Low-degree melt metasomatic origin of heavy Fe isotope enrichment in the MORB mantle

doi:10.1016/j.epsl.2022.117892

CORC > 海洋研究所 > 中国科学院海洋研究所 > 海洋地质与环境重点实验室

	Low-degree melt metasomatic origin of heavy Fe isotope enrichment in the MORB mantle
	Guo, Pengyuan 1,2,5; Niu, Yaoling 1,2,3,4; Chen, Shuo 1,2; Duan, Meng 1,2; Sun, Pu 1,2; Chen, Yanhong 4; Gong, Hongmei 1,2; Wang, Xiaohong 1,2
刊名	EARTH AND PLANETARY SCIENCE LETTERS
	2023
卷号	601 页码:12
关键词	mid-ocean ridge basalts Fe isotope upper mantle heterogeneity low-degree melt metasomatism Mid-Atlantic Ridge
ISSN号	0012-821X
DOI	10.1016/j.epsl.2022.117892
通讯作者	Guo, Pengyuan(guopy@qdio.ac.cn)
英文摘要	Studies of mid-ocean ridge basalts (MORB) show a variable Fe isotope composition of the oceanic upper mantle. To test a recent hypothesis that heavy Fe isotope enrichment in the MORB mantle results from the same process of incompatible element enrichment, we conduct an Fe isotope study of well -characterized MORB samples from a magmatically robust segment (OH-1) of the Mid-Atlantic Ridge (MAR) at similar to 35 degrees N. The data show large Fe isotope variation (556Fe = +0.03 to +0.18%0) that correlates well with the abundances and ratios of more-to-less incompatible elements and with Sr-Nd-Hf isotopes. Our findings in support of the hypothesis can be detailed as follows: (1) the oceanic upper mantle has a heterogeneous Fe isotope composition on varying small spatial scales with isotopically heavy Fe (high-556Fe) preferentially associated with pyroxenite lithologies; (2) such lithologies, which are also enriched in the progressively more incompatible elements, are of low-degree (low-F) melt metasomatic origin; (3) with all the conceivable processes considered, the low-F melt metasomatism takes place at the lithosphere-asthenosphere boundary (LAB) beneath ocean basins through crystallization of incipient (Low-F) melt in the seismic low velocity zone (LVZ) at the base of the growing oceanic lithosphere (i.e., LAB) over the Earth's history since the onset of plate tectonics, forming composite lithologies with geochemically enriched pyroxenite veins dispersed in the depleted peridotite matrix; (4) such mantle of composite lithology when transported to beneath the present-day ocean ridges will undergo decompression melting and produce MORB melts with geochemical trends of "melting-induced mixing" as observed at the MAR and global MORB; (5) we predict all this to be a globally common process and widespread.(c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).
资助项目	National Natural Science Foundation of China (NSFC) ; NSFC-Shandong Joint Fund for Marine Science Research Centers ; 111 Project ; [42076048] ; [91958215] ; [41776067] ; [41630968] ; [U1606401] ; [B18048]
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000885932200006
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/180262]
专题	海洋研究所_海洋地质与环境重点实验室
通讯作者	Guo, Pengyuan
作者单位	1.Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China 2.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Geol, Qingdao 266061, Peoples R China 3.Univ Durham, Dept Earth Sci, Durham DH1 3LE, England 4.China Univ Geosci, Beijing 100083, Peoples R China 5.Chinese Acad Sci, Inst Oceanol, 7 Nanhai Rd, Qingdao 266071, Shandong, Peoples R China
推荐引用方式 GB/T 7714	Guo, Pengyuan,Niu, Yaoling,Chen, Shuo,et al. Low-degree melt metasomatic origin of heavy Fe isotope enrichment in the MORB mantle[J]. EARTH AND PLANETARY SCIENCE LETTERS,2023,601:12.
APA	Guo, Pengyuan.,Niu, Yaoling.,Chen, Shuo.,Duan, Meng.,Sun, Pu.,...&Wang, Xiaohong.(2023).Low-degree melt metasomatic origin of heavy Fe isotope enrichment in the MORB mantle.EARTH AND PLANETARY SCIENCE LETTERS,601,12.
MLA	Guo, Pengyuan,et al."Low-degree melt metasomatic origin of heavy Fe isotope enrichment in the MORB mantle".EARTH AND PLANETARY SCIENCE LETTERS 601(2023):12.