Date of Award

5-2017

Degree Type

Honors College Thesis

Department

Geography and Geology

First Advisor

Franklin Heitmuller, Ph.D.

Advisor Department

Geography and Geology

Abstract

The Clayton Formation is a section of the Midway Group immediately above the Cretaceous-Paleogene boundary that contains marine fossils from the Paleocene Epoch. The formation is composed of glauconitic sand, clay, marl, and limestone. Fossils within the formation commonly occur in clay or are concentrated in conglomeratic lag lenses. To assess paleoecology of the region during the Paleocene, the Clayton Formation was sampled for fossil content at a distinctly visible exposure along Interstate 30 near Malvern, Arkansas, that was excavated as part of a landslide mitigation project. Complimentary sites were sampled nearby along the Ouachita River and behind a shopping center. Dark clay sediment was collected from the Interstate 30 site and the bulk matrixes were analyzed for fossil content. The fossil assemblage, complemented by lithologic descriptions at the sites and context with Paleocene geologic history in the Gulf of Mexico basin, was used to infer the paleoecology of the Clayton Formation near Malvern, Arkansas. Fossils from small boney fish, sharks, rays, oysters, small crocodiles, gastropods, decapods, bryozoans, dinoflagellates, and foraminifera indicate a shallow marine setting. The predominance of clay with lag lenses created from tidal channels further hones an interpretation of a protected, mud flat system.

Included in

Paleontology Commons

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