Odenville Limestone
Stratigraphic range: Ordovician
TypeFormation
Underliespost-Knox formations
OverliesNewala Limestone
Thickness0-366 feet
Location
Region Alabama
Country United States
Type section
Named forOdenville, Alabama
Named byCharles Butts

The Odenville Limestone is a geologic formation in Alabama. It preserves fossils dating from the early Ordovician Period.

As first described by geologist Charles Butts in a 1926 report on Alabama’s geology, the Odenville consisted of “impure argillaceous and siliceous dark fine-grained cherty limestone,” about fifty feet in thickness.[1]

Butts’ original type exposure could not be located by subsequent mappers, so the Odenville nomenclature was dropped and the formation was considered a locally-occurring facies of the underlying Newala Limestone.[2]

Keith Roberson in 1988,[3] and Ed Osborne in 1992,[4] demonstrated the Odenville is indeed a distinctive, mappable lithologic unit, and the term was restored to the Ordovician nomenclature used by the Geological Survey of Alabama in the Appalachian fold-and-thrust belt.[5]

As defined today, the Odenville Limestone is described as a dark gray, primarily dolomitic, stylonodular limestone[6] whose fossil assemblage includes brachiopods and sponges. It is the uppermost member of the Knox Group, a related suite of carbonate rocks deposited at the end of the Cambrian and beginning of the Ordovician.[7]

See also

References

  1. ↑ "Geology of Alabama" (PDF). Geological Survey of Alabama. p. 99. Retrieved November 13, 2022.
  2. ↑ Osborne, W. Edward; Irvin, G. Daniel (2002). Geology of the Odenville 7.5-Minute Quadrangle, St. Clair County, Alabama. Geological Survey of Alabama.
  3. ↑ Roberson, Keith (1988). The post–Knox unconformity and its relationship to bounding stratigraphy, Alabama Appalachians. Master's thesis, University of Alabama.
  4. ↑ Osborne, W. Edward (1992). Bedrock geology of the Cahaba Valley area between Helena and Lake Purdy, Shelby and Jefferson Counties, Alabama. Geological Survey of Alabama.
  5. ↑ "National Geologic Map Database - Geolex". U.S. Geological Survey. Retrieved November 13, 2022.
  6. ↑ Osborne, W. Edward; Irvin, G. Daniel (2002). "Cross Section A-A' and Explanation for the Geologic Map of the Odenville 7.5-Minute Quadrangle, St. Clair County, Alabama" (PDF). Geological Survey of Alabama. Retrieved November 13, 2022.
  7. ↑ Lacefield, Jim (2013). Lost Worlds in Alabama Rocks (second edition). Alabama Museum of Natural History. pp. 94–95.


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