Molybdenum isotope evidence for recycled oceanic crust in the mantle sources of continental intraplate mafic lavas, Emeishan Large Igneous Province

doi:10.1016/j.chemgeo.2024.122347

IOCAS-IR > 海洋地质与环境重点实验室

	Molybdenum isotope evidence for recycled oceanic crust in the mantle sources of continental intraplate mafic lavas, Emeishan Large Igneous Province
	Li, Jiyong1 ; Liu, Yi 2; Chen, Shuo 3
	2024-11-20
发表期刊	CHEMICAL GEOLOGY
ISSN	0009-2541
卷号	668 页码:14
通讯作者	Liu, Yi([email protected]) ; Chen, Shuo([email protected])
摘要	The chemical and lithological heterogeneities of Earth's mantle in oceanic settings have long been attributed to the presence of recycled materials such as subducted crust, oceanic or subcontinental lithosphere mantle and sediment, as evidenced by Mid-Ocean Ridge Basalts (MORB) and Ocean Island Basalts (OIB). However, the extent to which recycled materials contribute to mantle heterogeneity in continental settings remains uncertain. Here we present systematic Sr-Nd-Pb-Mo isotope data for the Pingchuan picritic porphyries and associated mafic rocks (basalts and gabbros) in the central Emeishan Large Igneous Province, southwestern China, to resolve this issue. In contrast to the gabbro samples that show continental crust contamination in variations of delta Mo-98/95 (relative to NIST SRM 3134, -0.35 +/- 0.03 to 0.03 +/- 0.02 parts per thousand), the Pingchuan picritic porphyries and basalts show a large range of delta Mo-98/95 (-0.32 +/- 0.01 to -0.15 +/- 0.06 parts per thousand) and broadly negative trend between delta Mo-98/95 and Ce/Mo ratios, which cannot be explained by post-magmatic alteration, crustal contamination, fractional crystallization, olivine accumulation, metasomatism or fluid-activity in the mantle source. They were most likely derived from incongruent melting of a heterogeneous mantle source, i.e., a deep mantle with chondritic-like delta Mo-98/95 (-0.15 +/- 0.01 parts per thousand) containing recycled oceanic crust (+ sediment) with light delta Mo-98/95 (< -0.32 parts per thousand). The basalts display low delta Mo-98/95 (-0.32 +/- 0.01 to -0.24 +/- 0.04 parts per thousand), high Sr-87/Sr-86(i) (0.7046 to 0.7059), TiO2, Sm/Yb, Dy/Yb and Ce/Mo, pointing to characteristics of melts produced by MORB-type eclogite (+ sediment) at relatively low degrees of partial melting. With increasing degrees of partial melting, melts produced by peridotite (Sr-87/Sr-86(i) = 0.7035 to 0.7043, chondritic-like delta Mo-98/95 = -0.18 +/- 0.03 to -0.15 +/- 0.06 parts per thousand) come to dominate, resulting in low TiO2, Sm/Yb, Dy/Yb and Ce/Mo of the Pingchuan picritic porphyries. From a global perspective, continental basalts also plot on the negative trend defined by the OIB datasets (delta Mo-98/95 vs. Ce/Mo). As such, Mo isotope may provide a robust tracer of recycled oceanic crust in shaping mantle heterogeneities that occur in both oceanic and continental settings.
关键词	Mantle heterogeneity Molybdenum isotope Recycled oceanic crust Continental intraplate mafic lavas Emeishan Large Igneous Province
DOI	10.1016/j.chemgeo.2024.122347
收录类别	SCI
语种	英语
资助项目	National Natural Science Foundation of China[42322605]; National Natural Science Foundation of China[42176087]; National Natural Science Foundation of China[41906050]; Laoshan Laboratory[LSKJ202204100]; Youth Innovation Promotion Association, Chinese Academy of Sciences[2021206]; Natural Science Fund of Southwest University of Science and Technology[22zx7172]
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:001307754700001
出版者	ELSEVIER
WOS关键词	TRACE-ELEMENT ; FLOOD BASALTS ; SOUTHWESTERN CHINA ; SW CHINA ; MAGMATIC DIFFERENTIATION ; PRIMITIVE MAGMAS ; IRON ISOTOPES ; U-PB ; FRACTIONATION ; GEOCHEMISTRY
引用统计
文献类型	期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/198283
专题	海洋地质与环境重点实验室
通讯作者	Liu, Yi; Chen, Shuo
作者单位	1.Southwest Univ Sci & Technol, Sch Environm & Resource, Key Lab Solid Waste Treatment & Resource Recycle, Minist Educ, Mianyang 621010, Peoples R China 2.Kunming Univ Sci & Technol, Fac Land Resources Engn, Kunming 650093, Peoples R China 3.Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Key Lab Ocean Observat & Forecasting, Qingdao 266071, Peoples R China
推荐引用方式 GB/T 7714	Li, Jiyong,Liu, Yi,Chen, Shuo. Molybdenum isotope evidence for recycled oceanic crust in the mantle sources of continental intraplate mafic lavas, Emeishan Large Igneous Province[J]. CHEMICAL GEOLOGY,2024,668:14.
APA	Li, Jiyong,Liu, Yi,&Chen, Shuo.(2024).Molybdenum isotope evidence for recycled oceanic crust in the mantle sources of continental intraplate mafic lavas, Emeishan Large Igneous Province.CHEMICAL GEOLOGY,668,14.
MLA	Li, Jiyong,et al."Molybdenum isotope evidence for recycled oceanic crust in the mantle sources of continental intraplate mafic lavas, Emeishan Large Igneous Province".CHEMICAL GEOLOGY 668(2024):14.