Mafic rocks of the Ordovician Famatinian magmatic arc (NW Argentina): New insights into the mantle contribution

Autores
Alasino, Pablo H.; Casquet, César; Pankhurst, Robert J.; Rapela, Carlos Washington; Dahlquist, Juan A.; Galindo, Carmen; Larrovere, Mariano A.; Recio, C.; Paterson, Scott R.; Colombo, Fernando; Baldo, Edgardo G.
Año de publicación
2016
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
We studied the petrogenesis of mafic igneous rocks in the Famatinian arc in the western Sierra Famatina (NW Argentina), an Early Ordovician middle-crustal section in the proto-Andean margin of Gondwana. Mafic rock types consist of amphibolite, metagabbro, and gabbro, as well as pod- and dike-like bodies of gabbro to diorite composition. Field relations together with geochemical and isotopic data for the mafic rocks of the western Sierra de Famatina (at 29°S) define two contrasting suites, which can be correlated with similar assemblages noted in other parts of the orogen. Amphibolite, metagabbro, and gabbro bodies are mostly the oldest intrusive rocks (older than 480 Ma), with the host tonalite and post-tonalite mafic dikes being slightly younger. The older mafic suite is tholeiitic to calc-alkaline and isotopically evolved, except for most of the amphibolite samples. The younger suite is calc-alkaline, typically displaying subduction-related geochemical signatures, and it is isotopically more juvenile. Whole-rock chemical composition and isotopic analyses are compatible with a progressive mixing of different isotopic reservoirs. Pyroxenite (±garnet) was likely the dominant source of the older gabbroic magmas, whereas peridotite dominated in the source of the younger suite, implying that the mafic magma experienced a progressive shift toward more juvenile compositions though time (over 20 m.y.). Pyroxenitederived melts could have been generated by lithospheric foundering followed by upwelling of primitive melts by adiabatic decompression of mantle wedge peridotite.
Centro de Investigaciones Geológicas
Materia
Ciencias Naturales
Geología
petrogenesis
mafic igneous rocks
Famatinian arc
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/140262

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spelling Mafic rocks of the Ordovician Famatinian magmatic arc (NW Argentina): New insights into the mantle contributionAlasino, Pablo H.Casquet, CésarPankhurst, Robert J.Rapela, Carlos WashingtonDahlquist, Juan A.Galindo, CarmenLarrovere, Mariano A.Recio, C.Paterson, Scott R.Colombo, FernandoBaldo, Edgardo G.Ciencias NaturalesGeologíapetrogenesismafic igneous rocksFamatinian arcWe studied the petrogenesis of mafic igneous rocks in the Famatinian arc in the western Sierra Famatina (NW Argentina), an Early Ordovician middle-crustal section in the proto-Andean margin of Gondwana. Mafic rock types consist of amphibolite, metagabbro, and gabbro, as well as pod- and dike-like bodies of gabbro to diorite composition. Field relations together with geochemical and isotopic data for the mafic rocks of the western Sierra de Famatina (at 29°S) define two contrasting suites, which can be correlated with similar assemblages noted in other parts of the orogen. Amphibolite, metagabbro, and gabbro bodies are mostly the oldest intrusive rocks (older than 480 Ma), with the host tonalite and post-tonalite mafic dikes being slightly younger. The older mafic suite is tholeiitic to calc-alkaline and isotopically evolved, except for most of the amphibolite samples. The younger suite is calc-alkaline, typically displaying subduction-related geochemical signatures, and it is isotopically more juvenile. Whole-rock chemical composition and isotopic analyses are compatible with a progressive mixing of different isotopic reservoirs. Pyroxenite (±garnet) was likely the dominant source of the older gabbroic magmas, whereas peridotite dominated in the source of the younger suite, implying that the mafic magma experienced a progressive shift toward more juvenile compositions though time (over 20 m.y.). Pyroxenitederived melts could have been generated by lithospheric foundering followed by upwelling of primitive melts by adiabatic decompression of mantle wedge peridotite.Centro de Investigaciones Geológicas2016-07info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf1105-1120http://sedici.unlp.edu.ar/handle/10915/140262enginfo:eu-repo/semantics/altIdentifier/issn/0016-7606info:eu-repo/semantics/altIdentifier/issn/1943-2674info:eu-repo/semantics/altIdentifier/doi/10.1130/b31417.1info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International (CC BY 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-03T11:04:14Zoai:sedici.unlp.edu.ar:10915/140262Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-03 11:04:14.34SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Mafic rocks of the Ordovician Famatinian magmatic arc (NW Argentina): New insights into the mantle contribution
title Mafic rocks of the Ordovician Famatinian magmatic arc (NW Argentina): New insights into the mantle contribution
spellingShingle Mafic rocks of the Ordovician Famatinian magmatic arc (NW Argentina): New insights into the mantle contribution
Alasino, Pablo H.
