Constraining a mafic thick crust model in the Andean Precordillera of the Pampean flat slab subduction region

Autores
Perez Lujan, Sofia Beatriz; Ammirati, Jean Baptiste; Alvarado, Patricia Monica; Vujovich, Graciela Irene
Año de publicación
2015
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Elastic properties in twelve representative rock samples from Central and Western Precordillera in the Andean backarc region of Argentina between 30 and 31S were estimated from detailed petrological analysis. Thus, P and S seismic-wave velocities (Vp, Vs) as well as Poisson´s ratio (s) among other parameterswere derived for gabbros, leuco-gabbros and wehrlites, in greenschist and amphibolite metamorphic conditions using a framework of a wide variety of empirical observations from active continental margins. In addition, Vs lithosphere models along two westeeast cross sections were obtainedusing a joint inversion of teleseismic Rayleigh waves and receiver functions. These models clearly delineate the upper-plate crustal structure and the flat-slab subduction of the Nazca plate at about 100 km depth in this region. The suggested seismic velocity structure shows a relatively low (<3.3 km/s) Vslayer located in the first 15e18 km depth, then an increase of it from 3.3 to 4 km/s between 20 and 55 km depth with a mayor change at 40 km depth beneath the Precordillera showing an increase in Vs from 3.3 to 3.8 km/s. The Moho discontinuity was identified at around 65 km depth beneath the Precordillera(Vs ¼ 4.3 km/s) and shows a low shear-wave velocity contrast in comparison with the upper continental mantle´s parameters. Using this seismological model, Vs estimations derived from the petrological analyses for the 12 collected samples can be projected at depths greater than 30 km. These geophysical andpetrological results agree with the hypothesis of a mafic thickened and partially eclogitized lower crust beneath the Precordillera, which has been predicted previously on a base of seismological studies only.Our petrological and seismological results collectively support a thick crustal model of a mafic eultramafic composition extending to middle-to-lower crustal levels beneath Central and Western Precordillera; this region correlates with a suture zone between the eastern Cuyania terrane and the western Chilenia terrane.
Fil: Perez Lujan, Sofia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Juan. Centro de Investigaciones de la Geosfera y Biosfera; Argentina
Fil: Ammirati, Jean Baptiste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Juan. Centro de Investigaciones de la Geosfera y Biosfera; Argentina. Ministerio de Ciencia, Tecnologí­a e Innovación Productiva. Agencia Nacional de Promoción Cientí­fica y Tecnológica. Fondo para la Investigación Cientí­fica y Tecnológica; Argentina
Fil: Alvarado, Patricia Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Juan. Centro de Investigaciones de la Geosfera y Biosfera; Argentina
Fil: Vujovich, Graciela Irene. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geologicas. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina
Materia
Seismic Velocities
Continental Crust
Mafic-Ultramafic Lithology
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
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CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
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oai:ri.conicet.gov.ar:11336/4913
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/4913
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Constraining a mafic thick crust model in the Andean Precordillera of the Pampean flat slab subduction regionPerez Lujan, Sofia BeatrizAmmirati, Jean BaptisteAlvarado, Patricia MonicaVujovich, Graciela IreneSeismic VelocitiesContinental CrustMafic-Ultramafic Lithologyhttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1Elastic properties in twelve representative rock samples from Central and Western Precordillera in the Andean backarc region of Argentina between 30 and 31S were estimated from detailed petrological analysis. Thus, P and S seismic-wave velocities (Vp, Vs) as well as Poisson´s ratio (s) among other parameterswere derived for gabbros, leuco-gabbros and wehrlites, in greenschist and amphibolite metamorphic conditions using a framework of a wide variety of empirical observations from active continental margins. In addition, Vs lithosphere models along two westeeast cross sections were obtainedusing a joint inversion of teleseismic Rayleigh waves and receiver functions. These models clearly delineate the upper-plate crustal structure and the flat-slab subduction of the Nazca plate at about 100 km depth in this region. The suggested seismic velocity structure shows a relatively low (<3.3 km/s) Vslayer located in the first 15e18 km depth, then an increase of it from 3.3 to 4 km/s between 20 and 55 km depth with a mayor change at 40 km depth beneath the Precordillera showing an increase in Vs from 3.3 to 3.8 km/s. The Moho discontinuity was identified at around 65 km depth beneath the Precordillera(Vs ¼ 4.3 km/s) and shows a low shear-wave velocity contrast in comparison with the upper continental mantle´s parameters. Using this seismological model, Vs estimations derived from the petrological analyses for the 12 collected samples can be projected at depths greater than 30 km. These geophysical andpetrological results agree with the hypothesis of a mafic thickened and partially eclogitized lower crust beneath the Precordillera, which has been predicted previously on a base of seismological studies only.Our petrological and seismological results collectively support a thick crustal model of a mafic eultramafic composition extending to middle-to-lower crustal levels beneath Central and Western Precordillera; this region correlates with a suture zone between the eastern Cuyania terrane and the western Chilenia terrane.Fil: Perez Lujan, Sofia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Juan. