GIS-based prospectivity mapping for orogenic gold: a case study from the Andorinhas region, Brasil

This study involves the generation of new geological and structural maps through analysis and interpretation from high resolution geophysical and remote sensing datasets over the Andorinhas region, located in the Rio Maria Granite-Greenstone Belt in the southern part of the Carajás Mineral Province, Brasil. Using available aeromagnetic, gamma-ray spectrometer data and Landsat imagery, revised geological and structural maps were generated for the area using GIS-based methodologies. The structural history was then reviewed based on field-based observations to give a timing to the structures relative to the mineralization in the region. Exploration targets for orogenic gold were then derived by integrating these datasets using the fuzzy logic technique for mineral prospectivity analysis. These targets were then followed up with higher resolution field mapping and geochemical sampling