Research ArticleSUBDUCTION ZONE

Geochemical evidence for mélange melting in global arcs

+ See all authors and affiliations

Science Advances  07 Apr 2017:
Vol. 3, no. 4, e1602402
DOI: 10.1126/sciadv.1602402

You are currently viewing the abstract.

View Full Text

Abstract

In subduction zones, sediments and hydrothermally altered oceanic crust, which together form part of the subducting slab, contribute to the chemical composition of lavas erupted at the surface to form volcanic arcs. Transport of this material from the slab to the overlying mantle wedge is thought to involve discreet melts and fluids that are released from various portions of the slab. We use a meta-analysis of geochemical data from eight globally representative arcs to show that melts and fluids from individual slab components cannot be responsible for the formation of arc lavas. Instead, the data are compatible with models that first invoke physical mixing of slab components and the mantle wedge, widely referred to as high-pressure mélange, before arc magmas are generated.

Keywords
  • Subduction zone
  • mass transfer
  • Sr isotopes
  • Nd isotopes
  • mantle melting
  • slab-mantle mixing
  • melange

This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.

View Full Text