Vicksburg group and Chickasawhay limestone

Chickasawhay limestone, sandy limestone, and sand, present only in eastern MS (mapped with it is the overlying Paynes Hammock sand of Miocene age); Vicksburg group, predominantly limestone and marl, but contains some bentonite and near the top, chocolate-colored clay and some sand.
State Mississippi
Name Vicksburg group and Chickasawhay limestone
Geologic age Oligocene
Lithologic constituents
Major
Sedimentary > Carbonate > Limestone
Minor
Unconsolidated > Coarse-detrital > Sand
Unconsolidated > Marl
Incidental
Unconsolidated > Fine-detrital > ClayChocolate-colored clay.
Sedimentary > Clastic > Mudstone > Claystone > BentoniteVicksburg group, predominantly limestone and marl, but contains some bentonite.
References

Moore, William Halsell, 1969, reprinted 1985, Geologic Map of Mississippi, Compiled by Bicker, A. R., Jr., a revision of the geologic map published by the MS Geological Survey in 1945 in cooperation with the USGS, revised from data submitted by Dr. E. E. Russell of MS State University from published reports of the MS Geological Survey and from field revisions, Mercury Maps Inc., Jackson, MS., scale 1:500,000.

NGMDB product
Counties Claiborne - Clarke - Hinds - Issaquena - Jasper - Jones - Madison - Rankin - Smith - Warren - Wayne - Yazoo