%0 Journal Article
%T Tectonostratigraphic analysis of the Late Triassic-Early Jurassic syn-rift sequence of the Neuqu谷n Basin in the Sa ic車 depocentre, Neuqu谷n Province, Argentina An芍lisis tectonoestratigr芍fico de la secuencia de sin-rift Tri芍sico Superior-Jur芍sico Inferior de la Cuenca Neuquina en el depocentro de Sa ic車, provincia del Neuqu谷n, Argentina
%A Leandro D'Elia
%A Martin Muravchik
%A Juan R Franzese
%A Luciano L車pez
%J Andean Geology
%D 2012
%I Servicio Nacional de Geolog赤a y Miner赤a (SERNAGEOMIN)
%X The initial syn-rift infill (Upper Triassic-Lower Jurassic) of the Neuqu谷n Basin involved a complex stacking of lava, pyroclastic and sedimentary units, in which volcanic rocks compose up to 72% of the infill. The high-quality outcrops of the southern Sa ic車 depocentre, which was uplifted and exposed during the Andean orogeny, were studied in order to determine the lithofacies arrangements, the tectonostratigraphic framework and the main controls over the syn-rift succession. The tectonostratigraphic study made it possible to determine three sections characterized by the predominance of effusive, pyroclastic or sedimentary deposits. These sections indicate three different evolutionary stages of the volcanic rifting. The onset of this rift stage was dominated by effusive rocks with minor ignimbrite and alluvial volcaniclastic units, which indicates the occurrence of composite volcanoes at the boundaries of the depocentre. The mid-rift stage was characterized by the development of fault-controlled, large ignimbrite deposits intebedded with volcaniclastic alluvial deposits and lava units, which suggests a volcano-tectonic depression related to asymmetrical and incremental subsidence. The end of the volcanic rifting event was marked by a decrease in the volume of the volcanic rocks and the occurrence of low-relief effusive aggradational volcanic edifices and lava fields in close relation with alluvial, deltaic and lacustrine units. The analysis of the syn-rift sequence in the Sa ic車 depocentre showed the complex relationships between tectonic and volcanic controls which occurred in different magnitudes and times during the rifting evolution. Los dep車sitos de sin-rift desarrollados durante la etapa de 'rifting' inicial (Tri芍sico Superior-Jur芍sico Inferior) de la Cuenca Neuquina est芍n constituidos por un arreglo complejo de unidades l芍vicas, pirocl芍sticas y sedimentarias, donde las rocas volc芍nicas componen hasta un 72% del relleno. La inversi車n andina caus車 la exhumaci車n y la excelente exposici車n de las rocas que componen este ciclo en el depocentro de Sa ic車, ubicado en el l赤mite sur de la Cuenca Neuquina. El objetivo del presente trabajo es el estudio del relleno sin-tect車nico inicial, poniendo especial 谷nfasis en los arreglos de facies, el marco tectonoestratigr芍fico y los principales controles que operaron durante la evoluci車n del relleno inicial de la cuenca en este depocentro. El an芍lisis estratigr芍fico y de facies revel車 la distribuci車n lateral y vertical de las unidades involucradas en el relleno, mientras que el estudio tectonoestratigr芍fico permiti車
%K Cuenca Neuquina
%K Argentina
%K Sin-rift
%K Tectonoestratigraf赤a
%K Volcanismo y sedimentaci車n
%K Neuqu谷n Basin
%K Argentina
%K Syn-rift
%K Tectonostratigraphy
%K Volcanism and sedimentation
%U http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062012000100007