New Madrid test well 1-X, 1390-1405 ft (Paleocene of the United States)

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: Porters Creek Formation, Paleocene (66.0 - 56.0 Ma)

Environment/lithology: marginal marine; hardground, micaceous, pyritic, gray claystone

• Small preidinioid dinoflagellates and freshwater algae belonging to Pediastrum are present throughout this interval, also suggesting brackish water deposition or at least a nearby source of fresh water.
• Steel-gray to dark-gray, hard, micaceous clay; disseminated organic material common; locally mottled yellow-buff; conchoidal fracture; locally fossiliferous; pyrite common.

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 231944: authorized by Phillip Jardine, entered by Hannah Morck on 06.10.2023

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
unclassified
  -
"small peridinioid forms" spp.
Chlorophyceae
  -
Pediastrum sp.
Pediastrum sp. Meyen 1829
Dinophyceae
 Gonyaulacales - Ceratiaceae
Odontochitina costata
Odontochitina costata Alberti 1961
reworked Cretaceous form
 Gonyaulacales - Areoligeraceae
Cyclonephelium sp.
Cyclonephelium sp. Deflandre and Cookson 1955
reworked Cretaceous form
 Peridiniales - Peridiniaceae
Chatangiella sp.
Chatangiella sp. Vozzhennikova 1967
reworked Cretaceous form
 Peridiniales - Deflandreaceae
Spinidinium densispinatum
 Dinoflagellata -
Spongodinium delitiense
Spongodinium delitiense Ehrenberg 1936
reworked Cretaceous form