Dating speleothems in Southern Italy (Apulia and Sardinia): palaeoclimate implications and speleogenetic hints

This study reports the results of a comprehensive radiometric dating campaign carried out on 51 speleothems from caves in Apulia and Sardinia during the last ~7 years. Around 230 ages were produced by exploiting the U-Th method. Sampling targeted 5 caves in Apulia and 12 caves in Sardinia. All caves are located around or below ~41?N latitude, representing an ideal location for the understanding of speleothem deposition in relation with the Mediterranean (past) climate. Concurrently, U-Th dates can be used as minimal ages for the caves in which they formed, hence procuring geochronological constraints on speleogenetic processes. The preliminary results attest that in both regions: i) There are evidences of speleothem deposition since ~600 thousands of years before present (ka), implying that speleogenesis occurred beforehand. According to cave morphology observations, and in relation with local geology, age formation of most of the explored caves is estimated at several million of years before present. ii) Speleothem deposition occurred during glacial (last glacial, MIS6, MIS8, MIS10) and interglacial (Holocene, MIS5, MIS7, MIS9, MIS13) stages over the last ~500 ka. This implies that climate during the glacial stages was never too cold and dry to impede speleothem deposition, as occurring in other parts of Europe.