Relationships between trace element composition in various quartz-bearing bedrocks (Vosgian Strengbach catchment, E. France) and Electron Spin Resonance (ESR)/Optically Stimulated Luminescence (OSL) properties

Quartz Optically Stimulated Luminescence (OSL) and Electron Spin Resonance (ESR) offer valuable quantitative tools both for dating a wide array of Quaternary deposits but also for understanding sediment provenance and dynamics. However, the variability of quartz sensitivity remains an issue, attributed either to (i) the intrinsic properties of source bedrock, (ii) processes during sediment transport and deposition, or (iii) both. This study tackles this key question by investigating quartz from magmatic, metamorphic, and sedimentary formations in the Strengbach catchment (Vosges Massif, France).

Using a combination of ESR, OSL, and LA-ICPMS trace element analyses, our study reveals significant relationships between quartz OSL/ESR sensitivities and source bedrock characteristics, such as lithology, crystallization conditions, and deformation histories. ESR Ti-centre and OSL signals are notably influenced by trace elements like Al, Li, and Ti. Samples that underwent high pressure during metamorphism along with those located in the tectonic shear zone show both lowest OSL and ESR intensities, while higher sensitivities are observed in plutonic rocks and sandstones. This suggests that (i) pressure can be one of the prevailing factors driving changes in OSL/ESR sensitivities (ii) enhanced OSL sensitivity in mature and recycled sediments underscores the impact of sedimentary transport and reworking. As preliminary results of along-stream, in situ measured OSL signal intensity show no spatial pattern, further investigations are required to explore this topic. Our results highlight the need for careful interpretation of ESR and OSL signals, both for dating or sourcing, particularly in sediments derived from metamorphic terrains.