USGS D-1138-CO. West Marble Creek (Ordovician of the United States)

Where: Jessamine County, Kentucky (37.9° N, 84.5° W: paleocoordinates 27.5° S, 63.2° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Belodina compressa conodont zone, Tyrone Limestone Formation (High Bridge Group), Rocklandian (460.9 - 449.5 Ma)

• "29 ft (10 m) above the base of the Tyrone Limestone"

• bed-level stratigraphic resolution

Environment/lithology: shallow subtidal; intraclastic, peloidal, shelly/skeletal grainstone

• " 'The Tyrone Limestone accumulated in quiet shallow water and was periodically exposed to the air' (Cressman, 1973, p. 13). Cressman and Noger (1976) concluded that the Camp Nelson and Tyrone limestones (High Bridge Group) were deposited in tidal flat and immediate subtidal carbonate environments analogous to those seen today in the Bahamas and Florida Bay." (Hoare & Pojeta, 2006)
• "a hard, white to gray, crystalline fossiliferous limestone unit, 3 ft thick, [...] Petrographically, this limestone would be classified as a biopelsparrudite (classification of Folk, 1962) or a fossiliferous grainstone (classification of Dunham, 1962). The unit contains poorly sorted whole and fragmentaIy silicified shells of nautiloids, gastropods, solitary corals, trepostome bryozoans, and pelecypods, plus intraclasts consisting of sub rounded fragments of micrite, all in a matrix of sand-sized peloidal and skeletal grains." (Frey, 1995)

Size class: macrofossils

Preservation: recrystallized, replaced with silica

Reposited in the USNM

Collection methods: bulk, acetic,

• " [...] specimens were obtained from bulk rock collections (36,000 pounds (lbs) of limestone) made by USGS field parties in the 1960's and 1970's." (Frey, 1995). This statement not only applies to the Marble Creek locality. For further details on collection methods see p. P22 in the primary reference

Primary reference: R. C. Frey. 1995. Middle and Upper Ordovician nautiloid cephalopods of the Cincinnati Arch region of Kentucky, Indiana, and Ohio. U.S. Geological Survey Professional Paper 1066P:1-126 [S. Holland/S. Holland]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 87962: authorized by Björn Kröger, entered by Torsten Liebrecht on 29.03.2009, edited by Pete Wagner

Creative Commons license: CC BY (attribution)

Taxonomic list

• see comments on lithology
unclassified
  -
Ostracoda
 Podocopida - Bairdiidae
Krausella sp. ostracod
 Palaeocopida -
 Leperditicopida - Leperditiidae
Strophomenata
 Strophomenida - Sowerbyellidae
Sowerbyella sp. Jones 1928
two specimens.
Bivalvia
 Cyrtodontida - Cyrtodontidae
Cyrtodonta sp. Billings 1858 clam
one specimen.
 Protobranchia - Ctenodontidae
Tancrediopsis sp. Beushausen 1895 clam
four specimens
Cephalopoda
 Orthocerida - Orthoceratidae
Pojetoceras floweri Frey 1995
USNM 468685A (suite of small, silicified, fragmentary specimens)
Polyplacophora
 Paleoloricata - Mattheviidae
Spicuchelodes cressmani Hoare and Pojeta 2006 chiton
145 intermediate plates one head plate # two tail plates.
Tetradium
  -