Where: New Madrid County, Missouri (36.4° N, 89.6° W: paleocoordinates 39.5° N, 69.8° W)

• coordinate estimated from map

• hand sample-level geographic resolution

When: Paleocene (66.0 - 56.0 Ma)

• The Old Breastworks Formation was tentatively identified as extending from 1339 to 1377 ft on the basis of cuttings and geophysical logs (p. 30). However, they also state that the samples are probably of late Midwayan Age representing the uppermost part of the Porters Creek Clay or the Old Brestworks Formation (p. 42).

Environment/lithology: marginal marine; micaceous, gray, yellow, silty, sandy claystone

Size class: microfossils

Preservation: original sporopollenin

Reposited in the USGS

Collection methods: core, chemical, hydrochloric, hydroflouric,

Primary reference: N. O. Frederiksen, L. M. Bybell, R. A. Christopher, A. J. Crone, L. E. Edwards, T. G. Gibson, J. E. Hazel, J. E. Repetski, D. P. Russ, C. C. Smith, and L.W. Ward. 1982. Biostratigraphy and paleoecology of lower Paleozoic, upper Cretaceous, and lower Tertiary rocks in U.S. Geological Survey New Madrid test wells, Southeastern Missouri. Tulane Studies in Geology and Paleontology 17(2):23-45 [P. Jardine/H. Morck]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 231939: authorized by Phillip Jardine, entered by Hannah Morck on 06.10.2023

Creative Commons license: CC BY (attribution)