Tuscaloosa Group; Gordo Formation (ALKg;1)

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.

State	Alabama
Name	Tuscaloosa Group; Gordo Formation
Geologic age	Cretaceous
Original map label	Kg
Primary rock type	sand
Secondary rock type	clay or mud
Other rock types	gravel; chert
Lithologic constituents	Major Unconsolidated > Fine-detrital > Clay (Bed)lenticular beds of locally carbonaceous partly mottled moderate-red and pale-red-purple clay Unconsolidated > Coarse-detrital > Sand (Bed)Massive beds of cross-bedded sand, gravelly sand. Minor Unconsolidated > Coarse-detrital > Gravel (Bed)lower part is predominantly a gravelly sand consisting cheifly of chert and quartz pebbles. Incidental Sedimentary > Chemical > Chert (Bed)lower part is predominantly a gravelly sand consisting cheifly of chert and quartz pebbles.
Map references	Szabo, M. W., Osborne, E. W., Copeland, C. W. Jr., Neathery; T. L., 1988, Geologic Map of Alabama, Geological Survey of Alabama Special Map 220, scale 1:250,000. [http://www.ogb.state.al.us/ogb/ogb_gisdata/algeomap.zip]
Unit references	Szabo, M. W., Osborne, E. W., Copeland, C. W. Jr., Neathery; T. L., 1988, Geologic Map of Alabama, Geological Survey of Alabama Special Map 220, scale 1:250,000. [http://www.ogb.state.al.us/ogb/ogb_gisdata/algeomap.zip]
Geographic coverage	Autauga - Bibb - Chilton - Colbert - Dallas - Elmore - Fayette - Franklin - Greene - Hale - Lamar - Lauderdale - Marion - Perry - Pickens - Tuscaloosa