Artículo
Mississippian lamprophyre dikes in western Sierras Pampeanas, Argentina: Evidence of transtensional tectonics along the SW margin of Gondwana
Martina, Federico
; Canelo, Horacio Nicolas
; Davila, Federico Miguel
; de Hollanda, María Helena M.; Teixeira, Wilson
Fecha de publicación:
04/2018
Editorial:
Pergamon-Elsevier Science Ltd
Revista:
Journal of South American Earth Sciences
ISSN:
0895-9811
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
In the Famatina range, Sierras Pampeanas of Argentina (SW Gondwana), subvertical calc-alkaline lamprophyric dike swarms crop out through >300 km. The dikes cut Ordovician units with a prominent NW-SE trending and are covered by continental sedimentary successions of Pennsylvanian to Permian age. The dikes show a strong structural control associated with Riedel fault systems. Detailed field analysis suggested a ∼N-S opening direction oblique to the attitude of dike walls and a left-lateral transtensional tectonics during the emplacement. 40Ar/39Ar geochronology of a lamprophyric sample defined a crystallization age (plateau; whole rock) of 357.1 ± 7.1 Ma (MSWD = 2.3). Coetaneous ductile zones with dominant strike-slip motion, documented along western Argentina for >600 km, suggest a regional event in SW Gondwana during the Mississippian. We propose that this deformation was the result of the counterclockwise fast rotation of Gondwana between 365 and 345 Ma, when the Famatina range and western Argentina occupied a sub-polar position. A transform margin along SW Gondwana better explains our (and others) data rather than a subduction margin. This scenario is also consistent with the occurrence of A-type granites and normal-fault basins within the foreland as well as bimodal volcanics.
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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; Canelo, Horacio Nicolas; Davila, Federico Miguel; de Hollanda, María Helena M.; Teixeira, Wilson; Mississippian lamprophyre dikes in western Sierras Pampeanas, Argentina: Evidence of transtensional tectonics along the SW margin of Gondwana; Pergamon-Elsevier Science Ltd; Journal of South American Earth Sciences; 83; 4-2018; 68-80
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