A fauna of reworked Paleozoic fossils has been found in chert pebbles from the Gulf Coastal Plain in eastern Columbia County, Arkansas, although the nearest mapped exposure of Mississippian and Pennsylvanian rocks are fifty-five miles northward in the southern edge of the Ouachita Mountains. The surficial rocks at the collection site have been referred to the Claiborne Group of Eocene age by the authors of the geological map of Arkansas. Additional outcrops containing similar Paleozoic fossils have been found within a 15-mile radius. The fauna includes both lacy and twig-like bryozoans, articulate brachiopods, tabulate and rugose corals, stalked echinoderms, gastropods, fusulinids and two trilobite pygidia (17 mm wide by 15 mm long and 16 mm wide by 5 mm long) of two distinct taxa. The fossils resemble those of a carbonate platform such as northern Arkansas but would have to be delivered southward before the Arkansas River drainage developed. The possibility of an origin from the south is being considered.
"Hypothetical Origins of Paleozoic Fossils from the Gulf Coastal Plain of Arkansas,"
Journal of the Arkansas Academy of Science: Vol. 54
, Article 5.
Available at: https://scholarworks.uark.edu/jaas/vol54/iss1/5