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DOI	10.1038/s41561-021-00870-6
	Earth's missing argon paradox resolved by recycling of oceanic crust
	Tucker, Jonathan M.; van Keken, Peter E.; Ballentine, Chris J.
发表日期	2022
ISSN	1752-0894
EISSN	1752-0908
起始页码	85
结束页码	+
卷号	15 期号:1 页码:10
英文摘要	Oceanic crust subduction sequesters substantial amounts of argon in the Earth's mantle, while atmosphere-derived argon affects only the isotopic composition and not the overall budget, according to geodynamic-geochemical models of mantle convection. The extent to which primordial mantle domains have survived billions of years of convective mixing is a fundamental question in mantle dynamics and geochemistry. The observation that around half of Earth's Ar-40 is missing from the atmosphere has been used to argue for a largely primordial, convectively isolated lower mantle. This hypothesis is apparently supported by lower Ar-40/Ar-36 ratios in the mantle source of ocean-island basalts compared with mid-ocean-ridge basalts. However, strongly layered convection is contradicted by seismic tomographic observations and geodynamic constraints. Using joint geodynamic-geochemical modelling of mantle convection, we show that high Ar-40 concentrations associated with K-rich subducted oceanic crust plus unmelted material dispersed throughout the mantle can fully account for Earth's Ar-40 budget. This solution to the missing Ar paradox requires neither a substantial reduction in Earth's assumed K concentration nor large isolated domains in the mantle. We additionally show that subducted atmosphere-derived Ar has little effect on the mantle Ar-40 budget but can substantially reduce mantle Ar-40/Ar-36 ratios. Unlike He and Ne isotope systems, whose variations reflect primarily incorporation of primordial material, mantle Ar-40/Ar-36 ratios may instead result from subduction of atmosphere-derived Ar into the deep mantle.
学科领域	Geosciences, Multidisciplinary
语种	英语
WOS研究方向	Geology
WOS记录号	WOS:000742312300001
来源期刊	NATURE GEOSCIENCE
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/272492
作者单位	Carnegie Institution for Science; Smithsonian Institution; Smithsonian National Museum of Natural History; University of Oxford
推荐引用方式 GB/T 7714	Tucker, Jonathan M.,van Keken, Peter E.,Ballentine, Chris J.. Earth's missing argon paradox resolved by recycling of oceanic crust[J],2022,15(1):10.
APA	Tucker, Jonathan M.,van Keken, Peter E.,&Ballentine, Chris J..(2022).Earth's missing argon paradox resolved by recycling of oceanic crust.NATURE GEOSCIENCE,15(1),10.
MLA	Tucker, Jonathan M.,et al."Earth's missing argon paradox resolved by recycling of oceanic crust".NATURE GEOSCIENCE 15.1(2022):10.