A zinc-iron isotope perspective on the nature and recent history of sub-arc lithosphere: Messages from Mariana Trough basalts
文献类型：期刊论文
| 作者 | Chen, Yanhong1,3,4; Sun, Pu5; Niu, Yaoling1,6; Castillo, Paterno2; Guo, Pengyuan5 |
| 刊名 | LITHOS
 |
| 出版日期 | 2025-11-01 |
| 卷号 | 512页码:10 |
| 关键词 | Zinc isotopes Back-arc basin basalts Dehydration-modified sub-arc lithospheric mantle Northern Mariana Trough |
| ISSN号 | 0024-4937 |
| DOI | 10.1016/j.lithos.2025.108147 |
| 通讯作者 | Chen, Yanhong(chenyh@cugb.edu.cn) ; Niu, Yaoling(yaoling.niu@foxmail.com) |
| 英文摘要 | The northern Mariana Trough (NMT) is a typical example of a developing back-arc basin. Due to upwelling asthenosphere in response to trench retreat-induced back-arc extension, the Mariana sub-arc lithosphere is progressively thinned from north to south and intruded by NMT basalts. Our previous study on NMT basaltic glasses from 17 to 23 degrees N using major element, trace element, and Sr-Nd-Pb-Hf-Fe isotope geochemistry showed that the abundances of fluid-insoluble elements (e.g., Nb, Ta, Zr, Hf, Ti and heavy rare earth elements) and delta Fe-56 values decrease with latitude, which is consistent with an asthenosphere source in the south and progressively more depleted harzburgitic sub-arc lithospheric mantle due to previous melt extraction towards north. To further characterize the sub-arc lithosphere, we analyze the same samples for Zn isotope compositions. With the general understanding that Fe and Zn share similar elemental and isotope behavior during magmatism under low S and relatively low fO(2) (low Fe3+) conditions, we should expect correlated delta Zn-66 and delta Fe-56 variations. However, the delta Zn-66 values of NMT basalts correlate with neither delta Fe-56 nor latitude but vary randomly (0.20 parts per thousand to 0.37 parts per thousand; average = 0.28 +/- 0.08 parts per thousand) within the range similar to that of mid-ocean ridge basalts (0.27 +/- 0.08 parts per thousand, N = 65). The decoupled Zn-Fe isotope variations of NMT basalts suggest that Zn must have experienced more complex subduction zone magmatic process(es) than previous demonstrated. With all the conceivable scenarios considered, we concur with our Fe isotope study that NMT magmatism results from increasing contribution of sub-arc lithospheric mantle from south (mature back-arc spreading) to north (early back-arc rifting), but the sub-arc lithosphere had been previously metasomatized by fluids released from the dehydration of serpentine in the subducting slab. Such fluids are enriched in heavy Zn and, thus, impart a high delta Zn-66 signature in the sub-arc lithosphere, in turn giving northern NMT basalts higher delta Zn-66 than predicted. The important message is that Zn isotopes can record the effect of slab serpentine-released fluids with heavy Zn in the modified sub-arc lithosphere, but Fe isotopes do not, because of the different behavior of Zn and Fe in fluid. Therefore, a comprehensive geochemical study of back-arc basin basalts can offer insights into the nature and history of the sub-arc lithospheric mantle. |
| WOS关键词 | MANTLE WEDGE ; PERIDOTITE XENOLITHS ; FRACTIONATION ; ZONE ; ZN ; MELT ; METASOMATISM ; GEOCHEMISTRY ; ENVIRONMENT ; MAGNESIUM |
| 资助项目 | National Natural Science Foundation of China (NSFC)[91958215] ; National Natural Science Foundation of China (NSFC)[42276071] ; The 111 Project[B20011] |
| WOS研究方向 | Geochemistry & Geophysics ; Mineralogy |
| 语种 | 英语 |
| WOS记录号 | WOS:001517491100001 |
| 出版者 | ELSEVIER |
| 源URL | [http://ir.qdio.ac.cn/handle/337002/202421]  |
| 专题 | 中国科学院海洋研究所 |
| 通讯作者 | Chen, Yanhong; Niu, Yaoling |
| 作者单位 | 1.China Univ Geosci, Beijing 100083, Peoples R China 2.Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA 3.China Univ Geosci, Sch Ocean Sci, Beijing 100083, Peoples R China 4.China Univ Geosci, Minist Educ, Key Lab Polar Geol & Marine Mineral Resources, Beijing 100083, Peoples R China 5.Chinese Acad Sci, Inst Oceanol, Qingdao 266071, Peoples R China 6.Laoshan Lab, Qingdao 266237, Peoples R China |
| 推荐引用方式 GB/T 7714 | Chen, Yanhong,Sun, Pu,Niu, Yaoling,et al. A zinc-iron isotope perspective on the nature and recent history of sub-arc lithosphere: Messages from Mariana Trough basalts[J]. LITHOS,2025,512:10. |
| APA | Chen, Yanhong,Sun, Pu,Niu, Yaoling,Castillo, Paterno,&Guo, Pengyuan.(2025).A zinc-iron isotope perspective on the nature and recent history of sub-arc lithosphere: Messages from Mariana Trough basalts.LITHOS,512,10. |
| MLA | Chen, Yanhong,et al."A zinc-iron isotope perspective on the nature and recent history of sub-arc lithosphere: Messages from Mariana Trough basalts".LITHOS 512(2025):10. |
入库方式： OAI收割
来源：海洋研究所
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