Neotectonic and seismicity in the northern portion of Tunuyán Depresion, Mendoza province

Abstract

This paper is focused on a series of faults occurring in the NW Tunuyán depression (localities of Lomas del Jaboncillo, Loma del Peral, Loma Sola del Diablo) and its possible tectonic activity during the late Pleistocene-Holocene. Two east verging reverse faults were found in Loma Sola del Diablo (northern sector of Lomas del Peral) which caused the superposition of undifferentiated Neogene sediments on top of fanglomeradic deposits of Los Mesones Formation (lower Pleistocene, Polanski 1963). Three scarps of nearly NS trend that face west were identified at Lomas del Jaboncillo, the largest situated eastward being known as Chupasangral fault. The cinematic of these faults was inferred to be reverse. No neotectonic activity was identified in the Holocene eolian cover (El Zampal Formation) which surrounds the studied elevations. The faults analyzed do not apparently affect the Holocene deposits and seem not to be related with present seismicity, although they constitute a potential seismogenic source for the studied area.