Langley Core, VA - 228.87-228.90 m (Chickahominy Fm) (Eocene of the United States)

Also known as 750.9-751.0 ft

Where: Hampton County, Virginia (37.1° N, 76.4° W: paleocoordinates 36.8° N, 68.1° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Chickahominy Formation, Late/Upper Eocene (37.2 - 33.9 Ma)

• SOURCE: collecton from 228.87-228.90 m (750.9-751.0 ft) in core. GENERAL STRATIGRAPHY: The base of the Chickahominy Fm in the Langley core represents the begining of in-place postimpact deposition. This contact is placed at a depth of 235.65 m (773.12 ft) in the core, where massive, calcareous, marine silty clay bearing in-place microfossils overlies horizonatlly laminated quartz-glauconite silt bearing mixed and altered microfossil assemblages. The Chickahominy Fm is a thick section of calcareous clay representing Late Eocene depositon. STRATIGRAPHIC RELATIONS: The Chickahominy Fm is overlain by a shallower marine unit, informally termed the Drummonds Corner beds of Early Oligocene age. BIOSTRATIGRAPHY: NP 19/20 abd NP 21 calcareous nannofossil zones and P15-P17 planktonic foram zones.

• bed-level stratigraphic resolution

Environment/lithology: offshore; lithified, silty, calcareous claystone

• DEPTH: no specific data reported. SALINITY: no specific data reported, apparently normal marine conditions. THERMAL TOLERANCES: no specific data reported. PAELOBIOGEOGRAPHY: no specific data reported.
• GENERAL LITHOLOGY: Massive, calcareous, silty clay

Size class: macrofossils

Reposited in the USNM

• SOURCE: occurrences of large recognizable species and any molluscan remains were noted. Fossiliferous samples were collected at selected intervals for precessing and further examination. Samples were washed, the fraction >850 um was retained, and molluscan fauna specimens recovered were sorted and identified. Generic assignments for extant groups were updated on the basis of Turgeon et al. (1998). COLLECTORS: Collected by NASA-USGS. REPOSITORIES: presumably reposited in USGS and USNM collections.

Primary reference: L. E. Edwards, J. A. Barron, D. Bukry, L.M. Bybell, T.M. Cronin, C.W. Poag, R.E. Weems and G.L. Wingard. 2005. Paleontology of the Upper Eocene to Quaternary Post Impact Section in the USGS-NASA Langley Core, Hampton Virginia. United States Geological Survey Professional Paper 1688:1-71 [A. Miller/A. Hendy/R. McClees-Funinan]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 61273: authorized by Austin Hendy, entered by Austin Hendy on 04.06.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Not exhaustive, but detailed considering limited material available from core. IDENTIFIED: presumably identified by L. Wingard (USGS). NOMENCLATURE: appears to be fairly modern.
Bivalvia
 Carditida - Astartidae
? Astarte sp. Sowerby 1816 clam