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

Détails

ID Serval
serval:BIB_D9C98757E2BB
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Oxidising agents in sub-arc mantle melts link slab devolatilisation and arc magmas.
Périodique
Nature communications
Auteur(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
Statut éditorial
Publié
Date de publication
29/08/2018
Peer-reviewed
Oui
Volume
9
Pages
3500
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: epublish
Résumé
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
Site de l'éditeur
Création de la notice
11/09/2018 8:40
Dernière modification de la notice
06/12/2018 7:12
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