ESR/U-series dating Eemian human occupations of Northern France

International audiencePalaeolithic sites associated to the Eemian Interglacial (MIS 5e) are very rare in Northern France and their preservation is restricted to very specific geological contexts, in association with carbonated tufa (Caours) or peat deposits (Waziers). In order to check the reliability of ESR/U-series method to date teeth recovered from archaeological levels in so specific geological environments, teeth were sampled on these two Middle Palaeolithic sites and systematic in situ dosimetry was performed using portable gamma spectrometer. The ESR/U-series ages obtained on the Caours site are very homogeneous allowing the calculation of a mean age equal to 125 ± 4 ka, in agreement with the geological age and other available geochronological data (U-series on carbonate, TL on heated flints, OSL on sediments) and despite an relatively heterogeneous dosimetric environment (gamma dose rate ranging between ca 200 to 450 µGy/a). At Waziers, reducing chemical environment linked to the peat lead to very specific U-series data of the analysed teeth (U content lower than 0.1 ppm in all the dental tissues, evidence of leaching in some tissues), but the mean ESR/U-series age, 129 ± 4 ka, is also in agreement with the available geological and palaeoenvironmental data. These two studies confirm the reliability of ESR/U-series method to date with relative accuracy archaeological levels linked to such relatively short climatic event