USGS 5092-CO, Tyrone C section (10-12 ft above base of Logana Mbr.) (Ordovician of the United States)

Where: Woodford County, Kentucky (38.0° N, 84.8° W: paleocoordinates 27.2° S, 63.3° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Logana Limestone Member (Lexington Limestone Formation), Kirkfieldian (457.3 - 449.6 Ma)

• "10-12 ft above base of Logana Member"; section no. 174

• group of beds-level stratigraphic resolution

Environment/lithology: open shallow subtidal; tabular, argillaceous limestone and shale

• "Cressman (1973) indicated that the Logana Member represented the height of the initial marine transgression, deposited under quiet-water conditions at water depths below wave base";

•sequence stratigraphy is according to McLaughlin et al. (2004, Palaeogeogr. Palaeoclimat. Palaeoecol., 210)

• " [...] interbedded, thin, planar, argillaceous limestone and shale [...] up to 50 ft thick [...] containing a more sparse fauna of dalmanellid brachiopods, bryozoans, pelecypods, univalved mollusks, and nautiloids."

Size class: macrofossils

Preservation: 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." This statement not only applies to the Tyrone C 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 87821: authorized by Björn Kröger, entered by Torsten Liebrecht on 25.03.2009, edited by Pete Wagner

Creative Commons license: CC BY (attribution)

Taxonomic list

• see comments on lithology
Rhynchonellata
 Orthida - Dalmanellidae
Dalmanella sulcata3 Cooper 1956
Tergomya
 Cyrtonellida - Cyrtolitidae
"Cyrtolites (Cyrtolites) retrorsus" = Cyrtolites retrorsus2
"Cyrtolites (Cyrtolites) retrorsus" = Cyrtolites retrorsus2 Ulrich and Scofield 1897
Cephalopoda
 Orthocerida - Proteoceratidae
Isorthoceras albersi Miller and Faber 1894
USNM 468701 (suite of specimens), 468702
Gorbyoceras cf. tetreauense Wilson 1961
USNM 468708 (suite of specimens)
Gastropoda
 Bellerophontida - Sinuitidae
Sinuites obesa2 Ulrich and Scofield 1897 snail
 Murchisoniina - Lophospiridae
Lophospira milleri1 Miller 1877 snail
Lophospira perangulata1 Hall 1847 snail