Reassessment of the volume of the Las Aguilas mafic-ultramafic intrusives, San Luis, Argentina, based on an alternative geophysical model
- Autores
- Zaffarana, Claudia Beatriz; Geuna, Silvana Evangelina; Poma, Stella Maris; Patiño Douce, Alberto
- Año de publicación
- 2011
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- In the Sierra de San Luis, Central Argentina, a belt of small and discontinuous lenses of mafic-ultramafic rocks intrude a polydeformed basement and are thought to be the cause of a local increase of the metamorphic grade from amphibolite to granulite facies conditions. This assumption was especially based on forward modelling of a huge gravity anomaly centered over the Sierra de San Luis, which lead some workers to think that a vast volume of mafic-ultramafic rocks lay in shallow levels. Here, we propose an alternative model to explain this anomaly, in which the mafic-ultramafic intrusion is not the ultimate source. Therefore, there is no need to propose a bigger size than that observed in outcrops for the mafic-ultramafic bodies. The thermal effect of the emplacement of mafic-ultramafic sills and dikes on the host rocks was estimated applying a simple analytical solution (error function) for heating of a semi-infinite half space (the country rocks) in contact with a hotter sheet of finite thickness (the mafic-ultramafic intrusion). Results indicate that the effect of the intrusion of these hot mafic magmas is local, because beyond a few hundred meters from the contact zone temperatures never exceed 600 °C, and a few km from the intrusion they barely increase 50 °C relative to the initial temperature. These results, together with the preservation of primary igneous characteristics (such as rhythmic layering) being overprinted by metamorphic textural changes, indicate that the intrusion occurred before regional deformation. It is suggested that the thermal anomaly in the Pringles Metamorphic Complex could have been mainly caused by factors inherent to their geodynamic setting.
Fil: Zaffarana, Claudia Beatriz. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Geuna, Silvana Evangelina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Poma, Stella Maris. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Patiño Douce, Alberto. University of Georgia; Estados Unidos - Materia
-
Gravimetric Model
Mafic-Ultramafic Rocks
Thermal Effect
Virorco - 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:11336/68810
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Reassessment of the volume of the Las Aguilas mafic-ultramafic intrusives, San Luis, Argentina, based on an alternative geophysical modelZaffarana, Claudia BeatrizGeuna, Silvana EvangelinaPoma, Stella MarisPatiño Douce, AlbertoGravimetric ModelMafic-Ultramafic RocksThermal EffectVirorcohttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1In the Sierra de San Luis, Central Argentina, a belt of small and discontinuous lenses of mafic-ultramafic rocks intrude a polydeformed basement and are thought to be the cause of a local increase of the metamorphic grade from amphibolite to granulite facies conditions. This assumption was especially based on forward modelling of a huge gravity anomaly centered over the Sierra de San Luis, which lead some workers to think that a vast volume of mafic-ultramafic rocks lay in shallow levels. Here, we propose an alternative model to explain this anomaly, in which the mafic-ultramafic intrusion is not the ultimate source. Therefore, there is no need to propose a bigger size than that observed in outcrops for the mafic-ultramafic bodies. The thermal effect of the emplacement of mafic-ultramafic sills and dikes on the host rocks was estimated applying a simple analytical solution (error function) for heating of a semi-infinite half space (the country rocks) in contact with a hotter sheet of finite thickness (the mafic-ultramafic intrusion). Results indicate that the effect of the intrusion of these hot mafic magmas is local, because beyond a few hundred meters from the contact zone temperatures never exceed 600 °C, and a few km from the intrusion they barely increase 50 °C relative to the initial temperature. These results, together with the preservation of primary igneous characteristics (such as rhythmic layering) being overprinted by metamorphic textural changes, indicate that the intrusion occurred before regional deformation. It is suggested that the thermal anomaly in the Pringles Metamorphic Complex could have been mainly caused by factors inherent to their geodynamic setting.Fil: Zaffarana, Claudia Beatriz. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Geuna, Silvana Evangelina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Poma, Stella Maris. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Patiño Douce, Alberto. University of Georgia; Estados UnidosPergamon-Elsevier Science Ltd2011-10info: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/11336/68810Zaffarana, Claudia Beatriz; Geuna, Silvana Evangelina; Poma, Stella Maris; Patiño Douce, Alberto; Reassessment of the volume of the Las Aguilas mafic-ultramafic intrusives, San Luis, Argentina, based on an alternative geophysical model; Pergamon-Elsevier Science Ltd; Journal of South American Earth Sciences; 32; 3; 10-2011; 183-1950895-9811CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S089598111100085Xinfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2011.06.003info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-nd/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T10:09:04Zoai:ri.conicet.gov.ar:11336/68810instacron: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 10:09:05.161CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse |
dc.title.none.fl_str_mv |
Reassessment of the volume of the Las Aguilas mafic-ultramafic intrusives, San Luis, Argentina, based on an alternative geophysical model |
title |
Reassessment of the volume of the Las Aguilas mafic-ultramafic intrusives, San Luis, Argentina, based on an alternative geophysical model |
spellingShingle |
Reassessment of the volume of the Las Aguilas mafic-ultramafic intrusives, San Luis, Argentina, based on an alternative geophysical model Zaffarana, Claudia Beatriz Gravimetric Model Mafic-Ultramafic Rocks Thermal Effect Virorco |
title_short |
Reassessment of the volume of the Las Aguilas mafic-ultramafic intrusives, San Luis, Argentina, based on an alternative geophysical model |
title_full |
