Underground production of Kr-81 detected in subsurface fluids
文献类型：期刊论文
| 作者 | Purtschert, R.1; Yokochi, R.2; Jiang, W.4; Lu, Z-T4; Mueller, P.3; Zappala, J.3; Van Heerden, E.5,9; Cason, E.5; Lau, M.6,10 ; Kieft, T. L.7
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| 刊名 | GEOCHIMICA ET COSMOCHIMICA ACTA
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| 出版日期 | 2021-02-15 |
| 卷号 | 295页码:65-79 |
| ISSN号 | 0016-7037 |
| 关键词 | Radiokrypton dating Groundwater Kapvaal cratom Fissiogenic production |
| DOI | 10.1016/j.gca.2020.11.024 |
| 英文摘要 | Radiokrypton dating using the long-lived natural isotope Kr-81 has been developed for determining the age of ancient groundwater. Kr-81 is attractive for this purpose because it is generally thought to be produced solely in the upper atmosphere. Its 229,000-year half-life, a spatially homogeneous distribution in the atmosphere, and the absence of anthropogenic sources makes it an ideal tracer to determine ages up to similar to 1.3 million years. As a noble gas, it is inert and thus not subject to interfering geochemical reactions that may alter the age information. We sought to date groundwater samples collected from deep (0.6-1.9 km) rock fractures in the Kaapvaal Craton, South Africa. Previous studies using other dating methods have estimated groundwater ages at these sites in the 1-100 million year range. Surprisingly, three of the four samples collected from flowing boreholes in gold and diamond mines showed Kr-81 isotopic abundances at 2-5 times the atmospheric value. This is the first time that underground production of Kr-81 has been detected, indicating that Kr-81 can be generated underground in measurable quantities in contrast to the long-held paradigm that such production is insignificant in natural rocks. A radionuclide production and release model is proposed in order to quantify the importance of different factors that affect the concentrations of Kr-81 in the groundwater. It is not only the high effective uranium content of the rock but also a higher Kr-81 fission yield than previously anticipated that are likely causing the elevated Kr-81 values in this case. In less extreme environments with average crustal composition (i.e. moderate U concentration), however, we anticipate that the underground production minimally affects groundwater Kr-81 dating as demonstrated. (C) 2020 The Author(s). Published by Elsevier Ltd. |
| 资助项目 | U.S. National Science Foundation[1141435] ; Department of Energy, Office of Nuclear Physics[DE-AC02-06CH11357] ; Swiss Science Foundation[200020_172550] ; National Key Research and Development Program of China[2016YFA0302200] ; Chinese Academy of Sciences[XDB21010200] |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| 出版者 | PERGAMON-ELSEVIER SCIENCE LTD |
| WOS记录号 | WOS:000614115300004 |
| 资助机构 | U.S. National Science Foundation ; Department of Energy, Office of Nuclear Physics ; Swiss Science Foundation ; National Key Research and Development Program of China ; Chinese Academy of Sciences |
| 源URL | [http://ir.idsse.ac.cn/handle/183446/8359]  |
| 专题 | 深海科学研究部_地外海洋系统研究室 |
| 通讯作者 | Purtschert, R. |
| 作者单位 | 1.Univ Bern, Climate & Environm Phys & Oeschger Ctr Climate Ch, CH-3012 Bern, Switzerland 2.Univ Chicago, Dept Geophys Sci, 5734 S Ellis Ave, Chicago, IL 60637 USA 3.Argonne Natl Lab, Div Phys, Lemont, IL 60439 USA 4.Univ Sci & Technol China, CAS Ctr Excellence Quantum Informat & Quantum Phy, Hefei Natl Lab Phys Sci Microscale, Hefei 230026, Peoples R China 5.Univ Free State, ZA-9300 Bloemfontein, South Africa 6.Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA 7.New Mexico Inst Min & Technol, Dept Biol, Socorro, NM 87801 USA 8.Swiss Fed Inst Aquat Sci & Technol, Eawag, CH-8600 Dubendorf, Switzerland 9.North West Univ, Ctr Water Sci & Management, Potchefstroom, South Africa 10.Chinese Acad Sci, Inst Deep Sea Sci & Engn, 28 Luhuitou Rd, Sanya 572000, Hainan, Peoples R China |
| 推荐引用方式 GB/T 7714 | Purtschert, R.,Yokochi, R.,Jiang, W.,et al. Underground production of Kr-81 detected in subsurface fluids[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2021,295:65-79. |
| APA | Purtschert, R..,Yokochi, R..,Jiang, W..,Lu, Z-T.,Mueller, P..,...&Onstott, T. C..(2021).Underground production of Kr-81 detected in subsurface fluids.GEOCHIMICA ET COSMOCHIMICA ACTA,295,65-79. |
| MLA | Purtschert, R.,et al."Underground production of Kr-81 detected in subsurface fluids".GEOCHIMICA ET COSMOCHIMICA ACTA 295(2021):65-79. |
入库方式： OAI收割
来源：深海科学与工程研究所
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