This study examines how different reference feldspar samples produce different signals using the infrared-radiofluorescence (IR-RF) dating method. By comparing individual grains, controlled grain mixtures, and natural sediment samples, we investigate how mineral chemistry and grain-to-grain variability affect the shape of IR-RF signal. These results help explain why the feldspar signal can vary within a single sample and support moving towards single-grain dating approaches for IR-RF.

We tested the reliability of infrared radiofluorescence (IR-RF) dating of K-feldspar on samples of known age. We compare several measurement protocols and analysis variants and determine the most appropriate version. Additionally, we compare these results with those obtained using infrared photoluminescence (IRPL), an alternative dating method for K-feldspar, for the same samples. Our results confirm the dating potential of IR-RF and highlight similarities and differences to other methods.

This is a preliminary study using a synchrotron light source to generate elemental maps, incorporating oxidation states, with a spatial resolution of <1 µm for individual grains within the K-feldspar density fraction. The elemental fingerprint characterizing grains with a signal suitable for infrared radiofluorescence dating reveals high levels of K, Pb, and Ba coupled with low levels of Fe and Ca. In contrast, grains exhibiting higher proportions of Fe and Ca produce an odd signal shape.