Caracterización de las rocas ultramáficas, máficas y metasedimentarias del Cordón del Peñasco, Precordillera Occidental, Mendoza.

BOEDO, F.L., VUJOVICH, G.I., BARREDO S.P.

Revista de la Asociación Geológica Argentina

Asociación Geológica Argentina

Lugar: Buenos Aires; Año: 2012 vol. 69 p. 275 - 285

0004-4822

Characterization of ultramafic, mafic and metasedimentary rocks of the Cordón del Peñasco, western Precordillera, Mendoza.In Cordón del Peñasco area, located in northern Mendoza province, western Precordillera, metasedimentites are in tectoniccontact with a mafic-ultramafic association. The former have been under greenschist facies metamorphism and two associationshave been recognized: carbonate metasiltstones and metasandstones and metapelites. The mafic-ultramafic associationis represented by serpentinized peridotites derived from dunites and harzburgites, layered gabbros in granulite facies; diabasedikes or sills, amigdaloid metabasalts and metahialoclastic rocks with low grade metamorphism. In this contribution, wehave estimated metamorphic temperatures on a mafic granulite (layered gabbro) based on garnet-clinopyroxene, obtaining atemperature of 884ºC. This suggests that these bodies have been under high temperature metamorphism and were later retrogressedto greenschist facies, evidenced by mineralogical and textural aspects. Regarding the metasedimentary units, thepaleoenvironment of the metasandstones and metapelites association corresponds to a continental slope with turbiditic sedimentation,as suggested by sedimentary structures. The carbonate metasiltstone unit belongs to a deep marine environment.These units have been assigned to Eopaleozoic times based on stratigraphic criteria and deformed and metamorphosed in lateDevonian as a consequence of Chanica orogeny.