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DOI	10.1038/s41561-019-0411-x
	Arc magmas oxidized by water dissociation and hydrogen incorporation in orthopyroxene
	Tollan P.; Hermann J.
发表日期	2019
ISSN	17520894
卷号	12 期号:8
英文摘要	Elevated H2O concentrations and oxygen fugacities are two fundamental properties that distinguish magmas formed in subduction zones from new crust generated at mid-ocean ridges. However, the mechanism of magma oxidation and how it relates to the increase in H2O remain unclear. In this study, we used infrared spectroscopy of mantle wedge orthopyroxene to trace the temporal and spatial evolution of oxygen fugacity during the transport of hydrous arc melts towards the crust. A positive correlation between equilibrium oxygen fugacity and orthopyroxene H2O concentrations for the peridotite samples studied allowed the assignment of specific, commonly observed absorption bands to redox-sensitive crystallographic defects. H2O content associated with these redox-sensitive defects increases in concentration across individual crystals, uniquely preserving the time-dependent transition from reduced to oxidized conditions during the migration of hydrous melts through the mantle wedge. A separate but related process of reaction with H2 occurring primarily during the earliest stages of melt–mantle reaction may be fundamental in generating the oxidized nature of hydrous melts. Our study proposes that the oxidized nature of arc magmas may not be a primary feature, but is instead acquired progressively as hydrous primary melts react with the surrounding mantle. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.
语种	英语
scopus关键词	chemical reaction; concentration (composition); detection method; hydrogen; magma; orthopyroxene; peridotite; redox conditions; subduction zone
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/124622
作者单位	Institut für Geologie, University of Bern, Bern, Switzerland
推荐引用方式 GB/T 7714	Tollan P.,Hermann J.. Arc magmas oxidized by water dissociation and hydrogen incorporation in orthopyroxene[J],2019,12(8).
APA	Tollan P.,&Hermann J..(2019).Arc magmas oxidized by water dissociation and hydrogen incorporation in orthopyroxene.Nature Geoscience,12(8).
MLA	Tollan P.,et al."Arc magmas oxidized by water dissociation and hydrogen incorporation in orthopyroxene".Nature Geoscience 12.8(2019).