Incomplete mixing of isotopically variable melts in the lower oceanic crust and its implications on mantle heterogeneity: Evidence from oceanic cumulates from Mid-Atlantic
文献类型：期刊论文
| 作者 | Wang, Jixin5,6; Li, Bing3,4; Zhang, Fangyi5,6; Liao, Renqiang5,6 ; Gu, Xiaoyan2; Li, Congying5,6; Sun, Weidong1,5,6
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| 刊名 | CHEMICAL GEOLOGY
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| 出版日期 | 2024-03-20 |
| 卷号 | 648页码:15 |
| 关键词 | Incomplete melt mixing Lower crustal gabbros In -situ plagioclase Sr isotopes Mid -Atlantic Ridge Pegmatites |
| ISSN号 | 0009-2541 |
| DOI | 10.1016/j.chemgeo.2024.121940 |
| 通讯作者 | Wang, Jixin(wangjixin@qdio.ac.cn) ; Li, Congying(licongying@qdio.ac.cn) |
| 英文摘要 | Abyssal peridotites and mid-ocean ridge basalts (MORB) offer only a partial glimpse into the mantle's composition and the magmatic process beneath the mid-ocean ridges. Recently, lower crustal cumulates have emerged as potential candidates for capturing a broader range of mantle heterogeneity and depicting a detailed process in MORB generating system. However, it remains uncertain to what extent the lower crustal cumulates can represent mantle source variability. In this study, we present detailed in-situ geochemical and isotopic data, including major and trace element compositions of minerals and in-situ Sr isotopic analysis on plagioclase from lower crustal cumulates collected at 14 degrees 45 ' N on the Mid-Atlantic Ridge (MAR). Trace element compositions of melt in equilibrium with clinopyroxenes from the lower crustal cumulates exhibit strong similarities to nearby MORBs. Exception is that the equilibrium melt of the core of a clinopyroxene oikocryst records a transitional MORB composition, different from the more enriched MORB composition at rims. This phenomenon, together with element changing in minerals from cores to rims, suggests a history of melt-rock interactions, during which more enriched melts transport through minerals that had previously crystallized from relatively more depleted melts. The in-situ 87Sr/86Sr ratios, which vary from 0.70249 to 0.70306, span the range of the global MORB Sr isotope values. Thus, both the trace element compositions and 87Sr/86Sr ratios of cumulate minerals confirm the coexistence of depleted and enriched melts. Our findings furtherly suggest that the melts from heterogenous mantle components underwent incomplete mixing in the lower oceanic crust, even in the crystal mush, thus preserving variable heterogeneities not seen in MORB. Through integrated analyses of geochemistry, isotopic data, and geophysical information from existing literature, we identify the most likely mantle components in the study area as depleted peridotites veined with recycled oceanic crust (pyroxenites). |
| WOS关键词 | TRACE-ELEMENTS ; GEOCHEMICAL MORPHOLOGY ; DEPLETED MANTLE ; HF ISOTOPES ; RIDGE ; PB ; BASALTS ; SR ; BENEATH ; TEMPERATURE |
| 资助项目 | National Natural Science Foundation of China[NSFC 42006051] ; National Natural Science Foundation of China[NSFC 42221005] ; National Natural Science Foundation of China[NSFC 42176070] ; Shandong Provincial Natural Science Foundation[ZR2020QD075] ; Strategic Priority Research Program (B) of Chinese Academy of Sciences[XDB42020303] ; State Key Laboratory of Marine Geology, Tongji University[MGK202006] |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001172939500001 |
| 出版者 | ELSEVIER |
| 源URL | [http://ir.qdio.ac.cn/handle/337002/184840]  |
| 专题 | 中国科学院海洋研究所 |
| 通讯作者 | Wang, Jixin; Li, Congying |
| 作者单位 | 1.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 2.Zhejiang Univ, Sch Earth Sci, Key Lab Geosci Big Data & Deep Resource Zhejiang P, Hangzhou 310058, Peoples R China 3.Key Lab Deep Sea Mineral Resources Dev, Shandong Preparatory, Qingdao 266061, Peoples R China 4.Minist Nat Resources, Metallogeny Inst Oceanog 1, Key Lab Marine Geol, Qingdao 266061, Peoples R China 5.Deep Sea Multidisciplinary Res Ctr, Laoshan Lab, Qingdao 266237, Peoples R China 6.Chinese Acad Sci, Inst Oceanog, Ctr Deep Sea Res, Qingdao 266071, Peoples R China |
| 推荐引用方式 GB/T 7714 | Wang, Jixin,Li, Bing,Zhang, Fangyi,et al. Incomplete mixing of isotopically variable melts in the lower oceanic crust and its implications on mantle heterogeneity: Evidence from oceanic cumulates from Mid-Atlantic[J]. CHEMICAL GEOLOGY,2024,648:15. |
| APA | Wang, Jixin.,Li, Bing.,Zhang, Fangyi.,Liao, Renqiang.,Gu, Xiaoyan.,...&Sun, Weidong.(2024).Incomplete mixing of isotopically variable melts in the lower oceanic crust and its implications on mantle heterogeneity: Evidence from oceanic cumulates from Mid-Atlantic.CHEMICAL GEOLOGY,648,15. |
| MLA | Wang, Jixin,et al."Incomplete mixing of isotopically variable melts in the lower oceanic crust and its implications on mantle heterogeneity: Evidence from oceanic cumulates from Mid-Atlantic".CHEMICAL GEOLOGY 648(2024):15. |
入库方式： OAI收割
来源：海洋研究所
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