The Deseado Massif is characterized by a middle to upper Jurassic bimodal extensive volcanic event. Most of the epithermal mineralization is hosted and genetically related to this event. Pinguino veins are hosted in older rocks, within a series of Triassic to Lower Jurassic continental sedimentary rocks (El Tranquilo Group) and felsic tuffs and tuffites (Roca Blanca Formation). This sequence was affected by mafic shallow intrusions and lava flows of the Cerro León Formation and then covered by the Jurassic volcanism. The area is interpreted as a dome structure produced by possible diorite intrusion at depth, with local deformations where shallow andesitic intrusions are present. A strike-slip zone with a major northwest-trending El Tranquilo Fault and several associated faults and lineaments was also defined.