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Ammirati, Jean Baptiste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Juan. Centro de Investigaciones de la Geosfera y Biosfera; Argentina. Ministerio de Ciencia, Tecnologí­a e Innovación Productiva. Agencia Nacional de Promoción Cientí­fica y Tecnológica. Fondo para la Investigación Cientí­fica y Tecnológica; ArgentinaFil: Alvarado, Patricia Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Juan. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Vujovich, Graciela Irene. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geologicas. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaElsevier2015-09-09info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/4913Perez Lujan, Sofia Beatriz; Ammirati, Jean Baptiste; Alvarado, Patricia Monica; Vujovich, Graciela Irene; Constraining a mafic thick crust model in the Andean Precordillera of the Pampean flat slab subduction region; Elsevier; Journal of South American Earth Sciences; 64; 2; 9-9-2015; 325-3380895-9811enginfo:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0895981115300572info:eu-repo/semantics/altIdentifier/doi/info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2015.09.005info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-nd/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T09:54:03Zoai:ri.conicet.gov.ar:11336/4913instacron: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:34982025-09-03 09:54:03.435CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Constraining a mafic thick crust model in the Andean Precordillera of the Pampean flat slab subduction region
title Constraining a mafic thick crust model in the Andean Precordillera of the Pampean flat slab subduction region
spellingShingle Constraining a mafic thick crust model in the Andean Precordillera of the Pampean flat slab subduction region
Perez Lujan, Sofia Beatriz
Seismic Velocities
Continental Crust
Mafic-Ultramafic Lithology
title_short Constraining a mafic thick crust model in the Andean Precordillera of the Pampean flat slab subduction region
title_full Constraining a mafic thick crust model in the Andean Precordillera of the Pampean flat slab subduction region
title_fullStr Constraining a mafic thick crust model in the Andean Precordillera of the Pampean flat slab subduction region
title_full_unstemmed Constraining a mafic thick crust model in the Andean Precordillera of the Pampean flat slab subduction region
title_sort Constraining a mafic thick crust model in the Andean Precordillera of the Pampean flat slab subduction region
dc.creator.none.fl_str_mv Perez Lujan, Sofia Beatriz
Ammirati, Jean Baptiste
Alvarado, Patricia Monica
Vujovich, Graciela Irene
author Perez Lujan, Sofia Beatriz
author_facet Perez Lujan, Sofia Beatriz
Ammirati, Jean Baptiste
Alvarado, Patricia Monica
Vujovich, Graciela Irene
author_role author
author2 Ammirati, Jean Baptiste
Alvarado, Patricia Monica
Vujovich, Graciela Irene
author2_role author
author
author
dc.subject.none.fl_str_mv Seismic Velocities
Continental Crust
Mafic-Ultramafic Lithology
topic Seismic Velocities
Continental Crust
Mafic-Ultramafic Lithology
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Elastic properties in twelve representative rock samples from Central and Western Precordillera in the Andean backarc region of Argentina between 30 and 31S were estimated from detailed petrological analysis. Thus, P and S seismic-wave velocities (Vp, Vs) as well as Poisson´s ratio (s) among other parameterswere derived for gabbros, leuco-gabbros and wehrlites, in greenschist and amphibolite metamorphic conditions using a framework of a wide variety of empirical observations from active continental margins. In addition, Vs lithosphere models along two westeeast cross sections were obtainedusing a joint inversion of teleseismic Rayleigh waves and receiver functions. These models clearly delineate the upper-plate crustal structure and the flat-slab subduction of the Nazca plate at about 100 km depth in this region. The suggested seismic velocity structure shows a relatively low (<3.3 km/s) Vslayer located in the first 15e18 km depth, then an increase of it from 3.3 to 4 km/s between 20 and 55 km depth with a mayor change at 40 km depth beneath the Precordillera showing an increase in Vs from 3.3 to 3.8 km/s. The Moho discontinuity was identified at around 65 km depth beneath the Precordillera(Vs ¼ 4.3 km/s) and shows a low shear-wave velocity contrast in comparison with the upper continental mantle´s parameters. Using this seismological model, Vs estimations derived from the petrological analyses for the 12 collected samples can be projected at depths greater than 30 km. These geophysical andpetrological results agree with the hypothesis of a mafic thickened and partially eclogitized lower crust beneath the Precordillera, which has been predicted previously on a base of seismological studies only.Our petrological and seismological results collectively support a thick crustal model of a mafic eultramafic composition extending to middle-to-lower crustal levels beneath Central and Western Precordillera; this region correlates with a suture zone between the eastern Cuyania terrane and the western Chilenia terrane.
