The role of recycled oceanic crust in the alkaline basalts: Evidence from Zn isotopic compositions of alkaline basalts from the Madeira hotspot (eastern North Atlantic)

doi:10.1016/j.chemgeo.2023.121606

	The role of recycled oceanic crust in the alkaline basalts: Evidence from Zn isotopic compositions of alkaline basalts from the Madeira hotspot (eastern North Atlantic)
	Liao, Renqiang1 ; Zhu, Hongli1 ; Geldmacher, Jorg 2; Li, Congying 1; Liu, He 1; Sun, Weidong1,3,4
	2023-09-30
发表期刊	CHEMICAL GEOLOGY
ISSN	0009-2541
卷号	635 页码:10
通讯作者	Zhu, Hongli(zhuhongli@qdio.ac.cn)
摘要	Plate tectonic processes introduce oceanic crust (as eclogite) into the sources of oceanic island basalts (OIB). The fate of this recycled material in the deep mantle is still poorly understood. Here we present a systematic study of Zn isotopes on well-characterized alkaline basalts (<5 Ma) from the Madeira Islands in the eastern North Atlantic. Our analyses show that the delta Zn-66 values of alkaline basalts range from 0.25 parts per thousand to 0.34 parts per thousand, with an average of 0.30 & PLUSMN; 0.05 parts per thousand (2SD, N = 15), which is similar to the average of mid-ocean ridge basalts (MORB) (0.28 +/- 0.03%0, 2SD), and similar to 0.14 parts per thousand higher than that of the asthenospheric mantle (0.16 +/- 0.06 parts per thousand, 2SD). However, these alkaline basalts have higher Zn/Fe ratios (up to 14.20) than MORB (generally less than 12). Model calculations show that the partial melting of mantle peridotite cannot simultaneously produce the observed MORBlike delta Zn-66 values and trace element ratios. After excluding the effects of post-eruption alteration, crystal fractionation, and the assimilation of crustal materials during magma upwelling on Zn isotopic compositions of the studied samples, we suggest that the MORB-like delta Zn-66 values reflect the mixing of peridotite melt and eclogite/ pyroxenite-derived melt in the magma source of the Madeira hotspot. This is supported by trace element ratios and radiogenic isotopes, such as high Zn/Fe and Dy/Yb ratios and 206Pb/204Pb values. Our new data provide independent evidence in support of the important role of recycled oceanic crust in the source and generation of alkaline OIBs, and also highlight that such sources are not ubiquitously carbonated.
关键词	Zinc isotopes Alkaline oceanic island basalts Madeira hotspot Recycled oceanic crust Mantle heterogeneity
DOI	10.1016/j.chemgeo.2023.121606
收录类别	SCI
语种	英语
资助项目	grants of Youth Innovation Promotion Association, Chinese Academy of Sciences[2020212] ; grants of Youth Innovation Promotion Association, Chinese Academy of Sciences[2022207] ; Shandong Provincial Natural Science Foundation[ZR2021QD098] ; National Natural Science Foundation of China[42206057] ; National Natural Science Foundation of China[42073011] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDB42020303]
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:001033439100001
出版者	ELSEVIER
WOS关键词	LATE CENOZOIC BASALTS ; MANTLE SOURCE ; ZINC ; FRACTIONATION ; SYSTEMATICS ; COPPER ; INSIGHTS ; CONSTRAINTS ; SUBDUCTION ; BEHAVIOR
引用统计	被引频次：1[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/182599
专题	深海极端环境与生命过程研究中心
通讯作者	Zhu, Hongli
作者单位	1.Chinese Acad Sci, Inst Oceanol, Ctr Deep Sea Res, Qingdao 266071, Peoples R China 2.GEOMAR Helmholtz Ctr Ocean Res Kiel, D-24148 Kiel, Germany 3.Deep Sea Multidisciplinary Res Ctr, Laoshan Lab, Qingdao 266237, Peoples R China 4.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
第一作者单位	深海极端环境与生命过程研究中心
通讯作者单位	深海极端环境与生命过程研究中心
推荐引用方式 GB/T 7714	Liao, Renqiang,Zhu, Hongli,Geldmacher, Jorg,et al. The role of recycled oceanic crust in the alkaline basalts: Evidence from Zn isotopic compositions of alkaline basalts from the Madeira hotspot (eastern North Atlantic)[J]. CHEMICAL GEOLOGY,2023,635:10.
APA	Liao, Renqiang,Zhu, Hongli,Geldmacher, Jorg,Li, Congying,Liu, He,&Sun, Weidong.(2023).The role of recycled oceanic crust in the alkaline basalts: Evidence from Zn isotopic compositions of alkaline basalts from the Madeira hotspot (eastern North Atlantic).CHEMICAL GEOLOGY,635,10.
MLA	Liao, Renqiang,et al."The role of recycled oceanic crust in the alkaline basalts: Evidence from Zn isotopic compositions of alkaline basalts from the Madeira hotspot (eastern North Atlantic)".CHEMICAL GEOLOGY 635(2023):10.