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White Bluff Formation

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White Bluff Formation
Stratigraphic range: Paleogene
TypeFormation
Unit ofJackson Group
Sub-unitsPastoria Sand Member, Caney Point Marl Member, Rison Clay Member
Lithology
Primarymarl, sand, clay
Location
Region Arkansas
Country United States
Type section
Named forWhite Bluff, along the Arkansas River

The White Bluff Formation is a marl, sand, and clay geologic formation in Arkansas that is part of the Jackson Group. It preserves fossils dating back to the Paleogene period, specifically the Eocene.

Description

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The White Bluff Formation is composed of three members: the Pastoria Sand Member, the Caney Point Marl Member, and the Rison Clay Member.[1] The Pastoria Sand is a clayey sand containing glauconite and mollusca fossils. The Caney Point Marl is a chalky clay with glauconite and various invertebrate fossils. The Rison Clay is a clay with interbedded silts containing foraminifera fossils and scattered mollusca molds.[1] The entire formation was deposited as a marine sequence.[1][2]

See also

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References

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  1. ^ a b c Wilbert, Jr., Louis J. (1953). "The Jacksonian Stage in southeastern Arkansas" (PDF). Arkansas Division of Geology Bulletin. 19: 37–56. Archived (PDF) from the original on 25 January 2017. Retrieved 29 June 2018.
  2. ^ McFarland, John D. (2004). "Stratigraphic summary of Arkansas" (PDF). Arkansas Geological Commission Information Circular. 36 (Revised ed.). Archived (PDF) from the original on 24 December 2016. Retrieved 29 June 2018.