Metamorphic and tectonic evolution at 31°36′S across a deep crustal zone from the Sierra Chica of Córdoba, Sierras Pampeanas, Argentina

Autores
Martino, Roberto Donato; Guereschi, Alina Beatriz; Anzil, Patricia Andrea
Año de publicación
2010
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
A geological section at 31°36′S cut the main structures of a representative area of the deep crust in the Sierra Chica (Sierras Pampeanas of Córdoba, Argentina), where associations of high-grade gneisses, migmatites, marbles, amphibolites and ultramafic rocks are recognized. A group of ultramafic bodies composed of serpentinized spinel harzburgites are associated with a basement affected by a M2-D2 regional metamorphism that developed the main S2 metamorphic foliation. Applying different thermobarometers to the varieties of garnet sillimanite gneisses and leucocratic garnet gneisses, a range of P-T conditions of 768-840 °C and 7.3-8.6 kb were obtained for M2. A strong D3 ductile deformation structured the ultramafic bodies, more viscous than the associated metamorphic rocks, generating large west-vergent sheath folds with tubular geometry. This constrictional deformation was developed in a simple shear regime, under high-temperature conditions, with a tectonic transport direction toward the northwest (~N 300°). Later, decompression and cooling down to amphibolite facies conditions occurred in all the rocks of the area during a retrograde M3 event. A range of P-T conditions of 588-710 °C and 5.2-7.3 kb were calculated for M3 in the gneisses of the area. The Sierra Chica ultramafic rocks outcrop as folded bodies, isolated between them and locally parallel to the S2 metamorphic foliation, therefore they cannot be correlated as a regional belt that could be interpreted as an ancient suture. Our hypothesis is that the ultramafic bodies are upper mantle relics of earlier emplacements into an accretionary prism that was entirely reworked during the Pampean orogeny. This same outcrop-pattern can also be recognized in the other ultramafic bodies in the Sierras de Córdoba. Hence, we suggest to avoid the use of the terms Eastern and Western Belts for the treatment of the ultramafic rocks in the Sierras de Córdoba. © 2010 Elsevier Ltd.
Fil: Martino, Roberto Donato. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
Fil: Guereschi, Alina Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
Fil: Anzil, Patricia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
Materia
High-Grade Gneisses
Metamorphism
Sierras Pampeanas
Structure
Tectonic Evolution
Ultramafic Rocks
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
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CONICET Digital (CONICET)
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Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/54547
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/54547
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repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Metamorphic and tectonic evolution at 31°36′S across a deep crustal zone from the Sierra Chica of Córdoba, Sierras Pampeanas, ArgentinaMartino, Roberto DonatoGuereschi, Alina BeatrizAnzil, Patricia AndreaHigh-Grade GneissesMetamorphismSierras PampeanasStructureTectonic EvolutionUltramafic Rockshttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1A geological section at 31°36′S cut the main structures of a representative area of the deep crust in the Sierra Chica (Sierras Pampeanas of Córdoba, Argentina), where associations of high-grade gneisses, migmatites, marbles, amphibolites and ultramafic rocks are recognized. A group of ultramafic bodies composed of serpentinized spinel harzburgites are associated with a basement affected by a M2-D2 regional metamorphism that developed the main S2 metamorphic foliation. Applying different thermobarometers to the varieties of garnet sillimanite gneisses and leucocratic garnet gneisses, a range of P-T conditions of 768-840 °C and 7.3-8.6 kb were obtained for M2. A strong D3 ductile deformation structured the ultramafic bodies, more viscous than the associated metamorphic rocks, generating large west-vergent sheath folds with tubular geometry. This constrictional deformation was developed in a simple shear regime, under high-temperature conditions, with a tectonic transport direction toward the northwest (~N 300°). Later, decompression and cooling down to amphibolite facies conditions occurred in all the rocks of the area during a retrograde M3 event. A range of P-T conditions of 588-710 °C and 5.2-7.3 kb were calculated for M3 in the gneisses of the area. The Sierra Chica ultramafic rocks outcrop as folded bodies, isolated between them and locally parallel to the S2 metamorphic foliation, therefore they cannot be correlated as a regional belt that could be interpreted as an ancient suture. Our hypothesis is that the ultramafic bodies are upper mantle relics of earlier emplacements into an accretionary prism that was entirely reworked during the Pampean orogeny. This same outcrop-pattern can also be recognized in the other ultramafic bodies in the Sierras de Córdoba. Hence, we suggest to avoid the use of the terms Eastern and Western Belts for the treatment of the ultramafic rocks in the Sierras de Córdoba. © 2010 Elsevier Ltd.Fil: Martino, Roberto Donato. