A Geochemical Study of Near-Shore Sediment Cores from Utah Lake, UT, USA

Several sediment core studies have been performed on Utah Lake over the past century, with recent studies providing detailed depositional history based on shallow core samples. To offer additional coverage, we collected 10 deeper sediment cores that extended at least 140 cm below the sediment–water interface from various locations across the lake and analyzed them for ICP-OES detectable elements, fractional calcium carbonate, and loss on ignition (as a proxy for fractional organic matter). Despite high water levels and equipment limitations restricting us to near-shore areas, our samples effectively represented the lake. Our findings revealed significant chemostratigraphic variability, indicating non-homogeneous lakebed sediment. Elements with higher min–max normalized mean concentrations showed strong correlations. Depth trends in the sediments indicated positive correlations for Mn, Al, Fe, K, and V, and negative correlations for Ba, Cu, Pb, Sr, and Zn, with P showing variable correlations. Some of our multidimensional scaling results exhibited geochemical shifts at 30–40 cm, supporting claims that this depth marks the onset of European settlement. Elevated Pb levels in the upper sediment layers are likely the result of mid-20th century leaded gasoline pollution. Sediment P is linked to Ca, Fe, and trace metal pollutants, suggesting both natural processes and human activities influence elemental distribution, though only a few cores showed P changes aligning with European settlement.