Tallahatta formation and Neshoba sand (MSEOt;0)

State	Mississippi
Name	Tallahatta formation and Neshoba sand
Geologic age	Eocene
Original map label	Et
Comments	Secondary unit descriptions from USGS Lexicon website (MS002) and MS004: Tallahatta Formation of Claiborne Group in Newton Co., MS, divided into lower Basic City Shale Member and upper Neshoba Sand Member. Neshoba is not encountered at the surface in Clarke Co., and is not considered a separate geologic unit in Lauderdale Co. Unit as exposed in study area is typically moderate- to dark reddish-brown, coarse- to fine-grained, consistently micaceous, locally glauconitic, massive, nonfossiliferous sand. Usually has mottled appearance. In the subsurface, it is typically grayish-orange, very coarse- to fine-grained, poorly sorted, subangular quartz sand, with appreciable glauconite and mica. Generally 10 ft thick; 15 ft in Test Hole A0-9. Contact with Basic City Shale Member is conformable. Upper contact with Winona Formation is disconformable. Represents a coarsening upward sequence of sediments produced as the sea regressed in a deltaic and strandplain environment. Measured section. Geologic map. Stratigraphic column (Merrill and others, 1985).
Primary rock type	claystone
Secondary rock type	clay or mud
Other rock types	sand; sandstone
Lithologic constituents	Major Unconsolidated > Fine-detrital > Clay (Bed)Southeast of Pearl River predominantly more or less glauconitic claystone and clay with lenses of sand and some sandstone; highly cross-bedded sand at base. Sedimentary > Clastic > Mudstone > Claystone (Bed)Southeast of Pearl River predominantly more or less glauconitic claystone and clay with lenses of sand and some sandstone; highly cross-bedded sand at base. Minor Sedimentary > Clastic > Sandstone (Lense)Southeast of Pearl River predominantly more or less glauconitic claystone and clay with lenses of sand and some sandstone; highly cross-bedded sand at base. Unconsolidated > Coarse-detrital > Sand (Bed)Southeast of Pearl River predominantly more or less glauconitic claystone and clay with lenses of sand and some sandstone; highly cross-bedded sand at base.
Map 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.
Unit 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. USGS Geologic Names Lexicon (GEOLEX) [http://ngmdb.usgs.gov/Geolex/] Merrill, R.K., Sims, J.J., Jr., Gann, D.E. and Liles, K.J., 1985, Newton County geology and mineral resources [Mississippi]: Mississippi Office of Geology Bulletin, no. 126, 108 p.
Geographic coverage	Attala - Benton - Calhoun - Carroll - Choctaw - Clarke - DeSoto - Grenada - Lafayette - Lauderdale - Leake - Marshall - Montgomery - Neshoba - Newton - Panola - Tallahatchie - Tate - Tippah - Winston - Yalobusha