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Geologic units in Bleckley county, Georgia

Neogene undifferentiated (Neogene) at surface, covers 55 % of this area

Includes Altamaha Grit (Dall, 1892); Citronelle Formation (Matson & Berry, 1916); and "Hawthorn Formation" (Cooke, 1939). (*) - outcrops of indurated sandstone and claystone

Suwannee Limestone and its residuum (Oligocene) at surface, covers 37 % of this area

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.

Twiggs Clay (Eocene) at surface, covers 4 % of this area

Twiggs Clay

Ocala Limestone (Eocene) at surface, covers 2 % of this area

Generally covered with Oligocene and Eocene residuum (Flint River Formation of Cooke, 1939); includes up-dip area, Tivola Limestone of Connell (1955). (*)- outcrops of Ocala Limestone on Dougherty Plain.

Stream alluvium (Quaternary) at surface, covers 1 % of this area

Stream alluvium and undifferentiated terrace deposits

Clinchfield Sand (Eocene) at surface, covers 1 % of this area

Clinchfield Sand

Cooper Marl (Eocene) at surface, covers 0.2 % of this area

It is now recognized that this unit is not the precise lithologic or biostratigraphic equivalent of type Cooper Marl (Huddlestun, Marsalis & Pickering, 1974).