Variables and potential models for the bleaching of luminescence signals in fluvial environments

被引:28
作者
Gray, Harrison J. [1 ,2 ]
Mahan, Shannon A. [1 ]
机构
[1] US Geol Survey, Denver Fed Ctr, Denver, CO 80225 USA
[2] Univ Colorado, Cooperat Inst Environm Res, Boulder, CO 80302 USA
关键词
Bleaching; OSL; Luminescence; Fluvial; Model; IRSL; OPTICALLY STIMULATED LUMINESCENCE; BEER-LAMBERT LAW; MULTIPLE-SCATTERING CORRECTIONS; ATTENUATION COEFFICIENT; SEDIMENTATION-RATES; IRRADIANCE; TRANSPORT; QUARTZ; OSL; THERMOLUMINESCENCE;
D O I
10.1016/j.quaint.2014.11.007
中图分类号
P9 [自然地理学];
学科分类号
0705 ; 070501 ;
摘要
Luminescence dating of fluvial sediments rests on the assumption that sufficient sunlight is available to remove a previously obtained signal in a process deemed bleaching. However, luminescence signals obtained from sediment in the active channels of rivers often contain residual signals. This paper explores and attempts to build theoretical models for the bleaching of luminescence signals in fluvial settings. We present two models, one for sediment transported in an episodic manner, such as flood-driven washes in arid environments, and one for sediment transported in a continuous manner, such as in large continental scale rivers. The episodic flow model assumes that the majority of sediment is bleached while exposed to sunlight at the near surface between flood events and predicts a power-law decay in luminescence signal with downstream transport distance. The continuous flow model is developed by combining the Beer-Lambert law for the attenuation of light through a water column with a general-order kinetics equation to produce an equation with the form of a double negative exponential. The inflection point of this equation is compared with the sediment concentration from a Rouse profile to derive a non-dimensional number capable of assessing the likely extent of bleaching for a given set of luminescence and fluvial parameters. Although these models are theoretically based and not yet necessarily applicable to real-world fluvial systems, we introduce these ideas to stimulate discussion and encourage the development of comprehensive bleaching models with predictive power. (C) 2014 Elsevier Ltd and INQUA. All rights reserved.
引用
收藏
页码:42 / 49
页数:8
相关论文
共 63 条
[1]  
Aitken M.J., 1998, An Introduction to Optical Dating: The Dating of Quaternary Sediments by the Use of Photon-Stimulated Luminescence
[2]   Residual OSL signals from modern Greenlandic river sediments [J].
Alexanderson, Helena .
GEOCHRONOMETRIA, 2007, 26 :1-9
[3]   Luminescence signals from modern sediments in a glaciated bay, NW Svalbard [J].
Alexanderson, Helena ;
Murray, Andrew S. .
QUATERNARY GEOCHRONOLOGY, 2012, 10 :250-256
[4]  
[Anonymous], 369 US EPA NAT EUTR
[5]  
[Anonymous], THESIS U OXFORD
[6]  
[Anonymous], THESIS U OXFORD ENGL
[7]  
[Anonymous], THE ATMOSPHERE
[8]  
[Anonymous], WORLD ENV WAT RES C
[9]  
[Anonymous], COASTAL ENG JAPAN
[10]  
[Anonymous], 2010, GEOMORPHOLOGY MECH C, DOI DOI 10.1017/CBO9780511794827