Dating the Triassic continental rift in the southern Andes : The Potrerillos Formation, Cuyo Basin, Argentina

Autores
Spalletti, Luis Antonio; Fanning, Christopher Mark; Rapela, Carlos Washington
Año de publicación
2008
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The Triassic successions of western Argentina commonly show thin pyroclastic levels intercalated within thick fluvial and lacustrine terrigenous deposits. The Potrerillos Formation is the thickest Triassic unit in the Cuyo Basin. It is composed of alternating cycles of gravelly- sandy- and muddy-dominated intervals, in which several laterally-continuous tuff horizons occur. U-Pb SHRIMP ages were determined on zircon grains from three tuff levels located between the lowermost and the middle sections of the Potrerillos Formation. The ages for the time of deposition of the tuffs are 239.2 ± 4.5 Ma, 239.7 ± 2.2 Ma and 230.3 ± 2.3 Ma (Middle Triassic). Chemical data indicate that these acid to intermediate volcaniclastic rocks are derived from coeval basic magmas displaying tholeiitic to slightly alkaline signatures. They are associated with the rift stage that followed the extensive post-orogenic volcanism of the Choiyoi Group, that in turn has been ascribed to slab break-off in neighbouring areas. Two of the studied samples also record a subpopulation of inherited zircon grains with crystallisation ages of 260-270 Ma. The latter are considered to be an indirect measurement for the age of the Choiyoi Group in the Cuyo basin. The rift-related Triassic event represents the culmination of the Gondwanian magmatic cycle, and is interpreted as the result of subduction cessation and anomalous heating of the upper mantle previous to the western Gondwana break-up.
Centro de Investigaciones Geológicas
Materia
Geología
Triassic
Cuyo basin
Argentina
U-pb zircon dating
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/95722
Acceder
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oai_identifier_str oai:sedici.unlp.edu.ar:10915/95722
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network_name_str SEDICI (UNLP)
spelling Dating the Triassic continental rift in the southern Andes : The Potrerillos Formation, Cuyo Basin, ArgentinaSpalletti, Luis AntonioFanning, Christopher MarkRapela, Carlos WashingtonGeologíaTriassicCuyo basinArgentinaU-pb zircon datingThe Triassic successions of western Argentina commonly show thin pyroclastic levels intercalated within thick fluvial and lacustrine terrigenous deposits. The Potrerillos Formation is the thickest Triassic unit in the Cuyo Basin. It is composed of alternating cycles of gravelly- sandy- and muddy-dominated intervals, in which several laterally-continuous tuff horizons occur. U-Pb SHRIMP ages were determined on zircon grains from three tuff levels located between the lowermost and the middle sections of the Potrerillos Formation. The ages for the time of deposition of the tuffs are 239.2 ± 4.5 Ma, 239.7 ± 2.2 Ma and 230.3 ± 2.3 Ma (Middle Triassic). Chemical data indicate that these acid to intermediate volcaniclastic rocks are derived from coeval basic magmas displaying tholeiitic to slightly alkaline signatures. They are associated with the rift stage that followed the extensive post-orogenic volcanism of the Choiyoi Group, that in turn has been ascribed to slab break-off in neighbouring areas. Two of the studied samples also record a subpopulation of inherited zircon grains with crystallisation ages of 260-270 Ma. The latter are considered to be an indirect measurement for the age of the Choiyoi Group in the Cuyo basin. The rift-related Triassic event represents the culmination of the Gondwanian magmatic cycle, and is interpreted as the result of subduction cessation and anomalous heating of the upper mantle previous to the western Gondwana break-up.Centro de Investigaciones Geológicas2008-09info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf267-283http://sedici.unlp.edu.ar/handle/10915/95722enginfo:eu-repo/semantics/altIdentifier/url/https://ri.conicet.gov.ar/11336/74327info:eu-repo/semantics/altIdentifier/url/http://revistes.ub.edu/index.php/GEOACTA/article/view/105.000000256info:eu-repo/semantics/altIdentifier/issn/1695-6133info:eu-repo/semantics/altIdentifier/doi/10.1344/105.000000256info:eu-repo/semantics/altIdentifier/hdl/11336/74327info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-sa/4.0/Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:20:21Zoai:sedici.unlp.edu.ar:10915/95722Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:20:22.015SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Dating the Triassic continental rift in the southern Andes : The Potrerillos Formation, Cuyo Basin, Argentina
title Dating the Triassic continental rift in the southern Andes : The Potrerillos Formation, Cuyo Basin, Argentina
spellingShingle Dating the Triassic continental rift in the southern Andes : The Potrerillos Formation, Cuyo Basin, Argentina
Spalletti, Luis Antonio
Geología
Triassic
Cuyo basin
Argentina
U-pb zircon dating
title_short Dating the Triassic continental rift in the southern Andes : The Potrerillos Formation, Cuyo Basin, Argentina
