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Jackson group

Jackson group - Yazoo clay, green and gray calcareous clay containing some sand and marl; Moodys Branch formation at base, shells embedded in glauconitic clayey quartz sand.
State Mississippi
Name Jackson group
Geologic age Eocene
Comments Secondary unit descriptions from USGS Lexicon website (MS002) and MS005: Upper Eocene (Bartonian-Priabonian) Jackson Group includes the Moodys Branch Formation, the Yazoo Clay, and the Crystal River Formation in the study area. Yazoo Clay is further subdivided into the North Twistwood Creek Clay, the Cocoa Sand, the Pachuta Marl, and the Shubuta Members. Jackson disconformably overlies middle Eocene Claiborne Group (Tew, 1992).
Primary rock type clay or mud
Secondary rock type sand
Other rock types
Lithologic constituents
Major
Unconsolidated > Fine-detrital > ClayYazoo clay, green and gray calcareous clay containing some sand and marl; Moodys Branch formation at base, shells embedded in glauconitic clayey quartz sand.
Minor
Unconsolidated > Coarse-detrital > SandYazoo clay, green and gray calcareous clay containing some sand and marl; Moodys Branch formation at base, shells embedded in glauconitic clayey quartz sand.
Unconsolidated > MarlYazoo clay, green and gray calcareous clay containing some sand and marl; Moodys Branch formation at base, shells embedded in glauconitic clayey quartz sand.
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)
Tew, B.H., 1992, Sequence stratigraphy, lithofacies relationships, and paleogeography of Oligocene strata in southeastern Mississippi and southwestern Alabama: Alabama Geological Survey Bulletin, no. 146, 73 p.
Counties Jasper - Newton - Rankin - Scott