The late stages of the Pampean Orogeny, Córdoba (Argentina): Evidence of postcollisional Early Cambrian slab break-off magmatism

Widespread rhyolitic and mafic volcanism in the northern and southern sectors respectively of Eastern Sierras Pampeanas, central western Argentina, are associated with an important phase of extension and uplift linked to slab break-off on latest stages of the Pampean Orogeny. The main orogenic defor...

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Detalles Bibliográficos
Publicado: 2015
Materias:
Cambrian
Neoproterozoic
Orogenic collapse
Rhyolites
Sierras Pampeanas
Western Gondwana
collision zone
emplacement
Gondwana
magmatism
orogeny
Proterozoic
rhyolite
uranium-lead dating
volcanism
zircon
Argentina
Cordoba [Argentina]
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v64_n_p351_Ramos
http://hdl.handle.net/20.500.12110/paper_08959811_v64_n_p351_Ramos
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_08959811_v64_n_p351_Ramos
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spelling paper:paper_08959811_v64_n_p351_Ramos2023-06-08T15:48:50Z The late stages of the Pampean Orogeny, Córdoba (Argentina): Evidence of postcollisional Early Cambrian slab break-off magmatism Cambrian Neoproterozoic Orogenic collapse Rhyolites Sierras Pampeanas Western Gondwana Cambrian collision zone emplacement Gondwana magmatism orogeny Proterozoic rhyolite uranium-lead dating volcanism zircon Argentina Cordoba [Argentina] Sierras Pampeanas Widespread rhyolitic and mafic volcanism in the northern and southern sectors respectively of Eastern Sierras Pampeanas, central western Argentina, are associated with an important phase of extension and uplift linked to slab break-off on latest stages of the Pampean Orogeny. The main orogenic deformation took place between 540 and 535 Ma based on new ages available for this region. New U-Pb ages in zircons from the Oncán Rhyolite and new and old recalculated zircons from Los Burros Rhyodacite in the northern sector of Sierras de Córdoba, together with new U-Pb ages of the southern sector, indicate that volcanic and subvolcanic rocks of both sectors are partially coeval and unconformably overlying and/or intruding the basement rocks during a period of exhumation and subsequent cooling at 530-520 Ma. These data are in agreement with previous estimates for the final uplift of the Sierras de Córdoba based on the K-Ar cooling ages. The southern sector of Eastern Sierras Pampeanas may represent deeper structural levels within the crust and is characterized by the occurrence of small mafic bodies with OIB-like signature. New and reinterpreted U-Pb SHRIMP and TIMS ages on zircons and monazites in the metamorphic associated rocks date this episode, which is related to a rapid slab break-off event at 519-515 Ma. This episode is also associated with the emplacement of peraluminous granitoids, and with the extension, cooling and final uplift of the rocks affected by the Pampean Orogeny all along the Eastern Sierras Pampeanas. © 2015 Elsevier Ltd. 2015 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v64_n_p351_Ramos http://hdl.handle.net/20.500.12110/paper_08959811_v64_n_p351_Ramos
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Cambrian
Neoproterozoic
Orogenic collapse
Rhyolites
Sierras Pampeanas
Western Gondwana
Cambrian
collision zone
emplacement
Gondwana
magmatism
orogeny
Proterozoic
rhyolite
uranium-lead dating
volcanism
zircon
Argentina
Cordoba [Argentina]
Sierras Pampeanas
spellingShingle Cambrian
Neoproterozoic
Orogenic collapse
Rhyolites
Sierras Pampeanas
Western Gondwana
Cambrian
collision zone
emplacement
Gondwana
magmatism
orogeny
Proterozoic
rhyolite
uranium-lead dating
volcanism
zircon
Argentina
Cordoba [Argentina]
Sierras Pampeanas
The late stages of the Pampean Orogeny, Córdoba (Argentina): Evidence of postcollisional Early Cambrian slab break-off magmatism
topic_facet Cambrian
Neoproterozoic
Orogenic collapse
Rhyolites
Sierras Pampeanas
Western Gondwana
Cambrian
collision zone
emplacement
Gondwana
magmatism
orogeny
Proterozoic
rhyolite
uranium-lead dating
volcanism
zircon
Argentina
Cordoba [Argentina]
Sierras Pampeanas
description Widespread rhyolitic and mafic volcanism in the northern and southern sectors respectively of Eastern Sierras Pampeanas, central western Argentina, are associated with an important phase of extension and uplift linked to slab break-off on latest stages of the Pampean Orogeny. The main orogenic deformation took place between 540 and 535 Ma based on new ages available for this region. New U-Pb ages in zircons from the Oncán Rhyolite and new and old recalculated zircons from Los Burros Rhyodacite in the northern sector of Sierras de Córdoba, together with new U-Pb ages of the southern sector, indicate that volcanic and subvolcanic rocks of both sectors are partially coeval and unconformably overlying and/or intruding the basement rocks during a period of exhumation and subsequent cooling at 530-520 Ma. These data are in agreement with previous estimates for the final uplift of the Sierras de Córdoba based on the K-Ar cooling ages. The southern sector of Eastern Sierras Pampeanas may represent deeper structural levels within the crust and is characterized by the occurrence of small mafic bodies with OIB-like signature. New and reinterpreted U-Pb SHRIMP and TIMS ages on zircons and monazites in the metamorphic associated rocks date this episode, which is related to a rapid slab break-off event at 519-515 Ma. This episode is also associated with the emplacement of peraluminous granitoids, and with the extension, cooling and final uplift of the rocks affected by the Pampean Orogeny all along the Eastern Sierras Pampeanas. © 2015 Elsevier Ltd.
title The late stages of the Pampean Orogeny, Córdoba (Argentina): Evidence of postcollisional Early Cambrian slab break-off magmatism
title_short The late stages of the Pampean Orogeny, Córdoba (Argentina): Evidence of postcollisional Early Cambrian slab break-off magmatism
title_full The late stages of the Pampean Orogeny, Córdoba (Argentina): Evidence of postcollisional Early Cambrian slab break-off magmatism
title_fullStr The late stages of the Pampean Orogeny, Córdoba (Argentina): Evidence of postcollisional Early Cambrian slab break-off magmatism
title_full_unstemmed The late stages of the Pampean Orogeny, Córdoba (Argentina): Evidence of postcollisional Early Cambrian slab break-off magmatism
title_sort late stages of the pampean orogeny, córdoba (argentina): evidence of postcollisional early cambrian slab break-off magmatism
publishDate 2015
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08959811_v64_n_p351_Ramos
http://hdl.handle.net/20.500.12110/paper_08959811_v64_n_p351_Ramos
_version_ 1768541995248123904

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