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Paulatto M, Laigle M, Galve A, Charvis P, Sapin M, Bayrakci G, Evain M, Kopp H. Dehydration of subducting slow-spread oceanic lithosphere in the Lesser Antilles. Nat Commun 2017; 8:15980. [PMID: 28691714 PMCID: PMC5508134 DOI: 10.1038/ncomms15980] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 05/18/2017] [Indexed: 11/25/2022] Open
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. During subduction water is transported into the mantle, but constraining its release remains challenging. Here, using seismic tomography of the Lesser Antilles arc, the authors track the multistage dehydration of the slab and its lateral variations associated with heterogeneous slab composition.
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Affiliation(s)
- Michele Paulatto
- Université Côte d'Azur, CNRS, IRD, Observatoire de la Côte d'Azur, Géoazur, 250 rue Albert Einstein, Sophia Antipolis, 06560 Valbonne, France.,Imperial College London, Earth Science and Engineering, Prince Consort Road, London SW7 2BP, UK
| | - Mireille Laigle
- Université Côte d'Azur, CNRS, IRD, Observatoire de la Côte d'Azur, Géoazur, 250 rue Albert Einstein, Sophia Antipolis, 06560 Valbonne, France
| | - Audrey Galve
- Université Côte d'Azur, CNRS, IRD, Observatoire de la Côte d'Azur, Géoazur, 250 rue Albert Einstein, Sophia Antipolis, 06560 Valbonne, France
| | - Philippe Charvis
- Université Côte d'Azur, CNRS, IRD, Observatoire de la Côte d'Azur, Géoazur, 250 rue Albert Einstein, Sophia Antipolis, 06560 Valbonne, France
| | - Martine Sapin
- Institut de Physique du Globe de Paris, PRES Sorbonne Paris-Cité, CNRS UMR 7154, 1 rue Jussieu, 75005 Paris, France
| | - Gaye Bayrakci
- University of Southampton, Ocean and Earth Science, European Way, Southampton SO14 3ZH, UK
| | - Mikael Evain
- IFREMER, Géosciences Marines, Centre Bretagne, ZI de la Pointe du Diable-CS 10070, 29280 Plouzané, France
| | - Heidrun Kopp
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, 24148 Kiel, Germany
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Chapter 2 New constraints on the late cretaceous/tertiary plate tectonic evolution of the caribbean. SEDIMENTARY BASINS OF THE WORLD 1999. [DOI: 10.1016/s1874-5997(99)80036-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Mauffret A, Leroy S. Chapter 21 Neogene intraplate deformation of the caribbean plate at the beata ridge. SEDIMENTARY BASINS OF THE WORLD 1999. [DOI: 10.1016/s1874-5997(99)80055-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Neumann GA, Zuber MT, Smith DE, Lemoine FG. The lunar crust: Global structure and signature of major basins. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/96je01246] [Citation(s) in RCA: 170] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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