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<OAI-PMH schemaLocation=http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd> <responseDate>2018-01-15T15:40:14Z</responseDate> <request identifier=oai:HAL:hal-00445247v1 verb=GetRecord metadataPrefix=oai_dc>http://api.archives-ouvertes.fr/oai/hal/</request> <GetRecord> <record> <header> <identifier>oai:HAL:hal-00445247v1</identifier> <datestamp>2018-01-11</datestamp> <setSpec>type:ART</setSpec> <setSpec>subject:sdu</setSpec> <setSpec>subject:phys</setSpec> <setSpec>subject:sde</setSpec> <setSpec>collection:CNRS</setSpec> <setSpec>collection:SDE</setSpec> <setSpec>collection:GM</setSpec> <setSpec>collection:GIP-BE</setSpec> <setSpec>collection:AGROPOLIS</setSpec> <setSpec>collection:INSU</setSpec> <setSpec>collection:UNIV-AG</setSpec> <setSpec>collection:B3ESTE</setSpec> <setSpec>collection:UNIV-MONTPELLIER</setSpec> </header> <metadata><dc> <publisher>HAL CCSD</publisher> <title lang=en>Mica, deformation fabrics and the seismic properties of the continental crust</title> <creator>Lloyd, Geoffrey E.</creator> <creator>Butler, Robert W. H.</creator> <creator>Casey, Martin</creator> <creator>MAINPRICE, David</creator> <contributor>Institute of Geophysics and Tectonics, The University of Leeds ; Université du Québec</contributor> <contributor>Geology and Petroleum Geology, School of Geosciences, University of Aberdeen ; Université du Québec</contributor> <contributor>Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS)</contributor> <description>International audience</description> <source>ISSN: 0012-821X</source> <source>Earth and Planetary Science Letters</source> <publisher>Elsevier</publisher> <identifier>hal-00445247</identifier> <identifier>https://hal.archives-ouvertes.fr/hal-00445247</identifier> <source>https://hal.archives-ouvertes.fr/hal-00445247</source> <source>Earth and Planetary Science Letters, Elsevier, 2009, 288 (1-2), pp.320-328. 〈10.1016/j.epsl.2009.09.035〉</source> <identifier>DOI : 10.1016/j.epsl.2009.09.035</identifier> <relation>info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2009.09.035</relation> <language>en</language> <subject lang=en>S-C fabrics</subject> <subject lang=en>seismic anisotropy</subject> <subject lang=en>continental tectonics</subject> <subject lang=en>mica</subject> <subject>[SDU.STU.GP] Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]</subject> <subject>[PHYS.PHYS.PHYS-GEO-PH] Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]</subject> <subject>[SDE.MCG] Environmental Sciences/Global Changes</subject> <type>info:eu-repo/semantics/article</type> <type>Journal articles</type> <description lang=en>Seismic anisotropy originating within the continental crust is used to determine kinematic flow lines within active mountain belts and is widely attributed to regionally aligned mica. However, naturally deformed micaceous rocks commonly show composite (e.g. S-C) fabrics. It is necessary therefore to understand how both varying mica content and differing intensities of multiple foliations impact on seismic interpretations in terms of deformation fields. An outcrop analogue for granitic mid-crustal deformed zones is used here to calibrate the seismic response against both parameters. Seismic responses are modelled using crystallographic preferred orientations for polymineralic, micaceous granitic gneisses, measured using Electron Back-Scatter Diffraction. The sample results are generalised by modelling the effects of variations in modal composition and the relative importance of deformation fabrics of variable orientation, so-called rock and fabric recipes. The maximum P- and S-anisotropy are calculated at 16.6% and 23.9% for single-foliation gneisses but for mixed (i.e. S-C) foliation gneisses these values reduce to 5.8% and 7.5% respectively. Furthermore, mixtures of multiple foliations generate significant variations in the geometry of the seismic anisotropy. This effect, coupled with the geographical orientation of fabrics in nature. can generate substantial variations in the orientation and magnitude of seismic anisotropy (especially for shear waves) as measured for the continental crust using existing receiver function and teleseismic near-vertical incidence methods. Thus, maps of seismic anisotropy varying with depth in deforming continents need not imply necessarily depth-varying deformation kinematics and tectonic decoupling.</description> <date>2009</date> </dc> </metadata> </record> </GetRecord> </OAI-PMH>