Where: Burleson County, Texas (30.6° N, 96.5° W: paleocoordinates 32.7° N, 85.6° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Stone City Member (Crockett Formation), Lutetian (47.8 - 41.3 Ma)

• The age of strata exposed at Stone City Bluff is established using biostratigraphy and radiometric dating of volcanic ash beds in the overlying Wheelock Member of the Crockett Formation. Calcareous nannoplankton indicates an age of biochronozone NP16 (Yancey and Davidoff, 1991, p. 80) and planktic foraminifers indicate deposition during the Morozovella lehneri (P12) or Orbulinoides beckmanni (P13) zones (Gaskell, 1989). A 25 cm thick volcanic ash bed present in overlying strata of the Crockett Formation, about 15 m above the Moseley bed (Kersey and Stanton, 1979), has an 40Ar/39Ar radiometric date of 41.841 ± 0.016 Ma (Heintz et al., 2015). The ash-bearing strata are further corroborated as upper part of biochronozone NP16 by Marie-Pierre Aubry (2002, unpublished report) and the upper part of biochronozone P12 (= E10–E11 biochronozones) by W. A. Berggren (2004, unpublished report), based on an overlap of Acarinina bullbrooki and Turborotalia pomeroli. Therefore, late Lutetian in age.

• group of beds-level stratigraphic resolution

Environment/lithology: transition zone or lower shoreface; unlithified, glauconitic, argillaceous sandstone

Size class: mesofossils

Primary reference: K. V. Palmer and D. C. Brann. 1965. Catalogue of the Paleocene and Eocene mollusca of the southern and eastern United States. Part 1. Pelecypoda, Amphineura, Peteropoda, Scaphopoda and Cephalopoda. Bulletins of American Paleontology 48:1-471 [M. Kosnik/M. Kosnik/J. Alroy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 90651: authorized by Jocelyn Sessa, entered by Laurie Eccles on 12.08.2009, edited by Ursula Smith

Creative Commons license: CC BY (attribution)