The Fire Creek deposit is considered to be a low-sulfidation, epithermal deposit.

Low-sulfidation epithermal systems are also referred to as quartz ± calcite ± adularia ± illite or adularia-sericite epithermal systems. These nomenclatures refer to the oxidation state of the ore fluid sulfur component, gangue mineralogy and hydrothermal fluid pH, respectively. Ore-fluids in a low-sulfidation hydrothermal system are reduced, have a near-neutral pH and are dominated by deeply-circulated meteoric water. These deposits form in the shallow crust, 0.5 to 1.5 miles at temperatures of greater than 300°C in subaerial volcanic settings. Steeply-dipping, open-space veins are common. Quartz is the principal gangue mineral and can be accompanied by chalcedony, adularia, illite, pyrite, calcite, and rhodochrosite. Boiling is the dominant metal deposition mechanism and commonly results in vein textures including crustiform-colloform bands and platy calcite and/or quartz-after-calcite pseudomorphs. Ore metals are usually Au-Ag, Ag-Au or Ag-Pb-Zn and, contrary to the ore-fluid source, metals in NNR-related epithermal deposits are sourced from mantle-derived basaltic magmas (Kamenov et al., 2007).

Zoned hydrothermal alteration comprises widespread and deep propylitization that grades upwards to clay, carbonate and zeolite formation. Proximal alteration comprises quartz, adularia, and pyrite. High-level advanced argillic alteration characterized by clay-carbonate-pyrite or ........

Mining methods include several different techniques such as end slice stoping with delayed backfill, also referred to as longhole stoping, and drift and fill stoping. The final choice of mining method will depend upon the geometry of the stope block, proximity to main access ramps, ventilation and escape routes, the relative strength or weakness of the mineralized material and adjacent wall rock, and finally the value or grade of the mineralized material. The choice of mining method will not be made until after the stope delineation and definition drilling is completed. Each method will be discussed briefly in the following paragraphs.

End Slice Stoping:
End slice, or longhole, stoping has the highest degree of mechanization of the three expected mining methods at the Project, is the lowest cost method and generally provides the lowest total cost per ounce. End slice stoping requires the greatest amount of waste development and can be mined to a minimum width of four feet. The potential for unplanned wall dilution with this method is the greatest.

The amount of mineralization that can be removed prior to backfilling will be constrained by the strength of the gangue material and jointing present immediately adjacent to the stope. Backfill, consisting of either waste rock or cemented rock fill, will be transported from the surface using the same haulage equipment used to remove mineralized material and waste rock from the mine. Where possible, waste ........

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