Article

Nature 425, 367-373 (25 September 2003) | doi:10.1038/nature01961; Received 1 October 2002; Accepted 23 July 2003

Bending-related faulting and mantle serpentinization at the Middle America trench

C. R. Ranero1, J. Phipps Morgan1, K. McIntosh2 & C. Reichert3

  1. GEOMAR and SFB574, Wischhofstrasse 1-3, 24148 Kiel, Germany
  2. Institute of Geophysics, University of Texas at Austin, 4412 Spicewood Springs Rd., Bldg 600, Austin, Texas 78759-8500, USA
  3. BGR, Bundesanstalt für Geowissenschaften and Rohstoffe, Stilleweg 2, 30655 Hannover, Germany

Correspondence to: C. R. Ranero1 Email: cranero@geomar.de

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The dehydration of subducting oceanic crust and upper mantle has been inferred both to promote the partial melting leading to arc magmatism and to induce intraslab intermediate-depth earthquakes, at depths of 50–300 km. Yet there is still no consensus about how slab hydration occurs or where and how much chemically bound water is stored within the crust and mantle of the incoming plate. Here we document that bending-related faulting of the incoming plate at the Middle America trench creates a pervasive tectonic fabric that cuts across the crust, penetrating deep into the mantle. Faulting is active across the entire ocean trench slope, promoting hydration of the cold crust and upper mantle surrounding these deep active faults. The along-strike length and depth of penetration of these faults are also similar to the dimensions of the rupture area of intermediate-depth earthquakes.