Date of Award

8-2022

Degree Type

Honors College Thesis

Academic Program

Geography BS

Department

Geography and Geology

First Advisor

Alyson A. Brink, Ph.D.

Advisor Department

Geography and Geology

Abstract

The Maastrichtian-age Blue Springs locality of the Coon Creek Member of the Ripley Formation is known for abundant, well-preserved marine fossils, including many genera of microfossils, bivalves, gastropods, decapods, cephalopods, actinopterygians, and other vertebrate organisms. This research contributes to the understanding of the paleontology of the site, as well as the changing paleoenvironmental conditions of the beds throughout deposition.

This project analyzed bulk material collected in 2021 from three fossiliferous beds at Blue Springs: the Lower Corbula Bed (Bed C), the Pebble Bed (Bed G), and the Exogyra-Pycnodonte Bed (Bed J). Unconsolidated material from Beds C and J was processed through wet sieving, and the resulting Bed J concentrate was picked for fossils under a microscope. The fossils were separated, identified, labeled, and imaged to provide a better understanding of the fossil faunal assemblage of Bed J, which was then compared to fossil material from the other beds to determine paleoenvironmental differences. Finally, the observed fossils from each bed were compiled with records from peer-reviewed articles to produce a fossil faunal composition list of all invertebrate and vertebrate fossil occurrences at the Blue Springs site (Appendix A). Such a list has not yet been published in the geologic literature, and it will be useful for professional researchers and amateur collectors interested in the paleontology of Blue Springs.

The results of this study, specifically the microfossil data, support that Bed J at the Blue Springs site was deposited in a shallow marine, near shore environment with normal salinities and moderate temperatures. The paleoenvironmental conditions of the site as a whole made it a survivable environment that supported over 140 taxa 71 million years ago, but further analysis of bulk material is necessary to determine what paleoenvironmental conditions are represented by the faunal assemblages of each bed.

Keywords: Blue Springs, Ripley Formation, Paleoenvironment, Maastrichtian, Cretaceous

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