Artículo
Mississippian volcanism in the south-central Andes: New U-Pb SHRIMP zircon geochronology and whole-rock geochemistry
Martina, Federico
; Viramonte, Jose Maria
; Astini, Ricardo Alfredo
; Martins Pimentel, Márcio; Dantas, Elton Luiz
Fecha de publicación:
03/2011
Editorial:
Elsevier Science
Revista:
Gondwana Research
ISSN:
1342-937X
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
In the northern extension of the Famatina and the southern Puna (NW Argentina) prominent rhyolitic volcanic rocks traditionally referred to as Ordovician are exposed, resting on metamorphic basement and covered by thick Late Paleozoic siliciclastic successions. We report new U-Pb SHRIMP ages from these rhyolites that show them to be of Mississippian (348-342Ma) age, thus identifying a previously unknown volcanic event in this portion of western Gondwana. Whole-rock geochemistry and Sr-Nd isotopic analyses suggest a crustal source for these rocks but with a juvenile input (εNd(t) between -2.91 and -0.3, and TDM values between 1.09 and 1.1Ga). This is different from the Early Paleozoic magmatism of western Argentina where crustal recycling took place without any involvement of mantle material. The Carboniferous magmatism is compatible with an extensional environment developed along the Terra Australis accretionary orogen as a result of tectonic switching processes. These rhyolites may be related to the coeval Mississippian A-type granites exposed to the east, in the Sierras Pampeanas, confirming the regional character of this magmatism.
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Identificadores
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Articulos(CICTERRA)
Articulos de CENTRO DE INVEST.EN CS.DE LA TIERRA
Articulos de CENTRO DE INVEST.EN CS.DE LA TIERRA
Citación
Martina, Federico; Viramonte, Jose Maria; Astini, Ricardo Alfredo; Martins Pimentel, Márcio; Dantas, Elton Luiz; Mississippian volcanism in the south-central Andes: New U-Pb SHRIMP zircon geochronology and whole-rock geochemistry; Elsevier Science; Gondwana Research; 19; 2; 3-2011; 524-534
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