Large magnesium isotopic fractionation in lunar agglutinatic glasses caused by impact-induced chemical diffusion
文献类型：期刊论文
| 作者 | Zhang, Le2,3; Wang, Cheng-Yuan2,3; Xian, Hai-Yang4; Wang, Jintuan2,3; Zhang, Yan-Qiang2,3; Bao, Zhian1; Lin, Mang2,3; Xu, Yi-Gang2,3 |
| 刊名 | GEOCHIMICA ET COSMOCHIMICA ACTA
 |
| 出版日期 | 2024-08-01 |
| 卷号 | 378页码:71-81 |
| 关键词 | Lunar impact glass Agglutinate Mg isotopes Chemical diffusion Laser ablation split stream |
| ISSN号 | 0016-7037 |
| DOI | 10.1016/j.gca.2024.06.019 |
| 英文摘要 | Impact glasses are abundant in the lunar regolith, and Mg isotopes have the potential to trace components from various lunar crustal reservoirs, which have recently been shown to exhibit large Mg isotopic fractionations. However, it remains unclear whether Mg isotopic fractionation occurs during the formation of impact glasses. In this study, we report in situ Mg isotopic and elemental compositional data for agglutinatic glasses returned by the Chang'e 5 mission and obtained using the laser ablation split stream technique. Vesicular textures, Fe-Ni alloys, tiny Fe droplets, and high Ni contents suggest the studied agglutinatic glasses had an impact origin. The agglutinatic glasses exhibit large Mg isotopic fractionation, with delta 26Mg values ranging from -1.36 %o to -0.01 %o. The lack of correlations between delta 26Mg values, Ni contents, and ratios between volatile and relatively refractory elements (K/La, Rb/Sr, and Ce/Pb) indicate the addition of a meteoritic component and evaporation was not the major process responsible for the measured Mg isotopic variations. In fact, the MgO profiles and correlations between delta 26Mg and MgO, Na2O, Sc, Sr, CaO/Al2O3, and delta Eu reflect Mg isotopic fractionation caused by Mg diffusion from a region with high Mg contents (i.e., more melted pyroxene) to one with lower contents (i.e., more melted plagioclase). Diffusion modeling shows that the duration of diffusion was less than a fraction of a second. Our results indicate that chemical diffusion can produce large Mg isotopic fractionation in impact glasses on a scale of at least tens of microns, and that isotopic fractionation driven by chemical diffusion needs to be considered when the Mg isotopic compositions of impact glasses are used to identify different lunar rock reservoirs. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001261031100001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/78315]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 通讯作者 | Zhang, Le |
| 作者单位 | 1.Northwest Univ, Dept Geol, State Key Lab Continental Dynam, Xian 710069, Peoples R China 2.Chinese Acad Sci, CAS Ctr Excellence Deep Earth Sci, Guangzhou Inst Geochem, Guangzhou 510640, Peoples R China 3.Chinese Acad Sci, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China 4.Chinese Acad Sci, Guangzhou Inst Geochem, CAS Key Lab Mineral & Metallogeny, Guangdong Prov Key Lab Mineral Phys & Mat, Guangzhou 510640, Peoples R China |
| 推荐引用方式 GB/T 7714 | Zhang, Le,Wang, Cheng-Yuan,Xian, Hai-Yang,et al. Large magnesium isotopic fractionation in lunar agglutinatic glasses caused by impact-induced chemical diffusion[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2024,378:71-81. |
| APA | Zhang, Le.,Wang, Cheng-Yuan.,Xian, Hai-Yang.,Wang, Jintuan.,Zhang, Yan-Qiang.,...&Xu, Yi-Gang.(2024).Large magnesium isotopic fractionation in lunar agglutinatic glasses caused by impact-induced chemical diffusion.GEOCHIMICA ET COSMOCHIMICA ACTA,378,71-81. |
| MLA | Zhang, Le,et al."Large magnesium isotopic fractionation in lunar agglutinatic glasses caused by impact-induced chemical diffusion".GEOCHIMICA ET COSMOCHIMICA ACTA 378(2024):71-81. |
入库方式： OAI收割
来源：广州地球化学研究所
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