Geophysical evidence for an extensive Pie de Palo Complex mafic-ultramafic belt, San Juan, Argentina
The recent completion of a high-resolution aeromagnetic survey over the Pie de Palo uplift of the western Sierras Pampeanas has revealed an area of large magnetic anomalies associated with the Pie de Palo Complex. The Las Pirquitas thrust, which has transported and uplifted the Pie de Palo Complex,...
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2009
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v28_n4_p325_Chernicoff http://hdl.handle.net/20.500.12110/paper_08959811_v28_n4_p325_Chernicoff |
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paper:paper_08959811_v28_n4_p325_Chernicoff2023-06-08T15:48:27Z Geophysical evidence for an extensive Pie de Palo Complex mafic-ultramafic belt, San Juan, Argentina Chernicoff, Carlos Jorge Vujovich, Graciela Irene Aeromagnetics Grenvillian mafic-ultramafic belt Sierra de Pie de Palo aeromagnetic survey dip Grenvillian orogeny mafic rock magnetic anomaly numerical model outcrop suture zone tectonic reconstruction thrust ultramafic rock uplift Argentina San Juan [Argentina] Sierra de Pie de Palo Sierras Pampeanas South America The recent completion of a high-resolution aeromagnetic survey over the Pie de Palo uplift of the western Sierras Pampeanas has revealed an area of large magnetic anomalies associated with the Pie de Palo Complex. The Las Pirquitas thrust, which has transported and uplifted the Pie de Palo Complex, is recognized for at least 30 km in a roughly NE direction along the western boundary of the Pie de Palo Complex, beyond its limited outcrop. The type of sediments of the Caucete Group in the footwall of the Las Pirquitas thrust, which are regarded as the leading edge of the Precordillera terrane, are associated with much less pronounced magnetic anomalies. In addition, a conspicuous, NNE trending, broad magnetic high stands out in the survey, several kilometers to the east of the main outcrops of the Pie de Palo Complex; this broad magnetic anomaly bisects the Pie de Palo basement block, and continues further south at least as far as 32°S, the southern boundary of the latest aeromagnetic survey. This magnetic anomaly is interpreted to represent a structure corresponding to the Grenvillian Precordillera-Pie de Palo tectonic boundary zone, and would comprise the buried largest part of the mafic-ultramafic belt. The geophysical model of the magnetic data indicates that the boundary zone dips to the east, possibly suggesting the existence of a set of synthetic east dipping, west-verging thrusts, of which only one major structure (Las Pirquitas thrust) is exposed; the possibility of other slivers of upthrust boundary zone material cannot be excluded. It is considered that the Pie de Palo Complex represents a small sliver upthrust from the unexposed boundary zone material (containing highly magnetic mafic-ultramafic rocks). The east-dipping, west verging structures associated with the Pie de Palo Complex are suggested to represent an Ordovician reactivation of a Grenvillian suture zone developed when the Precordillera basement and Pie de Palo terrane docked; this reactivation probably resulted from the collision of the Cuyania terrane onto the western margin of Gondwana. © 2009 Elsevier Ltd. All rights reserved. Fil:Chernicoff, C.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Vujovich, G.I. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v28_n4_p325_Chernicoff http://hdl.handle.net/20.500.12110/paper_08959811_v28_n4_p325_Chernicoff |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Aeromagnetics Grenvillian mafic-ultramafic belt Sierra de Pie de Palo aeromagnetic survey dip Grenvillian orogeny mafic rock magnetic anomaly numerical model outcrop suture zone tectonic reconstruction thrust ultramafic rock uplift Argentina San Juan [Argentina] Sierra de Pie de Palo Sierras Pampeanas South America |
| spellingShingle |
