USGS 4865-CO: Blackburn Memorial Bridge (Ordovician of the United States)

Also known as Cressman Section 174; Tyrone C section (Frey, 1995)

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

• coordinate estimated from map

• outcrop-level geographic resolution

When: Plectodina tenuis conodont zone, Logana Member (Lexington Formation), Shermanian (457.3 - 449.6 Ma)

• A. confluens zone

• group of beds-level stratigraphic resolution

Environment/lithology: open shallow subtidal; 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" (Frey, 1995).

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

• The interbedded calcisiltite and shale... contains nearly equal parts of limestone and shale.

Size class: macrofossils

Preservation: replaced with silica

Reposited in the USNM

Collection methods: bulk, acetic,

Primary reference: E. R. Cressman. 1973. Lithostratigraphy and depositional environments of the Lexington Limestone (Ordovician) of central Kentucky. USGS Professional Paper 768:1-61 [M. Patzkowsky/M. Patzkowsky/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 77144: authorized by Pete Wagner, entered by Pete Wagner on 21.12.2007, edited by Torsten Liebrecht

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Cephalopoda
 Orthocerida - Tripteroceratidae
Allumettoceras cf. tenerum1
Allumettoceras cf. tenerum1 Billings 1860
USNM 468739
Gastropoda
 Bellerophontida - Sinuitidae
Sinuites obesa2
Sinuites obesa2 Ulrich and Scofield 1897 snail
Tergomya
 Cyrtonellida - Cyrtolitidae
Cyrtolites retrorsus2
Cyrtolites retrorsus2 Ulrich and Scofield 1897
1Frey 1995; 2Wahlman 1992