An empirical study on the variability of luminescence ages for coeval sediment samples

IF 1.6 3区物理与天体物理 Q2 NUCLEAR SCIENCE & TECHNOLOGY

Radiation Measurements Pub Date : 2025-02-11 DOI:10.1016/j.radmeas.2025.107401

D. Constantin , R. Begy , D.A.G.J. Vandenberghe , D. Veres , A. Timar-Gabor

{"title":"An empirical study on the variability of luminescence ages for coeval sediment samples","authors":"D. Constantin , R. Begy , D.A.G.J. Vandenberghe , D. Veres , A. Timar-Gabor","doi":"10.1016/j.radmeas.2025.107401","DOIUrl":null,"url":null,"abstract":"<div><div>Optically stimulated luminescence (OSL) dating is a widely used numerical-age technique in Quaternary research. OSL age datasets at high vertical resolution are increasingly generated in order to quantify rates of processes or to identify gaps in the sediment record. However, incorporation of luminescence ages in age-depth models or age comparisons is not straightforward due to the variety and complex combination of uncertainties associated with luminescence dating. Moreover, previous studies reported on a variability in age results for coeval loess samples that is significantly larger than expected and remains to be understood.</div><div>In this study we aim to provide the first empirical assessment of the variability in the OSL ages in coeval sediment samples. Multiple samples have been collected at high horizontal resolution, from loess and an aeolian sand layers that bracket Campanian Ignimbrite/Y-5 tephra (<sup>40</sup>Ar/<sup>39</sup>Ar dated to 39.9 ± 0.1 ka), in southern Romania, southeastern Europe. All individual 63–90 μm quartz OSL ages are stratigraphically consistent with this independent age control within 1 σ or 2 σ uncertainty. There is a 1.7 % scatter in the individual ages in the sand layer and 4.6 % in the loess layer.</div><div>The various sources of uncertainty are detailed and we observe that the random sources of uncertainty have a limited contribution to the total uncertainty of the age and the systematic sources of uncertainty dominate. Weighted average ages of 46 ka and 39 ka are calculated for the sediment layers below and above the tephra, respectively. The overall random uncertainty of the weighted OSL ages (1.1 % sands, 1.6 % loess) is similar to the observed random uncertainty among individual OSL ages (0.8 % sands, 0.9 % loess) which indicates that the sources of variability in the OSL ages are properly accounted.</div><div>By averaging ages on multiple coeval samples, the precision (random uncertainty) of the age of the sedimentary context was improved with up to 1.9 % and 3.8 % in the sand and loess layers, respectively, compared to that on individual ages. Such an increase in precision of the age may lead to improvements in the precision of relative age-frameworks based on luminescence dating. However, averaging ages of coeval samples has a small effect on the overall uncertainty associated to the average weighted age, owing to a less than 10 % fractional contribution of overall random uncertainties to the total age uncertainty budget. Our empirical results show that for the samples investigated here it is not possible to obtain a luminescence age with an overall relative uncertainty of less than 6 %.</div></div>","PeriodicalId":21055,"journal":{"name":"Radiation Measurements","volume":"182 ","pages":"Article 107401"},"PeriodicalIF":1.6000,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Radiation Measurements","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1350448725000307","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"NUCLEAR SCIENCE & TECHNOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

Optically stimulated luminescence (OSL) dating is a widely used numerical-age technique in Quaternary research. OSL age datasets at high vertical resolution are increasingly generated in order to quantify rates of processes or to identify gaps in the sediment record. However, incorporation of luminescence ages in age-depth models or age comparisons is not straightforward due to the variety and complex combination of uncertainties associated with luminescence dating. Moreover, previous studies reported on a variability in age results for coeval loess samples that is significantly larger than expected and remains to be understood.

In this study we aim to provide the first empirical assessment of the variability in the OSL ages in coeval sediment samples. Multiple samples have been collected at high horizontal resolution, from loess and an aeolian sand layers that bracket Campanian Ignimbrite/Y-5 tephra (⁴⁰Ar/³⁹Ar dated to 39.9 ± 0.1 ka), in southern Romania, southeastern Europe. All individual 63–90 μm quartz OSL ages are stratigraphically consistent with this independent age control within 1 σ or 2 σ uncertainty. There is a 1.7 % scatter in the individual ages in the sand layer and 4.6 % in the loess layer.

