THE INTERNAL DOSE RATE IN QUARTZ GRAINS: EXPERIMENTAL DATA AND CONSEQUENCES FOR LUMINESCENCE DATING

This work considers the impact of the internal alpha and beta dose rates in quartz grains obtained from sandy sediments on the results of luminescence dating. The internal dose rates reported here (ca. 0.01-0.21 Gy middot ka(-1)) play a particularly important role, because of low (ca. 0.8-0.9 Gy middot ka(-1)) or very low (ca. 0.4-0.6 Gy middot ka(-1)) external dose rates. In these cases, the internal dose rates form a significant fraction of the total dose rates, often exceeding 10%. Ignoring this contribution would have made the considered luminescence ages artificially older. In our study, we measure both the internal alpha and beta contributions as the latter is usually neglected in the case of quartz. The dose rate measurements were performed using the innovative mu Dose system.