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Accueil du site > Articles > Environnement > Pétrologie > Geochemistry and Petrography of an ophiolitic suture from Mauritanides (...)

The axial zone of Mauritanides belt is characterized by the presence of numerous ophiolitic complexes. Regions of Agane and Gouérarate represent the northern outcrops of these oceanic formations. These two regions are characterized by the abundance of completely serpentinized formations. In the region of Agane, a geochemical study (major and trace elements) confirms that the protolith of serpentinite is a depleted peridotite which corresponds to former dunite-harzburgite, while other serpentinites appear to derive from ultramafic cumulates.

Amphibolites have an igneous protolith corresponding, to ancient basalt and gabbro formations. In contrast, birbirites from Gouérarate are derived from a highly refractory protolith. These facies correspond to former dunite-harzburgite. The metamorphic conditions at Gouérarate represent the highest metamorphic grade in the central Mauritanides belt. This metamorphism is attested by the occurrence of kyanite black rocks and eclogited pyroxenites. In both regions, the geochemical study of ultramafic formations and associated mafic facies suggests a common origin for these rocks. These formations show a tholeiitic signature with an oceanic character.

Mots clés : Serpentinites, Peridotites, Ophiolite, Suture, Mauritanides belts.

Auteur : Didi OULD MOCTAR

Co-auteur(s) : Didi OULD MOCTAR, Abdellah BOUSHABA, Michel DUBOIS & Mohamed BEN ABBOU

Publié le : 2015-05-17 Volume : 1 N° : 1315

Consultations : 384
Consultations : 277
Déclaration CNIL N°1288782 en date du 17 Avril 2008 ISSN en cours