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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>2018-01-15T15:40:33Z</responseDate> <request identifier=oai:HAL:hal-00424501v1 verb=GetRecord metadataPrefix=oai_dc>http://api.archives-ouvertes.fr/oai/hal/</request> <GetRecord> <record> <header> <identifier>oai:HAL:hal-00424501v1</identifier> <datestamp>2018-01-11</datestamp> <setSpec>type:ART</setSpec> <setSpec>subject:sdu</setSpec> <setSpec>subject:sde</setSpec> <setSpec>collection:CNRS</setSpec> <setSpec>collection:UNIV-PARIS7</setSpec> <setSpec>collection:SDE</setSpec> <setSpec>collection:GM</setSpec> <setSpec>collection:UPMC</setSpec> <setSpec>collection:GIP-BE</setSpec> <setSpec>collection:AGROPOLIS</setSpec> <setSpec>collection:INSU</setSpec> <setSpec>collection:USPC</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>Neoproterozoic and Hercynian metamorphic events in the Central Mauritanides: Implications for the geodynamic evolution of West Africa</title> <creator>Caby, Renaud</creator> <creator>Kienast, J. R.</creator> <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>Laboratoire de Géosciences Marines (LGM) ; Université Pierre et Marie Curie - Paris 6 (UPMC) - IPG PARIS - Université Paris Diderot - Paris 7 (UPD7) - Centre National de la Recherche Scientifique (CNRS)</contributor> <description>International audience</description> <source>ISSN: 0899-5362</source> <source>Journal of African Earth Sciences</source> <publisher>Elsevier</publisher> <identifier>hal-00424501</identifier> <identifier>https://hal.archives-ouvertes.fr/hal-00424501</identifier> <source>https://hal.archives-ouvertes.fr/hal-00424501</source> <source>Journal of African Earth Sciences, Elsevier, 2009, 53 (3), pp.122-136. 〈10.1016/j.jafrearsci.2008.09.004〉</source> <identifier>DOI : 10.1016/j.jafrearsci.2008.09.004</identifier> <relation>info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jafrearsci.2008.09.004</relation> <language>en</language> <subject lang=en>Mauritania</subject> <subject lang=en>Hercynian</subject> <subject lang=en>HP metamorphism</subject> <subject lang=en>Nappe tectonics</subject> <subject lang=en>West Africa</subject> <subject>[SDU.STU.TE] Sciences of the Universe [physics]/Earth Sciences/Tectonics</subject> <subject>[SDE.MCG] Environmental Sciences/Global Changes</subject> <type>info:eu-repo/semantics/article</type> <type>Journal articles</type> <description lang=en>Field and petrostructural investigations in the Central Mauritanides provide new precisions on the polyorogenic character of the nappe edifice of this belt. The upper structural unit exposed in the Gaoua area includes anatectic gneisses and high-grade metasediments affected by medium temperature, high-pressure metamorphism and cut by granitoids. They represent a basement unconformably overlain by a monometamorphic cover, the Gaoua Group, of assumed lower Paleozoic age. Late Paleozoic regional metamorphism of metapelites from this cover is characterized by pyrophyllite-kyanite-chloritoid assemblages equilibrated at T around 420 degrees C and P = 1 GPa. In the lower structural unit exposed in the south around Boufkerine-Farkaka, metapelites of the Gadel Group display slightly retrogressed garnet-kyanite-staurolite-rutile assemblages that equilibrated at T around 600 degrees C and P >= 1.2 GPa before the intrusion of 639 Ma old plutons. The Gadel Group locally overlies in unconformity polycyclic gneisses. This continental assemblage represents an outboard terrane inserted between two monocyclic greenschist facies terranes: remnants of oceanic lithosphere in the east and arc-derived metasediments and metavolcanics cut by 670 Ma old calc-alkaline plutons in the west. All units have been involved in late Paleozoic nappes emplaced to the east above the West African craton and its late Neoproterozoic to Cambro-ordovician cover. Though an east-directed vergence is locally recorded in the Neoproterozoic units, most early E-W trending stretching and mineral lineations are synchronous with greenschist facies metamorphism developed during the Late Paleozoic and roughly coeval with the Applachian nappe system.</description> <date>2009</date> </dc> </metadata> </record> </GetRecord> </OAI-PMH>