An amphibolitic source for adakitic I-type plutons in continental collision zones
文献类型：期刊论文
| 作者 | Li, Qi-Wei6,7; Nebel, Oliver6; Zhao, Jun-Hong7; Wang, Rui5; Jacobsen, Yona6; Richter, Marianne4,6; Wang, Qiang1,2,3; Cawood, Peter A.6 |
| 刊名 | EARTH AND PLANETARY SCIENCE LETTERS
 |
| 出版日期 | 2023 |
| 卷号 | 619页码:118324 |
| 关键词 | PORPHYRY CU-MO IRON ISOTOPE FRACTIONATION EASTERN GANGDESE BELT PARTITION-COEFFICIENTS GRANITIC-ROCKS FE ISOTOPES HF ISOTOPES ISLAND-ARC MIOCENE MANTLE |
| ISSN号 | 0012-821X |
| DOI | 10.1016/j.epsl.2023.118324 |
| 英文摘要 | Rocks with 'adakitic' affinities are widespread in continental collision zones, recording important information about crustal thickening. Residual garnet during partial melting of the lower crust is traditionally considered to be responsible for heavy rare earth element and Y depletion, which is a key characteristic feature of these rocks. However, magmatic garnet is rarely observed in such adakitic igneous rocks and associated protolithic eclogite is also rarely reported. Instead, amphibole is a proposed abundant phase in lower arc crust. Whilst both garnet- and amphibole-rich assemblages can act as potential sources for intracrustal intermediate-silicic melts, their distinctive fractionation of fSm/Nd and fLu/Hf should, with time, lead to different Nd-Hf isotopic compositions in high Sr/Y rocks. Here we report whole-rock radiogenic Sr-Nd-Hf and stable Fe isotope compositions of well-characterized Oligocene to Miocene (33-14 Ma), post-collisional high-K adakitic intrusions from the Gangdese belt, South Tibet. The plutons have a low alumina saturation index and depleted Dy/Yb, pointing to negligible amounts of sediment contribution. They are characterized by variable initial 87Sr/86Sr ratios (0.7048 to 0.7078), mostly negative ΕNd (?4.9 to +0.3), positive ΕHf values (+1.5 to +8.3), and variable but heavy δ57Fe values ranging from +0.04 ± 0.08‰ to +0.35 ± 0.08‰. Modeling of Fe isotopes and fractionation factors of fSm/Nd and fLu/Hf indicate an amphibolite source. A Nd-Hf isotope correlation that is quasi-parallel to the mantle array can be best explained by the evolution of amphibolitic lower crust with a residence time of ca. 400 Myrs. Although these adakitic rocks have depleted, mantle-like Hf isotope compositions, they are part of an existing, older crustal foundation and thus represent a process of crustal reworking, instead of crustal growth. Therefore, proportions of mantle-derived materials that contributed to the Phanerozoic crustal growth based on Hf-in-zircon signatures alone may be overestimated. Combined mineral and whole-rock radiogenic and stable isotopes are required to address this issue in the future. ? 2023 Elsevier B.V. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001055188000001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/80281]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 作者单位 | 1.College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing; 100049, China 2.CAS Center for Excellence in Deep Earth Science, Guangzhou; 510640, China 3.State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou; 510640, China 4.Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, Armilla, Granada; 18100, Spain 5.State Key Laboratory of Geological Processes and Mineral Resources, Institute of Earth Sciences, China University of Geosciences, Beijing; 100083, China 6.School of Earth, Atmosphere and Environment, Monash University, Clayton; VIC; 3800, Australia 7.State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, Wuhan; 430074, China |
| 推荐引用方式 GB/T 7714 | Li, Qi-Wei,Nebel, Oliver,Zhao, Jun-Hong,et al. An amphibolitic source for adakitic I-type plutons in continental collision zones[J]. EARTH AND PLANETARY SCIENCE LETTERS,2023,619:118324. |
| APA | Li, Qi-Wei.,Nebel, Oliver.,Zhao, Jun-Hong.,Wang, Rui.,Jacobsen, Yona.,...&Cawood, Peter A..(2023).An amphibolitic source for adakitic I-type plutons in continental collision zones.EARTH AND PLANETARY SCIENCE LETTERS,619,118324. |
| MLA | Li, Qi-Wei,et al."An amphibolitic source for adakitic I-type plutons in continental collision zones".EARTH AND PLANETARY SCIENCE LETTERS 619(2023):118324. |
入库方式： OAI收割
来源：广州地球化学研究所
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