Could sedimentary carbonates be recycled into the lower mantle? Constraints from Mg isotopic composition of Emeishan basalts

doi:10.1016/j.lithos.2017.09.007

	Could sedimentary carbonates be recycled into the lower mantle? Constraints from Mg isotopic composition of Emeishan basalts
	Tian, Heng-Ci 1,2; Yang, Wei 1; Li, Shu-Guang 3; Ke, Shan 3
刊名	LITHOS
	2017-11-01
卷号	292 页码:250-261
关键词	Mg Isotope Low-ti And High-ti Basalts Mantle Plume Recycled Sedimentary Carbonate
ISSN号	0024-4937
DOI	10.1016/j.lithos.2017.09.007
文献子类	Article
英文摘要	Whether or not sedimentary carbonates can be recycled into the lower mantle through subduction remains unclear. To further elucidate this issue, we investigate the Mg isotopic composition of Permian basalts from the Emeishan large igneous province (ELIP). Emeishan basalts can be divided into two major groups: the low-Ti and high-Ti basalts, which exhibit distinct major, trace element, and Sr-Nd-Pb isotopic compositions. However, they both possess mantle-like Mg isotopic compositions with delta Mg-26 values of -033 to -0.19%. and -0.35 to -0.19%0, respectively. Both the low-Ti and high-Ti basalts have experienced compositional evolution, e.g., fractional crystallization or crustal contamination, because their Mg-# (39.8-61.1) values are significantly lower than that of primary melt (similar to 72.0). However, their delta Mg-26 values do not vary with Mg-# indicating that the Mg isotopic compositions of the basalts were inherited from their mantle source. The low-Ti basalts are enriched in light rare earth elements with low epsilon(Nd)(t) values (mostly ranging from -10.5 to -8.8) and low Ce/Pb, high Ba/Th ratios, suggesting that they were derived from the lithospheric mantle that was metasomatized by slab-derived fluids. Their mantle-like Mg isotopic composition suggests that the metasomatism of slab derived fluids did not affect their Mg isotopic composition. This is consistent with most of the reported Arc basalts with mantle-like Mg isotopic compositions. On the other hand, the high-Ti basalts display an OIB-like trace element pattern and positive epsilon(Nd)(t) values (+ 02 similar to + 2.1), which were possibly derived from a mantle plume that originated from the lower mantle. Their mantle-like Mg isotopic composition indicates that sedimentary carbonates recycled into the lower mantle beneath the ELIP were limited (<2%). (C) 2017 Elsevier B.V. All rights reserved.
WOS关键词	LARGE IGNEOUS PROVINCE ; PLUME-LITHOSPHERE INTERACTION ; NORTH CHINA CRATON ; IONIZATION MASS-SPECTROMETRY ; CONTINENTAL FLOOD BASALTS ; PERMIAN-TRIASSIC BOUNDARY ; SW CHINA ; SOUTHWESTERN CHINA ; EASTERN CHINA ; GEOCHEMICAL CONSTRAINTS
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000416185500016
资助机构	National Science Foundation of China(41322022 ; National Science Foundation of China(41322022 ; 41230209 ; 41230209 ; 41221002) ; 41221002) ; National Science Foundation of China(41322022 ; National Science Foundation of China(41322022 ; 41230209 ; 41230209 ; 41221002) ; 41221002) ; National Science Foundation of China(41322022 ; National Science Foundation of China(41322022 ; 41230209 ; 41230209 ; 41221002) ; 41221002) ; National Science Foundation of China(41322022 ; National Science Foundation of China(41322022 ; 41230209 ; 41230209 ; 41221002) ; 41221002)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/82092]
专题	中国科学院地质与地球物理研究所
通讯作者	Yang, Wei; Li, Shu-Guang
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Earth & Planetary Phys, Beijing 100029, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.China Univ Geosci, State Key Lab Geol Proc & Mineral Resources, Beijing 100083, Peoples R China
推荐引用方式 GB/T 7714	Tian, Heng-Ci,Yang, Wei,Li, Shu-Guang,et al. Could sedimentary carbonates be recycled into the lower mantle? Constraints from Mg isotopic composition of Emeishan basalts[J]. LITHOS,2017,292:250-261.
APA	Tian, Heng-Ci,Yang, Wei,Li, Shu-Guang,&Ke, Shan.(2017).Could sedimentary carbonates be recycled into the lower mantle? Constraints from Mg isotopic composition of Emeishan basalts.LITHOS,292,250-261.
MLA	Tian, Heng-Ci,et al."Could sedimentary carbonates be recycled into the lower mantle? Constraints from Mg isotopic composition of Emeishan basalts".LITHOS 292(2017):250-261.