Using Airborne Magnetic and Radiometric Data to Unravel Auriferous Prospective Areas in the Pitangui Greenstone Belt, NW of Quadrilátero Ferrífero – MG

Abstract

The Pitangui Greenstone Belt (PGB), NW of the Quadrilátero Ferrífero, Brazil, is a meta-volcano-sedimentary sequence that hosts some important gold deposits recently discovered. Research has been made in the PGB to understand its gold mineral system, but the information regarding the prospective vectors associated with gold mineralization is still unclear. Here, we show the application of airborne magnetic and radiometric data to find the spatial relation between hydrothermal alteration zones and the structural framework of the PGB region. The results showed that the occurrence of gold deposits is associated with NW-SE structures and hydrothermal alteration zones. This association does not exist with E-W structures, which has direct implications on the relevance of these structures in the prospective modeling. Additionally, the application of radiometric data to map hydrothermal alteration zones showed that the limitations of this technique can generate anomalies not strictly associated with hydrothermal alteration processes. In this case, some anomalies could be linked with secondary processes like weathering, leaching, transportation and accumulation of mobile elements, such as K and U.