Exploring sources of variation in thermoluminescence emissions and anomalous fading in alkali feldspars

Alkali feldspars are routinely used in retrospective dosimetry using luminescence methods. However there is a signal loss over time, termed ‘anomalous fading’, which results age underestimation if uncorrected. Although significant improvements have been made recent years, dating of remains challenging. This paper investigates the relationships between chemistry, structural state and scale exsolution with thermoluminescence (TL) emission spectra infrared stimulated (IRSL) fading rates. We measure TL spectra, where possible linking recombination site to physical features feldspar crystals. show that rates lowest ordered end-member Na- K-feldspars but significantly greater disordered end-members, showing Al–Si order influences fading. As well as having very low rates, samples distinctive yellow-green dominant, while all other dominant blue emission. Perthites, i.e. exsolved members (Na,K)-feldspar solid solution, than end-members greatest semi-coherent macroperthite. propose Al–Si-order, occurrence defects dislocations at perthite lamellar interfaces influence anomalous feldspars. • dependent on mineral phases, framework disorder interfaces. Single-phase little Framework increases intensity IRSL rate.