Application of the single-aliquot regenerative-dose protocol to the 375 degrees C quartz TL signal

We report on investigations into the suitability of a single-aliquot regene rative-dose (SAR) protocol applied to the isothermal TL signal obtained fro m quartz held at 330 degreesC. Samples are first thermally and optically pr etreated to remove any signal from the 325 degreesC TL trap. It is shown th at the regenerated TL decay curve has the same shape as the natural one, an d that recuperation is negligible. Examination of the TL glow curve before and after isothermal measurement suggests that the isothermal signal comes mainly from the 375 degreesC TL peak, and a pulse anneal experiment is used to confirm this. This signal is bleached by simulated sunlight, with a fas t component (making up about 60% of the total natural signal) bleaching abo ut 30 rimes faster than a slower component. The SAR protocol is then applie d to 9 samples from various depositional environments, and it is shown that the resulting data satisfy the internal checks of reliability, i.e,, indep endence of prior treatment, and absence of recuperation. Examination of the sensitivity-corrected growth curve shows that the applicable age range for this signal may be only slightly greater than that from the OSL signal der ived from the 325 degreesC peak. This limited advantage is offset by the mu ch greater difficulty of bleaching. (C) 2000 Elsevier Science Ltd. All righ ts reserved.