DOI: 10.1016/j.quascirev.2014.02.001
Scopus记录号: 2-s2.0-84895754629
论文题名: Towards successful OSL sampling strategies in glacial environments: Deciphering the influence of depositional processes on bleaching of modern glacial sediments from jostedalen, southern norway
作者: King G.E. ; Robinson R.A.J. ; Finch A.A.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 89 起始页码: 94
结束页码: 107
语种: 英语
英文关键词: Glacial sediments
; Optically stimulated luminescence dating
; Partial bleaching
; Transport and depositional processes
Scopus关键词: Bleaching
; Cleaning
; Deposits
; Feldspar
; Feldspar deposits
; Glacial geology
; Luminescence
; Quartz
; Quartz deposits
; Weaving
; Accuracy and precision
; Depositional process
; Depositional setting
; Glacial environments
; Glacial sediments
; Luminescence properties
; Luminescence signals
; Optically stimulated luminescence
; Sediments
; bleaching
; depositional environment
; glacial deposit
; glacial environment
; luminescence
; Postglacial
; proglacial environment
; Norway
英文摘要: The optically stimulated luminescence (OSL) signals of quartz and K-feldspar are known to bleach poorly within some glacial settings, and can present a major challenge to dating applications. However, because the OSL signal is extremely sensitive to sunlight exposure history, the residual luminescence signals of modern glacial sediments also encode information about transport and depositional processes. Through examination of the residual luminescence properties (equivalent dose (De) and overdispersion values) of a suite of modern glacial sediments from different depositional settings (sandar, proglacial delta and main meltwater channel), this study provides insights not only into which sediments are likely to be fully bleached within glacial settings, but also into how OSL can be used to trace different depositional processes across sedimentary landforms. Improved understanding of the processes of sediment bleaching will enable better sample selection and may improve the accuracy and precision of OSL dating of glacial sediments. The luminescence signals of both coarse-grained quartz and K-feldspar with similar sediment sources are found to be sensitive to both depositional process and specific depositional setting. Whereas modern braid-bar-head deposits from the Nigardsdalen ice-proximal proglacial delta typically have ages of ≤3ka, similar depositional features from the Fåbergstølsgrandane sandur have residual ages of ≥26ka. Exploration of changing residual luminescence signals across individual sandur and proglacial delta braid-bar features shows that braid-bar-head deposits can retain large residual De values, while the partner braid-bar-tail deposits are almost completely bleached. The quartz OSL signal and K-feldspar IRSL50 and post-IR IRSL250 signals are shown to bleach at the same rate across the same bar feature and the IRSL50 K-feldspar signal is also shown to be completely bleached for bar-tail deposits in Nigardsdalen. Therefore the IRSL50 K-feldspar signal is suitable for dating some glacial deposits, circumventing the challenges associated with dim quartz signals. © 2014 The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60344
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Earth and Environmental Sciences, University of St Andrews, Irvine Building, North Street, St Andrews, Fife KY16 9AL, Scotland, United Kingdom
Recommended Citation:
King G.E.,Robinson R.A.J.,Finch A.A.. Towards successful OSL sampling strategies in glacial environments: Deciphering the influence of depositional processes on bleaching of modern glacial sediments from jostedalen, southern norway[J]. Quaternary Science Reviews,2014-01-01,89