Investigating the potential of rock surface burial dating using IRPL and IRSL imaging

Techniques for spatially resolved measurements of infrared-stimulated luminescence (IRSL) and novel Infrared-photoluminescence (IRPL) emissions have recently been developed for applications of rock surface dating. Such spatially resolved measurements overcome the need for separating out mineral fractions, speed-up sample preparation and measurement times, and data can be quickly processed provide high-resolution luminescence-depth profiles. Here, we investigate the potential of using spatially resolved IRPL and IRSL measurements for rock surface burial dating using two large (cm-scale) rock samples with controlled exposure and surface dose histories. We use a SAR style measurement protocol, with a test-dose normalisation step to monitor sensitivity changes, a preheat to remove unstable charges and a bleaching step to reset the IRPL signal. Through establishing the response of IRPL and IRSL to dose, we are able to construct 2D maps of equivalent doses (D_es) for each sample. The results here indicate that spatially resolving IRSL and IRPL from large rock samples has the potential to be used for rock surface burial dating and offers a means to investigate the spatial distribution of dose and mineral-dependent sensitivity changes through cm-scale rock samples.