Assessing the uncertainty on particle size and shape: Implications for ESR and OSL dating of quartz and feldspar grains. (October 2015)

• Record Type: Journal Article
• Authors: Duval, M.; Campaña, I.; Guilarte, V.; Miguens, L.; Iglesias, J.; González Sierra, S.
• Is Part Of: Radiation measurements. Volume 81(2015:Oct.)
• Page Start: 116
• Page End: 122
• Publication Date: 2015-10
• Subjects: ESR dating -- OSL dating -- Quartz -- Feldspar grains -- Size -- Shape -- Beta dose attenuations; Nuclear emulsions -- Periodicals; Particle tracks (Nuclear physics) -- Periodicals; Thermoluminescence -- Periodicals; Cosmic rays -- Periodicals; Radiation -- Measurement -- Periodicals; Radiometry -- Periodicals; Radiation Monitoring -- Periodicals; Émulsions nucléaires -- Périodiques; Particules (Physique nucléaire) -- Traces -- Périodiques; Thermoluminescence -- Périodiques; Rayonnement cosmique -- Périodiques; Radiométrie -- Périodiques; 539.77
• DOI: 10.1016/j.radmeas.2015.01.012
• Languages: English
• ISSNs: 1350-4487

Abstract

Abstract: Grain size and shape are two important parameters in Electron Spin Resonance (ESR) and Optically Stimulated Luminescence (OSL) dating of sediment, since they have a direct impact on several correction factors that are used for evaluating the dose rate. These parameters were evaluated by static image analysis for a wide range of quartz and feldspar grain samples. Our results indicate that there are many factors that may influence the final grain size and shape. Overall, grains are not perfect spheres, but should be rather approximated to smooth slightly elongated ellipsoids, with a width that is on average about 25% smaller than the length. For multiple grains dating, this may have an influence of a few percents on the beta dose rate evaluation, and thus even less on the total dose rate. However, in the case of single grain dating, the impact may be somewhat more significant given the large variability in size and shape between grains that may be encountered in a natural sediment. For beta micro-dosimetry purpose, it may be thus useful to better characterize the single grain that is going to be dated. Highlights: Grain size and shape are two important parameters in ESR and OSL dating of sediment. We measure grain size and shape of 19 sediment samples by static image analysis. Grains should be in general approximated to smooth slightly elongated ellipsoids. We identify the sources of uncertainty influencing grain size and shape. The Impact of these results on the dose rate evaluation is quantified.