Equilibrium inter-mineral titanium isotope fractionation: Implication for high-temperature titanium isotope geochemistry
文献类型：期刊论文
| 作者 | Wang, Wenzhong2; Huang, Shichun1; Huang, Fang3; Zhao, Xinmiao4; Wu, Zhongqing2,5 |
| 刊名 | GEOCHIMICA ET COSMOCHIMICA ACTA
 |
| 出版日期 | 2020-01-15 |
| 卷号 | 269页码:540-553 |
| 关键词 | Ti isotopes First-principle calculations Fe-Ti oxides Silicate minerals Equilibrium fractionation factors Magma differentiation |
| ISSN号 | 0016-7037 |
| DOI | 10.1016/j.gca.2019.11.008 |
| 英文摘要 | Equilibrium Ti isotope fractionation factors among major Ti-bearing minerals are critical for understanding Ti isotope fractionation during magmatic processes. We use the first-principles calculations based on the density functional theory (DFT) to obtain Ti isotope reduced partition function ratios (10(3)ln beta of Ti-49/Ti-47) in a series of important Ti-bearing minerals, including Ti-doped clinopyroxene, orthopyroxene, olivine, and pyrope, geikielite-ilmenite solid solutions, and rutile. There is a large variation in our calculated 10(3)ln beta, which are linearly correlated to their Ti force constants, a parameter related to the average Ti-O bond length and the Ti valence state. Among all studied minerals, silicates with Ti4+ occupying the tetrahedral Si site have the highest 10(3)ln beta, and rutile has the lowest 10(3)ln beta. The valence state also significantly controls the 10(3)ln beta. Typically, Ti3+-doped silicates have lower 10(3)ln beta than those of Ti4+-doped silicates. At the natural abundance levels, the 10(3)ln beta of Ti-Si(4+)-doped and Ti-Mg(3+)-doped (Ti3+ occupying the Mg site) silicate minerals show no concentration effect. That is, their 10(3)ln beta do not vary with their Ti4+ and Ti3+ contents, respectively. In contrast, the 10(3)ln beta of geikielite-ilmenite solutions significantly decrease with increasing Fe/(Fe + Mg) ratio. Our calculations predict no significant Ti isotope fractionation among Ti-Si(4+)-doped clinopyroxene, orthopyroxene, olivine, and pyrope (<0.08 % at 1200 K), whereas the 10(3)ln alpha between geikielite-ilmenite solutions and Ti-Si(4+)-doped clinopyroxene ranges from similar to-0.67 parts per thousand to -0.49 parts per thousand at 1200 K, supporting the hypothesis that Fe-Ti oxides are important fractionating Ti isotopes during magma differentiation. Finally, the large equilibrium Ti isotope fractionation between geikielite-ilmenite solutions and clinopyroxene suggests that Ti isotopes can be used as a thermometer with precision comparable to that of elemental geothermometer. (C) 2019 Elsevier Ltd. All rights reserved. |
| WOS关键词 | 1ST-PRINCIPLES CALCULATIONS ; SUBSTITUTION MECHANISMS ; ORTHO-PYROXENE ; SOLAR-SYSTEM ; HUBBARD-U ; CALCIUM ; TI ; OXYGEN ; HETEROGENEITY ; CHEMISTRY |
| 资助项目 | Chinese Academy of Sciences[XDB18000000] ; Natural Science Foundation of China[41590621] ; Natural Science Foundation of China[41473011] ; Natural Science Foundation of China[41721002] ; 111 Project ; Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund ; NSF[EAR-1524387] |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000502332400028 |
| 出版者 | PERGAMON-ELSEVIER SCIENCE LTD |
| 资助机构 | Chinese Academy of Sciences ; Chinese Academy of Sciences ; Natural Science Foundation of China ; Natural Science Foundation of China ; 111 Project ; 111 Project ; Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund ; Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund ; NSF ; NSF ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; Natural Science Foundation of China ; Natural Science Foundation of China ; 111 Project ; 111 Project ; Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund ; Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund ; NSF ; NSF ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; Natural Science Foundation of China ; Natural Science Foundation of China ; 111 Project ; 111 Project ; Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund ; Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund ; NSF ; NSF ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; Natural Science Foundation of China ; Natural Science Foundation of China ; 111 Project ; 111 Project ; Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund ; Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund ; NSF ; NSF |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/95867]  |
| 专题 | 地质与地球物理研究所_岩石圈演化国家重点实验室 |
| 通讯作者 | Wang, Wenzhong; Wu, Zhongqing |
| 作者单位 | 1.Univ Nevada, Dept Geosci, Las Vegas, NV 89154 USA 2.Univ Sci & Technol China, Sch Earth & Space Sci, Lab Seismol & Phys Earths Interior, Hefei 230026, Anhui, Peoples R China 3.Univ Sci & Technol China, Sch Earth & Space Sci, CAS Key Lab Crust Mantle Mat & Environm, Hefei 230026, Anhui, Peoples R China 4.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 5.CAS Ctr Excellence Comparat Plantel, Beijing, Peoples R China |
| 推荐引用方式 GB/T 7714 | Wang, Wenzhong,Huang, Shichun,Huang, Fang,et al. Equilibrium inter-mineral titanium isotope fractionation: Implication for high-temperature titanium isotope geochemistry[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2020,269:540-553. |
| APA | Wang, Wenzhong,Huang, Shichun,Huang, Fang,Zhao, Xinmiao,&Wu, Zhongqing.(2020).Equilibrium inter-mineral titanium isotope fractionation: Implication for high-temperature titanium isotope geochemistry.GEOCHIMICA ET COSMOCHIMICA ACTA,269,540-553. |
| MLA | Wang, Wenzhong,et al."Equilibrium inter-mineral titanium isotope fractionation: Implication for high-temperature titanium isotope geochemistry".GEOCHIMICA ET COSMOCHIMICA ACTA 269(2020):540-553. |
入库方式： OAI收割
来源：地质与地球物理研究所
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