Porphyry copper deposits in the Mexican Altiplano are related to Tertiary intrusive complexes ranging in composition from quartz monzonite to granodiorite. Although the sedimentary rocks affected by these intrusive complexes have undergone contact metasomatism and skarnification, the gold, copper, and silver mineralization occurs in porphyry alteration assemblages. In Aranzazu, it is characterized by propylitic alteration showing a transition into phyllic alteration, represented by quartz-sericite-illite-pyrite, with areas of potassic alteration, characterized by secondary biotite and K-feldspar; while in San Anton-Cerro del Gallo the strong potassic alteration is characterized by thin fractures filled mainly by K-feldspar and biotite, overprinted by propylitic alteration. Phyllic alteration is also present in restricted areas of sericite-quartz and pyrite.

There are two porphyry copper deposits with published resources (all inclusive) for over 2.1M Oz Au, 29M Oz Ag, and 927M Lb Cu. Primero´s San Anton-Cerro del Gallo property in Guanajuato State is the largest deposit and has published resources (all inclusive) for over 1.6M Oz Au, 15.4M Oz Ag, and 160M Lb Cu at grades of 0.64 g/t Au, 14.02 g/t Ag, and 0.06% Cu. Aranzazu property in Zacatecas State, owned by Aura Minerals has published resources (all inclusive) for over 484K Oz Au, 13.6M Oz Ag, and 768M Lb Cu at grades of 0.66 g/t Au, 17.90 g/t Ag, and 1.48% Cu.

The table below shows tonnages, grades, as well as gold, silver, and copper resources (all inclusive) for each of these deposits.