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

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-dom...

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Autores principales: Spalletti, Luis Antonio, Fanning, Christopher Mark, Rapela, Carlos Washington
Formato: Articulo
Lenguaje:Inglés
Publicado: 2008
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/95722
https://ri.conicet.gov.ar/11336/74327
http://revistes.ub.edu/index.php/GEOACTA/article/view/105.000000256
Aporte de:
id I19-R120-10915-95722
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Geología
Triassic
Cuyo basin
Argentina
U-pb zircon dating
spellingShingle Geología
Triassic
Cuyo basin
Argentina
U-pb zircon dating
Spalletti, Luis Antonio
Fanning, Christopher Mark
Rapela, Carlos Washington
Dating the Triassic continental rift in the southern Andes : The Potrerillos Formation, Cuyo Basin, Argentina
topic_facet Geología
Triassic
Cuyo basin
Argentina
U-pb zircon dating
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.
format Articulo
Articulo
author Spalletti, Luis Antonio
Fanning, Christopher Mark
Rapela, Carlos Washington
author_facet Spalletti, Luis Antonio
Fanning, Christopher Mark
Rapela, Carlos Washington
author_sort Spalletti, Luis Antonio
title Dating the Triassic continental rift in the southern Andes : The Potrerillos Formation, Cuyo Basin, Argentina
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
publishDate 2008
url http://sedici.unlp.edu.ar/handle/10915/95722
https://ri.conicet.gov.ar/11336/74327
http://revistes.ub.edu/index.php/GEOACTA/article/view/105.000000256
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