Description of the shallow layers at Antinaco-Los Colorados Valley, NW Argentina

We performed a geophysical study in Antinaco-Los Colorados Valley to determine the thickness of the sedimentary cover and the sequence of the more superficial layers. Eight magnetotelturic and four audiomagnetotelluric soundings were performed along an east-west profile. Analysis of the results indicates that a deep basin and a very conductive layer can be detected at a depth of around 400 m, coincident with the depth of drillings. This layer may be associated with the presence of aquifers. These studies also indicate that the basement is shallower to the east (1 km) and deeper to the west (3 km).