Ciencias Naturales
Geología
petrogenesis
mafic igneous rocks
Famatinian arc
title_short Mafic rocks of the Ordovician Famatinian magmatic arc (NW Argentina): New insights into the mantle contribution
title_full Mafic rocks of the Ordovician Famatinian magmatic arc (NW Argentina): New insights into the mantle contribution
title_fullStr Mafic rocks of the Ordovician Famatinian magmatic arc (NW Argentina): New insights into the mantle contribution
title_full_unstemmed Mafic rocks of the Ordovician Famatinian magmatic arc (NW Argentina): New insights into the mantle contribution
title_sort Mafic rocks of the Ordovician Famatinian magmatic arc (NW Argentina): New insights into the mantle contribution
dc.creator.none.fl_str_mv Alasino, Pablo H.
Casquet, César
Pankhurst, Robert J.
Rapela, Carlos Washington
Dahlquist, Juan A.
Galindo, Carmen
Larrovere, Mariano A.
Recio, C.
Paterson, Scott R.
Colombo, Fernando
Baldo, Edgardo G.
author Alasino, Pablo H.
author_facet Alasino, Pablo H.
Casquet, César
Pankhurst, Robert J.
Rapela, Carlos Washington
Dahlquist, Juan A.
Galindo, Carmen
Larrovere, Mariano A.
Recio, C.
Paterson, Scott R.
Colombo, Fernando
Baldo, Edgardo G.
author_role author
author2 Casquet, César
Pankhurst, Robert J.
Rapela, Carlos Washington
Dahlquist, Juan A.
Galindo, Carmen
Larrovere, Mariano A.
Recio, C.
Paterson, Scott R.
Colombo, Fernando
Baldo, Edgardo G.
author2_role author
author
author
author
author
author
author
author
author
author
dc.subject.none.fl_str_mv Ciencias Naturales
Geología
petrogenesis
mafic igneous rocks
Famatinian arc
topic Ciencias Naturales
Geología
petrogenesis
mafic igneous rocks
Famatinian arc
dc.description.none.fl_txt_mv We studied the petrogenesis of mafic igneous rocks in the Famatinian arc in the western Sierra Famatina (NW Argentina), an Early Ordovician middle-crustal section in the proto-Andean margin of Gondwana. Mafic rock types consist of amphibolite, metagabbro, and gabbro, as well as pod- and dike-like bodies of gabbro to diorite composition. Field relations together with geochemical and isotopic data for the mafic rocks of the western Sierra de Famatina (at 29°S) define two contrasting suites, which can be correlated with similar assemblages noted in other parts of the orogen. Amphibolite, metagabbro, and gabbro bodies are mostly the oldest intrusive rocks (older than 480 Ma), with the host tonalite and post-tonalite mafic dikes being slightly younger. The older mafic suite is tholeiitic to calc-alkaline and isotopically evolved, except for most of the amphibolite samples. The younger suite is calc-alkaline, typically displaying subduction-related geochemical signatures, and it is isotopically more juvenile. Whole-rock chemical composition and isotopic analyses are compatible with a progressive mixing of different isotopic reservoirs. Pyroxenite (±garnet) was likely the dominant source of the older gabbroic magmas, whereas peridotite dominated in the source of the younger suite, implying that the mafic magma experienced a progressive shift toward more juvenile compositions though time (over 20 m.y.). Pyroxenitederived melts could have been generated by lithospheric foundering followed by upwelling of primitive melts by adiabatic decompression of mantle wedge peridotite.
Centro de Investigaciones Geológicas
description We studied the petrogenesis of mafic igneous rocks in the Famatinian arc in the western Sierra Famatina (NW Argentina), an Early Ordovician middle-crustal section in the proto-Andean margin of Gondwana. Mafic rock types consist of amphibolite, metagabbro, and gabbro, as well as pod- and dike-like bodies of gabbro to diorite composition. Field relations together with geochemical and isotopic data for the mafic rocks of the western Sierra de Famatina (at 29°S) define two contrasting suites, which can be correlated with similar assemblages noted in other parts of the orogen. Amphibolite, metagabbro, and gabbro bodies are mostly the oldest intrusive rocks (older than 480 Ma), with the host tonalite and post-tonalite mafic dikes being slightly younger. The older mafic suite is tholeiitic to calc-alkaline and isotopically evolved, except for most of the amphibolite samples. The younger suite is calc-alkaline, typically displaying subduction-related geochemical signatures, and it is isotopically more juvenile. Whole-rock chemical composition and isotopic analyses are compatible with a progressive mixing of different isotopic reservoirs. Pyroxenite (±garnet) was likely the dominant source of the older gabbroic magmas, whereas peridotite dominated in the source of the younger suite, implying that the mafic magma experienced a progressive shift toward more juvenile compositions though time (over 20 m.y.). Pyroxenitederived melts could have been generated by lithospheric foundering followed by upwelling of primitive melts by adiabatic decompression of mantle wedge peridotite.
publishDate 2016
dc.date.none.fl_str_mv 2016-07
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
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status_str publishedVersion
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info:eu-repo/semantics/altIdentifier/issn/1943-2674
info:eu-repo/semantics/altIdentifier/doi/10.1130/b31417.1
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
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Creative Commons Attribution 4.0 International (CC BY 4.0)
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repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
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