Crustal deformation of the Andean foreland at 31° 30′S (Argentina) constrained by magnetotelluric survey
- Autores
- Orozco, Luz Amparo; Favetto, Alicia Beatriz; Pomposiello, Maria Cristina; Rossello, Eduardo Antonio; Booker, John
- Año de publicación
- 2013
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- Twenty-five new long-period magnetotelluric sites near 31.5°S were collected in a west–east profile. This profile and the previous one, aligned with and adjacent to the eastern end, have been merged to form a single profile of more than 700 km long, extending from the Precordillera to the Chaco-Pampean Plain. The geotectonic scenario is characterized by a modern flat subduction zone of the Nazca plate located at a depth of around 120 km and clearly defined by the distribution of earthquake hypocenters recorded by local and regional networks. A “bulge” shape at 68.5°W, with an anomalous dip to the west, is observed within this segment. The smooth slab deformation might result from the restriction on eastward motion due to the presence of an electrically resistive zone. The magnetotelluric model shows that this thick zone of increased resistivity is found from shallow crustal levels to upper mantle depths. The bulge geometry allows hot fluids and volatiles to rise from the deeper asthenospheric wedge, and reach the lower crust reducing its viscosity and letting it flow. The zones of low resistivity in the lower crust show spatial correlation with the areas of foreland deformation from Precordillera to the Sierras Pampeanas and may also suggest a ductile regime. Shear zones reactivated by Cenozoic faulting must necessarily have their roots in the levels of the ductile lower crust associated to conductive channels. The zone where the lower crust is closer to the surface coincides with the areas of greatest structural relief and erosion. The interface between the folded ductile lower crust and the brittle upper crust might act as the main level of décollement of the bordering structures between the Precordillera, Sierra de Pie de Palo and the Sierras Pampeanas. In addition, the geometry of the interface might be conditioning the vergence of those structures.
Fil: Orozco, Luz Amparo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotopica; Argentina
Fil: Favetto, Alicia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotopica; Argentina
Fil: Pomposiello, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotopica; Argentina
Fil: Rossello, Eduardo Antonio. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Booker, John. University of Washington; Estados Unidos - Materia
-
Magnetotellurics
Flat Slab
Sierras Pampeanas
Terranes - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
- Repositorio
- Institución
- Consejo Nacional de Investigaciones Científicas y Técnicas
- OAI Identificador
- oai:ri.conicet.gov.ar:11336/15869
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Crustal deformation of the Andean foreland at 31° 30′S (Argentina) constrained by magnetotelluric surveyOrozco, Luz AmparoFavetto, Alicia BeatrizPomposiello, Maria CristinaRossello, Eduardo AntonioBooker, JohnMagnetotelluricsFlat SlabSierras PampeanasTerraneshttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1Twenty-five new long-period magnetotelluric sites near 31.5°S were collected in a west–east profile. This profile and the previous one, aligned with and adjacent to the eastern end, have been merged to form a single profile of more than 700 km long, extending from the Precordillera to the Chaco-Pampean Plain. The geotectonic scenario is characterized by a modern flat subduction zone of the Nazca plate located at a depth of around 120 km and clearly defined by the distribution of earthquake hypocenters recorded by local and regional networks. A “bulge” shape at 68.5°W, with an anomalous dip to the west, is observed within this segment. The smooth slab deformation might result from the restriction on eastward motion due to the presence of an electrically resistive zone. The magnetotelluric model shows that this thick zone of increased resistivity is found from shallow crustal levels to upper mantle depths. The bulge geometry allows hot fluids and volatiles to rise from the deeper asthenospheric wedge, and reach the lower crust reducing its viscosity and letting it flow. The zones of low resistivity in the lower crust show spatial correlation with the areas of foreland deformation from Precordillera to the Sierras Pampeanas and may also suggest a ductile regime. Shear zones reactivated by Cenozoic faulting must necessarily have their roots in the levels of the ductile lower crust associated to conductive