Abstract

Stromatolites are large, layered calcareous deposits, typically found by the shore of oceans or lakes. These are formed due to interactions of cyanobacteria – a photosynthetic organism – and the surroundings, specifically, introduced sediment and minerals in the water. The resulting stromatolite formations have a variety of external and internal structures influenced by the environment in which they form. The Green River Formation is a large lacustrine deposit that formed in what is the present-day United States during the middle Eocene, and is known for a large variety of fossils, including stromatolites. The stromatolites being investigated in the Green River Formation are some of the most recent deposits, formed ~45 million years ago, around the time the lakes were fully evaporating. This research investigates if changes in stromatolites reflect the changes in the fluctuations of the lake the samples formed in. The stromatolites were collected from two locations within Sanpete valley, White Hill and Temple Hill. When investigating sample stromatolites, the alterations in their internal formation, echoed in oxygen isotope analysis results, show minute changes in water that reflect small changes in the stages of lake recession.

Advisor

Lyon, Eva

Department

Geology

Disciplines

Geology | Hydrology | Paleontology

Keywords

paleontology, stromatolites, Green River, geology, Sanpete Valley, lake level change

Publication Date

2025

Degree Granted

Bachelor of Arts

Document Type

Senior Independent Study Thesis

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