Abstract

The influence of human activity on surrounding environments is an important field of research. With respect to aquatic settings, lacustrine deposits provide excellent proxies of environmental change since the sediment accumulates at a relatively constant rate, recording environmental change. This study employs isotopic, mineral, and chemical records from Farmington Bay freeze cores, in particular δ13C, δ15N, and 210Pb isotopes as well as phosphorus level fluctuation and trace metal analysis. In particular, 210Pb isotopes permit estimation of the age of sediment with depth and δ15N, δ13C, and concentration of P provides a record of changing nutrient sources and level of eutrophication. Results from 210Pb isotopes have allowed ages to be assigned to depths along the core dating back roughly 100 years at 30 cm. At this depth, a dramatic shift in the δ15N isotope is observed. Initial δ15N levels indicated a nutrient source related to agriculture. However, beginning around 100 years ago, the δ15N shows the main nutrient source for the bay became wastewater which correlates to the completion of a sewage canal in 1911 that began routing wastewater directly into the bay. Results have also shown a large rise in phosphorus levels beginning around 1970 which may be due to the construction of the automobile causeway that isolated Farmington Bay from the rest of the Great Salt Lake.

Degree

MS

College and Department

Geological Sciences

Rights

https://lib.byu.edu/about/copyright/

Date Submitted

2020-06-01

Document Type

Thesis

Handle

http://hdl.lib.byu.edu/1877/etd11846

Keywords

geology, Farmington Bay, Great Salt Lake, freeze core, isotope, wastewater, phosphorus, nitrogen, carbon, diatoms, causeway

Language

english

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