Testing the potential of a low temperature feldspar luminescence dating approach using yellow stimulation

可靠的测年方法对于研究过去气候和古环境变化的时间至关重要。发光测年通常用于建立陆地沉积物档案的年代学框架，所谓的PIRIR协议，即长石信号在耗尽IR50信号后在高温下被激发，主要用于测定产生已经饱和或普遍存在问题的石英发光信号的沉积物的年代。这些升高的温度测量通常没有或可以忽略不计的褪色，但例如，剂量残留物可能是有问题的，并导致对全新世或上更新世沉积物特别相关的年龄高估。通过我们的研究活动，我们的目标是测试在低温下测量的后红外黄色刺激长石信号的潜力，以更好地克服高剂量残留物或不必要的热转移等问题。我们的假设是获得稳定的长石发射，它通过亚导带水平引导电子。对这种方法的初步研究表明，Pir-Yosl信号在第四纪沉积物测年方面似乎非常有希望。在这种方法中，在红外漂白(以下称为Pir-Yosl)之后在50°C下测量黄色刺激长石信号。因此，我们现在想从发射光谱、信号稳定性、饱和度和可漂白性等方面对黄色受激信号进行系统的研究。此外，我们计划在一组可以按时间顺序控制的样本上测试该协议，这些样本的时间跨度从中更新世到近代。

Robust dating methods are crucial to study the timing of past shifts in climate and palaeoenvironment. Luminescence dating is often used to establish chronological frameworks for terrestrial sediment archives and so called pIRIR protocols, in which the feldspar signal is stimulated at elevated temperatures after depleting the IR50 signal, are mostly applied to date sediments yielding an already saturated or generally problematic quartz luminescence signal. These elevated temperature measurements often show no or negligible fading but e.g. dose residuals can be problematic and lead to age overestimation what is especially relevant for Holocene or Upper Pleistocene sediments. With our research-campaign we aim at testing the potential of a post-IR yellow stimulated feldspar signal measured at low temperatures to better overcome problems such as high dose residuals or unwanted thermal transfer. Our hypothesis is to obtain a stable feldspar emission, which guides electrons via a sub-conduction band level. First studies on the approach, in which the yellow stimulated feldspar signal is measured at 50°C following an IR-bleach (named hereafter pIR-YOSL), show that the pIR-YOSL signal seems very promising to date Quaternary sediments. Therefore, we now want to systematically study the yellow stimulated signal in terms of emission-spectra, signal stability, saturation and bleachability. Furthermore we plan to test the protocol on a set of samples for which chronological control is available and spanning from Middle-Pleistocene to recent age.