Tests preparatory to applying an SAR protocol to red emission quartz using thermoluminescence

Abstract

Red TL (RTL) emission quartz has potential benefit for luminescence dating, due to the high dose saturation level and long-term stability of the TL signal. Concerning the equivalent dose determination, we investigated whether the single aliquot regenerative-dose (SAR) TL protocol would be successful in the case of RTL quartz from Japan. For the investigation, simulation tests were undertaken using sets of RTL quartz which were given known laboratory beta doses. Four different beta doses and three preheating conditions with two kinds of RTL quartz samples were employed for the simulation. Among the preheating conditions used, the simulated equivalent dose values obtained by using preheating at 220 ∘ C for 10 s and 260 ∘ C for 10 s were shown to be in far better agreement with the given beta doses. In the beginning of the experiments, the samples were first heated to 500 ∘ C for 60 s prior to the administration of simulation beta doses, in order to remove any residual TL signal. Thus, in terms of dating natural quartz samples, the implications of our results are limited to the samples which have been affected by syn- or post-depositional heating (e.g. volcanic debris flows, overlying lava flows, etc.). Our simulation results show a possibility that the RTL quartz employed in this study is capable of being applied to the SAR approach. In addition, it seems feasible to extend the time range of luminescence dating well beyond the usual range by the conventional quartz OSL methods.