Aeromagnetics Grenvillian mafic-ultramafic belt Sierra de Pie de Palo aeromagnetic survey dip Grenvillian orogeny mafic rock magnetic anomaly numerical model outcrop suture zone tectonic reconstruction thrust ultramafic rock uplift Argentina San Juan [Argentina] Sierra de Pie de Palo Sierras Pampeanas South America Chernicoff, Carlos Jorge Vujovich, Graciela Irene Geophysical evidence for an extensive Pie de Palo Complex mafic-ultramafic belt, San Juan, Argentina |
| topic_facet |
Aeromagnetics Grenvillian mafic-ultramafic belt Sierra de Pie de Palo aeromagnetic survey dip Grenvillian orogeny mafic rock magnetic anomaly numerical model outcrop suture zone tectonic reconstruction thrust ultramafic rock uplift Argentina San Juan [Argentina] Sierra de Pie de Palo Sierras Pampeanas South America |
| description |
The recent completion of a high-resolution aeromagnetic survey over the Pie de Palo uplift of the western Sierras Pampeanas has revealed an area of large magnetic anomalies associated with the Pie de Palo Complex. The Las Pirquitas thrust, which has transported and uplifted the Pie de Palo Complex, is recognized for at least 30 km in a roughly NE direction along the western boundary of the Pie de Palo Complex, beyond its limited outcrop. The type of sediments of the Caucete Group in the footwall of the Las Pirquitas thrust, which are regarded as the leading edge of the Precordillera terrane, are associated with much less pronounced magnetic anomalies. In addition, a conspicuous, NNE trending, broad magnetic high stands out in the survey, several kilometers to the east of the main outcrops of the Pie de Palo Complex; this broad magnetic anomaly bisects the Pie de Palo basement block, and continues further south at least as far as 32°S, the southern boundary of the latest aeromagnetic survey. This magnetic anomaly is interpreted to represent a structure corresponding to the Grenvillian Precordillera-Pie de Palo tectonic boundary zone, and would comprise the buried largest part of the mafic-ultramafic belt. The geophysical model of the magnetic data indicates that the boundary zone dips to the east, possibly suggesting the existence of a set of synthetic east dipping, west-verging thrusts, of which only one major structure (Las Pirquitas thrust) is exposed; the possibility of other slivers of upthrust boundary zone material cannot be excluded. It is considered that the Pie de Palo Complex represents a small sliver upthrust from the unexposed boundary zone material (containing highly magnetic mafic-ultramafic rocks). The east-dipping, west verging structures associated with the Pie de Palo Complex are suggested to represent an Ordovician reactivation of a Grenvillian suture zone developed when the Precordillera basement and Pie de Palo terrane docked; this reactivation probably resulted from the collision of the Cuyania terrane onto the western margin of Gondwana. © 2009 Elsevier Ltd. All rights reserved. |
| author |
Chernicoff, Carlos Jorge Vujovich, Graciela Irene |
| author_facet |
Chernicoff, Carlos Jorge Vujovich, Graciela Irene |
| author_sort |
Chernicoff, Carlos Jorge |
| title |
Geophysical evidence for an extensive Pie de Palo Complex mafic-ultramafic belt, San Juan, Argentina |
| title_short |
Geophysical evidence for an extensive Pie de Palo Complex mafic-ultramafic belt, San Juan, Argentina |
| title_full |
Geophysical evidence for an extensive Pie de Palo Complex mafic-ultramafic belt, San Juan, Argentina |
| title_fullStr |
Geophysical evidence for an extensive Pie de Palo Complex mafic-ultramafic belt, San Juan, Argentina |
| title_full_unstemmed |
Geophysical evidence for an extensive Pie de Palo Complex mafic-ultramafic belt, San Juan, Argentina |
| title_sort |
geophysical evidence for an extensive pie de palo complex mafic-ultramafic belt, san juan, argentina |
| publishDate |
2009 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v28_n4_p325_Chernicoff http://hdl.handle.net/20.500.12110/paper_08959811_v28_n4_p325_Chernicoff |
| work_keys_str_mv |
AT chernicoffcarlosjorge geophysicalevidenceforanextensivepiedepalocomplexmaficultramaficbeltsanjuanargentina AT vujovichgracielairene geophysicalevidenceforanextensivepiedepalocomplexmaficultramaficbeltsanjuanargentina |
| _version_ |
1768542088560902144 |