Polymetallicore-shoots discovery and modelization with geoelectric surveys: Pingüino project, Deseado Massif

Abstract

The Deseado Massif has numerous gold and silver epithermal occurrences related to the middle to upper Jurassic magmatic event. The Pingüino project, according to particular structural conditions, exposes lower Jurassic magmatic rocks which belong to the beginning of the extensional event. This is conditioning the location of an atypical mineralization, characterized by the overlapping of polymetallic (Zn, In, Pb, Ag, Au, Cu, with As, Cd, Sn, W,Bi) and argentiferous ore (Ag and Au, with Zn and Pb). The discovery of this mineralization was carried our since 2004 by Argentex Mining Corporation, with participation of the geological group of the Instituto de Recursos Minerales (INREMI) since 2005. Considering all the exploration techniques, the induced polarization geoelectric survey is the most precise and trustable method toexplore polymetallic veins in the area. The chargeability anomalies, controlled in the field, are an unequivocal exploration tool. As an example, one of the seven areas surveyed by the geological-geophysical team of the INREMI was considered. Three categories of chargeability anomalies were defined: A, B and C, in decreasing order of importance, according to intensity, vertical and lateral continuity, and spatial relationship with outcropping mineralization.The most important anomaly was drilled, and one of the holes (P200-08) becomes the most important base metal intersection of the entire project (12.49 meterswith 2.25 gr/ton Au equivalent, 13.44 % between Zn and Pb and 31 gr/ton In).