Investigations of the performance of quartz single aliquot D-E determination procedures

摘要

Over the past few years a variety of equivalent dose (DE) determination techniques for quartz, which are truly single aliquot-based, have been proposed. Such methods avoid the need for inter-aliquot normalisation, and provide considerable improvements in the precision of equivalent dose (DE) estimates. Much of the research leading to these developments have been based on detailed investigations of a few samples, primarily from Australia. All 'protocols' developed have performed impressively. It is necessary, however, to verify the consistency of the single aliquot DE determination methods on a wide range of samples before they can be considered as prescribed or standard. We have analysed approximately 100 samples from a range of sedimentary environments and geological provinces in an attempt to confirm the robustness of the single aliquot techniques. Up to 65% of samples measured in our laboratory were not suited to analysis via application of single aliquot additive dose (SAAD) procedures. This relates to a range of factors, including lack of sample sensitivity and dose dependent sensitivity changes. Furthermore, we have observed some problems in dating young sediments using single aliquot regeneration (SAR) methods. Critically, we observe that sample to sample variability on quartz luminescence (thermally- and optically-stimulated) behaviour is considerable, and many samples are found to exhibit behaviour which contrasts greatly from that described in recent phenomenological studies. (C) 2000 Elsevier Science Ltd. All rights reserved. [References: 24]