New REE data at karst springs

We collected samples from 16 spring in central PA and and an urban karst area just outside Philly and had them analyzed for REE.  Rare earth elements (REE) have been used in previous studies to differentiate aquifer source rock and weathering processes, as their concentrations are affected by sorption, oxidation and complexation, but they haven’t been used as much in karst settings.  Comparing behavior of light rare earth elements (LREE) and heavy rare earth elements (HREE) showed both low ratios and high ratios for springs previously classified as conduit-dominated. Springs with both seasonal variation and little seasonal variation displayed Ce and Eu anomalies. The Ce and Eu anomalies along with the low LREE ratios can be indicative of shorter flow paths. This discrepancy between REE results and flow classification could provide a useful complementary means for further understanding karst spring behavior.