High-pressure/low-temperature metamorphism in the collision zone between the Chilenia and Cuyania microcontinents (western Precordillera, Argentina)

In central-western Argentina, an Early Paleozoic belt including mafic-ultramafic bodies, marine metasedimentary rocks and high-pressure rocks occur along the western margin of the Precordillera and in the Frontal Cordillera. First pressure-temperature estimates are presented here for low-grade rocks...

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Autores principales: Boedo, Florencia Lucila, Vujovich, Graciela Irene
Publicado: 2016
Materias:
Devonian
Geothermobarometry
Greenschist facies
Mafic-ultramafic belt
Peñasco formation
Phengite
Pseudosections
collision zone
geobarometry
geothermometry
Gondwana
greenschist facies
mafic rock
metamorphism
phengite
ultramafic rock
Argentina
Precordillera
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v72_n_p227_Boedo
http://hdl.handle.net/20.500.12110/paper_08959811_v72_n_p227_Boedo
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_08959811_v72_n_p227_Boedo
record_format dspace
spelling paper:paper_08959811_v72_n_p227_Boedo2023-06-08T15:48:55Z High-pressure/low-temperature metamorphism in the collision zone between the Chilenia and Cuyania microcontinents (western Precordillera, Argentina) Boedo, Florencia Lucila Vujovich, Graciela Irene Devonian Geothermobarometry Greenschist facies Mafic-ultramafic belt Peñasco formation Phengite Pseudosections collision zone Devonian geobarometry geothermometry Gondwana greenschist facies mafic rock metamorphism phengite ultramafic rock Argentina Precordillera In central-western Argentina, an Early Paleozoic belt including mafic-ultramafic bodies, marine metasedimentary rocks and high-pressure rocks occur along the western margin of the Precordillera and in the Frontal Cordillera. First pressure-temperature estimates are presented here for low-grade rocks of the southern sector of this belt based on two metasedimentary and one metabasaltic sample from the Peñasco Formation. Peak metamorphic conditions resulted within the range of 345–395 °C and 7.0–9.3 kbar within the high-pressure greenschist facies. The corresponding low metamorphic gradient of 13 °C/km is comparable with subduction related geothermal gradients. Comparison between these results and data from other localities of the same collision zone (Guarguaraz and Colohuincul complexes) confirms a collision between Chilenia and the composite margin of western Gondwana and suggests a stronger crustal thickening in the south of the belt, causing exhumation of more deeply buried sequences. During the Early Paleozoic a long-lived marine sedimentation coupled with the intrusion of MORB-like basalts occurred along a stable margin before the collision event. This contrasts with the almost contemporaneous sedimentation registered during accretion in accretionary prism settings and additionally proves the development of a collision zone along western Precordillera and the eastern Frontal Cordillera as well as the existence of Chilenia as a separate microcontinent. © 2016 Elsevier Ltd Fil:Boedo, F.L. 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. 2016 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v72_n_p227_Boedo http://hdl.handle.net/20.500.12110/paper_08959811_v72_n_p227_Boedo
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Devonian
Geothermobarometry
Greenschist facies
Mafic-ultramafic belt
Peñasco formation
Phengite
Pseudosections
collision zone
Devonian
geobarometry
geothermometry
Gondwana
greenschist facies
mafic rock
metamorphism
phengite
ultramafic rock
Argentina
Precordillera
spellingShingle Devonian
Geothermobarometry
Greenschist facies
Mafic-ultramafic belt
Peñasco formation
Phengite
Pseudosections
collision zone
Devonian
geobarometry
geothermometry
Gondwana
greenschist facies
mafic rock
metamorphism
phengite
ultramafic rock
Argentina
Precordillera
Boedo, Florencia Lucila
Vujovich, Graciela Irene
High-pressure/low-temperature metamorphism in the collision zone between the Chilenia and Cuyania microcontinents (western Precordillera, Argentina)
topic_facet Devonian
Geothermobarometry
Greenschist facies
Mafic-ultramafic belt
Peñasco formation
Phengite
Pseudosections
collision zone
Devonian
geobarometry
geothermometry
Gondwana
greenschist facies
mafic rock
metamorphism
phengite
ultramafic rock
Argentina
Precordillera
description In central-western Argentina, an Early Paleozoic belt including mafic-ultramafic bodies, marine metasedimentary rocks and high-pressure rocks occur along the western margin of the Precordillera and in the Frontal Cordillera. First pressure-temperature estimates are presented here for low-grade rocks of the southern sector of this belt based on two metasedimentary and one metabasaltic sample from the Peñasco Formation. Peak metamorphic conditions resulted within the range of 345–395 °C and 7.0–9.3 kbar within the high-pressure greenschist facies. The corresponding low metamorphic gradient of 13 °C/km is comparable with subduction related geothermal gradients. Comparison between these results and data from other localities of the same collision zone (Guarguaraz and Colohuincul complexes) confirms a collision between Chilenia and the composite margin of western Gondwana and suggests a stronger crustal thickening in the south of the belt, causing exhumation of more deeply buried sequences. During the Early Paleozoic a long-lived marine sedimentation coupled with the intrusion of MORB-like basalts occurred along a stable margin before the collision event. This contrasts with the almost contemporaneous sedimentation registered during accretion in accretionary prism settings and additionally proves the development of a collision zone along western Precordillera and the eastern Frontal Cordillera as well as the existence of Chilenia as a separate microcontinent. © 2016 Elsevier Ltd
author Boedo, Florencia Lucila
Vujovich, Graciela Irene
author_facet Boedo, Florencia Lucila
Vujovich, Graciela Irene
author_sort Boedo, Florencia Lucila
title High-pressure/low-temperature metamorphism in the collision zone between the Chilenia and Cuyania microcontinents (western Precordillera, Argentina)
title_short High-pressure/low-temperature metamorphism in the collision zone between the Chilenia and Cuyania microcontinents (western Precordillera, Argentina)
title_full High-pressure/low-temperature metamorphism in the collision zone between the Chilenia and Cuyania microcontinents (western Precordillera, Argentina)
title_fullStr High-pressure/low-temperature metamorphism in the collision zone between the Chilenia and Cuyania microcontinents (western Precordillera, Argentina)
title_full_unstemmed High-pressure/low-temperature metamorphism in the collision zone between the Chilenia and Cuyania microcontinents (western Precordillera, Argentina)
title_sort high-pressure/low-temperature metamorphism in the collision zone between the chilenia and cuyania microcontinents (western precordillera, argentina)
publishDate 2016
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v72_n_p227_Boedo
http://hdl.handle.net/20.500.12110/paper_08959811_v72_n_p227_Boedo
work_keys_str_mv AT boedoflorencialucila highpressurelowtemperaturemetamorphisminthecollisionzonebetweenthechileniaandcuyaniamicrocontinentswesternprecordilleraargentina
AT vujovichgracielairene highpressurelowtemperaturemetamorphisminthecollisionzonebetweenthechileniaandcuyaniamicrocontinentswesternprecordilleraargentina
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