title_full Dating the Triassic continental rift in the southern Andes : The Potrerillos Formation, Cuyo Basin, Argentina
title_fullStr Dating the Triassic continental rift in the southern Andes : The Potrerillos Formation, Cuyo Basin, Argentina
title_full_unstemmed Dating the Triassic continental rift in the southern Andes : The Potrerillos Formation, Cuyo Basin, Argentina
title_sort Dating the Triassic continental rift in the southern Andes : The Potrerillos Formation, Cuyo Basin, Argentina
dc.creator.none.fl_str_mv Spalletti, Luis Antonio
Fanning, Christopher Mark
Rapela, Carlos Washington
author Spalletti, Luis Antonio
author_facet Spalletti, Luis Antonio
Fanning, Christopher Mark
Rapela, Carlos Washington
author_role author
author2 Fanning, Christopher Mark
Rapela, Carlos Washington
author2_role author
author
dc.subject.none.fl_str_mv Geología
Triassic
Cuyo basin
Argentina
U-pb zircon dating
topic Geología
Triassic
Cuyo basin
Argentina
U-pb zircon dating
dc.description.none.fl_txt_mv The Triassic successions of western Argentina commonly show thin pyroclastic levels intercalated within thick fluvial and lacustrine terrigenous deposits. The Potrerillos Formation is the thickest Triassic unit in the Cuyo Basin. It is composed of alternating cycles of gravelly- sandy- and muddy-dominated intervals, in which several laterally-continuous tuff horizons occur. U-Pb SHRIMP ages were determined on zircon grains from three tuff levels located between the lowermost and the middle sections of the Potrerillos Formation. The ages for the time of deposition of the tuffs are 239.2 ± 4.5 Ma, 239.7 ± 2.2 Ma and 230.3 ± 2.3 Ma (Middle Triassic). Chemical data indicate that these acid to intermediate volcaniclastic rocks are derived from coeval basic magmas displaying tholeiitic to slightly alkaline signatures. They are associated with the rift stage that followed the extensive post-orogenic volcanism of the Choiyoi Group, that in turn has been ascribed to slab break-off in neighbouring areas. Two of the studied samples also record a subpopulation of inherited zircon grains with crystallisation ages of 260-270 Ma. The latter are considered to be an indirect measurement for the age of the Choiyoi Group in the Cuyo basin. The rift-related Triassic event represents the culmination of the Gondwanian magmatic cycle, and is interpreted as the result of subduction cessation and anomalous heating of the upper mantle previous to the western Gondwana break-up.
Centro de Investigaciones Geológicas
description The Triassic successions of western Argentina commonly show thin pyroclastic levels intercalated within thick fluvial and lacustrine terrigenous deposits. The Potrerillos Formation is the thickest Triassic unit in the Cuyo Basin. It is composed of alternating cycles of gravelly- sandy- and muddy-dominated intervals, in which several laterally-continuous tuff horizons occur. U-Pb SHRIMP ages were determined on zircon grains from three tuff levels located between the lowermost and the middle sections of the Potrerillos Formation. The ages for the time of deposition of the tuffs are 239.2 ± 4.5 Ma, 239.7 ± 2.2 Ma and 230.3 ± 2.3 Ma (Middle Triassic). Chemical data indicate that these acid to intermediate volcaniclastic rocks are derived from coeval basic magmas displaying tholeiitic to slightly alkaline signatures. They are associated with the rift stage that followed the extensive post-orogenic volcanism of the Choiyoi Group, that in turn has been ascribed to slab break-off in neighbouring areas. Two of the studied samples also record a subpopulation of inherited zircon grains with crystallisation ages of 260-270 Ma. The latter are considered to be an indirect measurement for the age of the Choiyoi Group in the Cuyo basin. The rift-related Triassic event represents the culmination of the Gondwanian magmatic cycle, and is interpreted as the result of subduction cessation and anomalous heating of the upper mantle previous to the western Gondwana break-up.
publishDate 2008
dc.date.none.fl_str_mv 2008-09
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
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://sedici.unlp.edu.ar/handle/10915/95722
url http://sedici.unlp.edu.ar/handle/10915/95722
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://ri.conicet.gov.ar/11336/74327
info:eu-repo/semantics/altIdentifier/url/http://revistes.ub.edu/index.php/GEOACTA/article/view/105.000000256
info:eu-repo/semantics/altIdentifier/issn/1695-6133
info:eu-repo/semantics/altIdentifier/doi/10.1344/105.000000256
info:eu-repo/semantics/altIdentifier/hdl/11336/74327
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-sa/4.0/
Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-sa/4.0/
Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
dc.format.none.fl_str_mv application/pdf
267-283
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
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reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
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