Stochastic modelling of multi-grain equivalent dose (De) distributions: Implications for OSL dating of sediment mixtures

被引:312
作者
Arnold, L. J. [1 ]
Roberts, R. G. [1 ]
机构
[1] Univ Wollongong, GeoQuEST Res Ctr, Sch Earth & Environm Sci, Wollongong, NSW 2522, Australia
基金
澳大利亚研究理事会;
关键词
Optically stimulated luminescence dating; Sediment mixing; Finite mixture model; Stochastic modelling; Equivalent dose distributions; OPTICALLY STIMULATED LUMINESCENCE; JINMIUM ROCK SHELTER; SOUTHERN HIGH-PLAINS; MIDDLE STONE-AGE; SINGLE GRAINS; NORTHERN AUSTRALIA; BLOMBOS CAVE; STATISTICAL-MODELS; DUNE SAND; QUARTZ;
D O I
10.1016/j.quageo.2008.12.001
中图分类号
P9 [自然地理学];
学科分类号
0705 ; 070501 ;
摘要
A number of recent optically stimulated luminescence (OSL) studies have cited post-depositional mixing as a dominant source of equivalent dose (D-e) scatter across a range of sedimentary environments, including those previously considered 'best suited' for OSL dating. The potentially insidious nature of sediment mixing means that this problem may often only be identifiable by careful statistical analysis of D-e data sets. This study aims to address some of the important issues associated with the characterisation and statistical treatment of mixed D-e distributions at the multi-grain scale of analysis, using simulated D-e data sets produced with a simple stochastic model. Using this Monte Carlo approach we were able to generate theoretical distributions of single-grain D-e values, which were then randomly mixed together to simulate multi-grain aliquot D-e distributions containing a known number of mixing components and known corresponding burial doses. A range of sensitivity tests were undertaken using sediment mixtures with different aged dose components, different numbers of mixing components, and different types of dose component distributions (fully bleached, heterogeneously bleached and significantly overdispersed D-e distributions). The results of our modelling simulations reveal the inherent problems encountered when dating mixed sedimentary samples with multi-grain D-e estimation techniques. 'Phantom' dose components (i.e. discrete dose populations that do not correspond to the original single-grain mixing components) are an inevitable consequence of the 'averaging' effects of multi-grain D-e analysis, and prevent the correct number of mixing components being identified with the finite mixture model (FMM) for all of the multi-grain mixtures tested. Our findings caution against use of the FMM for multi-grain aliquot De data sets, even when the aliquots consist of only a few grains. (C) 2008 Elsevier Ltd. All rights reserved.
引用
收藏
页码:204 / 230
页数:27
相关论文
共 61 条
[41]   Optical dating of deep-sea sediments using single grains of quartz: a comparison with radiocarbon [J].
Olley, JM ;
De Deckker, P ;
Roberts, RG ;
Fifield, LK ;
Yoshida, H ;
Hancock, G .
SEDIMENTARY GEOLOGY, 2004, 169 (3-4) :175-189
[42]   Optical dating of Holocene sediments from a variety of geomorphic settings using single grains of quartz [J].
Olley, JM ;
Pietsch, T ;
Roberts, RG .
GEOMORPHOLOGY, 2004, 60 (3-4) :337-358
[43]   Disequilibria in the uranium decay series in sedimentary deposits at Allen's Cave, Nullarbor Plain, Australia: Implications for dose rate determinations. [J].
Olley, JM ;
Roberts, RG ;
Murray, AS .
RADIATION MEASUREMENTS, 1997, 27 (02) :433-443
[44]   Single-grain optical dating of grave-infill associated with human burials at Lake Mungo, Australia [J].
Olley, Jon M. ;
Roberts, Richard G. ;
Yoshida, Hiroyuki ;
Bowler, James M. .
QUATERNARY SCIENCE REVIEWS, 2006, 25 (19-20) :2469-2474
[45]   Middle paleolithic assemblages from the Indian subcontinent before and after the Toba super-eruption [J].
Petraglia, Michael ;
Korisettar, Ravi ;
Boivin, Nicole ;
Clarkson, Christopher ;
Ditchfield, Peter ;
Jones, Sacha ;
Koshy, Jinu ;
Lahr, Marta Mirazon ;
Oppenheimer, Clive ;
Pyle, David ;
Roberts, Richard ;
Schwenninger, Jean-Luc ;
Arnold, Lee ;
White, Kevin .
SCIENCE, 2007, 317 (5834) :114-116
[46]   Dating the Ramat Saharonim Late Neolithic desert cult site [J].
Porat, Naomi ;
Rosen, Steven A. ;
Boaretto, Elisabetta ;
Avni, Yoav .
JOURNAL OF ARCHAEOLOGICAL SCIENCE, 2006, 33 (10) :1341-1355
[47]   Mammalian responses to Pleistocene climate change in southeastern Australia [J].
Prideaux, Gavin J. ;
Roberts, Richard G. ;
Megirian, Dirk ;
Westaway, Kira E. ;
Hellstrom, John C. ;
Olley, Jon Im. .
GEOLOGY, 2007, 35 (01) :33-36
[48]   Optical and radiocarbon dating at Jinmium rock shelter in northern Australia [J].
Roberts, R ;
Bird, M ;
Olley, J ;
Galbraith, R ;
Lawson, E ;
Laslett, G ;
Yoshida, H ;
Jones, R ;
Fullagar, R ;
Jacobsen, G ;
Hua, Q .
NATURE, 1998, 393 (6683) :358-362
[49]  
Roberts R.G., 1998, Ancient TL, V16, P19
[50]   Optical dating of single and multiple grains of quartz from jinmium rock shelter, northern Australia, part 2, Results and implications [J].
Roberts, RG ;
Galbraith, RF ;
Olley, JM ;
Yoshida, H ;
Laslett, GM .
ARCHAEOMETRY, 1999, 41 :365-395