|Geologic age||Upper Cretaceous|
Unconsolidated > Fine-detrital > Clay (Bed)Light-gray cross-bedded to massive glauconitic sand and sandy clay and calcareous sandstone.
Unconsolidated > Coarse-detrital > Sand (Bed)Light-gray cross-bedded to massive glauconitic sand and sandy clay and calcareous sandstone.
Sedimentary > Clastic > Sandstone > Arenite > Calcarenite (Bed)Light-gray cross-bedded to massive glauconitic sand and sandy clay and calcareous sandstone.
|Comments||Secondary unit descriptions from USGS Lexicon website (MS002) and MS007: Coffee Formation of Selma Group is the uppermost unit of Cretaceous age present in Tishomingo Co., and the only unit representing the Selma. No complete section is present in the report area as the unit is truncated by erosion. It is composed of very fine- to medium-grained, micaceous, glauconitic, quartz sand, thinly interbedded and interlaminated with light- to medium-gray, silty clay. The Coffee is replaced by the main body of chalky Selma strata in southern Lee and northwestern Itawamba Cos. The Tupelo Tongue is a very fossiliferous phase representing the southernmost extension of the Coffee Formation. Outcrop belt attains a maximum width of 8 mi in northwestern part of Tishomingo Co. Thickness is 150 ft at the surface of northwestern Tishomingo Co., 275 ft in Prentiss Co. to the south, and only about 100 ft in Lee Co. Disconformably overlies the Tombigbee Sand Member of the Eutaw Formation; unconformably underlies Tennessee River terrace deposits. Age is Late Cretaceous (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/
Wingard, G.L., 1993, A detailed taxonomy of Upper Cretaceous and lower Tertiary Crassatellidae in eastern North America; an example of the nature of extinction: U.S. Geological Survey Professional Paper, 1535, 131 p.
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.
|Counties||Alcorn - Itawamba - Lee - Prentiss - Tishomingo|