Earth:Suwannee Limestone

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Suwannee Limestone
Stratigraphic range: Oligocene
TypeGeological formation
UnderliesHawthorn Group-Arcadia Formation
OverliesOcala Limestone
Thickness160 ft (49 m)
Lithology
PrimaryLimestone
Location
RegionNorth Florida
Country United States
ExtentLeon to Hamilton to Taylor counties
Type section
Named forSuwannee River
Named byC.W. Cooke and W.C. Mansfield
Location of Suwannee Formation in red.

The Suwannee Limestone is an Early Oligocene geologic formation of exposed limestones in North Florida, United States .

Description

Suwannee Limestone is found in the peninsula carbonate outcroppings on the northwestern, northeastern and southwestern flanks of the Ocala Platform. However, Suwannee Limestone is not present on an area known as Orange Island on the eastern side of the Ocala Platform due to erosion, nondeposition or both.[1] This limestone is present in southeastern Leon, Jefferson, Madison, Taylor, Lafayette counties as well as Hamilton along the upper Suwannee River basin, and southward into Suwannee County, Florida.

Early Oligocene Suwannee Limestone was recognized in the northwestern peninsula by P. F. Huddleston in 1993 as a triple subdivision of Suwannee Limestone, Ellaville Limestone, and Suwannacoochee Dolostone.[2] The Suwannacoochee Dolostone was later officially renamed as the Suwannacoochee Dolomite.[3]

Sedimentology

Suwannee Limestone consists of a white to cream, poorly to well hardened, fossil rich, vuggy to moldic grainstone and packstone. The dolomitized parts of the Suwannee Limestone are gray, tan, light brown to moderate brown, moderately to well indurated (hard), finely to coarsely crystalline, dolomite with limited occurrences of fossil-bearing beds. Limestone in silicate form is common in Suwannee Limestone.[4][5]

Stratigraphy

The Suwannee Limestone overlies the Ocala Limestone and forms part of the intermediate confining unit/aquifer system. (USGS)

Fossil content

References

  1. Bryan, J.R., 1991, Stratigraphic and paleontologic studies of Paleocene and Oligocene carbonate facies of the eastern Gulf Coastal Plain: unpublished Ph.D. dissertation, University of Tennessee, Knoxville, TN, 324 p.
  2. Huddleston, P.F., A revision of the lithostratigraphic units of the Coastal Plain of Georgia - The Oligocene: Georgia Geological Survey Bulletin 105, 152 p.
  3. Stamm, N., 2018, Geologic Unit: Suwannacoochee. National Geologic Map Database Geolex — Unit Summary, U.S. Department of the Interior, U.S. Geological Survey, Reston Virginia.
  4. Cooke, C. W., and Mansfield, W. C., 1936, Suwanne Limestone of Florida (abstract): Geological Society of America Proceedings, 1935, p. 71–72.
  5. USGS: Geology of Florida