Integração de dados de aerogamaespectrometria, eletrorresistividade e polarização induzida – aplicação no estudo de áreas com mineralização aurífera na mina Cerro Rico, Lavras do Sul, RS

Abstract

The Cerro Rico Mine is geologically located at east from the Complexo Intrusivo Lavras do Sul and it was already studied and explored by several different companies. Currently, its exploration license belongs to the Amarillo Gold Corporation. The main remark for the area is the presence of zones with hydrothermal changes, caused by the intrusion of igneous bodies, according to previous studies. This research intends to perform a geophysical study, in detailed scale, of most likely anomalous sectors that may be associated to the gold and base metal producing mineralization, in addition to the identification of faults and fractures that may be serving as a conduct to the circulation of water with minerals association. Initially, the anomalous sectors were identified through airborne gamma-ray spectrometric data processing followed by Eletroresistivity and Induced Polarization studies through the sectors. The F factor anomalous contours shown a magnitude order of 1.04 and they are associated to hydrothermal change zones. The estimated models for the electrical resistivity curves showed an order of magnitude between 49 and 28,859 ohm m and the models estimated for the loadability curve showed an order of magnitude ranging from 0.01 to 14 mV / V, where the matching resistive lows With anomalous values of chargeability in SEV 04, 05 and 06, possibly indicates the presence of pyrite mineralizations associated with gold. Based on the integration of the aerogamaespectrometric, eletroresistivity data and probing holes of the Amarillo Gold Corporation it was possible to verify evidence of possible mineralization in SEV 03 and 06, in addition to the identification of a probable fractured zone with uplift of the basement between SEV 03 and SEV 04. The goal of the research, beyond the characterization of hydrothermal change zones, is to demonstrate the potential from the conjunct application of the airborne gamma-ray spectrometric data processing, eletroresistivity and Induced Polarization methods in order to contribute for the geologic – geophysical characterization of the Cerro Rico Mine.