Presenter Information

Lisa M. Reeves


Geosciences and Geological and Petroleum Engineering

Funding Source

The donors of the Petroleum Research Fund, administered by the American Chemical Society are kindly acknowledged for supporting this project.

Meeting Name

4th Annual UMR Undergraduate Research Symposium (1994: Mar. 23, Rolla, MO)


The Vicksburg Group in the eastern Gulf Coast of the United States belongs to one of the most complete and continuous Paleogene strata in the world. Previous studies in this region have neglected the rich palynomorph assemblages of the Lower Oligocene units of the Vicksburg Group. Four samples from Wayne County Mississippi were analyzed for palynological information on the Vicksburg Group. The initial objective of the study was to understand the principles of palynology and the basis for sporomorph identification. A minimum of 300 specimens were counted per slide to determine the distribution of sporomorphs in the sediments. Two hundred and twelve different species of sporomorphs have been identified. The proportion of nonmarine palynomorphs (sporomorphs and fungal remains) relative to marine palynomorphs (dinoflagellates, acritarchs, and microforaminiferal test linings) were also determined in order to evaluate the influence of sea-level fluctuations in the area. The basal unit of the Vicksburg Group (Forest Hill Sand), previously interpreted as deposits of a highstand systems tract, is dominated by nonmarine palynomorphs. This deposit has a high species diversity dominated by Ouercoidites. Carva. Mominites. Siltaria. Cupressacites. and Cupuliferoipollenites. Higher units (Mint Spring Marl and Marianna Limestone), considered part of a transgressive system tract, have fewer sporomorph species and are dominated by marine palynomorphs. The assemblage is verv rich in two taxodiaceous conifer pollen species resembling Seuuoia. Fluctuations in sea-level and sediment supply piay a major role in the number of sporomorph taxa recovered from the lithostratigraphic units of the Vicksburg Group. The concentration of the two Sequoia type pollen species can be used to identify transgressive deposition (in particular the Mint Spring Marl and Marianna Limestone) near the Mississippi-Alabama boarder. The prominence of certain pollen taxa (Ouercus. Sequoia. Taxodium. Castanea. and Cvrilla) suggest warm, temperate climatic conditions. The climate was, however, cooler than the relatively wami conditions of the Early and Middle Eocene.

Document Type



1st place

Presentation Date

23 Mar 1994