Transition of subduction-related magmatism from slab melting to dehydration at 2.5 Ga

doi:10.1016/j.precamres.2019.105524

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	Transition of subduction-related magmatism from slab melting to dehydration at 2.5 Ga
	Liu, He 1,2,3; Sun, Wei-dong 1,2,3; Deng, Jiang-Hong 1
刊名	PRECAMBRIAN RESEARCH
	2020-02-01
卷号	337 页码:5
关键词	Archean plate subduction Arc felsic rocks Slab melting Dehydration Garnet
ISSN号	0301-9268
DOI	10.1016/j.precamres.2019.105524
通讯作者	Sun, Wei-dong(weidongsun@qdio.ac.cn)
英文摘要	The Archean plate tectonics and subduction-related magmatism have been concerned for several decades. Here we investigate the Archean plate subduction from a new perspective, using the secular records of global-scale non-TTG (tonalite-trondhjemite-granodiorite) felsic rocks with arc-like geochemical affinities. The statistical results show that the La/Yb and Sm/Yb of non-TTG arc felsic rocks evolved at high values in the Archean, and decreased sharply at 2.5 Ga. This abrupt transition indicates a significant change of the petrogenesis. During the Archean, the oceanic crust subducted into the mantle along a high geothermal gradient and reached the conditions of partial melting with garnet stable in the residue, resulting in high La/Yb and Sm/Yb in the arc felsic rocks. As a consequence of the secular cooling of the mantle, the geothermal gradient of a post-Archean subducting cold oceanic crust intersected with the stability limits of hydrous minerals before it reached the wet solidus of basalts, so that the dehydration occurred preferentially and resulted in a drier crust with a much higher temperature of solidus. As such, the post-Archean arc felsic rocks were mostly originated from melting of the hydrated mantle wedge overlying the subducted oceanic slab. The magma source of the arc felsic rocks thereafter became much shallower, corresponding to the low La/Yb and Sm/Yb of those rocks as a consequence of the less stable garnet in the residue. We thus conclude that the subduction-related magmatism changed from slab melting to dehydration model at 2.5 Ga.
资助项目	Strategic Priority Research Program of the Chinese Academy of Sciences[XDA22050103] ; National Key R&D Program of China[2016YFC0600408]
WOS研究方向	Geology
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000510527900005
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/165262]
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	Sun, Wei-dong
作者单位	1.Chinese Acad Sci, Ctr Deep Sea Res, Inst Oceanol, 7 Nanhai Rd, Qingdao 266071, Peoples R China 2.Chinese Acad Sci, Ctr Ocean Megasci, 7 Nanhai Rd, Qingdao 266071, Peoples R China 3.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Mineral Resources, Qingdao 266237, Peoples R China
推荐引用方式 GB/T 7714	Liu, He,Sun, Wei-dong,Deng, Jiang-Hong. Transition of subduction-related magmatism from slab melting to dehydration at 2.5 Ga[J]. PRECAMBRIAN RESEARCH,2020,337:5.
APA	Liu, He,Sun, Wei-dong,&Deng, Jiang-Hong.(2020).Transition of subduction-related magmatism from slab melting to dehydration at 2.5 Ga.PRECAMBRIAN RESEARCH,337,5.
MLA	Liu, He,et al."Transition of subduction-related magmatism from slab melting to dehydration at 2.5 Ga".PRECAMBRIAN RESEARCH 337(2020):5.