Interrupciones extensionales en el desarrollo de la faja plegada y corrida de Malargüe (36°S).

BRUNO COLAVITTO; ANDRÉS FOLGUERA; LUCIA SAGRIPANTI; SOFIA IANNELLI; VICTOR VALENCIA; ALFONSO ENCINAS; LUCAS FENNELL

Congreso; XX Congreso Geológico Argentino; 2017

A series of extensional events have been documented during a period of tectonic quiescence in the Malargüe FTB. This period begins with the eruption of a volcanic succession in an intra-arc basin, where a maximum age of deposition of 67,1 ± 1,3 Ma allows its correlation with other volcanic units located along the arc and a series of marine transgressions both in the fore- and retro-arc. A second extensional event was identified in the retro-arc, where a thick pile of basalts with an intraplate signature were erupted within a series of half-grabens during the Late Oligocene ? Early Miocene. This event shows a generalized extensional regime during this times, where the structures of the fold and thrust belt were bounded by a series of extensional basins, both in the arc and retro-arc. A structural section connecting both areas gives a shortening of 12,72 km (9,13%) and shows tectonic inversion dominating in both extremes of the section and the generation of new thrusts dominating in the center, in accordance with the location of the extensional basins described in this work.