%0 Journal Article
%A Arnold, Lee
%A Demuro, Martina
%A Spooner, Nigel
%A Prideaux, Gavin
%A McDowell, Matthew Charles
%A Camens, Aaron B.
%A Reed, Elizabeth H.
%A Parés, Josep M.
%A Arsuaga, Juan Luis
%A Bermúdez de Castro, José María
%A Carbonell i Roura, Eudald
%T Single-grain TT-OSL bleaching characteristics: Insights from modern analogues and OSL dating comparisons
%D 2018
%@ 1871-1014
%U https://hdl.handle.net/20.500.14352/11991
%X Previous assessments of thermally transferred optically stimulated luminescence (TT-OSL) signal resetting in natural sedimentary settings have been based on relatively limited numbers of observations, and have been conducted primarily at the multi-grain scale of equivalent dose (De) analysis. In this study, we undertake a series of single-grain TT-OSL bleaching assessments on nineteen modern and geological dating samples from different sedimentary environments. Daylight bleaching experiments performed over several weeks confirm that single-grain TT-OSL signals are optically reset at relatively slow, and potentially variable, rates. Single-grain TT-OSL residual doses range between 0 and 24 Gy for thirteen modern samples, with >50% of these samples yielding weighted mean De values of 0 Gy at 2σ. Single-grain OSL and TT-OSL dating comparisons performed on well-bleached and heterogeneously bleached late Pleistocene samples from Kangaroo Island, South Australia, yield consistent replicate age estimates. Our results reveal that (i) single-grain TT-OSL residuals can potentially be reduced down to insignificant levels when compared with the natural dose range of interest for most TT-OSL dating applications; (ii) the slow bleaching properties of TT-OSL signals may not necessarily limit their dating applicability to certain depositional environments; and (iii) non-trivial differences may be observed between single-grain and multi-grain TT-OSL bleaching residuals in some modern samples. Collectively, these findings suggest that single-grain TT-OSL dating may offer advantages over multi-grain TT-OSL dating in certain complex depositional environments.
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