The Alegria deposit is located at the northern flank of the Alegria Synform. The lithotypes form parallel lenses trending NE-SW/50SE with elongation in the N70E direction, arranged as an imbricated system. The formation of the deposit is due to tectono-metamorphism and supergenic processes. Three phases of tectono-metamorphism processes are recognized, of Precambrian age. The supergenic processes are related to the Cenozoic tectonics and morphogenesis, and imposed the more strong transformations, as martitization, goethitization, limonitization and formation of clay minerals.