Pinos Altos lies in the Sierra Madre gold belt, on the northeast margin of the Ocampo Caldera, which hosts many epithermal gold and silver occurrences.

The property is underlain by volcanic sequences and intrusive rocks disturbed by faulting. Its geological focus is a horst structure (an uplifted block of rocks) at least 10 kilometres long by 3 kilometres wide, defined by the Reyna de Plata Fault to the north and the Santo Niño Fault to the south. 

Mineralization on the property tends to be in epithermal low-sulphidation quartz-adularia vein systems with breccias and stockworks carrying gold and silver, which are associated with the Santo Niño and Reyna de Plata structures marking the main horst structure. There is also gold-silver mineralization in quartz-calcite-adularia veins associated with the Mascota-Carola-Bravo structures.

Deposits

The most significant mineralization found on the property consists of four zones hosted by the Santo Niño Fault – the El Apache, Oberon de Weber, Santo Niño and Cerro Colorado lenses. More than 60% of the current Pinos Altos mineral reserve is located in the steeply dipping Santo Niño vein zone, which is up to 40 metres thick and 2.5 kilometres long. It has a vertical extent of more than 750 metres, and remains open to the west and at depth.

The San Eligio zone, about 500 metres northeast of the Santo Niño zone, is part of the main mine project and continues to show promise. It is open along strike and at depth.

There are several other promising zones that are associated with the horst feature in the northwest part of the property. The Creston Mascota deposit is 7 kilometres northwest of the Santo Niño deposit, and is similar to it but dips shallowly to the west. Creston Mascota is about 1,000 metres long and 4 to 30 metres thick.  A stand-alone pit and heap leach operation was built at Creston Mascota in 2010, with commercial production achieved in March 2011. Exploration at Creston Mascota will focus on extending this orebody toward the Carola and Mina Bravo zones to extend the mine life of this satellite operation.

The Reyna de Plata and Sinter zones are part of the Reyna de Plata Fault (northwest-southeast). The Reyna de Plata deposit, divided into the Reyna de Plata Central and East veins, locally presents abundant zones of breccia and stockwork of white quartz, representing the mineralization in the area.

The Cubiro mineralization discovered in 2009 is 2 kilometres west of Creston Mascota. Cubiro is a surface deposit with depth potential that strikes northwest, has a steep dip and has been followed along strike for about 850 metres. Drilling has intersected significant gold and silver mineralization up to 30 metres wide. The Cubiro deposit remains open along strike to the northwest and at depth to the west. The topography at Cubiro is challenging, and it is possible that an underground access may be required to further the exploration in that area.