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Guereschi, Alina Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Anzil, Patricia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaPergamon-Elsevier Science Ltd2010-11info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/54547Martino, Roberto Donato; Guereschi, Alina Beatriz; Anzil, Patricia Andrea; Metamorphic and tectonic evolution at 31°36′S across a deep crustal zone from the Sierra Chica of Córdoba, Sierras Pampeanas, Argentina; Pergamon-Elsevier Science Ltd; Journal of South American Earth Sciences; 30; 1; 11-2010; 12-280895-9811CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0895981110000428info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2010.07.008info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-11-26T08:50:55Zoai:ri.conicet.gov.ar:11336/54547instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-11-26 08:50:55.961CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Metamorphic and tectonic evolution at 31°36′S across a deep crustal zone from the Sierra Chica of Córdoba, Sierras Pampeanas, Argentina
title Metamorphic and tectonic evolution at 31°36′S across a deep crustal zone from the Sierra Chica of Córdoba, Sierras Pampeanas, Argentina
spellingShingle Metamorphic and tectonic evolution at 31°36′S across a deep crustal zone from the Sierra Chica of Córdoba, Sierras Pampeanas, Argentina
Martino, Roberto Donato
High-Grade Gneisses
Metamorphism
Sierras Pampeanas
Structure
Tectonic Evolution
Ultramafic Rocks
title_short Metamorphic and tectonic evolution at 31°36′S across a deep crustal zone from the Sierra Chica of Córdoba, Sierras Pampeanas, Argentina
title_full Metamorphic and tectonic evolution at 31°36′S across a deep crustal zone from the Sierra Chica of Córdoba, Sierras Pampeanas, Argentina
title_fullStr Metamorphic and tectonic evolution at 31°36′S across a deep crustal zone from the Sierra Chica of Córdoba, Sierras Pampeanas, Argentina
title_full_unstemmed Metamorphic and tectonic evolution at 31°36′S across a deep crustal zone from the Sierra Chica of Córdoba, Sierras Pampeanas, Argentina
title_sort Metamorphic and tectonic evolution at 31°36′S across a deep crustal zone from the Sierra Chica of Córdoba, Sierras Pampeanas, Argentina
dc.creator.none.fl_str_mv Martino, Roberto Donato
Guereschi, Alina Beatriz
Anzil, Patricia Andrea
author Martino, Roberto Donato
author_facet Martino, Roberto Donato
Guereschi, Alina Beatriz
Anzil, Patricia Andrea
author_role author
author2 Guereschi, Alina Beatriz
Anzil, Patricia Andrea
author2_role author
author
dc.subject.none.fl_str_mv High-Grade Gneisses
Metamorphism
Sierras Pampeanas
Structure
Tectonic Evolution
Ultramafic Rocks
topic High-Grade Gneisses
Metamorphism
Sierras Pampeanas
Structure
Tectonic Evolution
Ultramafic Rocks
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv A geological section at 31°36′S cut the main structures of a representative area of the deep crust in the Sierra Chica (Sierras Pampeanas of Córdoba, Argentina), where associations of high-grade gneisses, migmatites, marbles, amphibolites and ultramafic rocks are recognized. A group of ultramafic bodies composed of serpentinized spinel harzburgites are associated with a basement affected by a M2-D2 regional metamorphism that developed the main S2 metamorphic foliation. Applying different thermobarometers to the varieties of garnet sillimanite gneisses and leucocratic garnet gneisses, a range of P-T conditions of 768-840 °C and 7.3-8.6 kb were obtained for M2. A strong D3 ductile deformation structured the ultramafic bodies, more viscous than the associated metamorphic rocks, generating large west-vergent sheath folds with tubular geometry. This constrictional deformation was developed in a simple shear regime, under high-temperature conditions, with a tectonic transport direction toward the northwest (~N 300°). Later, decompression and cooling down to amphibolite facies conditions occurred in all the rocks of the area during a retrograde M3 event. A range of P-T conditions of 588-710 °C and 5.2-7.3 kb were calculated for M3 in the gneisses of the area. The Sierra Chica ultramafic rocks outcrop as folded bodies, isolated between them and locally parallel to the S2 metamorphic foliation, therefore they cannot be correlated as a regional belt that could be interpreted as an ancient suture. Our hypothesis is that the ultramafic bodies are upper mantle relics of earlier emplacements into an accretionary prism that was entirely reworked during the Pampean orogeny. This same outcrop-pattern can also be recognized in the other ultramafic bodies in the Sierras de Córdoba. Hence, we suggest to avoid the use of the terms Eastern and Western Belts for the treatment of the ultramafic rocks in the Sierras de Córdoba. © 2010 Elsevier Ltd.
