Honors Program Theses

Award/Availability

Open Access Honors Program Thesis

First Advisor

Alexa Clements

Abstract

Reconstructing the history of ice sheet dynamics is essential for understanding how past climate change has shaped modern landscapes. The Laurentide Ice Sheet advanced and retreated multiple times over North America during the Pleistocene Epoch. Although there is widespread sedimentary evidence for the most recent glacial episode, much of the evidence of older glaciations has been overwritten by more recent glacial advances. This study focuses on Paddison Run, an exposed Pleistocene sequence near Cincinnati, Ohio, that has previously been interpreted as Illinoian in age. Five distinct units were identified within the exposure, based on centimeter logging of this section, high-resolution sampling, and grain size and geochemical analyses. Individual samples were processed using sediment sieves to assess grain size distribution within and between units. Individual representative sample splits were then analyzed for elemental composition using a handheld XRF. Sediments within this succession fine upwards, with grain sizes between 500-250 μm in the lowest unit and fining upward to between 125-63 μm. Results also indicate that iron concentrations are highest in units A and C, indicating they were deposited in higher-energy, shallow water environments. The overlying units are composed of finer sediments and have lower iron concentrations, representing the transition into a deeper, lower-energy environment. In addition, fine laminations at the base of Unit B and several large dimictite clasts are consistent with the formation of a glacial lake with occasional ice-rafted debris deposition. These features are consistent with previous work documenting the formation of ice-dammed lakes in the region. A sharp contact between the lake sediments and a distinct diamictic bed may represent a later advance of the ice sheet, erosion, and subsequent deposition of glacial till. The findings provide a high-resolution record demonstrating the complex environmental responses to changes in the position of the ice sheet margin.

Year of Submission

2026

Department

Department of Earth and Environmental Sciences

University Honors Designation

A thesis submitted in partial fulfillment of the requirements for the designation University Honors

Date Original

2026

Object Description

1 PDF file (18 pages)

Creative Commons License

Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.

Language

en

File Format

application/pdf

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