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dc.contributor.author
Rivalenti, Giorgio
dc.contributor.author
Mazzucchelli, Maurizio
dc.contributor.author
Zanetti, Alberto
dc.contributor.author
Vannucci, Riccardo
dc.contributor.author
Bollinger, Claire
dc.contributor.author
Hémond, Christophe
dc.contributor.author
Bertotto, Gustavo Walter
dc.date.available
2019-08-16T18:28:25Z
dc.date.issued
2007-11
dc.identifier.citation
Rivalenti, Giorgio; Mazzucchelli, Maurizio; Zanetti, Alberto; Vannucci, Riccardo; Bollinger, Claire; et al.; Xenoliths from Cerro de los Chenques (Patagonia): An example of slab-related metasomatism in the backarc lithospheric mantle; Elsevier Science; Lithos; 99; 1-2; 11-2007; 45-67
dc.identifier.issn
0024-4937
dc.identifier.uri
http://hdl.handle.net/11336/81741
dc.description.abstract
The alkali basalts of the Cerro de los Chenques quaternary backarc volcano (200 km E of the volcanic arc) carry to the surface abundant spinel-facies mantle xenoliths (lherzolites, harzburgites and dunites). The clinopyroxene geochemistry indicates that the pristine mantle was a lherzolite with Depleted Mantle (DM) composition, recording either melting episodes triggered by infiltration of a metasomatic agent or only enrichment of highly incompatible elements in those sectors where percolation occurred under decreasing fluid volume. Metasomatism was operated by a fluid originated in garnet-bearing assemblages that induced olivine and clinopyroxene dissolution, variations in the Sr and Nd isotopic signatures (i.e. pre-metasomatic mantle: 87Sr/86Sr = 0.702712 and 143Nd/144Nd = 0.513495; xenoliths recording the highest metasomatism: 87Sr/86Sr = 0.704234 and143Nd/144Nd = 0.512870), and increase in LILE and LREE, but not in Nb and Ti. The resulting geochemical characteristics are similar to those observed in arc magmas and are consistent with the signatures of sediments and basalts forming the upper part of the subducted Nazca plate. Evidence for element fractionation operated by infiltration of the host alkali basalts and related reactive porous-flow processes are lacking or weak. The granoblastic texture of the xenoliths, bearing no evidence of deformation, rules out the hypothesis that the Chenques mantle formed in the subarc and was transported 200 km to the east by reverse corner flow. Alternatively, it is suggested that the slab components were released as supercritical fluids beneath Chenques (at ∼ 6 GPa) by phengite breakdown. Fluids flowed through, and reacted with, the hidden garnet-facies mantle and reached the observed spinel-facies level. Reactions in the hidden mantle region led the supercritical fluid to increase (La/Sm)N, Th, U, Nb, Pb and Sr while decreasing its initial (Sm/Yb)N and Ti.
dc.format
application/pdf
dc.language.iso
eng
dc.publisher
Elsevier Science
dc.rights
info:eu-repo/semantics/openAccess
dc.rights.uri
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.subject
Backarc Mantle Lithosphere
dc.subject
Nazca Plate
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Patagonia
dc.subject
Subducted Slab Fluids
dc.subject.classification
Geología
dc.subject.classification
Ciencias de la Tierra y relacionadas con el Medio Ambiente
dc.subject.classification
CIENCIAS NATURALES Y EXACTAS
dc.title
Xenoliths from Cerro de los Chenques (Patagonia): An example of slab-related metasomatism in the backarc lithospheric mantle
dc.type
info:eu-repo/semantics/article
dc.type
info:ar-repo/semantics/artículo
dc.type
info:eu-repo/semantics/publishedVersion
dc.date.updated
2019-08-15T16:04:44Z
dc.journal.volume
99
dc.journal.number
1-2
dc.journal.pagination
45-67
dc.journal.pais
Países Bajos
dc.journal.ciudad
Amsterdam
dc.description.fil
Fil: Rivalenti, Giorgio. Università di Modena e Reggio Emilia; Italia
dc.description.fil
Fil: Mazzucchelli, Maurizio. Università di Modena e Reggio Emilia; Italia
dc.description.fil
Fil: Zanetti, Alberto. Istituto di Geoscienze e Georisorse; Italia
dc.description.fil
Fil: Vannucci, Riccardo. Istituto di Geoscienze e Georisorse; Italia. Università di Pavia; Italia
dc.description.fil
Fil: Bollinger, Claire. Centre National de la Recherche Scientifique; Francia
dc.description.fil
Fil: Hémond, Christophe. Centre National de la Recherche Scientifique; Francia
dc.description.fil
Fil: Bertotto, Gustavo Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina
dc.journal.title
Lithos
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0024493707001065
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/doi/https://doi.org/10.1016/j.lithos.2007.05.012
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