中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Osmium isotope compositions and highly siderophile element abundances in abyssal peridotites from the Southwest Indian Ridge: Implications for evolution of the oceanic upper mantle

文献类型:期刊论文

作者Li, Wei4; Liu, Chuanzhou3; Tao, Chunhui2,4; Jin, Zhenmin1
刊名LITHOS
出版日期2019-11-15
卷号346页码:14
ISSN号0024-4937
关键词Abyssal peridotite Highly siderophile elements Mantle metasomatism Re-Os isotopes Southwest Indian Ridge
DOI10.1016/j.lithos.2019.105167
英文摘要Abyssal peridotites are extensively exposed on the seafloor of amagmatic segments at the ultraslow spreading Southwest Indian Ridge (SWIR). This study presents abundances of highly siderophile elements (HSEs; Os, Ir, Ru, Pt, Pd and Re) and Re-Os isotope compositions as well as major and trace element concentrations of nine spinel-facies peridotites from the Dragon Bone amagmatic segment (similar to 53 degrees E) and the easternmost part (similar to 63.5 degrees E and 69.5 degrees E) of the SWIR These peridotites have experienced intense serpentinization and seafloor weathering in addition to variable degrees of melt depletion (bulk rock Al2O3 = 0.74-2.73 wt%). Low-temperature alterations, however, have a negligible effect on Os isotope compositions and concentrations of platinum-group elements. The 63.5 E peridotites displayed sub-chondritic Os/Ir and chondritic Pt/Ir ratios and slightly variable Re/Ir and Pd/Ir ratios. The observed positive covariance between Re-187/Os-188 ratios and gamma Os, Re and Pd abundances can be explained most likely by interaction of mantle residues with radiogenic basaltic melts, which is consistent with the petrographic observations indicative of melt infiltration. The 53 degrees E peridotites, on the other hand, displayed larger variations in Os isotopes and relative HSE abundances, indicating a more complex evolutionary history. High Re abundances and Os-187/Os-188 ratios in some 53 degrees E samples attest to Re and radiogenic Os addition, probably through reaction with S-undersaturated hydrous melts. Specifically, sample 21V-S9-D5-2 exhibited a high Os-187/Os-188 ratio (0.148) and enrichment of Cu and Pt abundances, implying interaction with an oxidizing agent. Although the Re-Os isotopes of SWIR peridotites were superimposed by variable metasomatic processes, they preserve the ancient Os isotope signature (similar to 1Ga) and record the melting episode at similar to 0.7 Ga during the closure of the Mozambique Ocean. We infer that ancient depleted and hence buoyant mantle exists beneath the SWIR, which probably supports the weakly magmatic rifted Marion Rise. (C) 2019 Elsevier B.V. All rights reserved.
WOS关键词PLATINUM-GROUP ELEMENTS ; MID-ATLANTIC RIDGE ; CONVECTING UPPER-MANTLE ; NI-CU SULFIDES ; OS ISOTOPES ; DEPLETED MANTLE ; MELT EXTRACTION ; IN-SITU ; LITHOSPHERIC MANTLE ; TRACE-ELEMENTS
资助项目National Key R&D Program of China[2018YFC0309903] ; China Postdoctoral Science Foundation[2018M632435] ; Second Institute of Oceanography Postdoctoral project[JB1802]
WOS研究方向Geochemistry & Geophysics ; Mineralogy
语种英语
出版者ELSEVIER
WOS记录号WOS:000488335600027
资助机构National Key R&D Program of China ; National Key R&D Program of China ; China Postdoctoral Science Foundation ; China Postdoctoral Science Foundation ; Second Institute of Oceanography Postdoctoral project ; Second Institute of Oceanography Postdoctoral project ; National Key R&D Program of China ; National Key R&D Program of China ; China Postdoctoral Science Foundation ; China Postdoctoral Science Foundation ; Second Institute of Oceanography Postdoctoral project ; Second Institute of Oceanography Postdoctoral project ; National Key R&D Program of China ; National Key R&D Program of China ; China Postdoctoral Science Foundation ; China Postdoctoral Science Foundation ; Second Institute of Oceanography Postdoctoral project ; Second Institute of Oceanography Postdoctoral project ; National Key R&D Program of China ; National Key R&D Program of China ; China Postdoctoral Science Foundation ; China Postdoctoral Science Foundation ; Second Institute of Oceanography Postdoctoral project ; Second Institute of Oceanography Postdoctoral project
源URL[http://ir.iggcas.ac.cn/handle/132A11/93874]  
专题地质与地球物理研究所_岩石圈演化国家重点实验室
通讯作者Li, Wei
作者单位1.China Univ Geosci, State Key Lab Geol Proc & Mineral Resources, Wuhan 430074, Hubei, Peoples R China
2.Shanghai Jiao Tong Univ, Sch Oceanog, Shanghai 200240, Peoples R China
3.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China
4.Minist Nat Resources, State Ocean Adm, Inst Oceanog 2, Key Lab Submarine Geosci, Hangzhou 310012, Zhejiang, Peoples R China
推荐引用方式
GB/T 7714
Li, Wei,Liu, Chuanzhou,Tao, Chunhui,et al. Osmium isotope compositions and highly siderophile element abundances in abyssal peridotites from the Southwest Indian Ridge: Implications for evolution of the oceanic upper mantle[J]. LITHOS,2019,346:14.
APA Li, Wei,Liu, Chuanzhou,Tao, Chunhui,&Jin, Zhenmin.(2019).Osmium isotope compositions and highly siderophile element abundances in abyssal peridotites from the Southwest Indian Ridge: Implications for evolution of the oceanic upper mantle.LITHOS,346,14.
MLA Li, Wei,et al."Osmium isotope compositions and highly siderophile element abundances in abyssal peridotites from the Southwest Indian Ridge: Implications for evolution of the oceanic upper mantle".LITHOS 346(2019):14.

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