中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Lead atmospheric deposition rates and isotopic trends in Asian dust during the last 9.5 kyr recorded in an ombrotrophic peat bog on the eastern Qinghai-Tibetan Plateau

文献类型:期刊论文

作者Large, DJ (Large, David J.)[3]; Dong, SF (Dong, Shuofei)[1]; Weiss, DJ (Weiss, Dominik J.)[1,2]; Ferrat, M (Ferrat, Marion)[1]; Spiro, B (Spiro, Baruch)[2]; Sun, YB (Sun, Youbin)[4]; Gallagher, K (Gallagher, Kerry)[5]
刊名GEOCHIMICA ET COSMOCHIMICA ACTA
出版日期2012-04-01
卷号82页码:4-22
文献子类期刊论文
英文摘要

A full understanding of the atmospheric Pb cycle in Asia during the Holocene is key to palaeoclimate studies of past atmospheric circulation patterns, as well as to assess the impact of increasing industrial activities in this region. However, long-term records of atmospheric Pb isotopic trends in Asia are still sparse. Consequently, we study changes in the concentrations, fluxes and isotopic signature of deposited Pb contained in a (14)C-dated peat core from the eastern Qinghai-Tibetan Plateau, dating back to 9.5 kyr BP, and present the first peat record of the changing isotopic composition of atmospheric Pb in dust in Asia during this time. Lead concentrations and fluxes vary between 2.96-21.58 mu g g(-1) and 0.06-3.52 mg m(-2) y(-1), respectively, with an average Pb baseline of 6.80 +/- 4.18 mu g g(-1). These values agree with other Pb studies of lake and peat archives in China but are one order of magnitude larger than early and mid-Holocene values measured in Europe. Lead isotopic variability throughout the core is small, varying between (206)Pb/(207)Pb = 1.190-1.197, (206)Pb/(204)Pb = 18.648-18.786, (207)Pb/(204)Pb = 15.666-15.694 and (208)Pb/(204)Pb = 38.890-39.090. The application of Bayesian trans-dimensional changepoint modelling to the Pb dataset enabled the identification of eight significant changes in the isotopic composition of the deposited Pb. Such changes mark different phases of atmospheric Pb deposition, and hence variations in atmospheric circulation patterns and environmental conditions. Temporal variations in the potential natural and/or anthropogenic Pb sources are assessed based on the (206)Pb, (207)Pb, (208)Pb and (204)Pb isotopic composition and the 1/[Pb] ratio of the peat samples. Our results suggest that Pb deposition throughout the Holocene was governed by local deposition and long-range input from natural dust sources in northwestern (Taklamakan desert and Qaidam basin) and northern China (Badain Jaran and Tengger deserts). Input from the northern sources seems to have been particularly important between 3.1-2.7 kyr BP and 1.7-0.9 kyr BP, suggesting a possible strengthening of the East Asian winter monsoon, in agreement with previous reconstructions in Asia. Based on the Pb/Sc and isotopic composition profiles we do not note any evidence for anthropogenic Pb derived from the thriving mining or smelting activities in northern and eastern China in the last few millennia, suggesting that atmospheric deposition to this region of the eastern Tibetan Plateau was dominated by natural Pb fluxes. These can serve as a true Asian "background" value against which anthropogenic impacts can be quantified. Our results confirm that the combination of radiogenic isotopes (Pb) and trace elements in peat bogs enables observational reconstructions of changes in past regional atmospheric circulation. Such records will enable more refined interpretations of marine and terrestrial palaeorecords in Asia and the Pacific and consequently provide further constraints for changes in ocean and atmospheric circulation and for the testing of palaeoclimate models of circulation patterns.

语种英语
源URL[http://ir.ieecas.cn/handle/361006/10201]  
专题地球环境研究所_古环境研究室
通讯作者Ferrat, M (Ferrat, Marion)[1]
作者单位1.Department of Earth Sciences and Engineering, Imperial College London, London SW7 2AZ, UK;
2.Department of Mineralogy, The Natural History Museum, Cromwell Road, London SW7 5BD, UK;
3.Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK;
4.State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075, China;
5.Ge´osciences, Universite´ de Rennes 1, Rennes 35042, France
推荐引用方式
GB/T 7714
Large, DJ ,Dong, SF ,Weiss, DJ ,et al. Lead atmospheric deposition rates and isotopic trends in Asian dust during the last 9.5 kyr recorded in an ombrotrophic peat bog on the eastern Qinghai-Tibetan Plateau[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2012,82:4-22.
APA Large, DJ .,Dong, SF .,Weiss, DJ .,Ferrat, M .,Spiro, B .,...&Gallagher, K .(2012).Lead atmospheric deposition rates and isotopic trends in Asian dust during the last 9.5 kyr recorded in an ombrotrophic peat bog on the eastern Qinghai-Tibetan Plateau.GEOCHIMICA ET COSMOCHIMICA ACTA,82,4-22.
MLA Large, DJ ,et al."Lead atmospheric deposition rates and isotopic trends in Asian dust during the last 9.5 kyr recorded in an ombrotrophic peat bog on the eastern Qinghai-Tibetan Plateau".GEOCHIMICA ET COSMOCHIMICA ACTA 82(2012):4-22.

入库方式: OAI收割

来源:地球环境研究所

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