Yazoo Clay

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Yazoo Clay
TypeFormation
Unit ofJackson Group
Sub-unitsNorth Twistwood Creek Member, Cocoa Sand Member, Pachuta Marl Member, and Shubuta Member
OverliesMoodys Branch Formation
Lithology
Primaryclay
Othersand, marl
Location
Region Alabama,  Louisiana, and  Mississippi
CountryUnited States
Type section
Named forYazoo River

Yazoo Clay is a clay geologic formation in Alabama, Louisiana, and Mississippi. It was named after a bluff along the Yazoo River at Yazoo City, Mississippi.[1] 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 from the Eocene, including the prehistoric cetaceans Basilosaurus and Zygorhiza, and the marine snake Pterosphenus.[1][2] Sharks, rays, eels, and fish have also been found from the formation.[3]

See also[edit]

References[edit]

  1. ^ a b 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.
  3. ^ https://www.mdeq.ms.gov/wp-content/uploads/2017/06/Circular_1.pdf