channels. The zone where the lower crust is closer to the surface coincides with the areas of greatest structural relief and erosion. The interface between the folded ductile lower crust and the brittle upper crust might act as the main level of décollement of the bordering structures between the Precordillera, Sierra de Pie de Palo and the Sierras Pampeanas. In addition, the geometry of the interface might be conditioning the vergence of those structures.Fil: Orozco, Luz Amparo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotopica; ArgentinaFil: Favetto, Alicia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotopica; ArgentinaFil: Pomposiello, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotopica; ArgentinaFil: Rossello, Eduardo Antonio. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Booker, John. University of Washington; Estados UnidosElsevier Science2013-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/15869Orozco, Luz Amparo; Favetto, Alicia Beatriz; Pomposiello, Maria Cristina; Rossello, Eduardo Antonio; Booker, John; Crustal deformation of the Andean foreland at 31° 30′S (Argentina) constrained by magnetotelluric survey; Elsevier Science; Tectonophysics; 582; 1-2013; 126-1390040-1951enginfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.tecto.2012.09.030info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0040195112006312info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-nd/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T09:37:27Zoai:ri.conicet.gov.ar:11336/15869instacron: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:34982025-09-29 09:37:27.224CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse |
dc.title.none.fl_str_mv |
Crustal deformation of the Andean foreland at 31° 30′S (Argentina) constrained by magnetotelluric survey |
title |
Crustal deformation of the Andean foreland at 31° 30′S (Argentina) constrained by magnetotelluric survey |
spellingShingle |
Crustal deformation of the Andean foreland at 31° 30′S (Argentina) constrained by magnetotelluric survey Orozco, Luz Amparo Magnetotellurics Flat Slab Sierras Pampeanas Terranes |
title_short |
Crustal deformation of the Andean foreland at 31° 30′S (Argentina) constrained by magnetotelluric survey |
title_full |
Crustal deformation of the Andean foreland at 31° 30′S (Argentina) constrained by magnetotelluric survey |
title_fullStr |
Crustal deformation of the Andean foreland at 31° 30′S (Argentina) constrained by magnetotelluric survey |
title_full_unstemmed |
Crustal deformation of the Andean foreland at 31° 30′S (Argentina) constrained by magnetotelluric survey |
title_sort |
Crustal deformation of the Andean foreland at 31° 30′S (Argentina) constrained by magnetotelluric survey |
dc.creator.none.fl_str_mv |
Orozco, Luz Amparo Favetto, Alicia Beatriz Pomposiello, Maria Cristina Rossello, Eduardo Antonio Booker, John |
author |
Orozco, Luz Amparo |
author_facet |
Orozco, Luz Amparo Favetto, Alicia Beatriz Pomposiello, Maria Cristina Rossello, Eduardo Antonio Booker, John |
author_role |
author |
author2 |
Favetto, Alicia Beatriz Pomposiello, Maria Cristina Rossello, Eduardo Antonio Booker, John |
author2_role |
author author author author |
dc.subject.none.fl_str_mv |
Magnetotellurics Flat Slab Sierras Pampeanas Terranes |
topic |
Magnetotellurics Flat Slab Sierras Pampeanas Terranes |
purl_subject.fl_str_mv |
https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 |
dc.description.none.fl_txt_mv |
Twenty-five new long-period magnetotelluric sites near 31.5°S were collected in a west–east profile. This profile and the previous one, aligned with and adjacent to the eastern end, have been merged to form a single profile of more than 700 km long, extending from the Precordillera to the Chaco-Pampean Plain. The geotectonic scenario is characterized by a modern flat subduction zone of the Nazca plate located at a depth of around 120 km and clearly defined by the distribution of earthquake hypocenters recorded by local and regional networks. A “bulge” shape at 68.5°W, with an anomalous dip to the west, is observed within this segment. The smooth slab deformation might result from the restriction on eastward motion due to the presence of an electrically resistive zone. The magnetotelluric model shows that this thick zone of increased resistivity is found from shallow crustal levels to upper mantle depths. The bulge geometry allows hot fluids and volatiles to rise from the deeper asthenospheric wedge, and reach the lower crust reducing its viscosity and letting it flow. The zones of low resistivity in the lower crust show spatial correlation with the areas of foreland deformation from