Garnet effect on Nd-Hf isotope decoupling: Evidence from the Jinfosi batholith, Northern Tibetan Plateau
文献类型：期刊论文
| 作者 | Huang, Hui1,2; Niu, Yaoling1,3,4; Mo, Xuanxue1 |
| 刊名 | LITHOS
 |
| 出版日期 | 2017-03-01 |
| 卷号 | 274页码:31-38 |
| 关键词 | Garnet effect Nd-Hf isotope decoupling TTG The North Qilian Orogenic Belt |
| 英文摘要 | The initial Nd and Hf isotope ratios of a 420 Ma post-collisional dioritic-granitic batholith from the Northern Tibetan plateau define a negative trend above and orthogonal to the epsilon(Hf)(t)-epsilon(Nd)(t) terrestrial array. This uncommon trend offers an insight into the origin of the puzzling Nd-Hf isotope decoupling in the crustal rocks. On this trend, samples depleted in heavy rare earth elements (HREEs, i.e., [Dy/Yb](N) >> 1) deviate most from the terrestrial array whereas samples with flat HREEs (i.e., [Dy/Yb](N) >= 1) deviate less or plot within the terrestrial array, pointing to the controlling effect of garnet in the magma source. Ancient garnet-bearing residues after melt extraction will have elevated Lu/Hf ratios and can evolve with time to produce high epsilon(Hf)(t) at a low epsilon(Nd)(t) value. Mixing of melts-derived from such source lithologies (high Lu/Hf) with melts possessing a within-terrestrial array Nd-Hf isotopic composition (low Lu/Hf) best explains the observed trend orthogonal to the terrestrial array. The samples from the Jinfosi batholith with the most decoupled Nd-Hf isotope compositions require a larger degree (>40%) and ancient (i.e.,>= 1.8 Gyr) previous melt extraction from their source. It follows that the ancient melts with depleted HREEs complementary to those garnet-bearing residues should have low epsilon(Hf) values and plot below the terrestrial array, which is indeed shown by some Archean/Paleoproterozic ITGs.(C) 2017 Elsevier B.V. All rights reserved. |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000397375400003 |
| 版本 | 出版稿 |
| 源URL | [http://ir.qdio.ac.cn/handle/337002/136777]  |
| 专题 | 海洋研究所_海洋地质与环境重点实验室 |
| 作者单位 | 1.China Univ Geosci, Sch Earth Sci & Mineral Resources, Beijing 100083, Peoples R China 2.Univ Washington, Dept Earth & Space Sci, Isotope Lab, Seattle, WA 98195 USA 3.Univ Durham, Dept Earth Sci, Durham DH1 3LE, England 4.Chinese Acad Sci, Inst Oceanol, Qingdao 266071, Peoples R China |
| 推荐引用方式 GB/T 7714 | Huang, Hui,Niu, Yaoling,Mo, Xuanxue. Garnet effect on Nd-Hf isotope decoupling: Evidence from the Jinfosi batholith, Northern Tibetan Plateau[J]. LITHOS,2017,274:31-38. |
| APA | Huang, Hui,Niu, Yaoling,&Mo, Xuanxue.(2017).Garnet effect on Nd-Hf isotope decoupling: Evidence from the Jinfosi batholith, Northern Tibetan Plateau.LITHOS,274,31-38. |
| MLA | Huang, Hui,et al."Garnet effect on Nd-Hf isotope decoupling: Evidence from the Jinfosi batholith, Northern Tibetan Plateau".LITHOS 274(2017):31-38. |
入库方式： OAI收割
来源：海洋研究所
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