Zinc isotopic systematics of the South China Sea basalts and implications for its behavior during plate subduction

doi:10.1016/j.chemgeo.2020.119582

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	Zinc isotopic systematics of the South China Sea basalts and implications for its behavior during plate subduction
	Liao, Renqiang 1,2,3; Zhu, Hongli 2,3; Deng, Jianghong 2,3; Zhang, Lipeng 2,3; Li, He 2,3; Li, Congying 2,3; Liu, He 2,3; Sun, Weidong 1,2,3
刊名	CHEMICAL GEOLOGY
	2020-05-20
卷号	541 页码:12
关键词	Zinc isotopes The South China Sea IODP Expedition 349 Partial melting Plate subduction
ISSN号	0009-2541
DOI	10.1016/j.chemgeo.2020.119582
通讯作者	Zhu, Hongli(zhuhongli@qdio.ac.cn)
英文摘要	Zinc isotopes is a new tracer for deep materials recycling. However, its behavior during plate subduction remains obscure. To address this issue, here we present high precision Zn isotopic compositions (delta delta Zn-66) of basalts recovered from International Ocean Discovery Program (IODP) Expedition 349 in the South China Sea (SCS), which have been influenced by various amounts of subducted materials. Based on (La/Sm)(N) values, these basalts are classified into N-MORB ((La/Sm)(N) < 1) and E-MORB ((La/Sm)(N) >= 1) types. The results show that both of the N-MORB and E-MORB type basalts have similar and homogeneous Zn isotopic compositions with delta Zn-66 ranging from 0.22 to 0.28 parts per thousand and 0.24 to 0.31 parts per thousand, respectively. These values are similar to that of typical MORB reported in the literature (0.28 +/- 0.03 parts per thousand), but are systematically higher than the estimated average value of depleted MORB-type mantle (DMM, 0.18 parts per thousand). The lack of correlations between delta Zn-66 and geochemical indicators of magma differentiation (e.g., MgO, SiO2, CaO/Al2O3) suggests that crystal fractionation has a limited effect on Zn isotope fractionation. Even though the mantle sources of the SCS basalts are clearly affected by various amounts of subducted materials, there are no correlations between delta Zn-66 and indicators of subducted components (e.g., Ce/Pb, Nb/U, Ba/La, Sr-87/Sr-86). This implies that insignificant amount of Zn was transported from the subducting slab to the mantle sources of the SCS basalts, so that subducted materials have a limited effect on Zn isotopic compositions of the SCS basalts studied here. Therefore, the observed offset of delta Zn-66 (similar to 0.10 parts per thousand) between the mantle and the SCS basalts studied here should be primarily controlled by Zn isotope fractionation during mantle partial melting with no need for contributions from subduction materials.
资助项目	Strategic Priority Research Program (A) of the Chinese Academy of Sciences[XDA22050103] ; Qingdao National Laboratory for Marine Science and Technology[2017ASKJ02] ; Taishan Scholar Program of Shandong[ts201712075] ; AoShan Talents Cultivation Program by Qingdao National Laboratory for Marine Science and Technology[2017ASTCP-OS07]
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000537202100006
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/167584]
专题	海洋研究所_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.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 2.Chinese Acad Sci, Ctr Deep Sea Res, Ctr Ocean Megasci, Inst Oceanol, Qingdao 266071, Peoples R China 3.Pilot Natl Lab Marine Sci & Technol, Lab Marine Mineral Resources, Qingdao 266237, Peoples R China
推荐引用方式 GB/T 7714	Liao, Renqiang,Zhu, Hongli,Deng, Jianghong,et al. Zinc isotopic systematics of the South China Sea basalts and implications for its behavior during plate subduction[J]. CHEMICAL GEOLOGY,2020,541:12.
APA	Liao, Renqiang.,Zhu, Hongli.,Deng, Jianghong.,Zhang, Lipeng.,Li, He.,...&Sun, Weidong.(2020).Zinc isotopic systematics of the South China Sea basalts and implications for its behavior during plate subduction.CHEMICAL GEOLOGY,541,12.
MLA	Liao, Renqiang,et al."Zinc isotopic systematics of the South China Sea basalts and implications for its behavior during plate subduction".CHEMICAL GEOLOGY 541(2020):12.