Precordillera to the Sierras Pampeanas and may also suggest a ductile regime. Shear zones reactivated by Cenozoic faulting must necessarily have their roots in the levels of the ductile lower crust associated to conductive channels. The zone where the lower crust is closer to the surface coincides with the areas of greatest structural relief and erosion. The interface between the folded ductile lower crust and the brittle upper crust might act as the main level of décollement of the bordering structures between the Precordillera, Sierra de Pie de Palo and the Sierras Pampeanas. In addition, the geometry of the interface might be conditioning the vergence of those structures. Fil: Orozco, Luz Amparo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotopica; Argentina Fil: Favetto, Alicia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotopica; Argentina Fil: Pomposiello, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotopica; Argentina Fil: Rossello, Eduardo Antonio. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Booker, John. University of Washington; Estados Unidos |
description |
Twenty-five new long-period magnetotelluric sites near 31.5°S were collected in a west–east profile. This profile and the previous one, aligned with and adjacent to the eastern end, have been merged to form a single profile of more than 700 km long, extending from the Precordillera to the Chaco-Pampean Plain. The geotectonic scenario is characterized by a modern flat subduction zone of the Nazca plate located at a depth of around 120 km and clearly defined by the distribution of earthquake hypocenters recorded by local and regional networks. A “bulge” shape at 68.5°W, with an anomalous dip to the west, is observed within this segment. The smooth slab deformation might result from the restriction on eastward motion due to the presence of an electrically resistive zone. The magnetotelluric model shows that this thick zone of increased resistivity is found from shallow crustal levels to upper mantle depths. The bulge geometry allows hot fluids and volatiles to rise from the deeper asthenospheric wedge, and reach the lower crust reducing its viscosity and letting it flow. The zones of low resistivity in the lower crust show spatial correlation with the areas of foreland deformation from Precordillera to the Sierras Pampeanas and may also suggest a ductile regime. Shear zones reactivated by Cenozoic faulting must necessarily have their roots in the levels of the ductile lower crust associated to conductive channels. The zone where the lower crust is closer to the surface coincides with the areas of greatest structural relief and erosion. The interface between the folded ductile lower crust and the brittle upper crust might act as the main level of décollement of the bordering structures between the Precordillera, Sierra de Pie de Palo and the Sierras Pampeanas. In addition, the geometry of the interface might be conditioning the vergence of those structures. |
publishDate |
2013 |
dc.date.none.fl_str_mv |
2013-01 |
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/11336/15869 Orozco, Luz Amparo; Favetto, Alicia Beatriz; Pomposiello, Maria Cristina; Rossello, Eduardo Antonio; Booker, John; Crustal deformation of the Andean foreland at 31° 30′S (Argentina) constrained by magnetotelluric survey; Elsevier Science; Tectonophysics; 582; 1-2013; 126-139 0040-1951 |
url |
http://hdl.handle.net/11336/15869 |
identifier_str_mv |
Orozco, Luz Amparo; Favetto, Alicia Beatriz; Pomposiello, Maria Cristina; Rossello, Eduardo Antonio; Booker, John; Crustal deformation of the Andean foreland at 31° 30′S (Argentina) constrained by magnetotelluric survey; Elsevier Science; Tectonophysics; 582; 1-2013; 126-139 0040-1951 |
dc.language.none.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.tecto.2012.09.030 info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0040195112006312 |
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 application/pdf application/pdf |
dc.publisher.none.fl_str_mv |
Elsevier Science |
publisher.none.fl_str_mv |
Elsevier Science |
dc.source.none.fl_str_mv |
reponame:CONICET Digital (CONICET) instname:Consejo Nacional de Investigaciones Científicas y Técnicas |
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CONICET Digital (CONICET) |
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CONICET Digital (CONICET) |
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Consejo Nacional de Investigaciones Científicas y Técnicas |
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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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