Abstract
The Tuzgle volcano (24°03'S, 66°29'W), situated in the southern part of the South American Andean Altiplano (Argentine northwest region, called Puna) is in the central part of an Ordovician depression. This paper presents the results of ten magnetotelluric stations near the volcano zone, investigating resistivity anomalies in the crust that could be related to the observed geothermal anomaly. The analysis of the signals (periods between 10-1 and 10000 seconds) was performed, using tensor analysis. One-dimensional models of the resistivity distribution in the Earth were proposed. The results were compared with the previous information. This study revealed resistivity structure down to several kilometers. Three high conductive layers were detected. The first layer is situated between 0.67 and 1.7 km depth, the second layer between 6 and 8.6 km depth and the third layer at 31 km depth. The second layer might be a magmatic chamber beneath the Tuzgle volcano.
