%0 Journal Article
%T Deformaci車n andina en el cord車n del Hielo Azul al oeste de El Bols車n: Implicancias en la evoluci車n tect車nica de la Cordillera Norpatag車nica en R赤o Negro, Argentina
%A Tobal
%A Jonathan E
%A Rojas Vera
%A Emilio
%A Folguera
%A Andr谷s
%A Ramos
%A V赤ctor A
%J Andean geology
%D 2012
%I Scientific Electronic Library Online
%R 10.5027/andgeoV39n3-a05
%X this geological study, carried out in the cord車n del hielo azul, west of the el bols車n town (r赤o negro province, argentina), shows the different relationships between the early jurassic cordilleran volcanosedimentary sequence, the middle-upper jurassic cordilleran patagonian batholith and the cenozoic volcanic rocks of the ventana formation exposed in the patagonian cordillera of r赤o negro. through structural analysis, a series of previously unknown complex deformational structures have been identified. it has been observed that the sequence of volcanic rocks that outcrop on the cerro lindo, just west of el bols車n, is bounded by a backthrust in the eastern side and by an out of sequence thrust to the west; two other thrusts affect the sequence, with associated folded structures. to the north, on the west side of cerro hielo azul, these lower jurassic volcanic rocks are in tectonic contact with the cenozoic rocks of the ventana formation. based on these observations, we inferred that an extensional fault controlled deposition of the cenozoic volcanic rocks, being subsequently inverted, superimposing these rocks on the jurassic volcanics. the different recognized faults exerted a first order control in the building of the mountain front and are robust evidence to establish the tectonic framework and uplift history of the north patagonian andes. this deformation took place from the eocene to the late miocene. a pre-oligocene contractional pulse led to the development of a thin-skinned fold and thrust belt affecting the jurassic volcanics. during the oligocene a regional extensional event resulted in the formation of basins such as the one recognized on cerro silvia, where the ventana formation crops out. a second contractional pulse took place during the miocene and led to the development of a thick-skinned fold and thrust belt with deep faults that built the present mountain front.
%K north patagonian andes
%K structure
%K andean tectonics
%K fold and thrust belt
%K argentina.
%U http://www.scielo.cl/scielo.php?script=sci_abstract&pid=S0718-71062012000300005&lng=en&nrm=iso&tlng=en