Knowledge Management System Of Guangzhou Institute of Geochemistry，CAS
Yu, Yang1,2; Huang, Xiao-Long1,2; Lai, Yu-Ming3; Li, Jie1 ; Xu, Yi-Gang1,2; Chung, Sun-Lin4,5; Setiawan, Iwan6; Yang, Fan1,2
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| Different B-Mo isotopic fractionation processes controlled by redox conditions in the subduction zone | |
| Source Publication | CHEMICAL GEOLOGY
 |
| ISSN | 0009-2541 |
| 2023-10-05 | |
| Volume | 636Pages:12 |
| DOI | 10.1016/j.chemgeo.2023.121646 |
| Language | 英语 |
| WOS Research Area | Geochemistry & Geophysics |
| Abstract | The control of redox conditions on the geochemical recycling process in subduction zones is still poorly understood due to large uncertainties in oxygen fugacity (fO2) for subducted slabs. We present the first systematic geochemical and B-Mo-Sr-Nd-Hf-Pb isotopic data for continental arc basalts (CABs) and back-arc basalts (BABs) from Sumatra to investigate the relationships between oxygen fugacity and B-Mo isotopic fractionation processes during subduction. The Sumatran CABs and BABs yield high FeOT/MgO ratios and low K2O contents (0.48-1.42 wt%) and can be classified as tholeiitic. They have variable Sr-Nd-Hf-Pb isotopic compositions, consistent with the input of different amounts of melt from subducted terrigenous sediments into mantle sources. The BAB samples show much lower 611B (-9.0%o to -7.3%o) values than the CABs (611B =-7.0%o to +0.17%o), reflecting significant B isotopic fractionation during multistage melting of subducted sediments. This is distinct from the similar 698/95Mo values for the Sumatran CABs (-0.21%o to -0.01%o) and BABs (-0.17%o to -0.08%o), suggesting limited Mo isotopic fractionation during subduction. The Sumatran CABs show low V/Yb ratios, suggesting that melts from subducted sediments were possibly generated at fO2 values lower than FMQ + 1.5. The limited Mo isotopic fractionation could be induced by the relatively low fO2 during melting of subducted sediments, which would significantly decrease the mobility of Mo but have no influence on B. Alternatively, rocks from highly oxidized arcs, such as the Izu arc (e.g., >FMQ + 3), exhibit across-arc lightening trends for both B and Mo isotopes, which is consistent with enhanced Mo isotopic fractionation due to elevation of fO2 during subduction. Thus, the B-Mo isotopes of arc rocks could provide diagnostic indicators for distinct geochemical recycling processes controlled by changes in redox conditions in subduction zones. |
| Keyword | Subduction zone Arc magmatism B-Mo isotopic fractionation Oxygen fugacity Sumatra |
| WOS ID | WOS:001051600300001 |
| Indexed By | SCI |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.gig.ac.cn/handle/344008/74671 |
| Collection | 同位素地球化学国家重点实验室 |
| Corresponding Author | Huang, Xiao-Long |
| Affiliation | 1.Chinese Acad Sci, Guangzhou Inst Geochem, CAS Ctr Excellence Deep Earth Sci, State Key Lab Isotope Geochem, Guangzhou, Peoples R China 2.Southern Marine Sci & Engn Guangdong Lab Guangzhou, Guangzhou, Peoples R China 3.Natl Taiwan Normal Univ, Dept Earth Sci, Taipei, Taiwan 4.Acad Sinica, Inst Earth Sci, Taipei, Taiwan 5.Natl Taiwan Univ, Dept Geosci, Taipei, Taiwan 6.Natl Res & Innovat Agcy BRIN, Res Ctr Geol Resources, Bandung, Indonesia |
| Recommended Citation GB/T 7714 | Yu, Yang,Huang, Xiao-Long,Lai, Yu-Ming,et al. Different B-Mo isotopic fractionation processes controlled by redox conditions in the subduction zone[J]. CHEMICAL GEOLOGY,2023,636:12. |
| APA | Yu, Yang.,Huang, Xiao-Long.,Lai, Yu-Ming.,Li, Jie.,Xu, Yi-Gang.,...&Yang, Fan.(2023).Different B-Mo isotopic fractionation processes controlled by redox conditions in the subduction zone.CHEMICAL GEOLOGY,636,12. |
| MLA | Yu, Yang,et al."Different B-Mo isotopic fractionation processes controlled by redox conditions in the subduction zone".CHEMICAL GEOLOGY 636(2023):12. |
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