Article thumbnail

Dehydration of subducting slow-spread oceanic lithosphere in the Lesser Antilles

By Michele Paulatto, Mireille Laigle, Audrey Galve, Philippe Charvis, Martine Sapin, Gaye Bayrakci, Mikael Evain and Heidrun Kopp

Abstract

Subducting slabs carry water into the mantle and are a major gateway in the global geochemical water cycle. Fluid transport and release can be constrained with seismological data. Here we use joint active-source/local-earthquake seismic tomography to derive unprecedented constraints on multi-stage fluid release from subducting slow-spread oceanic lithosphere. We image the low P-wave velocity crustal layer on the slab top and show that it disappears beneath 60–100 km depth, marking the depth of dehydration metamorphism and eclogitization. Clustering of seismicity at 120–160 km depth suggests that the slab’s mantle dehydrates beneath the volcanic arc, and may be the main source of fluids triggering arc magma generation. Lateral variations in seismic properties on the slab surface suggest that serpentinized peridotite exhumed in tectonized slow-spread crust near fracture zones may increase water transport to sub-arc depths. This results in heterogeneous water release and directly impacts earthquakes generation and mantle wedge dynamics

Publisher: 'Springer Science and Business Media LLC'
Year: 2017
DOI identifier: 10.1038/ncomms15980
OAI identifier: oai:archimer.ifremer.fr:50321
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • https://archimer.ifremer.fr/do... (external link)
  • https://archimer.ifremer.fr/do... (external link)
  • https://archimer.ifremer.fr/do... (external link)
  • https://archimer.ifremer.fr/do... (external link)
  • https://archimer.ifremer.fr/do... (external link)
  • https://archimer.ifremer.fr/do... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.