Abstract

GIAMBIAGI, L.; ALVAREZ, P.P.; BECHIS, F.  and  TUNIK, M.. Influence of the Triassic-Jurassic rift structures on the deformation style of the Aconcagua and Maragüe fold and thrust belts, Mendoza. Rev. Asoc. Geol. Argent. [online]. 2005, vol.60, n.4, pp.662-671. ISSN 0004-4822.

The Aconcagua and Malargüe fold and thrust belts developed in the Cordillera Principal, which between 32º- 34º and 34º-36º S latitude respectively, show a complex interaction between the sedimentary cover and the basement as a result of the existence of Triassic-Jurassic rift-related normal faults of the northern part of the Neuquén basin. Structural studies, together with chronological analysis of the deformation in the thin-skinned and thick-skinned zones, indicate that the evolution of both belts was controlled by the presence of NNW-trending border faults of the Atuel, Nieves Negras - Alvarado and Yeguas Muertas depocentres of the Neuquén basin. In this study we analyze three possible mechanisms of interaction between the thin-skinned and thick-skinned deformation. For the Aconcagua FTB, we propose that the pre-existing normal faults controlled the location of ramps within the basement. For the southernmost part of the Aconcagua FTB and the northern part of the Malargüe FTB we propose a mechanism of tectonic inversion of rift-related faults, together with short-cut faults, which propagated into the sedimentary cover generation the thin-skinned deformational area.

Keywords : Fold and thrust belt; Malargüe; Aconcagua; Neuquén Basin; Jurassic; Andean deformation.

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