The San Martín mine is considered to be a typical example of a low sulfidation epithermal deposit, and the geological model used for exploration as well as the mineral resource estimation is that of a low sulfidation vein type deposit. Epithermal deposits form at shallow depths in volcanic-hydrothermal and geothermal environments, typically at temperatures between 160°C and 300°C (White and Hedenquist, 1995). They define a spectrum with two end members, low and high sulfidation (Hedenquist et al., 1998).

Fluid inclusion microthermometry carried out in sphalerite, quartz and fluorite for the Zuloaga vein indicates average homogenization temperatures and salinities of 297°C and 4.1 wt% NaCl eq (Albinson et al., 2001). The homogenization temperatures and low salinities (diluted fluids) in the Zuloaga vein and the alteration-mineral assemblage (interstratified illite/smectite in Zuloaga and Rosario) are consistent with low sulfidation vein-type deposits described by White and Hedenquist (1995) and Hedenquist et al. (1998). The presence of epidote in Zuloaga, Rosario and Other Veins is also consistent with the homogenization temperatures around 300°C determined for Zuloaga by Albinson et al (2001).

In the opinion of the QP, the deposits in the San Martín mine area are considered to be examples of low sulfidation epithermal deposits. The Miocene age of the mineralization and its association with volcanic rocks of the Upper Volcanic Series is also found for ot ........

San Martín veins and deposits are hosted on the side of a mountain range. Access to the workings is through adits developed horizontally, followed by ascendant and descendent ramps developed in waste.

All mine workings in San Martín are located above the water table, and no evidence of water bodies have been found during exploration. There are water inflows in the workings close to surface, mainly during the rainy season, but these inflows are managed by pumping.

Geotechnical studies have been completed in support of design parameters for the excavations, as well as ground support requirements.

San Martín currently uses cut-and-fill mining using resue to extract the mineralization. Resue is a mining variation that implements a two-phased process where the ore is extracted first and then the mining section is extended to allow access to mining equipment for subsequent cuts. A combination of jumbo and conventional (hand-held pneumatic) drills are used and the type of drill used depends on mining widths and availability of the jumbos.

The current minimum mining width used at site for cut-and-fill mining is 0.8 m, and 2.5 m for equipment access. After the resue portion is mined (typically the mineralization), additional waste is mined to allow for equipment access. Mined waste either reports to the surface waste storage facility or is used as fill for subsequent lifts. When mineralization that is greater than 2.5 m in width is mined, no ........

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