Artículo
From alluvial fan to playa: an Upper Jurassic ephemeral fluvial system, Neuquén Basin, Argentina
Fecha de publicación:
12/2005
Editorial:
Elsevier Science
Revista:
Gondwana Research
ISSN:
1342-937X
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
The Upper Jurassic fill of the back-arc Neuquén Basin includes a lowstand wedge known as the Tordillo Formation. The studied deposits crop out along a N-S to oriented belt that runs parallel to the Andean magmatic arc. They are limited to the south by the east-west oriented positive structure of the Huincul arch formed as a result of Upper Jurassic tectonic inversion. The Tordillo deposits were formed in an and fluvial-dominated system characterised by systematic downstream changes in architectural style. A gravelly and sandy bedload fluvial system is recognised in the southern upstream sector. The reduced thickness and the coarse grain size suggest steep gradients, excess of bedload supply and a low subsidence rate. Thicker and finer-grained deposits prevail to the north and northeast. They were formed under arid conditions in a wadi-sand flat-playa fluvial system. This distal facies association indicates increased accommodation owing to high rates of subsidence relative to coarse siliciclastic sedimentation rates. These low-gradient deposits are characterised by cyclic alternations of mud-dominated and sand-dominated packages interpreted as high- and low-accommodation systems tracts. The overall fining upward stacking pattern of the Tordillo Formation suggests a change towards higher accommodation rates. This is accompanied by frequent development of soil horizons and darker primary and reworked pyroclastic deposits. These attributes indicate a stronger explosive volcanic activity associated with increased precipitation and high water table emplacement towards the end of the Tordillo lowstand wedge. © 2005 International Association for Gondwana Research, Japan.
Palabras clave:
Argentina
,
Facies Models
,
Fluvial Sedimentology
,
Jurassic
,
Neuquen Basin
Archivos asociados
Licencia
Identificadores
Colecciones
Articulos(CIG)
Articulos de CENTRO DE INVEST.GEOLOGICAS (I)
Articulos de CENTRO DE INVEST.GEOLOGICAS (I)
Citación
Spalletti, Luis Antonio; Colombo Piñol, Ferran; From alluvial fan to playa: an Upper Jurassic ephemeral fluvial system, Neuquén Basin, Argentina; Elsevier Science; Gondwana Research; 8; 3; 12-2005; 363-383
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