formation (Cretaceous) at surface, covers 0.1 % of this area

Eutaw Formation - Grayish-green sand, fine-grained, glauconitic, micaceous; interbedded with gray laminated clays which commonly contain carbonized or silicified wood. (Mapped with Coffee except in Hardin County and southeastern Decatur County.) Thickness 0 to 180 feet; thins northward

Lithology: sand; clay or mud

Tuscaloosa Group; Gordo Formation (Cretaceous) at surface, covers < 0.1 % of this area

Gordo Formation - (Tuscaloosa Group), Massive beds of cross-bedded sand, gravelly sand, and lenticular beds of locally carbonaceous partly mottled moderate-red and pale-red-purple clay; lower part is predominantly a gravelly sand consisting chiefly of chert and quartz pebbles. Not mapped east of the Tallapooza River.

Lithology: sand; clay or mud; gravel; chert

High-level alluvial deposits (Quaternary-Tertiary) at surface, covers < 0.1 % of this area

High-level Alluvial Deposits - Iron-stained gravel, sand, silt, and clay; variable in thickness but generally less then 60 feet thick.

Lithology: gravel; sand; silt; clay or mud

Tuscumbia Limestone (Mississippian) at surface, covers < 0.1 % 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

Tuscaloosa formation (Upper Cretaceous) at surface, covers 13 % of this area

Tuscaloosa formation - Light and vari-colored irregularly bedded sand, clay, and gravel; gravel is mostly in lower portion.

Lithology: sand; clay or mud; gravel

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

Fort Payne Formation - Bedded chert, calcareous and dolomitic, somewhat crinoidal; and minor shale. Thin green shale (Maury) at base. Average thickness about 200 feet.

Lithology: chert; shale

Coffee Sand (Cretaceous) at surface, covers < 0.1 % of this area

Coffee Sand - Loose fine-grained sand, light-gray, sparsely glauconitic, locally interbedded with laminated lignitic clay. Thickness 25 to 200 feet; thins northward.

Lithology: sand; clay or mud

Pride Mountain Formation (Mississippian) at surface, covers < 0.1 % 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

Chester group (Devonian) at surface, covers 0.6 % of this area

Chester group - Chattanooga shale (Carboniferous or Devonian) and underlying limestones of Early Devonian age.

Lithology: shale; limestone

Coffee sand (Upper Cretaceous) at surface, covers 3 % of this area

Coffee sand - (Selma group), Light-gray cross-bedded to massive glauconitic sand and sandy clay and calcareous sandstone.

Lithology: sand; clay or mud; calcarenite

Eutaw formation (Tombigbee sand member) (Late Cretaceous) at surface, covers 12 % of this area

Eutaw formation (Tombigbee sand member) - massive fine glauconitic sand.

Lithology: sand