Postcollisional mafic igneous rocks record recycling of noble gases by deep subduction of the continental crust

doi:10.1016/j.lithos.2016.02.025

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 地球深部结构与过程研究室

	Postcollisional mafic igneous rocks record recycling of noble gases by deep subduction of the continental crust
	Dai, Li-Qun 1; Zheng, Yong-Fei 1; He, Huai-Yu 2; Zhao, Zi-Fu 1
刊名	LITHOS
	2016-05-01
卷号	252 页码:135-144
关键词	Noble gases Crustal recycling Crust-mantle interaction Continental subduction Supracrustal material
DOI	10.1016/j.lithos.2016.02.025
文献子类	Article
英文摘要	Recycling of noble gases from crustal rocks into the mantle is indicated not only by oceanic basalts and mantle xenoliths, but also by ultrahigh-pressure metamorphic rocks in collisional orogens. It is intriguing whether noble gases in continental crust were recycled into the mantle by deep subduction of the continental crust to mantle depths. Here we firstly report the He, Ne and Ar isotopic compositions of pyroxene from postcollisional mafic igneous rocks in the Dabie orogen, China. The results show that the pyroxene separates from the mafic rocks have low He-3/He-4 ratios of 0.002 to 1.8 Ra and air-like Ne isotope compositions. Furthermore, the pyroxene exhibits low Ar-40/Ar-36 ratios of 393.6 to 1599.8, close to those of the air. In combination with whole-rock geochemistry it is found that pyroxene He-3/He-4 ratios are correlated with whole-rock (La/Yb)(N) and Sr/Y ratios, epsilon(Nd)(t) values and MgO contents. These observations demonstrate the mass transfer from the deeply subducted continental crust to the overlying mantle wedge, recording the source mixing between the crust-derived melt and the mantle peridotite in the continental subduction zone. A direct addition of the crustal He via crust derived melt to the mantle leads to the extremely low He-3/He-4 ratios in the orogenic lithospheric mantle, and the dissolved atmospheric Ar and Ne in the subducted supracrustal rocks results in the air-like Ar and Ne isotope ratios. Therefore, the noble gas isotopic signatures of supracrustal rocks were carried into the mantle by the continental deep subduction to subarc depths and then transferred to the postcollisional mafic igneous rocks via the melt-peridotite reaction at the slab-mantle interface in a continental subduction channel. Our finding firstly establishes the slab-mantle interaction model for recycling of supracrustal noble gases in the continental subduction zone. (c) 2016 Elsevier B.V. All rights reserved.
WOS关键词	PRESSURE METAMORPHIC ROCKS ; SUBCONTINENTAL LITHOSPHERIC MANTLE ; DABIE OROGEN CONSTRAINTS ; HE-AR ISOTOPES ; CENTRAL CHINA ; SULU OROGEN ; GEOCHEMICAL CONSTRAINTS ; CHEMICAL GEODYNAMICS ; PERIDOTITE XENOLITHS ; MESOZOIC GRANITOIDS
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
语种	英语
WOS记录号	WOS:000374599800010
资助机构	Chinese Ministry of Science and Technology(2015CB856100) ; Chinese Ministry of Science and Technology(2015CB856100) ; National Natural Science Foundation of China(41573001 ; National Natural Science Foundation of China(41573001 ; 41125012) ; 41125012) ; Chinese Ministry of Science and Technology(2015CB856100) ; Chinese Ministry of Science and Technology(2015CB856100) ; National Natural Science Foundation of China(41573001 ; National Natural Science Foundation of China(41573001 ; 41125012) ; 41125012)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/53517]
专题	地质与地球物理研究所_地球深部结构与过程研究室
作者单位	1.Univ Sci & Technol China, Sch Earth & Space Sci, CAS Key Lab Crust Mantle Mat & Environm, Hefei 230026, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, CAS Key Lab Earths Deep Interior, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Dai, Li-Qun,Zheng, Yong-Fei,He, Huai-Yu,et al. Postcollisional mafic igneous rocks record recycling of noble gases by deep subduction of the continental crust[J]. LITHOS,2016,252:135-144.
APA	Dai, Li-Qun,Zheng, Yong-Fei,He, Huai-Yu,&Zhao, Zi-Fu.(2016).Postcollisional mafic igneous rocks record recycling of noble gases by deep subduction of the continental crust.LITHOS,252,135-144.
MLA	Dai, Li-Qun,et al."Postcollisional mafic igneous rocks record recycling of noble gases by deep subduction of the continental crust".LITHOS 252(2016):135-144.