The surface and near-surface geology of the Atlantic Coastal Plain from Cape Fear, North Carolina to Cape Canaveral, Florida, below 76 m (250 ft) in altitude, comprises Pliocene and Pleistocene fluvial marine, back-barrier, barrier, and shallow-shelf sand, silt, and clay. The fossil content of age-equivalent Pliocene and Pleistocene sediments decreases from the Cape Fear area southward into Georgia. In the Carolinas, fossils are common. Paleontological analyses and isotopic and chemical age determinations, combined with lithostratigraphic studies and geologic mapping, have resulted in the establishment of a regional time-stratigraphic framework. In Georgia, fossils are scarce. Most known fossil localities are in early late Pliocene sediments paleontologically dated between 3.5 and 2.8 Ma. Microfossil data suggest the presence of at least two other Pliocene units—late early Pliocene (4.2-4.0 Ma) and latest late Pliocene (2.4-1.8 Ma). Fossil data are insufficient to differentiate Pleistocene units, but there are distinctive changes in shell morphology and species abundance of foraminifera in sediments topographically above and topographically below 9 m (30 ft) in altitude. No isotopic or paleomagnetic data are available for Pliocene or Pleistocene sediments in Georgia. There has been no detailed geologic mapping. Regional mapping dates to the turn of the century.

The fossil-poor nature of both onshore and offshore Pliocene and Pleistocene Coastal Plain sediments in the Georgia part of the Atlantic Coastal Plain may be due to any one or combination of the following: styles and rates of regional and/or local uplift; sediment load of the numerous rivers that drain this region; freshwater influence on estuarine and nearshore littoral environments; shoreline configuration relative to major ocean currents; dissolution as the result of weathering, and erosion.