Highly weathered sands and sandy clays of lower Tertiary age
Providence Sand, includes Perote Member
Stream alluvium and undifferentiated terrace deposits
Ripley Formation
Nanafalia Formation
Nanafalia, Porters Creek, and Clayton Formations, undifferentiated
Up-dip equivalent of Lisbon and Tallahatta Formations
Cusseta Sand
Eocene and Oligocene Residuum, undifferentiated
As mapped includes lower Eocene Bashi Marl Member of the Hatchetigbee Formation
Twiggs Clay
Clayton Formation
As mapped, includes Chattahoochee Limestone in Seminole and Decatur Cos.; Flint River Formation, in part, (Cooke, 1939); Jacksonboro Limestone in Screven Co.; and Glendon and Marianna Limestones in Pulaski Co.
Blufftown Formation