Optically stimulated luminescence dating using quartz

Abstract

Optically Stimulated Luminescence (OSL) signals from quartz can be used to determine the timing of deposition of sedimentary archives. OSL dating uses the accumulation of energy stored in a crystal structure to measure time. This stored energy is absorbed from ionising radiation, and is released (reset) by heat or daylight. The total energy (dose) absorbed since last resetting is measured using OSL, and divided by the rate of storage (dose rate) to give the time elapsed from the last heating or daylight exposure. In this Primer, we introduce the quartz OSL method and outline the signal resetting processes.We describe the origins and quantification of the dose rate and describe the daylight-sensitive OSL signal most appropriate to dose estimation. The most widely used dose measurement method is then introduced, together with quality-control procedures. A broad set of geological and archaeological studies are used to illustrate the wide range of potential applications, and we describe the challenges arising from different deposition environments and summarize evidence for the precision and accuracy of published ages. Uncertainties and minimum reporting are discussed together with methodological limitations, particularly when applied to young and old sediments. Finally, we highlight the anticipated future developments in the field.

Using calibrated surface roughness dating to estimate coastal dune ages at K'gari (Fraser Island) and the Cooloola Sand Mass, Australia

“…All OSL samples were processed and analysed at the Utah State University Luminescence Laboratory. Ages were determined utilizing single‐aliquot regenerative dose (SAR) analysis of small aliquots of quartz sand (Murray & Wintle, 2000; Murray et al, 2021). Samples were analysed using small aliquot (~10 grains) analysis to reduce scatter caused by grain‐to‐grain variability in dose rate (micro‐dosimetry) (e.g.…”

“…We calculate separate PDFs for OSL‐dated and modelled dune ages with 0.05 kyr bin intervals for 12 kyr (240 total bins) and assume that the age estimates represent the median value with normally distributed errors. As a conservative estimate of error, we utilize a constant 10% relative standard error (RSE) for predictive age, which is frequently applied for OSL dating (Murray et al, 2021). We normalize each PDF by total number of dunes used to generate the curve.…”

OCTOPUS database (v.2)

“…Cosmogenic radionuclide (CRN) exposure dating (Granger et al, 2013;Schaefer et al, 2022), luminescence dating (Rhodes, 2011;Murray et al, 2021), and radiocarbon dating (Hajdas et al, 2021) are geochronological techniques that are the most widely applicable to the recent geological past. All three of the techniques allow determination of the deposition age of sediments and associated materials, and cosmogenic radionuclides can also be used to quantify the rate at which landforms or landscapes are lowered by physical and chemical erosion processes.…”

“…For example, of the 285 publications reporting CRN-derived denudation rates over the past 25 years, only 18 publications include datasets of n ≥ 50 10 Be measurements, with the median number of data points per publication remaining constant over this period at a value of ∼ 15. Furthermore, the lack of formal reporting standards (Schaefer et al, 2022;Murray et al, 2021;Hajdas et al, 2021) coupled with the disconnect that exists in some cases between the researchers collecting the samples and interpreting the ages and/or rates and the researchers preparing the samples and undertaking the measurements means that the techniques often produce datasets that are unmanaged. These datasets may become forgotten once the study has been completed and results are published, and they may not include sufficient levels of supporting information for the quality of the raw data to be easily determined or for the raw data to be reusable with confidencefor example, in instances where data need to be recalculated due to updated measurement standards and/or data reduction protocols.…”

Optical Dating of Quartz Grains From the Minjiang Fluvial Terraces in the Sonpan Area on the Eastern Margin of the Tibetan Plateau

“…For such partially bleached samples, their MAM ages are generally considered to represent the true burial ages of well-bleached grains (Galbraith et al, 1999). However, the application of the MAM to some samples may result in significant age underestimation (e.g., Thomsen et al, 2016;Singh et al, 2017;Murray et al, 2021). In this study, the samples exhibit large OD values ranging from 23% to 56%, even for the four loess samples (grain size of 63-90 µm was used for three samples) with an average OD value of 36.3% ± 5.6%.…”