Comparisons of equivalent dose values obtained with different protocols using a lacustrine sediment sample from Xuchang, China

Comparisons of seven protocols for equivalent dose (De) determination using the conventional optically stimulated luminescence (OSL) signal and the recuperation OSL (ReOSL) signal were made on a sample that is representative of a series of samples taken from a lacustrine sedimentary sequence at the archaeological site of Xuchang Man. Fine-grained quartz (4–11 μm) was extracted and the OSL signal was found to be dominated by the fast component. The De values obtained using different protocols varied from 222 ± 4 Gy to 368 ± 8 Gy. The dose response curves were all fitted with a single saturating exponential function except in the case of the multiple-aliquot additive dose protocol with sensitivity correction for the recuperated OSL signal (ReMAAD). The characteristic saturation dose (D0) values obtained with the conventional OSL signal varied between 107 ± 6 Gy and 154 ± 7 Gy and showed no relationship with De values. The ReMAAD dose response curve was linear, and yielded an equivalent dose of 269 ± 12 Gy. The ReMAAD protocol may potentially serve as a means of dating relatively older samples provided the bleaching at the time of deposition was complete.