The various sources of uncertainty are detailed and we observe that the random sources of uncertainty have a limited contribution to the total uncertainty of the age and the systematic sources of uncertainty dominate. Weighted average ages of 46 ka and 39 ka are calculated for the sediment layers below and above the tephra, respectively. The overall random uncertainty of the weighted OSL ages (1.1 % sands, 1.6 % loess) is similar to the observed random uncertainty among individual OSL ages (0.8 % sands, 0.9 % loess) which indicates that the sources of variability in the OSL ages are properly accounted.

By averaging ages on multiple coeval samples, the precision (random uncertainty) of the age of the sedimentary context was improved with up to 1.9 % and 3.8 % in the sand and loess layers, respectively, compared to that on individual ages. Such an increase in precision of the age may lead to improvements in the precision of relative age-frameworks based on luminescence dating. However, averaging ages of coeval samples has a small effect on the overall uncertainty associated to the average weighted age, owing to a less than 10 % fractional contribution of overall random uncertainties to the total age uncertainty budget. Our empirical results show that for the samples investigated here it is not possible to obtain a luminescence age with an overall relative uncertainty of less than 6 %.

查看原文本刊更多论文

同年代沉积物样品发光年龄变异性的实证研究

光激发光测年是第四纪研究中广泛使用的一种数字测年技术。越来越多地生成高垂直分辨率的OSL年龄数据集，以便量化过程的速率或确定沉积物记录中的空白。然而，由于与发光测年相关的不确定性的多样性和复杂组合，将发光年龄纳入年龄深度模型或年龄比较并非直截了当。此外，先前的研究报告了同时期黄土样品的年龄结果的变异性，这比预期的要大得多，仍然有待了解。在这项研究中，我们的目标是提供第一个经验评估的变化在OSL年龄在同时期的沉积物样品。在欧洲东南部罗马尼亚南部，以高水平分辨率从坎帕尼亚Ignimbrite/Y-5 tephra （40Ar/39Ar年代为39.9±0.1 ka）的黄土和风成砂层中收集了多个样品。所有63-90 μm石英OSL年龄在地层上都与这种独立的年龄控制在1 σ或2 σ的不确定性范围内一致。沙层和黄土层各年龄层的分散率分别为1.7%和4.6%。本文详细介绍了各种不确定性来源，我们观察到随机不确定性来源对年龄总不确定性的贡献有限，而系统不确定性来源占主导地位。经加权平均年龄计算，其下部和上部沉积层的年龄分别为46 ka和39 ka。加权OSL年龄（1.1%砂，1.6%黄土）的总体随机不确定性与观测到的单个OSL年龄（0.8%砂，0.9%黄土）的随机不确定性相似，这表明OSL年龄变异的来源得到了合理的考虑。通过对多个同期样品的平均年龄，砂层和黄土层沉积背景年龄的精度（随机不确定性）分别比单个年龄提高了1.9%和3.8%。这种年龄精度的提高可能导致基于发光定年的相对年龄框架精度的提高。然而，同期样本的平均年龄对与平均加权年龄相关的总体不确定性的影响很小，因为总体随机不确定性对总年龄不确定性预算的分数贡献小于10%。我们的经验结果表明，对于这里调查的样品，不可能获得总体相对不确定性小于6%的发光年龄。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Radiation Measurements 工程技术-核科学技术

CiteScore

4.10

自引率

20.00%

发文量

116

审稿时长

48 days

期刊介绍： The journal seeks to publish papers that present advances in the following areas: spontaneous and stimulated luminescence (including scintillating materials, thermoluminescence, and optically stimulated luminescence); electron spin resonance of natural and synthetic materials; the physics, design and performance of radiation measurements (including computational modelling such as electronic transport simulations); the novel basic aspects of radiation measurement in medical physics. Studies of energy-transfer phenomena, track physics and microdosimetry are also of interest to the journal. Applications relevant to the journal, particularly where they present novel detection techniques, novel analytical approaches or novel materials, include: personal dosimetry (including dosimetric quantities, active/electronic and passive monitoring techniques for photon, neutron and charged-particle exposures); environmental dosimetry (including methodological advances and predictive models related to radon, but generally excluding local survey results of radon where the main aim is to establish the radiation risk to populations); cosmic and high-energy radiation measurements (including dosimetry, space radiation effects, and single event upsets); dosimetry-based archaeological and Quaternary dating; dosimetry-based approaches to thermochronometry; accident and retrospective dosimetry (including activation detectors), and dosimetry and measurements related to medical applications.