Using quartz OSL signals from SAR cycles for sediment provenance studies

Quartz optically stimulated luminescence (OSL) sensitivity is varied and related to Earth surface processes and, thus, it has been shown to be a useful tool for appraising sediment recycling and provenance investigations. These investigations are mainly based on OSL data purposely measured for sensitivity calculations. However, it has been recently shown that the relative sensitivity of the quartz OSL fast component (%BOSL_F) from the first test dose (T_n) signal from an OSL dating measurement using the Single Aliquot Regenerative-dose (SAR) protocol can be used to discriminate sediment sources. Here, we investigate the possibility of characterizing %BOSL_F for provenance purposes using not only T_n signals but all other OSL signals obtained over SAR protocol cycles from OSL dating measurements. We address the %BOSL_F behaviour over SAR cycles (if conservative or not), the %BOSL_F dependency on dose-size, differences between %BOSL_F values given by natural/regenerative and test dose signals, and %BOSL_F application for provenance studies. Quartz sand grains data from twenty Late Quaternary sediment samples, representing orogenic and cratonic sources and diverse depositional contexts from South America, Africa, and Asia, are included in the analysis. All calculations were performed using data that have been previously obtained for equivalent dose estimation. The key finding is that the averaged %BOSL_F of all SAR signals was representative of the samples' characteristic sensitivity and could satisfactorily discriminate samples from known sources, mainly in the case of high-sensitivity samples. We could distinguish sediment source areas by averaging the %BOSL_F of OSL signals from SAR natural/regenerative and test doses together. Likewise, laboratories worldwide could produce regional/global sediment provenance fingerprinting reference data using their dating measurements accumulated throughout the last decade.