Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1016/j.chemgeo.2007.07.019 |
Time series delta Mg-26 analysis in speleothem calcite: Kinetic versus equilibrium fractionation, comparison with other proxies and implications for palaeoclimate research | |
Buhl, D.; Immenhauser, A.; Smeulders, G.; Kabiri, L.; Richter, D. K. | |
通讯作者 | Immenhauser, A. |
来源期刊 | CHEMICAL GEOLOGY
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ISSN | 0009-2541 |
出版年 | 2007 |
卷号 | 244期号:3-4页码:715-729 |
英文摘要 | Magnesium-isotope time series MC-ICP-MS analyses from a Pleistocene speleothem - collected in a limestone cave in NW Africa (Morocco) - are reported and discussed in a process-oriented context. In addition, high-resolution C, O and Sr-isotope data, and Mg and Sr element abundances were compiled from the same stalagmite. Sub-samples were collected along the stalagmite growth axis and a second data set was drilled perpendicularly within one growth interval (Hendy test). The analytical results show clearly co-variant, systematic and cyclical fluctuations for all proxies collected along the growth axis and - with respect to the analytical error - invariant data within one growth increment. Magnesium-isotope ratios (delta Mg-26) fluctuate between -4.39 parts per thousand +/- 0.02 2 sigma arid -4.17 parts per thousand +/- 0.05 2 sigma and are within the range of published results of speleothem calcite from limestone caves. The difference of 0.22 parts per thousand is significantly beyond the error of the external reproducibility of 0.03 parts per thousand 2 sigma for 626 Mg. Considering the analytical error, neither a purely kinetic nor an equilibrium fractionation process explains the observed isotope pattern. For the time being, it is suggested that two external factors drive the speleothem Mg-isotope cyclicity: (1) climate-driven (arid versus humid) variances in the precipitation rate of a carbonate phase from meteoric water within the karstic system prior to entering the cave system; and (2) changing rates of silicate (aeolian matedal) versus carbonate weathering. Both of these processes fractionate the Mg-isotopic composition of runoff/seepage water. There is evidence that the magnesium-isotope system, applied to spelcothem archives, bears significant information concerning continental climatic variability in arid zones and deserves further research. (C) 2007 Elsevier B.V. All rights reserved. |
英文关键词 | magnesium isotopes speleothems kinetic fractionation equilibrium fractionation climate proxy |
类型 | Article |
语种 | 英语 |
国家 | Germany ; Netherlands ; Morocco |
收录类别 | SCI-E |
WOS记录号 | WOS:000250284900023 |
WOS关键词 | ISOTOPIC COMPOSITION ; MONSOON VARIABILITY ; MG ; MAGNESIUM ; CAVE ; CLIMATE ; GEOCHEMISTRY ; STALAGMITE ; RESOLUTION ; CARBONATE |
WOS类目 | Geochemistry & Geophysics |
WOS研究方向 | Geochemistry & Geophysics |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/153780 |
作者单位 | (1)Ruhr Univ Bochum, Inst Geol Mineral & Geophys, D-44801 Bochum, Germany;(2)Vrije Univ Amsterdam, Fac Earth & Life Sci, NL-1081 HV Amsterdam, Netherlands;(3)FSTE, Dept Geol, SCEEP, LFS, Er Rachidia 52000, Morocco |
推荐引用方式 GB/T 7714 | Buhl, D.,Immenhauser, A.,Smeulders, G.,et al. Time series delta Mg-26 analysis in speleothem calcite: Kinetic versus equilibrium fractionation, comparison with other proxies and implications for palaeoclimate research[J],2007,244(3-4):715-729. |
APA | Buhl, D.,Immenhauser, A.,Smeulders, G.,Kabiri, L.,&Richter, D. K..(2007).Time series delta Mg-26 analysis in speleothem calcite: Kinetic versus equilibrium fractionation, comparison with other proxies and implications for palaeoclimate research.CHEMICAL GEOLOGY,244(3-4),715-729. |
MLA | Buhl, D.,et al."Time series delta Mg-26 analysis in speleothem calcite: Kinetic versus equilibrium fractionation, comparison with other proxies and implications for palaeoclimate research".CHEMICAL GEOLOGY 244.3-4(2007):715-729. |
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