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Eclogite as a seismic marker in subduction channels: Seismic velocities, anisotropy, and petrofabric of Cabo Ortegal eclogite tectonites (Spain)

2010; Geological Society of America; Volume: 123; Issue: 3-4 Linguagem: Inglês

10.1130/b30226.1

1943-2674

B. Ábalos, David M. Fountain, José Ignacio Gil Ibarguchi, P. Puelles,

earthquake and tectonic studies

Research Article| March 01, 2011 Eclogite as a seismic marker in subduction channels: Seismic velocities, anisotropy, and petrofabric of Cabo Ortegal eclogite tectonites (Spain) B. Ábalos; B. Ábalos † 1Departamento de Geodinámica, Universidad del País Vasco, P.O. Box 644, E-48080 Bilbao, Spain †E-mail: benito.abalos@ehu.es Search for other works by this author on: GSW Google Scholar D.M. Fountain; D.M. Fountain 2National Science Foundation, Earth Sciences Division, Geosciences Directorate, Tectonics Program, Room 785, 4201 Wilson Boulevard, Arlington, Virginia 22230, USA Search for other works by this author on: GSW Google Scholar J.I. Gil Ibarguchi; J.I. Gil Ibarguchi 3Departamento de Mineralogía y Petrología, Universidad del País Vasco, P.O. Box 644, E-48080 Bilbao, Spain Search for other works by this author on: GSW Google Scholar P. Puelles P. Puelles 1Departamento de Geodinámica, Universidad del País Vasco, P.O. Box 644, E-48080 Bilbao, Spain Search for other works by this author on: GSW Google Scholar Author and Article Information B. Ábalos † 1Departamento de Geodinámica, Universidad del País Vasco, P.O. Box 644, E-48080 Bilbao, Spain D.M. Fountain 2National Science Foundation, Earth Sciences Division, Geosciences Directorate, Tectonics Program, Room 785, 4201 Wilson Boulevard, Arlington, Virginia 22230, USA J.I. Gil Ibarguchi 3Departamento de Mineralogía y Petrología, Universidad del País Vasco, P.O. Box 644, E-48080 Bilbao, Spain P. Puelles 1Departamento de Geodinámica, Universidad del País Vasco, P.O. Box 644, E-48080 Bilbao, Spain †E-mail: benito.abalos@ehu.es Publisher: Geological Society of America Received: 18 Dec 2009 Revision Received: 15 Feb 2010 Accepted: 17 Feb 2010 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2011 Geological Society of America GSA Bulletin (2011) 123 (3-4): 439–456. https://doi.org/10.1130/B30226.1 Article history Received: 18 Dec 2009 Revision Received: 15 Feb 2010 Accepted: 17 Feb 2010 First Online: 08 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 B. Ábalos, D.M. Fountain, J.I. Gil Ibarguchi, P. Puelles; Eclogite as a seismic marker in subduction channels: Seismic velocities, anisotropy, and petrofabric of Cabo Ortegal eclogite tectonites (Spain). GSA Bulletin 2011;; 123 (3-4): 439–456. doi: https://doi.org/10.1130/B30226.1 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 SocietyGSA Bulletin Search Advanced Search Abstract High-pressure, sheath-like fold-nappes made of normal–mid ocean ridge basalt (N-MORB) eclogites, high-pressure volcanic-arc granulites, arc-root lithospheric mantle peridotites, and shallow crustal volcanosedimentary gneisses were amalgamated at deep realms of an Eohercynian orogenic channel and currently crop out in the Cabo Ortegal Complex. Compressional seismic-wave velocity measurements determined in eclogite at confining pressures of 600 MPa range from 8.4 to 7.3 km/s, whereas anisotropy varies between 0.7% and 3.2%. Shear-wave velocities range from 4.8 to 4.2 km/s, and the respective anisotropies vary between 0.1% and 3.4%. The Poisson's ratios are low (0.25–0.265), independent of the degree of retrogression or deformation. Seismic velocities and anisotropy are related to the fabric of omphacite, and calculated eclogite anisotropy is not symmetrical with respect to the tectonic fabrics. Calculated seismic-reflection coefficients induced by lithological, structural, and rock petrofabric variations of eclogites show that these can be identified as reflectors imprinting a particular, penetrative, and dipping fabric to discrete seismic-profile segments of paleosubduction settings. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.