The CMC is a polymetallic hydrothermal, brittle low sulphidation deposit hosted in the andesitic rocks of the Rímac Formation. The veins exhibit pinch-swell type behavior typical of hydrothermal systems found within compressional and extensional structural environments. Vein widths reach upwards of 2.0 m and with a mean width of 0.6 m. The veins are known to split into two or more branches separated by waste rock materials.

The CMC property is almost entirely underlain by the Rímac Formation andesitic volcanic rocks. The base of the sequence is composed of brecciated volcanic rocks overlain by andesitic flows, agglomerate and tuff towards the top of the Cerro Huamanjune at approximately 4,500 masl elevation.

Mineralization at CMC is that of an anastomosed system where most of the secondary and tertiary veins branch off either from the main vein or the secondary veins. This has produced the necessary conduits to be filled by mineralized hydrothermal fluids. The overall system trends towards the NE at approximately 15°, and the veins are primarily sub-vertical to steeply NW dipping. It is thought that the anastomosed vein system is part of a larger tectonic shear zone with associated secondary and tertiary tensional veins.

The three main veins on the CMC property include the Wellington, Constancia and Animas veins. These veins define three structurally dislocated blocks from which a series of secondary and tertiary tensional veins splits off. ........

With all of this previous activity, CMC has established mine access portals, level development, raises and underground infrastructure that, in most cases, can be utilized for future operations. The proposed CMC restart considers utilizing existing mine infrastructure, access portals, rail transfer levels, ramps, and ancillary mine systems to produce approximately 550 tpd (198,000 tonnes per year) from underground mining. Multiple veins will be mined at the same time and sequenced to maximize value. A ramp-up period will be needed since existing access levels can be rehabilitated to allow for stope development.

Due to the geometry of the mineralized zones, highly selective mining methods must be used for all veins at CMC. Two mining methods are proposed, both as variants of the overhand cut-and-fill (CAF) mining methods. In cases where the vein width is narrower than 0.50 m, resue mining will be used. Resue mining involves selectively blasting and removing mineralized material, prior to blasting waste, to make-up the total minimum mining width of 0.90 m. This mining process is slower and more labor intensive than traditional overhand CAF, but it reduces the amount of waste rock that is shipped to the process plant.

In cases where the vein width is greater than 0.50 m, traditional overhand CAF mining will be used with waste rock as the backfill. In both cases, production stope dimensions are 50 m high by 60 m along strike. These two methods have been histo ........

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