Gateway to the Paleobiology Database
MGS #40 (Oligocene of the United States)

Where: Wayne County, Mississippi (31.7° N, 88.7° W: paleocoordinates 31.9° N, 82.2° W)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Red Bluff Formation, Rupelian (33.9 - 28.4 Ma)

• The Red Bluff Formation as exposed is Clarke and Wayne counties, Mississippi, consists of fossiliferous, dark clay,silty clay,with zones of ironstone concretions in the lower part. These sediments disconformably overlie the blue-gray, blocky, marine clay of the Shubuta Clay Member of the Yazoo Formation and were deposited during in shallow marine shelf, prodelta, and marginal delta bay enviroments. Along the Chickasawhay River in Wayne County, the lower portion of the Red Bluff Formation is very fossiliferous. Well-preserved fossils in this basal zone occur in abundance in narrow, glauconitic, sand lenses within the clay. Irregular ironstone concretions occur along fosiliferous zones in the lower Red Bluff Formation and show up on electric logs as one or two "kicks" on the resistivity curve at the base of the formation.

• formation-level stratigraphic resolution

Environment/lithology: offshore; poorly lithified, gray, silty, sandy siltstone and ironstone

Size class: mesofossils

Preservation: original aragonite, original calcite

Collection methods: bulk, mechanical,

• bivalves only

Primary reference: D. T. Dockery. 1982. Lower Oligocene Bivalvia of the Vicksburg Group in Mississippi. Mississippi Department of Natural Resources Bureau of Geology 123:1-261 [L. Ivany/S. DeLong] more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 5787: authorized by Linda Ivany, entered by Sarah DeLong on 02.12.1999, edited by Laurie Eccles

Creative Commons license: CC BY (attribution)