Fil: Perez Lujan, Sofia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Juan. Centro de Investigaciones de la Geosfera y Biosfera; Argentina
Fil: Ammirati, Jean Baptiste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Juan. Centro de Investigaciones de la Geosfera y Biosfera; Argentina. Ministerio de Ciencia, Tecnologí­a e Innovación Productiva. Agencia Nacional de Promoción Cientí­fica y Tecnológica. Fondo para la Investigación Cientí­fica y Tecnológica; Argentina
Fil: Alvarado, Patricia Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Juan. Centro de Investigaciones de la Geosfera y Biosfera; Argentina
Fil: Vujovich, Graciela Irene. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geologicas. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina
description Elastic properties in twelve representative rock samples from Central and Western Precordillera in the Andean backarc region of Argentina between 30 and 31S were estimated from detailed petrological analysis. Thus, P and S seismic-wave velocities (Vp, Vs) as well as Poisson´s ratio (s) among other parameterswere derived for gabbros, leuco-gabbros and wehrlites, in greenschist and amphibolite metamorphic conditions using a framework of a wide variety of empirical observations from active continental margins. In addition, Vs lithosphere models along two westeeast cross sections were obtainedusing a joint inversion of teleseismic Rayleigh waves and receiver functions. These models clearly delineate the upper-plate crustal structure and the flat-slab subduction of the Nazca plate at about 100 km depth in this region. The suggested seismic velocity structure shows a relatively low (<3.3 km/s) Vslayer located in the first 15e18 km depth, then an increase of it from 3.3 to 4 km/s between 20 and 55 km depth with a mayor change at 40 km depth beneath the Precordillera showing an increase in Vs from 3.3 to 3.8 km/s. The Moho discontinuity was identified at around 65 km depth beneath the Precordillera(Vs ¼ 4.3 km/s) and shows a low shear-wave velocity contrast in comparison with the upper continental mantle´s parameters. Using this seismological model, Vs estimations derived from the petrological analyses for the 12 collected samples can be projected at depths greater than 30 km. These geophysical andpetrological results agree with the hypothesis of a mafic thickened and partially eclogitized lower crust beneath the Precordillera, which has been predicted previously on a base of seismological studies only.Our petrological and seismological results collectively support a thick crustal model of a mafic eultramafic composition extending to middle-to-lower crustal levels beneath Central and Western Precordillera; this region correlates with a suture zone between the eastern Cuyania terrane and the western Chilenia terrane.
publishDate 2015
dc.date.none.fl_str_mv 2015-09-09
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/11336/4913
Perez Lujan, Sofia Beatriz; Ammirati, Jean Baptiste; Alvarado, Patricia Monica; Vujovich, Graciela Irene; Constraining a mafic thick crust model in the Andean Precordillera of the Pampean flat slab subduction region; Elsevier; Journal of South American Earth Sciences; 64; 2; 9-9-2015; 325-338
0895-9811
url http://hdl.handle.net/11336/4913
identifier_str_mv Perez Lujan, Sofia Beatriz; Ammirati, Jean Baptiste; Alvarado, Patricia Monica; Vujovich, Graciela Irene; Constraining a mafic thick crust model in the Andean Precordillera of the Pampean flat slab subduction region; Elsevier; Journal of South American Earth Sciences; 64; 2; 9-9-2015; 325-338
0895-9811
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0895981115300572
info:eu-repo/semantics/altIdentifier/doi/
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2015.09.005
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
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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