Oxidising agents in sub-arc mantle melts link slab devolatilisation and arc magmas.

Details

Serval ID
serval:BIB_D9C98757E2BB
Type
Article: article from journal or magazin.
Collection
Publications
Title
Oxidising agents in sub-arc mantle melts link slab devolatilisation and arc magmas.
Journal
Nature communications
Author(s)
Bénard A., Klimm K., Woodland A.B., Arculus R.J., Wilke M., Botcharnikov R.E., Shimizu N., Nebel O., Rivard C., Ionov D.A.
ISSN
2041-1723 (Electronic)
ISSN-L
2041-1723
Publication state
Published
Issued date
29/08/2018
Peer-reviewed
Oui
Volume
9
Pages
3500
Language
english
Notes
Publication types: Journal Article
Publication Status: epublish
Abstract
Subduction zone magmas are more oxidised on eruption than those at mid-ocean ridges. This is attributed either to oxidising components, derived from subducted lithosphere (slab) and added to the mantle wedge, or to oxidation processes occurring during magma ascent via differentiation. Here we provide direct evidence for contributions of oxidising slab agents to melts trapped in the sub-arc mantle. Measurements of sulfur (S) valence state in sub-arc mantle peridotites identify sulfate, both as crystalline anhydrite (CaSO <sub>4</sub> ) and dissolved SO <sub>4</sub> <sup>2-</sup> in spinel-hosted glass (formerly melt) inclusions. Copper-rich sulfide precipitates in the inclusions and increased Fe <sup>3+</sup> /∑Fe in spinel record a S <sup>6+</sup> -Fe <sup>2+</sup> redox coupling during melt percolation through the sub-arc mantle. Sulfate-rich glass inclusions exhibit high U/Th, Pb/Ce, Sr/Nd and δ <sup>34</sup> S (+ 7 to + 11‰), indicating the involvement of dehydration products of serpentinised slab rocks in their parental melt sources. These observations provide a link between liberated slab components and oxidised arc magmas.
Pubmed
Web of science
Publisher's website
Open Access
Yes
Create date
11/09/2018 8:40
Last modification date
09/05/2019 2:02
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