Caracterização dos alvos cascavel e tinteiro, Greenstone Belt de Faina, GO : implicações na identificação de novos alvos potenciais para exploração mineral

Abstract

The Faina Greenstone Belt is located in the southern sector of the Goiás Archean block and has been investigated since the 18 th century because of its gold deposits. Recent studies have revealed the polymetallic potential of the belt, which is indicated by the anomalous levels of Ag, Cu, Fe and Co in addition to Mn, Ba, Li, Ni, Cr and Zn. This study was developed based on a detailed analysis of two selected target sites, Cascavel and Tinteiro, and multisource data, such as airborne geophysics, geochemistry and geological information, were used to create a final prospectivity map from the integration of all these data. The applied methodology used to obtain this map was fuzzy logic. The gold mineralization of Cascavel target is inserted in an orogenic system and occurs in two overlapping quartz veins systems, called Mestre-Cascavel and Cuca, embedded in quartzite with an average thickness of 50 cm and guidance N45°-60°W/25°SW with free coarse gold in grains 2-3 mm to 3 cm. The potentiality map created for this prospect generated four first-order favorable areas for mineralization and new medium-favorability foci. The Tinteiro area, derived from studies conducted by Orinoco do Brasil Mineração Ltd., shows polymetallic mineralization associated with an iron oxide copper gold ore deposit (IOCG) system poterior to Cascavel target mineralization. Its prospectivity map generated 19 new target sites with the potential for Au, Cu and Ag mineralization, suggesting new directions for future prospecting programs.