Characterization of Quaternary faults by electric resistivity tomography in the Andean Precordillera of Western Argentina

Structural and geomorphic surface observations are frequently insufficient for a proper geometric and kinematic characterization of Quaternary faults. In order to improve the geological knowledge of three Quaternary faults in the Precordillera of western Argentina (30°46′ S-32°24′ S, 69°07′ W-69°15′...

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Publicado: 2009
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v28_n3_p217_Fazzito
http://hdl.handle.net/20.500.12110/paper_08959811_v28_n3_p217_Fazzito
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spelling paper:paper_08959811_v28_n3_p217_Fazzito2023-06-08T15:48:26Z Characterization of Quaternary faults by electric resistivity tomography in the Andean Precordillera of Western Argentina Andes Argentina Electrical Resistivity Tomography Geoelectrical method Neotectonics Precordillera Quaternary faults electrical method electrical resistivity extensional tectonics fault plane geoelectric field neotectonics Quaternary strike-slip fault tomography Argentina South America Structural and geomorphic surface observations are frequently insufficient for a proper geometric and kinematic characterization of Quaternary faults. In order to improve the geological knowledge of three Quaternary faults in the Precordillera of western Argentina (30°46′ S-32°24′ S, 69°07′ W-69°15′ W), a shallow 2D Electrical Resistivity Tomography (ERT) survey was performed along seven short cross-sections, perpendicular to the fault traces. The survey was carried out across the San Bartolo fault, the Los Avestruces high and the El Tigre fault in the Precordillera of western Argentina in the San Juan and Mendoza provinces. During the survey, different electrical arrangements were assessed, including different arrays (dipole-dipole and Wenner-Schlumberger), diverse electrode separations and different depth of investigation. Tomographic models showed low resistivity zones lying below the fault scarps, as well as significant resistivity contrasts across the inferred fault-zones in the subsurface. This information permitted better characterization of the geometry and kinematics of these fault zones. ERT results showed that the San Bartolo fault is extensional. In the Los Avestruces high a positive inversion of an extensional fault was recorded by the electrical images. In the resistivity sections of the El Tigre strike-slip fault, a near vertical fault plane associated with blind splays could be identified. Our results confirm that the resistivity method is a valuable tool to image fault planes and to characterize the general geometry of extensional, reverse and strike slip faults at depth. © 2009 Elsevier Ltd. All rights reserved. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v28_n3_p217_Fazzito http://hdl.handle.net/20.500.12110/paper_08959811_v28_n3_p217_Fazzito
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Andes
Argentina
Electrical Resistivity Tomography
Geoelectrical method
Neotectonics
Precordillera
Quaternary faults
electrical method
electrical resistivity
extensional tectonics
fault plane
geoelectric field
neotectonics
Quaternary
strike-slip fault
tomography
Argentina
South America
spellingShingle Andes
Argentina
Electrical Resistivity Tomography
Geoelectrical method
Neotectonics
Precordillera
Quaternary faults
electrical method
electrical resistivity
extensional tectonics
fault plane
geoelectric field
neotectonics
Quaternary
strike-slip fault
tomography
Argentina
South America
Characterization of Quaternary faults by electric resistivity tomography in the Andean Precordillera of Western Argentina
topic_facet Andes
Argentina
Electrical Resistivity Tomography
Geoelectrical method
Neotectonics
Precordillera
Quaternary faults
electrical method
electrical resistivity
extensional tectonics
fault plane
geoelectric field
neotectonics
Quaternary
strike-slip fault
tomography
Argentina
South America
description Structural and geomorphic surface observations are frequently insufficient for a proper geometric and kinematic characterization of Quaternary faults. In order to improve the geological knowledge of three Quaternary faults in the Precordillera of western Argentina (30°46′ S-32°24′ S, 69°07′ W-69°15′ W), a shallow 2D Electrical Resistivity Tomography (ERT) survey was performed along seven short cross-sections, perpendicular to the fault traces. The survey was carried out across the San Bartolo fault, the Los Avestruces high and the El Tigre fault in the Precordillera of western Argentina in the San Juan and Mendoza provinces. During the survey, different electrical arrangements were assessed, including different arrays (dipole-dipole and Wenner-Schlumberger), diverse electrode separations and different depth of investigation. Tomographic models showed low resistivity zones lying below the fault scarps, as well as significant resistivity contrasts across the inferred fault-zones in the subsurface. This information permitted better characterization of the geometry and kinematics of these fault zones. ERT results showed that the San Bartolo fault is extensional. In the Los Avestruces high a positive inversion of an extensional fault was recorded by the electrical images. In the resistivity sections of the El Tigre strike-slip fault, a near vertical fault plane associated with blind splays could be identified. Our results confirm that the resistivity method is a valuable tool to image fault planes and to characterize the general geometry of extensional, reverse and strike slip faults at depth. © 2009 Elsevier Ltd. All rights reserved.
title Characterization of Quaternary faults by electric resistivity tomography in the Andean Precordillera of Western Argentina
title_short Characterization of Quaternary faults by electric resistivity tomography in the Andean Precordillera of Western Argentina
title_full Characterization of Quaternary faults by electric resistivity tomography in the Andean Precordillera of Western Argentina
title_fullStr Characterization of Quaternary faults by electric resistivity tomography in the Andean Precordillera of Western Argentina
title_full_unstemmed Characterization of Quaternary faults by electric resistivity tomography in the Andean Precordillera of Western Argentina
title_sort characterization of quaternary faults by electric resistivity tomography in the andean precordillera of western argentina
publishDate 2009
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v28_n3_p217_Fazzito
http://hdl.handle.net/20.500.12110/paper_08959811_v28_n3_p217_Fazzito
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