Control of Mesozoic extensional structures on the Andean deformation in the northern sector of the Malargüe fold and thrust belt

BECHIS, F.; GIAMBIAGI, L.; YAGUPSKY, D. L.; CRISTALLINI, E. O.; GARCÍA V.; MESCUA, J.

Niza, Francia

Simposio; 7th International Symposium on Andean Geodynamics; 2008

Introduction The study area is located in the northern sector of the Malargüe fold and thrust belt, in the Central Andes of central-western Argentina. In this sector of the belt, Andean deformation inverted a Late Triassic to Early Jurassic extensional depocentre of the Neuquén basin (Kozlowski  et al., 1993; Manceda and Figueroa, 1995; Giambiagi et al., in press). The main goal of this contribution is to identify the principal controls exerted by the extensional structures over the Andean deformation in the northern sector of the Malargüe fold and thrust belt. Our study is based on data obtained from detailed structural and geological field mapping, integrated with subsurface information. The orientation, timing and structural style of the Andean structures were compared with the extensional architecture of the Atuel depocentre, previously addressed by Manceda and Figueroa (1995), Lanés (2002, 2005) and Giambiagi et al. (2005). In addition, the mapped structures were compared with the results obtained from scaled sandbox analogue models simulating the deformation of a half-graben oblique to the shortening direction during the evolution of a fold and thrust belt.