Implications of K, Cu and Zn isotopes for the formation of tektites
文献类型:期刊论文
作者 | Jiang, Yun1,2,3,4![]() |
刊名 | GEOCHIMICA ET COSMOCHIMICA ACTA
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出版日期 | 2019-08-15 |
卷号 | 259页码:170-187 |
关键词 | Tektites K isotopes Zn isotopes Cu isotopes Moderately Volatile Elements |
ISSN号 | 0016-7037 |
DOI | 10.1016/j.gca.2019.06.003 |
通讯作者 | Wang, Kun(wangkun@wustl.edu) |
英文摘要 | Tektites are mm to cm sized glassy objects generated through high-energy meteoroid impacts on the surface of the Earth under high temperature and pressure, and reducing conditions. They are the products of large-scale catastrophic events in Earth's history and can be used to understand the behavior of moderately volatile elements (e.g., K and Zn) during impact vaporization events. Here, we report bulk K isotopic compositions of tektites from three different strewn fields and "in-situ" profile analysis of both K and Zn isotopes in one complete tektite. All tektites span a narrow range in their K isotopic compositions (delta K-41(BSE): -0.10 +/- 0.03 parts per thousand to 0.16 +/- 0.04 parts per thousand), revealing no discernible K isotopic fractionation from the Bulk Silicate Earth (BSE) and upper continental crust materials, which is consistent with previous results. In contrast, Zn isotopes show a large variation (delta Zn-66: -0.39 +/- 0.02 parts per thousand to 2.38 +/- 0.03 parts per thousand) even within one specimen. In order to provide a coherent explanation for the different behavior of moderately volatile elements (K, Zn and Cu), we have conducted thermochemical calculations to compute the partial vapor pressures of Cu2O, K2O, and ZnO dissolved in silicate melts as a function of temperature, pressure, oxygen and chlorine fugacities. In a large range of the parameter space, the calculations show that Cu and Zn can be vaporized much easier than K and thus produce large isotopic fractionation. In contrast, the lithophile element K is more prone to remain in the silicate melt because of its very low activity coefficient in the melt, and thus the K isotopes remain unfractionated. This study provides new constraints on the formation of tektites and is consistent with a "bubble-stripping" model to explain the extreme water and volatiles depletion in tektites. (C) 2019 Elsevier Ltd. All rights reserved. |
WOS关键词 | EXPERIMENTAL VAPOR FRACTIONATION ; RIES IMPACT STRUCTURE ; IVORY-COAST TEKTITES ; SOUTH CHINA SEA ; MC-ICP-MS ; AUSTRALASIAN TEKTITES ; SILICATE MELTS ; CHEMICAL-COMPOSITION ; PARENT CRATER ; GEOCHEMISTRY |
WOS研究方向 | Geochemistry & Geophysics |
语种 | 英语 |
WOS记录号 | WOS:000474198900011 |
出版者 | PERGAMON-ELSEVIER SCIENCE LTD |
源URL | [http://libir.pmo.ac.cn/handle/332002/27288] ![]() |
专题 | 中国科学院紫金山天文台 |
通讯作者 | Wang, Kun |
作者单位 | 1.Chinese Acad Sci, Purple Mt Observ, CAS Key Lab Planetary Sci, Nanjing 210008, Jiangsu, Peoples R China 2.CAS Ctr Excellence Comparat Planetol, Nanjing, Jiangsu, Peoples R China 3.Washington Univ, Dept Earth & Planetary Sci, One Brookings Dr, St Louis, MO 63130 USA 4.Washington Univ, McDonnell Ctr Space Sci, One Brookings Dr, St Louis, MO 63130 USA 5.Macau Univ Sci & Technol, State Key Lab Planetary Sci, Taipa, Macau, Peoples R China 6.Harvard Univ, Dept Earth & Planetary Sci, 20 Oxford St, Cambridge, MA 02138 USA |
推荐引用方式 GB/T 7714 | Jiang, Yun,Chen, Heng,Fegley, Bruce, Jr.,et al. Implications of K, Cu and Zn isotopes for the formation of tektites[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2019,259:170-187. |
APA | Jiang, Yun.,Chen, Heng.,Fegley, Bruce, Jr..,Lodders, Katharina.,Hsu, Weibiao.,...&Wang, Kun.(2019).Implications of K, Cu and Zn isotopes for the formation of tektites.GEOCHIMICA ET COSMOCHIMICA ACTA,259,170-187. |
MLA | Jiang, Yun,et al."Implications of K, Cu and Zn isotopes for the formation of tektites".GEOCHIMICA ET COSMOCHIMICA ACTA 259(2019):170-187. |
入库方式: OAI收割
来源:紫金山天文台
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