Reassessment of the volume of the Las Aguilas mafic-ultramafic intrusives, San Luis, Argentina, based on an alternative geophysical model |
title_fullStr |
Reassessment of the volume of the Las Aguilas mafic-ultramafic intrusives, San Luis, Argentina, based on an alternative geophysical model |
title_full_unstemmed |
Reassessment of the volume of the Las Aguilas mafic-ultramafic intrusives, San Luis, Argentina, based on an alternative geophysical model |
title_sort |
Reassessment of the volume of the Las Aguilas mafic-ultramafic intrusives, San Luis, Argentina, based on an alternative geophysical model |
dc.creator.none.fl_str_mv |
Zaffarana, Claudia Beatriz Geuna, Silvana Evangelina Poma, Stella Maris Patiño Douce, Alberto |
author |
Zaffarana, Claudia Beatriz |
author_facet |
Zaffarana, Claudia Beatriz Geuna, Silvana Evangelina Poma, Stella Maris Patiño Douce, Alberto |
author_role |
author |
author2 |
Geuna, Silvana Evangelina Poma, Stella Maris Patiño Douce, Alberto |
author2_role |
author author author |
dc.subject.none.fl_str_mv |
Gravimetric Model Mafic-Ultramafic Rocks Thermal Effect Virorco |
topic |
Gravimetric Model Mafic-Ultramafic Rocks Thermal Effect Virorco |
purl_subject.fl_str_mv |
https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 |
dc.description.none.fl_txt_mv |
In the Sierra de San Luis, Central Argentina, a belt of small and discontinuous lenses of mafic-ultramafic rocks intrude a polydeformed basement and are thought to be the cause of a local increase of the metamorphic grade from amphibolite to granulite facies conditions. This assumption was especially based on forward modelling of a huge gravity anomaly centered over the Sierra de San Luis, which lead some workers to think that a vast volume of mafic-ultramafic rocks lay in shallow levels. Here, we propose an alternative model to explain this anomaly, in which the mafic-ultramafic intrusion is not the ultimate source. Therefore, there is no need to propose a bigger size than that observed in outcrops for the mafic-ultramafic bodies. The thermal effect of the emplacement of mafic-ultramafic sills and dikes on the host rocks was estimated applying a simple analytical solution (error function) for heating of a semi-infinite half space (the country rocks) in contact with a hotter sheet of finite thickness (the mafic-ultramafic intrusion). Results indicate that the effect of the intrusion of these hot mafic magmas is local, because beyond a few hundred meters from the contact zone temperatures never exceed 600 °C, and a few km from the intrusion they barely increase 50 °C relative to the initial temperature. These results, together with the preservation of primary igneous characteristics (such as rhythmic layering) being overprinted by metamorphic textural changes, indicate that the intrusion occurred before regional deformation. It is suggested that the thermal anomaly in the Pringles Metamorphic Complex could have been mainly caused by factors inherent to their geodynamic setting. Fil: Zaffarana, Claudia Beatriz. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Geuna, Silvana Evangelina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Poma, Stella Maris. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Patiño Douce, Alberto. University of Georgia; Estados Unidos |
description |
In the Sierra de San Luis, Central Argentina, a belt of small and discontinuous lenses of mafic-ultramafic rocks intrude a polydeformed basement and are thought to be the cause of a local increase of the metamorphic grade from amphibolite to granulite facies conditions. This assumption was especially based on forward modelling of a huge gravity anomaly centered over the Sierra de San Luis, which lead some workers to think that a vast volume of mafic-ultramafic rocks lay in shallow levels. Here, we propose an alternative model to explain this anomaly, in which the mafic-ultramafic intrusion is not the ultimate source. Therefore, there is no need to propose a bigger size than that observed in outcrops for the mafic-ultramafic bodies. The thermal effect of the emplacement of mafic-ultramafic sills and dikes on the host rocks was estimated applying a simple analytical solution (error function) for heating of a semi-infinite half space (the country rocks) in contact with a hotter sheet of finite thickness (the mafic-ultramafic intrusion). Results indicate that the effect of the intrusion of these hot mafic magmas is local, because beyond a few hundred meters from the contact zone temperatures never exceed 600 °C, and a few km from the intrusion they barely increase 50 °C relative to the initial temperature. These results, together with the preservation of primary igneous characteristics (such as rhythmic layering) being overprinted by metamorphic textural changes, indicate that the intrusion occurred before regional deformation. It is suggested that the thermal anomaly in the Pringles Metamorphic Complex could have been mainly caused by factors inherent to their geodynamic setting. |
publishDate |
2011 |
dc.date.none.fl_str_mv |
2011-10 |
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/11336/68810 Zaffarana, Claudia Beatriz; Geuna, Silvana Evangelina; Poma, Stella Maris; Patiño Douce, Alberto; Reassessment of the volume of the Las Aguilas mafic-ultramafic intrusives, San Luis, Argentina, based on an alternative geophysical model; Pergamon-Elsevier Science Ltd; Journal of South American Earth Sciences; 32; 3; 10-2011; 183-195 0895-9811 CONICET Digital CONICET |
url |
http://hdl.handle.net/11336/68810 |
identifier_str_mv |
Zaffarana, Claudia Beatriz; Geuna, Silvana Evangelina; Poma, Stella Maris; Patiño Douce, Alberto; Reassessment of the volume of the Las Aguilas mafic-ultramafic intrusives, San Luis, Argentina, based on an alternative geophysical model; Pergamon-Elsevier Science Ltd; Journal of South American Earth Sciences; 32; 3; 10-2011; 183-195 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/http://www.sciencedirect.com/science/article/pii/S089598111100085X info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2011.06.003 |
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 |
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 |
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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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1842270068187070464 |
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13.13397 |