Research Article| December 01, 2006 Interplate patchiness and subduction-erosion mechanisms: Evidence from depth-migrated seismic images at the central Ecuador convergent margin F. Sage; F. Sage 1Université P. et M. Curie-Paris 6, Géosciences Azur, BP48, 06235 Villefranche-sur-Mer cedex, France Search for other works by this author on: GSW Google Scholar J.-Y. Collot; J.-Y. Collot 2Institut pour la Recherche et le Développement, Géosciences Azur, BP48, 06235 Villefranche-sur-Mer cedex, France Search for other works by this author on: GSW Google Scholar C.R. Ranero C.R. Ranero 3Institucio Catalana de Recerca i Estudis Avançats, Instituto de Ciencias del Mar, Consejo Superior de Investigaciones Cientificas, Pg. Maritim de la Barceloneta 37-49, 08003 Barcelona, Spain Search for other works by this author on: GSW Google Scholar Author and Article Information F. Sage 1Université P. et M. Curie-Paris 6, Géosciences Azur, BP48, 06235 Villefranche-sur-Mer cedex, France J.-Y. Collot 2Institut pour la Recherche et le Développement, Géosciences Azur, BP48, 06235 Villefranche-sur-Mer cedex, France C.R. Ranero 3Institucio Catalana de Recerca i Estudis Avançats, Instituto de Ciencias del Mar, Consejo Superior de Investigaciones Cientificas, Pg. Maritim de la Barceloneta 37-49, 08003 Barcelona, Spain Publisher: Geological Society of America Received: 07 Mar 2006 Revision Received: 16 Jun 2006 Accepted: 21 Jun 2006 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 The Geological Society of America, Inc. Geology (2006) 34 (12): 997–1000. https://doi.org/10.1130/G22790A.1 Article history Received: 07 Mar 2006 Revision Received: 16 Jun 2006 Accepted: 21 Jun 2006 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation F. Sage, J.-Y. Collot, C.R. Ranero; Interplate patchiness and subduction-erosion mechanisms: Evidence from depth-migrated seismic images at the central Ecuador convergent margin. Geology 2006;; 34 (12): 997–1000. doi: https://doi.org/10.1130/G22790A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Prestack depth-migrated seismic lines provide accurate images of the convergent Ecuadorian margin, where the southern flank of the Carnegie Ridge subducts. The margin is fronted by a 5–7-km-wide compressional sediment prism. Beneath the slope, margin thinning is accomplished by gradual thinning of the lower part of the basement, accompanied by pervasive seaward-dipping normal faulting, indicating basal subduction erosion at a low-friction plate interface. Along the plate boundary, a thin subduction channel locally thickens to form low-velocity, ∼600-m-thick lenses of underthrusted fluid-rich sediment supplied by slope mass wasting. The contrast between the fluid-rich sediment and the surrounding thinner and drier sections of the subduction channel creates a three- dimensional patchiness across the plate boundary, implying variations in mechanical interplate coupling. The subduction channel patchiness modulates subduction erosion processes by alternately favoring margin basement weakening and material removal. Basement weakening would occur (1) at the base of the upper plate, where enhanced reflectivity indicates basement damage by overpressured fluids from the subduction channel, and (2) at the basement apex, where basement breakup is caused by superposition of compressional and extensional fault systems resulting from time-variable interplate mechanical coupling. The detachment of rock debris in the higher coupled sections and the subsequent dragging of the fragments into the subduction channel cause tectonic erosion. Deeper in the subduction, the subduction channel patchiness may influence processes like earthquake nucleation and rupture propagation and material recycling in the mantle. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.