Molybdenum isotope insights into recycling of wedge serpentinite and fore-arc crust in subduction zones
文献类型：期刊论文
| 作者 | Liu, Hai-Quan5,6; Tian, Feng4,6; Hoernle, Kaj2,3; Li, Jie6 ; Huang, Xiao-Long5,6; Zhang, Le6; Bindeman, Ilya1; Xu, Yi-Gang4,5,6
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| 刊名 | CHEMICAL GEOLOGY
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| 出版日期 | 2024-10-05 |
| 卷号 | 665页码:12 |
| 关键词 | Molybdenum isotopes Fore-arc crust Serpentinite Adakite High-Mg andesite |
| ISSN号 | 0009-2541 |
| DOI | 10.1016/j.chemgeo.2024.122302 |
| 英文摘要 | Fore-arc crust and mantle wedge serpentinite, dragged down by the subducting slab, play a critical role in enriching the sub-arc mantle source of arc magmas. However, discriminating between these two components in arc magmas remains challenging because the fore-arc crust may contain serpentinite components inherited from previous subduction event(s). Here we present molybdenum concentration and isotope data, coupled with reanalyzed and published geochemical data, for common representatives of circum-Pacific high-Mg andesites and adakites. Elevated S98/95Mo values (-0.13%o to 0.00%o) in the Kamchatka and Aleutian high-Mg andesites are associated with elevated Mo/Ce (0.026 to 0.075), Ba/Th (138 to 808), and Sb/Ce (0.0026 to 0.0192) ratios, as well as Sr-Nd-Hf-Pb isotope compositions close to the depleted mantle and moderated S18O values (+6.6%o to +7.8%o). These characteristics are consistent with compositional contributions from slab-derived aqueous fluids via fore-arc serpentinites. In contrast, decreasing S98/95Mo values (-0.07%o to -0.48%o) in the Cascadia and Setouchi high-Mg andesites as well as four adakites from Fiji and the Austral Volcanic Zone, are generally accompanied by decreasing Mo/Ce (0.036 to 0.002) and Sb/Ce (0.0066 to 0.0002) ratios, increasing Sr/Y ratios (15 to 207), and Sr-Nd-Hf-Pb-O isotopic variations ranging from values reflecting altered oceanic crust to those resembling sediment input. These features can be accounted for by an increasing melt contribution from the subducted oceanic crust. Nine adakites from the Aleutians, Fiji, Panama, and the Austral Volcanic Zone exhibit S98/95Mo values (-0.19%o to -0.04%o) higher than the depleted mantle but lower Mo/Ce ratios (0.007 to 0.018) and low to moderate Sb/Ce ratios (0.0002 to 0.0025), indicating a potential serpentinite contribution. However, elevated Sr/Y ratios (57 to 295), unradiogenic Sr-Pb isotopes, radiogenic Nd-Hf isotopes, and moderate S18O values (+6.3%o to +6.5%o) suggest that these adakites are derived from fore-arc crust dragged down by the descending oceanic crust. The circum-Pacific adakites in this study show a decrease in S98/95Mo with decreasing Mo/Ce, consistent with partial melting of oceanic crust and 98Mo pre-enriched fore-arc crust, respectively, having lost 98Mo during subduction dehydration. Thus, our study not only distinguishes the components between eroded fore-arc crust and wedge serpentinite but also indicates a major role of both dehydration and melting in facilitating material transfer in subduction zones. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001291541600001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/80546]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 通讯作者 | Liu, Hai-Quan; Bindeman, Ilya |
| 作者单位 | 1.Univ Oregon, Dept Earth Sci, Eugene, OR 97403 USA 2.Univ Kiel, Inst Geosci, Ludewig Meyn Str 10, D-24118 Kiel, Germany 3.GEOMAR Helmholtz Ctr Ocean Res Kiel, Wischhofstr 1-3, D-24148 Kiel, Germany 4.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 5.Southern Marine Sci & Engn Guangdong Lab Guangzhou, Guangzhou 511458, Peoples R China 6.Chinese Acad Sci, Guangzhou Inst Geochem, CAS Ctr Excellence Deep Earth Sci, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China |
| 推荐引用方式 GB/T 7714 | Liu, Hai-Quan,Tian, Feng,Hoernle, Kaj,et al. Molybdenum isotope insights into recycling of wedge serpentinite and fore-arc crust in subduction zones[J]. CHEMICAL GEOLOGY,2024,665:12. |
| APA | Liu, Hai-Quan.,Tian, Feng.,Hoernle, Kaj.,Li, Jie.,Huang, Xiao-Long.,...&Xu, Yi-Gang.(2024).Molybdenum isotope insights into recycling of wedge serpentinite and fore-arc crust in subduction zones.CHEMICAL GEOLOGY,665,12. |
| MLA | Liu, Hai-Quan,et al."Molybdenum isotope insights into recycling of wedge serpentinite and fore-arc crust in subduction zones".CHEMICAL GEOLOGY 665(2024):12. |
入库方式： OAI收割
来源：广州地球化学研究所
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