Shallow and Deep Electric Structures in the Tolhuaca Geothermal System (S. Chile) Investigated by Magnetotellurics

The geoelectric properties of the geothermal system associated with Tolhuaca volcano were investigated by three-dimensional (3D) inversion magnetotelluric (MT) data. This study presents first resistivity model derived from 3D MT to have a better understanding its magmatic and hydrothermal system. We selected data 54 stations for inversion. performed series tests changing type be inverted, as well starting obtain in agreement geology. final conductive body (<20 Ωm) located 2 km below summit volcano, inferred shallow storage compartment. also distinguish ~300 m thick layer high conductivity (<10 corresponding argillic alteration. includes two resistive bodies (~200 upper crust laterally displaced alteration west beneath extinct Tolhuaca, which would correspond reservoir (~1000 surface) deep (>1800 that had so far not been identified previous models. result this provides new insights into complexity