The modern hydrogeochemistry of small pools in Corchia Cave, Italy: implications for palaeoclimate reconstruction
Résumé
Several small lakes occupy a number of levels in the Galleria delle Stalattiti of Corchia Cave, Italy. An important feature of two such lakes is the presence of actively growing, subaqueous calcite mounds. Drill cores from these mounds have been the subject of investigations for several years. 234U-238U ages from the base of these cores, combined with stable isotope data from U-Pb-dated stalagmites collected metres away, suggest that some of the mounds have been growing since ~1 Ma. To provide baseline data for interpreting the geochemical variations of these cores, we commenced a study of modern lake-water chemistry, including stable isotopes of H, C and O, trace elements and organic matter content. Besides demonstrating the exceptionally stable state of these lake systems, the combining of core-top geochemistry with source-water chemistry allows us to explore water-calcite isotope and trace element partitioning, and to evaluate the suitability of this unusual speleothem-forming environment for clumped-isotope palaeothermometry. Preliminary results will be presented in this poster.