Journal article
Rock surface and sand-sized sediment quartz dating using optically stimulated luminescence of a Middle-to-Upper Palaeolithic sequence at the Bordes-Fitte rock shelter (Les Roches d'Abilly, Central France)
In this study, we use optically stimulated luminescence (OSL) to establish a robust absolute chronology for the lower part of the stratigraphic record at “Les Roches d'Abilly”, an important Palaeolithic site in Central France. There, lithic assemblages recording the Middle-to-Upper Palaeolithic transition and the behaviour of Neanderthal and Anatomically Modern Human populations are preserved.
At the Bordes-Fitte rock shelter, part of “Les Roches d'Abilly”, the archaeo-stratigraphic record has been sealed and preserved by the collapse of the shelter roof and this site has provided important data on the timing of human occupations and Middle-to-Upper Palaeolithic transition in this region.
Here, we first obtain burial ages using standard multi-grain quartz techniques on sand-sized sediment grains and then investigate the information available in blue-stimulated luminescence-depth profiles into the surfaces of four quartz-rich cobbles found in the sedimentary record below the various collapses of the shelter roof.
These profiles show qualitative evidence for past daylight exposure and a single burial event, allowing the data to be analysed quantitatively using a multiple-event mathematical model. Based on the results of this modelling, it is concluded that at least part of the cobble surfaces were well-bleached at burial and thus that estimated rock surface burial ages are unlikely to be significantly affected by incomplete bleaching.
However, it appears that not all cobble surfaces were well-bleached, demonstrating the importance of only using surface doses derived from those cobble layers that can be shown to have been well-bleached at burial. The rock-surface burial ages of the most recent burial event are consistent with the quartz OSL ages derived from the surrounding sediments, giving burial ages of ∼50 ka.
The OSL ages are consistent with previously published 14C age control, although a single 14C age (uncalibrated age of 41,900±1,500 yr BP) of a lower unit may underestimate the OSL ages. This study provides a reliable absolute OSL chronology for the Bordes-Fitte rock shelter constraining the Middle-to-Upper Palaeolithic transition to occur between 44±2 ka and 48±3 ka ago (at the 68% confidence level).
Language: | English |
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Year: | 2022 |
Pages: | 101406 |
ISSN: | 18780350 and 18711014 |
Types: | Journal article |
DOI: | 10.1016/j.quageo.2022.101406 |
ORCIDs: | 0000-0001-5559-1862 , Thomsen, Kristina J. , Sohbati, Reza and Jain, Mayank |