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

Type Article
Date 2017-07
Language English
Author(s) Paulatto Michele1, 2, Laigle Mireille1, Galve Audrey1, Charvis Philippe1, Sapin Martine3, Bayrakci Gaye4, Evain MikaelORCID5, Kopp Heidrun6
Affiliation(s) 1 : Univ Cote Azur, CNRS, Observ Cote Azur, Geoazur,IRD, 250 Rue Albert Einstein, F-06560 Valbonne, France.
2 : Imperial Coll London, Earth Sci & Engn, Prince Consort Rd, London SW7 2BP, England.
3 : CNRS, UMR 7154, Sorbonne Paris Cite, Inst Phys Globe Paris,PRES, 1 Rue Jussieu, F-75005 Paris, France.
4 : Univ Southampton, Ocean & Earth Sci, European Way, Southampton SO14 3ZH, Hants, England.
5 : IFREMER, Ctr Bretagne, Geosci Marines, ZI Pointe Diable CS 10070, F-29280 Plouzane, France.
6 : GEOMAR Helmholtz Ctr Ocean Res Kiel, Wischhofstr 1-3, D-24148 Kiel, Germany.
Source Nature Communications (2041-1723) (Nature Publishing Group), 2017-07 , Vol. 8 , P. 15980 (1-11)
DOI 10.1038/ncomms15980
WOS© Times Cited 19
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.

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Supplementary Information 10 7 MB Open access
Peer Review File 20 290 KB Open access
Supplementary Movie 1 36 MB Open access
Supplementary Movie 2 33 MB Open access
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How to cite 

Paulatto Michele, Laigle Mireille, Galve Audrey, Charvis Philippe, Sapin Martine, Bayrakci Gaye, Evain Mikael, Kopp Heidrun (2017). Dehydration of subducting slow-spread oceanic lithosphere in the Lesser Antilles. Nature Communications, 8, 15980 (1-11). Publisher's official version : https://doi.org/10.1038/ncomms15980 , Open Access version : https://archimer.ifremer.fr/doc/00392/50321/