Publication Date


Document Type


Committee Members

Rebecca Teed, Ph.D. (Committee Chair); Chris Barton, Ph.D. (Committee Member); Audrey McGowin, Ph.D. (Committee Member); Stacey Hundley, Ph.D. (Other)

Degree Name

Master of Science (MS)


This study combines various paleoecological proxies found within a sediment core extracted from Crystal Lake, Medway, Ohio in order to assess the lake’s sensitivity to past climate changes and how that may have affected lake water levels. Crystal Lake is a natural kettle lake formed at the end of the Wisconsin glaciation. It is now surrounded by approximately 500 residential homes and is privately owned by the HOA of Crystal Lake. A sediment core was extracted from Crystal Lake in 2007 and has been carbon dated to 18000 years before present, indicating that it contains a complete sedimentary history from late Pleistocene until today. Loss on ignition (LOI) and pollen data completed by previous colleagues will help build a context for this study’s research in the contribution of North American freshwater snails, in particular, three species of Valvata, as paleoecologic proxies of past aquatic habitats. Pollen data used to reconstruct vegetation changes known as climate zones have shown a progression of vegetation through several stages from postglacial initial colonization to modern vegetative landscape. LOI data shows changes in lithographic composition which can infer periods of eutrophication and correlates with vegetation shifts. The number and consistency of Valvata shells retrieved from the core align nicely with the transition of climate zones. However, because sample size was small, and little is known about the mechanisms of shell transport within the lake, more data is needed and this study remains inconclusive as to the usefulness of the Valvata as climate proxies in Crystal Lake, Ohio.

Page Count


Department or Program

Department of Earth and Environmental Sciences

Year Degree Awarded


Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.