The Pennington Formation is a geologic formation named for Pennington Gap, Virginia.[1] It can be found in outcrops along Pine Mountain and Cumberland Mountain in Kentucky, Virginia, and Tennessee, where it is the uppermost Mississippian-age formation.[1] The name has also been applied to similar Mississippian strata in the Cumberland Escarpment of eastern Kentucky, though the rocks in that area were later renamed to the Paragon Formation.[2]

Pennington Formation
Stratigraphic range: Carboniferous
TypeFormation
Location
Region Virginia
Country United States

According to general usage among geologists, the Pennington Formation corresponds to shales, sandstones, and thin limestone beds located above the highest massive limestone bed of the Newman Formation.[2] Paleosols have also been preserved in a Pennington outcrop at Pound Gap, recording a series of fluctuations in climate between dry and wet conditions.[3] The Pennington Formation has been inferred to represent a coastal environment transitioning between a Mississippian marine basin and Pennsylvanian coal swamps.[4]

Some parts of the Pennington Formation preserve fossils, including conodonts which are useful for biostratigraphic dating. Conodont dating indicates that the Pennington Formation formed near the end of the Mississippian subperiod of the Carboniferous period.[3] The Pennington Formation is considered equivalent to the Hinton, Princeton, and Bluestone formations of the Mauch Chunk Group, which is exposed further north in West Virginia.[4]

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References edit

  1. ^ a b Butts, Charles. Geology and Oil Possibilities of the Northern Part of Overton County, Tenn., and of Adjoining Parts of Clay, Pickett and Fentress Counties, pp. 25-26 (Williams Printing 1919).
  2. ^ a b Ettensohn, Frank et al. "Slade and Paragon Formations — New Stratigraphic Nomenclature for Mississippian Rocks Along the Cumberland Escarpment in Kentucky", U.S. Geological Survey Bulletin 1605-B, p. 4 (1984).
  3. ^ a b Kahmann, Julia A.; Driese, Steven G. (2008-03-31). "Paleopedology and geochemistry of Late Mississippian (Chesterian) Pennington Formation paleosols at Pound Gap, Kentucky, USA: Implications for high-frequency climate variations". Palaeogeography, Palaeoclimatology, Palaeoecology. 259 (4): 357–381. doi:10.1016/j.palaeo.2007.09.022. ISSN 0031-0182.
  4. ^ a b Ettensohn, Frank R.; Chesnut, Donald R. (1985). "Depositional environments and stratigraphy of the Pennington Formation, Upper Visean-Namurian A, East-Central and Eastern Kentucky, USA" (PDF). Congrès International de Stratigraphie et de Géologie du Carbonifère. 10: 269–283.

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