Yazoo Clay

Yazoo Clay
Yazoo Clay
Stratigraphic range: Late Eocene
Type	Formation
Unit of	Jackson Group
Sub-units	North Twistwood Creek Member, Cocoa Sand Member, Pachuta Marl Member, and Shubuta Member
Underlies	Crystal River Formation
Overlies	Moodys Branch Formation
Lithology
Primary	clay
Other	sand, marl
Location
Region	Alabama, Louisiana, Mississippi
Country	United States
Type section
Named for	Yazoo River

The Yazoo Clay is a late Eocene clay geologic formation in Alabama, Louisiana, and Mississippi. It was named after a bluff along the Yazoo River at Yazoo City, Mississippi. It contains is a type of clay known as montmorillonite, making it a poor foundation material due to the fact that moisture causes extreme changes in volume. Sand, pyrite, and marl have all been noted in the formation. It preserves fossils including the prehistoric cetaceans Basilosaurus and Zygorhiza, and the marine snake Pterosphenus. Sharks, rays, eels, and fish have also been found from the formation.

References

1 2 Monroe, Watson H. (1954). "Geology of the Jackson Area Mississippi" (PDF). United States Geological Survey Bulletin. 986: 56–62. Retrieved 27 June 2018.
↑ Breard, Sylvester Q.; Stringer, Gary L. (1995). "Paleoenvironment of a Diverse Marine Vertebrate Fauna from the Yazoo Clay (Late Eocene) at Copenhagen, Caldwell Parish, Louisiana" (PDF). Gulf Coast Association of Geological Societies Transactions. 45. Archived from the original (PDF) on 2023-05-21. Retrieved 2023-05-21.
↑ "YAZOO CLAY: Engineering Aspects and Environmental Geology of an Expansive Clay" (PDF). Archived from the original (PDF) on 2021-04-16.

Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Archived from the original on 25 March 2022. Retrieved 17 December 2021.
Hosman, R.L. (1996). "Regional Stratigraphy and Subsurface Geology of Cenozoic Deposits, Gulf Coastal Plain, South-Central United States" (PDF). United States Geological Survey Professional Paper. 1416-G: G22.

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[monroe-1] 1 2 Monroe, Watson H. (1954). "Geology of the Jackson Area Mississippi" (PDF). United States Geological Survey Bulletin. 986: 56–62. Retrieved 27 June 2018.

[2] Breard, Sylvester Q.; Stringer, Gary L. (1995). "Paleoenvironment of a Diverse Marine Vertebrate Fauna from the Yazoo Clay (Late Eocene) at Copenhagen, Caldwell Parish, Louisiana" (PDF). Gulf Coast Association of Geological Societies Transactions. 45. Archived from the original (PDF) on 2023-05-21. Retrieved 2023-05-21.

[3] "YAZOO CLAY: Engineering Aspects and Environmental Geology of an Expansive Clay" (PDF). Archived from the original (PDF) on 2021-04-16.

Yazoo Clay

See also

References