Preliminary U concentrations were determined in our speleothems allowing us to constraint the amount required for subsequent dating. Samples were drilled along the central axis and underwent a chemical preparation consisting in a complete dissolution of the drilled material, spiking with our triple spike solution with known U-233, U-236 and Th-229 content, and a final separation of U and Th on specific ion exchange resin.
Finally, the prepared samples were measured in our recently installed Neptune Plus Multicollector Inductively Coupled Plasma ion source Mass Spectrometer (MC-ICP-MS) and results calibrated for a final corrected age.