Where: Smith County, Mississippi (32.0° N, 89.5° W: paleocoordinates 32.3° N, 83.0° W)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Mint Spring Formation, Rupelian (33.9 - 28.1 Ma)

• The Mint Spring Formation grades upward into the more calcareous sediments of the Marianna Limestone. Above the Mint Spring - Marianna contact, aragonitic shells generally have been leached leaving only the molds. The Marianna Limestone is only about two feet thick at Vicksburg, Mississippi and thickens eastward to forty-seven feet in Wayne County. In the latter area it is a soft limestone (lime mudstone and wackestone) with hard ledges in the lower part. In central and eastern Mississippi, it contains significant beds of calcareous sand. The Mint Spring- Marianna transgressive sequence began with the subsidence of Forest Hill delta systems. As the northern Gulf waters transgressed inland over the delta plain and estuarine enviroments, the Mint Spring Formation was deposited as a destructional shelf sand in the near-shore environments. Carbonates of the Marianna Limestone were deposited above this sand in the deeper waters of an offshore carbonate shelf.

• formation-level stratigraphic resolution

Environment/lithology: offshore; poorly lithified, sandy, calcareous lime mudstone and wackestone

Size class: mesofossils

Preservation: replaced with 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/M. Uhen]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 5867: authorized by Linda Ivany, entered by Sarah DeLong on 09.12.1999

Creative Commons license: CC BY (attribution)