Lithium Enrichment and Isotopic Variation in Minerals from Peridotite Xenoliths from Northwestern Ethiopian Plateau
文献类型：期刊论文
| 作者 | Alemayehu, Melesse1,2; Zhang, Hong-Fu1,3; Sakyi, Patrick Asamoah4; Haji, Muhammed5 |
| 刊名 | JOURNAL OF THE GEOLOGICAL SOCIETY OF INDIA
 |
| 出版日期 | 2018 |
| 卷号 | 91期号:1页码:99-108 |
| ISSN号 | 0016-7622 |
| DOI | 10.1007/s12594-018-0825-x |
| 文献子类 | Article |
| 英文摘要 | We report Lithium (Li) concentrations and isotopic compositions for co-existing olivine, orthopyroxene (opx), and clinopyroxene (cpx) mineral separates from depleted and metasomatised peridotite xenoliths hosted by basaltic lavas from northwestern Ethiopian plateau (Gundeweyn area). The peridotites contain five lherzolites and one harzburgite and are variably depleted and enriched in LREE relative to HREE. In both depleted and enriched lherzolites, Li is preferentially incorporated into olivine (2.4-3.3 ppm) compared to opx (1.4-2.1 ppm) and cpx (1.4-2.0 ppm) whereas the Li contents of olivines (5.4 ppm) from an enriched harzburgiteare higher than those of lherzolites. Olivines from the samples show higher Li abundances than normal mantle olivines (1.6-1.9 ppm) indicating the occurrence of Li enrichments through melt-preroditite interaction. The average delta(7) Li values range from +2.2 to +6.0 parts per thousand in olivine, from -0.1 to +2.0 parts per thousand in opx and from -4.4 to -0.9 parts per thousand in cpx from the lherzolites. The Li isotopic composition (3.5 parts per thousand) of olivines from harzburgite fall within the range of olivine from lherzolites but the opxs show low in delta Li-7 (-2.0 parts per thousand). Overall Li isotopic compositions of olivines from the peridotites fall within the range of normal mantle olivine, delta Li-7 values of similar to+4 +/- 2 parts per thousand within uncertainty, reflecting metasomatism (enrichment) of the peridotites by isotopically heavy Li-rich asthenospheric melt. Li isotope zonation is also observed in most peridotite minerals. Majority of olivine grains display isotopically heavy cores and light rims and the reverse case is observed for some olivine grains. Orthopyroxene and clinopyroxene grains show irregular distribution in delta Li-7. These features of Li isotopic compositions within and between grains in the samples reflect the effect of diffusion-driven isotopic fractionation during meltperidotite interaction and cooling processes. |
| WOS关键词 | NORTH CHINA CRATON ; EAST-AFRICAN RIFT ; LITHOSPHERIC MANTLE BENEATH ; LI-ISOTOPE ; CARBONATITE METASOMATISM ; GEOCHEMICAL EVIDENCE ; SOUTHERN ETHIOPIA ; ICP-MS ; ULTRAMAFIC XENOLITHS ; OROGENIC ECLOGITES |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000422950300013 |
| 出版者 | SPRINGER INDIA |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/82429]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Alemayehu, Melesse |
| 作者单位 | 1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, POB 9825, Beijing 100029, Peoples R China 2.Adama Sci & Technol Univ, Sch Appl Sci, Dept Appl Geol, POB 1888, Adam, Ethiopia 3.Northwest Univ Xian, Dept Geol, State Key Lab Continental Dynam, Xian 710069, Shaanxi, Peoples R China 4.Univ Ghana, Dept Earth Sci, POB LG 58, Legon Accra, Ghana 5.Chinese Acad Sci, Inst Geol & Geophys, Div Engn Geol & Water Resources, POB 9825, Beijing 100029, Peoples R China |
| 推荐引用方式 GB/T 7714 | Alemayehu, Melesse,Zhang, Hong-Fu,Sakyi, Patrick Asamoah,et al. Lithium Enrichment and Isotopic Variation in Minerals from Peridotite Xenoliths from Northwestern Ethiopian Plateau[J]. JOURNAL OF THE GEOLOGICAL SOCIETY OF INDIA,2018,91(1):99-108. |
| APA | Alemayehu, Melesse,Zhang, Hong-Fu,Sakyi, Patrick Asamoah,&Haji, Muhammed.(2018).Lithium Enrichment and Isotopic Variation in Minerals from Peridotite Xenoliths from Northwestern Ethiopian Plateau.JOURNAL OF THE GEOLOGICAL SOCIETY OF INDIA,91(1),99-108. |
| MLA | Alemayehu, Melesse,et al."Lithium Enrichment and Isotopic Variation in Minerals from Peridotite Xenoliths from Northwestern Ethiopian Plateau".JOURNAL OF THE GEOLOGICAL SOCIETY OF INDIA 91.1(2018):99-108. |
入库方式： OAI收割
来源：地质与地球物理研究所
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