Considering sedimentary U uptake in external dose rate determinations for ESR and luminescent dating

• Published in: Quaternary international Vol. 68-71; pp. 329 - 343
• Main Authors: Blackwell, Bonnie A.B, Blickstein, Joel I.B
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2000
• ISSN: 1040-6182; 1873-4553
• DOI: 10.1016/S1040-6182(00)00056-2

At many archaeological sites, including Bau de l'Aubesier, La Quina, and La Chaise-de-Vouthon, artefacts, teeth, and bones occur in heterogeneous (“lumpy”) sedimentary deposits that include bone and tooth fragments. Due to uranium (U) uptake by the bones and teeth in the adjacent sediment, the external dose rate experienced by teeth, bones, or the sediment itself will have changed over time. Such changes must be considered when calculating dose-dependent ages, whether thermoluminescent (TL) age for burnt flint artefacts, optically stimulated luminescent (OSL) or radioluminescent (RL) ages for sediment, or electron spin resonance (ESR) ages for the teeth therein. U uptake (or loss) in the sedimentary bone and tooth fragments can be modelled in the same manner as U uptake (or loss) in the dated teeth. Compared to dose rates derived from single bulk sedimentary geochemical analyses, volumetrically averaged sedimentary dose rates at Bau de l'Aubesier show significant differences depending on the model adopted for the U uptake in order to calculate the dosimetric contribution from the sedimentary components that had absorbed U.