Suwannee Limestone

Suwannee Limestone Stratigraphic range: Oligocene
Type	Geological formation
Underlies	Hawthorn Group-Arcadia Formation
Overlies	Ocala Limestone
Thickness	160 feet
Lithology
Primary	Limestone
Location
Region	North Florida
Country	United States
Extent	Leon to Hamilton to Taylor counties
Type section
Named for	Suwanee River
Named by	C.W. Cooke and W.C. Mansfield

Location of Suwannee Formation in red.

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

Age

Period: Paleogene
Epoch: Early Oligocene
Faunal stage: Rupelian ~33.9 to ~23 mya, calculates to a period of approximately 16.9 million years

Location

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 Suwanee Limestone was recognized in the northwestern peninsula by P. F. Huddleston in 1993 as a triple subdivision of Suwanee Limestone, Ellaville Limestone, and Suwannacoochee Dolostone.^[2]

Composition

Suwanee 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, dolostone with limited occurrences of fossil bearing beds. Limestone in silicate form is common in Suwannee Limestone.^[3][4]

Overlay

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

Fossils

• Foraminifers
• Echinoids
• Bryozoans
• Mollusks

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Stratigraphic and paleontologic studies of Paleocene and Oligocene carbonate facies of the eastern Gulf Coastal Plain: unpublished Ph.D. dissertation, University of Tennessee, Knoxville, TN, 324 p.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. Cooke, C. W., and Mansfield, W. C., 1936, Suwanne Limestone of Florida (abstract): Geological Society of America Proceedings, 1935, p. 71–72.
4. USGS: Geology of Florida