Seltzer, Clara2023-08-312023-08-312023-08https://hdl.handle.net/11299/256252Faculty advisor: Peter KangThe geologic setting and agricultural land use of Southeastern Minnesota raises concerns about regional nitrate contamination. To better understand potential groundwater and contaminant flow pathways, mineralogical assessment of a core sampled near Bear Spring was conducted. Bear Spring is a perennial spring within the Ordovician age Galena-Spillville karst, approximately 3 km outside of Eyota, MN in Olmsted County. X-ray diffraction (XRD) analysis on 123 samples taken at varying depths revealed that the core was composed of four main minerals: calcite, dolomite, ankerite, and quartz. Dolomitization appeared to be present throughout most of the core, with less abundance at lower depths. This coincides with an increase in shale and quartz. Additionally, XRD analysis did not reveal an observed pattern of mineral alteration near suspected natural fractures as initially hypothesized due to visual observations of color shifts. Data from this study will be used in future hydrogeologic models that can predict groundwater flow and contaminant reactive transport.enReport