USGS Loc. 12321 - Brooksville [Suwannee Lmst] (Oligocene of the United States)

Where: Hernando County, Florida (28.6° N, 82.4° W: paleocoordinates 28.6° N, 76.1° W)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Suwannee Limestone Formation (Vicksburg Group), Rupelian (33.9 - 28.1 Ma)

• Cunningham et al. (1998) identified Suwannee LS as Early Oligocene age. Cooke and Mansfield (1936) assigned Suwannee to Vicksburg group. Suwannee assigned to Rupelian Stage (early Oligocene) by Brewster-Wingard et al. (1987) and COSUNA (1988).

• formation-level stratigraphic resolution

Environment/lithology: lithified, white limestone

• Author notes that the fauna indicate warm water conditions rather than cold.
• The formation consists almost entirely of limestone. The unweathered rock is a granular to dense, compact, usually cream-colored rather pure limestone. The lower par is at many places more granular than the upper. Mossom (1925) provided the following lithologic description from the Suwannee LS quarry of the Florida Hard Rock Products Co., Brooksville, FL: Silica - 6.54%; Iron and aluminum - 1.44%; Calcium carbonate - 91.09%; Magnesium carbonate - trace; Undetermined - 0.93%

Collected by Mansfield, Gunter; reposited in the USNM

Collection methods: surface (float), surface (in situ),

• COLLECTOR: W.C. Mansfield, H. Gunter. REPOSITORY: USNM.

Primary reference: C. W. Cooke. 1959. Cenozoic echinoids of eastern United States. United States Geological Survey Professional Papers 321:1-106 [L. Villier/L. Villier/M. Hopkins]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 155936: authorized by Austin Hendy, entered by Austin Hendy on 04.05.2014

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Limited to echinoidea, but molluscs are probably present. NOMENCLATURE: Authoritative publication with species-resolution identifications, but somewhat antiquated nomenclature.
Echinoidea
 Spatangoida - Schizasteridae
Agassizia (Anisaster) mossomi Cooke 1942 heart urchin
 Stomopneustoida - Stomechinidae
Phymotaxis mansfieldi Cooke 1941 sea urchin