| Abstrakt: |
Rare Earth Elements (REEs) are increasingly used for (high-tech) industrial applications and green technology, but their baseline concentrations and long-term distribution patterns in the Great Lakes remain poorly understood. We studied dissolved REE concentrations in >80 surface water samples collected from Lakes Huron, Erie and Ontario in 2021 and 2022 to assess their average concentration ranges. Following Oddo-Harkins rule, average REE concentration ranges abundances varied significantly (>3 orders-of-magnitude) between elements. In both years, concentrations were heterogeneous spatially across the lakes, but while Lake Huron had the highest dissolved REE levels, no accumulation of REE levels upstream-to-downstream through the lakes was observed. Light REEs were enriched over heavy REEs particularly in samples closer to shore, implying that riverine input is a major pathway by which these REEs are loaded to the lakes. Finally, we used normalization and pattern-filling to assess non-geogenic contributions and observed anomalies for Gd, Eu and Ce, particularly in Lake Ontario. As we are further examining REE sourcing, redox fractionation, and the role of select biogeochemical processes (sedimentation), this work provides important baseline information on REE dynamics in the Great Lakes. [ABSTRACT FROM AUTHOR] |
