Navidad mineralisation is epithermal, as demonstrated by widespread open space-filling crustiform and cockade textures in the gangue minerals (carbonate, barite) and sulphide assemblages. The abundance of base metals, combined with carbonate-rich gangue, suggests that the deposit is intermediate, rather than low, sulphidation in style. Typical high sulphidation sulphides and gangue minerals are absent, but there is rare late stage kaolinite and minor hydrothermal alunite that implies late ingress of a hypogene acid fluid.

In all of the Navidad deposits the gangue minerals are principally calcite with minor barite. Silica is less important and occurs mostly as chalcedony and late amethyst. Ore minerals recognizable with a hand lens include: native silver, clots of black sulphide comprising argentite/acanthite, discrete grains of sphalerite, galena, chalcopyrite, cuprite, bornite, native copper and copper carbonates (malachite, azurite). Similar styles of mineralisation and a similar paragenesis occur in most of the deposits. However, the proportion of sulphides varies considerably. Loma de La Plata is silver-rich, but is sulphide-poor and contains very low levels of lead, zinc and copper. Various pulses of mineralisation are observed, principally at Galena Hill.

The principal metal association is Ag-Pb. Other associations include Ag-Pb-Cu and Cu-Ag and, more rarely, Ag-Zn. Occasionally there is Ag only, or Cu-Pb-Zn or simply isolated occurrences of thes ........

The mining will be done by conventional open cut mining methods with the ore and associated non-economic material being mined on 5 m high benches and the non-economic material only tonnage being mined on 10 m high benches. The ore and non-economic material will be drilled and blasted, then loaded into 150 t trucks by a combination of backhoe loaders (17.0 m3 bucket size) and hydraulic front shovels (23.2 m3). The mine equipment fleet has been sized to accomplish the following tasks:

- Drill and blast the ore and non-economic material tonnage on a combination of 5 and 10 m benches.
- Load ore and non-economic material using either the backhoes (ore and associated noneconomic material on 5 m benches) or the hydraulic shovels (non-economic material on 10 m benches).
- Haul the ore to the primary crusher or adjacent run of mine ore stockpile.
- Haul non-economic material to its final destination, including hauling non-economic material to the 7A tailing impoundment area (but not construction of the embankment).
- Construct and maintain all roads used by the mine equipment, including berms and ditches.
- Maintain all non-economic material storage locations.
- Clean up in active mining areas.
- Other activities as needed to maintain a good working environment in the mine areas.

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