untitled
<OAI-PMH schemaLocation=http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd>
<responseDate>2018-01-15T15:38:00Z</responseDate>
<request identifier=oai:HAL:hal-00534035v1 verb=GetRecord metadataPrefix=oai_dc>http://api.archives-ouvertes.fr/oai/hal/</request>
<GetRecord>
<record>
<header>
<identifier>oai:HAL:hal-00534035v1</identifier>
<datestamp>2018-01-11</datestamp>
<setSpec>type:ART</setSpec>
<setSpec>subject:sdu</setSpec>
<setSpec>collection:CNRS</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>Fluid transfer into the wedge controlled by high-pressure hydrofracturing in the cold top-slab mantle</title>
<creator>Padron-Navarta, J. A.</creator>
<creator>Tommasi, Andrea</creator>
<creator>Garrido, Carlos J.</creator>
<creator>Lopez Sanchez-Vizcaino, Vicente</creator>
<creator>Teresa Gomez-Pugnaire, Maria</creator>
<creator>Jabaloy, Antonio</creator>
<creator>Vauchez, Alain</creator>
<contributor>Departamento De Mineralogía Y Petrología, Facultad De Ciencias, Universidad De Granada ; 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>
<contributor>Instituto Andaluz de Ciencias de la Tierra (IACT) ; Universidad de Granada (UGR) - Consejo Superior de Investigaciones Científicas [Spain] (CSIC)</contributor>
<contributor>Departamento de Geología [Jaén] ; Universidad de Jaén (UJA)</contributor>
<contributor>Departamento de Mineralogía y Petrología, Universidad de Granada ; Université du Québec</contributor>
<contributor>Departamento de Geodinámica, Universidad de Granada ; Université du Québec</contributor>
<description>International audience</description>
<source>ISSN: 0012-821X</source>
<source>Earth and Planetary Science Letters</source>
<publisher>Elsevier</publisher>
<identifier>hal-00534035</identifier>
<identifier>https://hal.archives-ouvertes.fr/hal-00534035</identifier>
<source>https://hal.archives-ouvertes.fr/hal-00534035</source>
<source>Earth and Planetary Science Letters, Elsevier, 2010, 297 (1-2), pp.271-286. 〈10.1016/j.epsl.2010.06.029〉</source>
<identifier>DOI : 10.1016/j.epsl.2010.06.029</identifier>
<relation>info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2010.06.029</relation>
<language>en</language>
<subject lang=en>subduction</subject>
<subject lang=en>fluid flow</subject>
<subject lang=en>hydrofracturing</subject>
<subject lang=en>chlorite-harzburgite</subject>
<subject lang=en>spinifex texture</subject>
<subject lang=en>recrystallization</subject>
<subject>[SDU.STU.PE] Sciences of the Universe [physics]/Earth Sciences/Petrography</subject>
<type>info:eu-repo/semantics/article</type>
<type>Journal articles</type>
<description lang=en>Before attaining the mantle wedge, where they trigger partial melting, volatiles released from dehydration reactions in the slab have to migrate across a relatively cold (<750 degrees C), peridotite-layer above the incoming slab. In order to unravel the mechanisms allowing for this initial stage of fluid transport, we performed a detailed field and microstructural study of metamorphic prograde peridotites in the Cerro del Almirez ultramafic massif (Betic Cordillera, Spain), where evidences of one of the most important dehydration reactions in subduction zones, the high-pressure antigorite breakdown (P = 1.6-1.9 GPa and T approximate to 680 degrees C), can be mapped in the field. This reaction led to arborescent growth of centimeter-size olivine and orthopyroxene, producing a chlorite-harzburgite with a spinifex-like texture. Microstructural observations and crystal preferred (CPO) mapping show no evidences of solid-state deformation during the prograde growth of olivine and orthopyroxene at the expenses of antigorite. However, a few tens to a hundred meters away from the reaction front, the metamorphic texture is partially obliterated by grain-size reduction in roughly planar conjugate zones, a few mm to meters wide. Grain size reduction zones (GSRZ) are characterized by (1) sharp contacts with undeformed spinifex-like texture domains, (2) important reduction of the olivine grain size (60-250 mu m), (3) olivine color change from brownish to colorless, (4) decrease in the modal amount of orthopyroxene, and (5) at the mm- to cm-scale, irregular shapes and abrupt terminations. Field and microstructural observations exclude that relative displacement took place across these GSRZ. Changes in modal composition imply reactions with fluids undersaturated in silica. Analysis of olivine crystal-preferred orientations (CPO) in GSRZ shows patterns similar, but more dispersed, than those in neighboring spinifex-like domains. It also reveals mm- to cm-scale discrete domains with rather homogeneous crystallographic orientations suggesting inheritance from the preexisting spinifex-like olivines in the host peridotite. Misorientation angles between neighboring grains in the GSRZ show peaks at similar to 5-10 degrees and similar to 20 degrees, but rotations are not crystallographically controlled. Based on these observations, we rule out the formation of the GSRZ by dynamic recrystallization during dislocation creep and propose that they record brittle deformation (microcraking) of the spinifex-like chlorite-harzburgite, probably induced by hydrofracturing at high pressure and relative low temperature conditions (680-710 degrees C). High-pressure hydrofracturing can, thus, be invoked as an efficient mechanism for fluid flow across the cold top-slab mantle layer, hence allowing the slab-derived fluids to ingress in the wedge.</description>
<date>2010</date>
</dc>
</metadata>
</record>
</GetRecord>
</OAI-PMH>