Fil: Martino, Roberto Donato. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
Fil: Guereschi, Alina Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
Fil: Anzil, Patricia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
description A geological section at 31°36′S cut the main structures of a representative area of the deep crust in the Sierra Chica (Sierras Pampeanas of Córdoba, Argentina), where associations of high-grade gneisses, migmatites, marbles, amphibolites and ultramafic rocks are recognized. A group of ultramafic bodies composed of serpentinized spinel harzburgites are associated with a basement affected by a M2-D2 regional metamorphism that developed the main S2 metamorphic foliation. Applying different thermobarometers to the varieties of garnet sillimanite gneisses and leucocratic garnet gneisses, a range of P-T conditions of 768-840 °C and 7.3-8.6 kb were obtained for M2. A strong D3 ductile deformation structured the ultramafic bodies, more viscous than the associated metamorphic rocks, generating large west-vergent sheath folds with tubular geometry. This constrictional deformation was developed in a simple shear regime, under high-temperature conditions, with a tectonic transport direction toward the northwest (~N 300°). Later, decompression and cooling down to amphibolite facies conditions occurred in all the rocks of the area during a retrograde M3 event. A range of P-T conditions of 588-710 °C and 5.2-7.3 kb were calculated for M3 in the gneisses of the area. The Sierra Chica ultramafic rocks outcrop as folded bodies, isolated between them and locally parallel to the S2 metamorphic foliation, therefore they cannot be correlated as a regional belt that could be interpreted as an ancient suture. Our hypothesis is that the ultramafic bodies are upper mantle relics of earlier emplacements into an accretionary prism that was entirely reworked during the Pampean orogeny. This same outcrop-pattern can also be recognized in the other ultramafic bodies in the Sierras de Córdoba. Hence, we suggest to avoid the use of the terms Eastern and Western Belts for the treatment of the ultramafic rocks in the Sierras de Córdoba. © 2010 Elsevier Ltd.
publishDate 2010
dc.date.none.fl_str_mv 2010-11
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/54547
Martino, Roberto Donato; Guereschi, Alina Beatriz; Anzil, Patricia Andrea; Metamorphic and tectonic evolution at 31°36′S across a deep crustal zone from the Sierra Chica of Córdoba, Sierras Pampeanas, Argentina; Pergamon-Elsevier Science Ltd; Journal of South American Earth Sciences; 30; 1; 11-2010; 12-28
0895-9811
CONICET Digital
CONICET
url http://hdl.handle.net/11336/54547
identifier_str_mv Martino, Roberto Donato; Guereschi, Alina Beatriz; Anzil, Patricia Andrea; Metamorphic and tectonic evolution at 31°36′S across a deep crustal zone from the Sierra Chica of Córdoba, Sierras Pampeanas, Argentina; Pergamon-Elsevier Science Ltd; Journal of South American Earth Sciences; 30; 1; 11-2010; 12-28
0895-9811
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0895981110000428
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2010.07.008
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Pergamon-Elsevier Science Ltd
publisher.none.fl_str_mv Pergamon-Elsevier Science Ltd
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
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instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.011256

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