|Geologic age||Upper Cretaceous|
Unconsolidated > Fine-detrital > Clay (Bed)More or less cross-bedded and thinly laminated glauconitic sand and clay; basal part includes the McShan formation, greenish-gray, micaceous, locally very glauconitic, very fine-grained sand and thin-bedded light-gray clay.
Unconsolidated > Coarse-detrital > Sand (Bed)More or less cross-bedded and thinly laminated glauconitic sand and clay; basal part includes the McShan formation, greenish-gray, micaceous, locally very glauconitic, very fine-grained sand and thin-bedded light-gray clay.
Unconsolidated > Coarse-detrital > GravelSmall chert gravels may be present in basal beds.
|Comments||Units Ke and Ket are combined in the map description, but have separate symbols, colors and descriptions, so split them up here. Secondary unit descriptions from USGS Lexicon website (MS002) and MS007: "In the absence of new nomenclature concerning the Eutaw, the name is utilized in this report as defined in Stephenson and Monroe (1938 and 1940) as Eutaw Group, Formation, and Member designations." The McShan Formation is the lowermost unit of the Eutaw Group and unconformably overlies the Tuscaloosa Group. The Eutaw Formation overlies the McShan Formation and underlies the Selma Group. The Eutaw Formation is divided into the Lower Eutaw Member (Counce Member of Russell, 1965) and the upper Tombigbee Sand Member. The Lower Eutaw Member is 180 to 550 ft thick downdip, in the subsurface of MS, and contains an abundance of red-brown shale and pyroclastic material locally. Thickness is 120 to 150 ft thick in east-central MS and west-central AL. [Usage in this report is not is accordance with the 1983 North American Stratigraphic Code.] (Merrill and others, 1988).|
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.
USGS Geologic Names lexicon found at: http://ngmdb.usgs.gov/Geolex/
Merrill, R.K., Gann, D.E. and Jennings, S.P., 1988, Tishomingo County geology and mineral resources [Mississippi]: Mississippi Office of Geology Bulletin, no. 127, 178 p.
Dowsett, H.J., 1989, Documentation of the Santonian-Campanian and Austinian-Tayloran Stage boundaries in Mississippi and Alabama using calcareous microfossils: U.S. Geological Survey Bulletin, 1884, 20 p.
|Counties||Clay - Itawamba - Lowndes - Monroe - Prentiss - Tishomingo|