The North Bullion Deposit occurs in similar host rocks as the Pinion Deposit and is also considered to be a Carlin-type, sedimentary-rock-hosted deposit. I has similarities to Nevada Gold Mines’ Rain Deposit approximately 7 kilometers to the north. Mineralization is submicroscopic, disseminated, and hosted principally in sedimentary rocks, with some mineralization in felsic dikes and sills as well.
Mineralization is focused in the footwall of the Bullion fault zone. Faults appear to be important controls on mineralization. In general, gold-silver mineralization is localized in gently to moderately dipping, strongly sheared rocks of the Webb and Tripon Pass formations, in dissolution-collapse breccia developed above and within silty micrite of the Tripon Pass Formation, and calcarenite of the Devils Gate Limestone. The top of gold mineralization varies from 105 m to 400 m below the surface and varies in dip from 10° to 45° to the east. Gold is associated with “sooty” sulfide minerals, silica, carbon, clay, barite, realgar, and orpiment.
The North Bullion Resource contains material from 3 closely spaced zones and consist of the POD, Sweet Hollow and North Bullion deposits. It has a resource estimate prepared in accordance with NI 43-101 consisting of a Indicated Mineral Resource of 2.92 million tonnes grading 0.96 g/t Au, totaling 90,100 ounces of gold and an Inferred Resource of 10.97 million tonnes grading 2.28 g/t Au, totaling 805,800 ounces of gold, using a cut-off grade of 0.14 g/Au/t for near surface oxide and 1.25 to 2.25 Au/t for near surface sulfide and underground sulfide respectively.
The details of the individual zones can be further defined as follows: The The Sweet Hollow and POD oxide Indicated and Inferred Mineral Resource uses a cut-off grade of 0.14 g/t Au, which is constrained within an optimized pit shell and includes an Indicated Mineral Resource of 2.92 million tonnes at 0.96 g/t Au for 90,100 contained ounces of gold and an Inferred Mineral Resource of 3.36 million tonnes at 0.43 g/t Au for 46,600 contained ounces of gold. The North Bullion deposit sulphide Inferred Mineral Resource uses a cut-off grade of 1.25 g/t Au, which is constrained within an optimized pit shell, and is comprised of 2.05 million tonnes at 2.60 g/t Au for 171,400 contained ounces of gold. The North Bullion deposit underground Inferred Mineral Resource, which is reported at a lower 2.25 g/t Au cut-off grade, comprises 5.55 million tonnes at 3.29 g/t Au for 587,700 contained ounces of gold.