Heavy magnesium isotopic compositions of basalts erupted during arc inception: Implications for the mantle source underlying the nascent Izu-Bonin-Mariana arc
文献类型：期刊论文
| 作者 | Yuan, Shuai2,3,4 ; Li, He2,4,5; Arculus, Richard J.7; He, Yongsheng1; Ke, Shan1; Sun, Weidong3,4,6
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| 刊名 | GEOCHIMICA ET COSMOCHIMICA ACTA
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| 出版日期 | 2023-07-01 |
| 卷号 | 352页码:14-23 |
| 关键词 | Mg isotopes Basalts Nascent arc Ultra-depleted mantle Serpentinite components |
| ISSN号 | 0016-7037 |
| DOI | 10.1016/j.gca.2023.04.017 |
| 通讯作者 | Li, He(lihe@qdio.ac.cn) |
| 英文摘要 | Basalts formed during the early development of an arc are usually buried, but they record critical information relating to the mantle source of the overriding plate prior to the addition of subducting slab components. Basalts recovered at Site U1438 of International Ocean Discovery Program (IODP) Expedition 351, in the Amami Sankaku Basin (ASB), formed during the transition from forearc basalt (FAB) and boninite eruptions to stratovolcano developments in the Izu-Bonin-Mariana (IBM) arc. In this study, we present magnesium (Mg) isotopic data (delta 26Mg) for the ASB basalt core samples, formed at arc inception in the absence of down-going slab components, and report the implications of these data for the characteristics of the mantle sources underlying the proto-IBM arc. The delta 26Mg values of the ASB basalts range from -0.21%o to +0.08%o, with an average value of -0.13 +/- 0.07%o. These values are systematically higher than those of mid-ocean ridge basalts (MORBs) (-0.25 +/- 0.06%o). No obvious effects of post-eruptive alteration, fractional crystallization, partial melting, or subduction component addition can be identified in the Mg isotopic compositions either of the ASB basalts or their mantle source, given the absence of correlations between the delta 26Mg values and the proxies of these processes (e.g., K/Nb, Nb/Zr, Ba/La, Nb/Y, etc.). We conclude that the high delta 26Mg values of the ASB basalts are inherited from their mantle source that was enriched in heavy Mg isotopes. Melting of an ultra-depleted, refractory spinel peridotite source containing talc-bearing serpentinite components can explain the origin of the heavy Mg isotopic compositions in the ASB basalts. The presence of water-rich serpentinite components in the mantle provides a new perspective on how a refractory mantle source can undergo partial melting at temperatures and pressures similar to the formation of MORBs without the influence of subducted materials, which has important implications for the initiation of plate subduction. Furthermore, the Mg isotopic contributions of subducted additions and mantle source materials should be carefully discussed in future studies due to the heterogeneity of Mg isotopes in the mantle. |
| WOS关键词 | SUBDUCTION INITIATION ; CONTINENTAL-CRUST ; OCEANIC-CRUST ; MG ; FRACTIONATION ; ORIGIN ; CHINA ; GEOCHEMISTRY ; MAGMATISM ; RECORD |
| 资助项目 | National Natural Science Foundation of China[91958110] ; National Natural Science Foundation of China[92258303] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDB42020203] ; Taishan Scholars Program[tsqn202211251] ; Open Research Project from the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences[GPMR202111] |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001002459500001 |
| 出版者 | PERGAMON-ELSEVIER SCIENCE LTD |
| 源URL | [http://ir.qdio.ac.cn/handle/337002/183238]  |
| 专题 | 中国科学院海洋研究所 |
| 通讯作者 | Li, He |
| 作者单位 | 1.China Univ Geosci, State Key Lab Geol Proc & Mineral Resources, Beijing 100083, Peoples R China 2.Lab Marine Mineral Resources, Laoshan Lab, Qingdao 266237, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 4.Chinese Acad Sci, Inst Oceanol, Ctr Deep Sea Res, Qingdao 266071, Peoples R China 5.Chinese Acad Sci, Inst Oceanol, 7 Nanhai Rd, Qingdao 266071, Peoples R China 6.Deep Sea Multidisciplinary Res Ctr, Laoshan Lab, Qingdao 266237, Peoples R China 7.Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 2601, Australia |
| 推荐引用方式 GB/T 7714 | Yuan, Shuai,Li, He,Arculus, Richard J.,et al. Heavy magnesium isotopic compositions of basalts erupted during arc inception: Implications for the mantle source underlying the nascent Izu-Bonin-Mariana arc[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2023,352:14-23. |
| APA | Yuan, Shuai,Li, He,Arculus, Richard J.,He, Yongsheng,Ke, Shan,&Sun, Weidong.(2023).Heavy magnesium isotopic compositions of basalts erupted during arc inception: Implications for the mantle source underlying the nascent Izu-Bonin-Mariana arc.GEOCHIMICA ET COSMOCHIMICA ACTA,352,14-23. |
| MLA | Yuan, Shuai,et al."Heavy magnesium isotopic compositions of basalts erupted during arc inception: Implications for the mantle source underlying the nascent Izu-Bonin-Mariana arc".GEOCHIMICA ET COSMOCHIMICA ACTA 352(2023):14-23. |
入库方式： OAI收割
来源：海洋研究所
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