Datazione ESR/U-series di smalto dentale fossile: applicazione a resti dentari provenienti da alcuni siti Paleolitici italiani

Combined ESR/U-series dating method has been frequently applied in geochronology over the past twenty years, allowing the dating of fossil teeth from different archaeological and palaeontological sites. ESR dating is based on the measurement of the number of paramagnetic centres in a mineral lattice (e.g. hydroxyapatite in fossil enamel), caused by alpha-, beta- and gamma- radiations due to natural radioelements (U, Th and daughters, and K). The two main parameters that have to be measured in order to obtain an age, are the Palaeodose (the dose received by the sample between the ¿zeroing¿ and the time of measurement) and the annual dose (the mean dose received, due to natural radioactivity, during one year). A part of this annual dose is related to the fact that, during the burial period, the sample could incorporate Uranium from the surrounding sediment. In fact, due to their different chemical compositions, this uptake will influence the different tissues of the same tooth. This U-uptake has to be reconstructed for each tissue by the combination of ESR method with the U-series one. In the present work, coupled ESR and U-series method has been applied on fossil teeth in order to date archaeological layers from four different Palaeolithic sites on the Italian peninsula: Ciota Ciara cave (Piedmont), Valle Giumentina (Abruzzo), Poggetti Vecchi (Tuscany) and Isoletta (Latium). The estimated ESR/U-series ages obtained are all in agreement with other dating results, except for the Ciota Ciara cave for which the obtained results are older than expected.