Catahoula formation (MSMIc;0)

State	Mississippi
Name	Catahoula formation
Geologic age	Miocene
Original map label	Mc
Comments	Secondary unit description from USGS Lexicon website (MS002), and MS011: Catahoula of this study has been arbitrarily defined as those sediments found above the Vicksburg limestones, or the Bucatunna Formation, and beneath the Citronelle or terrace deposits of previous workers. Catahoula sediments show a greater degree of induration than those of similar appearance in the area. A mappable contact between the Catahoula and overlying Hattiesburg Formation has never been found and because they are so similar, the authors recommend that they be considered a single mapping unit. The Catahoula crops out in the mapping area, only in the Mize quad. Unit is composed of sandy silt, silt, and clay, interbedded with sandstone layers. The silt and clay commonly display blocky to conchoidal rock fracture. The sandstones are fine-grained. Kaolinite is the dominant clay mineral. Unit also contains mica and smectite. Age is Miocene (Li and Meylan, 1994).
Primary rock type	sand
Secondary rock type	sandstone
Other rock types	clay or mud; quartzite; gravel
Lithologic constituents	Major Unconsolidated > Coarse-detrital > SandIrregularly bedded gray sand. Minor Unconsolidated > Coarse-detrital > GravelSome gravel. Unconsolidated > Fine-detrital > ClayMottled red and gray, green, and chocolate-colored clay. Sedimentary > Clastic > Sandstone Incidental Metamorphic > Metasedimentary > Metaclastic > QuartziteSome quartzite.
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/] Li, Zebao and Meylan, M.A., 1994, Lithostratigraphy and petrology of Neogene and Pleistocene sedimentary rocks, south-central Mississippi: Gulf Coast Association of Geological Societies Transactions, v. 44, p. 383-392.
Geographic coverage	Adams - Claiborne - Clarke - Copiah - Covington - Greene - Hinds - Jasper - Jefferson - Jones - Lawrence - Lincoln - Perry - Rankin - Simpson - Smith - Warren - Wayne