The Pinion deposit is considered to be Carlin-type, sedimentary-rock-hosted deposits. Precious metal mineralization is generally submicroscopic, disseminated, and hosted principally in sedimentary rocks, with some mineralization in felsic dikes and sills as well. Unlike most Carlin-type systems, the Pinion deposit contains substantial silver which adds to the economics of the deposit.
This deposit is situated in a sequence of Paleozoic sedimentary rocks exposed within large horst blocks in which the sedimentary rocks have been broadly folded into a south- to southeastward-plunging, asymmetric anticline. The axis of this Pinion anticline trends approximately N50ºW to N60ºW and can be traced for approximately 3.2km. The limbs of the anticline dip shallowly at 10° to 25° to the west, and more steeply at 35° to 50° to the east. Disseminated gold and silver mineralization at the Pinion deposit is strongly controlled by a 3m to 120m-thick dissolution-collapse breccia at the contact between calcarenite of the Devils Gate Limestone and the overlying silty micrite of the Tripon Pass Formation. Gold deposition was contemporaneous with breccia development, quartz veins formation, silica ± barite replacement and infill of open spaces.
The mineral reserve estimate for Pinion is based on an open pit mine plan and production schedule, a gold price of $1,275 per ounce and a silver price of $16.50 per ounce. The Pinion mineral reserve estimate comprises a Probable Mineral Reserve of 16.81 million tonnes averaging 0.63 g/t Au and 4.65 g/t Ag representing a total of 341,000 contained ounces of gold and 2.51 million contained ounces of silver, and a Proven Reserve of 1.07 million tonnes averaging 0.66 g/t Au and 5.2 g/t Ag, representing a total of 23,000 contained ounces of gold and 191,000 contained ounces of silver.
The mineral resource estimate for Pinion was constrained within a $1,500 per ounce of gold optimized pit shell using gold cut-off grades of 0.14 g/t Au for heap leach material (oxide and transitional). The Pinion mineral resource estimate comprises a Measured Mineral Resource of 1.30 million tonnes averaging 0.64 g/t Au and 5.15 g/t Ag representing a total of 27,000 contained ounces of gold and 216,000 contained ounces of silver, an Indicated Mineral Resource of 27.62 million tonnes averaging 0.58 g/t Au and 4.18 g/t Ag representing a total of 517,000 contained ounces of gold and 3.71 million contained ounces of silver, and an additional Inferred Mineral Resource of 10.81 million tonnes averaging 0.64 g/t Au and 3.80 g/t Ag representing a further 224,000 contained ounces of gold and 1.32 million contained ounces of silver. Mineral Resources are inclusive of Mineral Reserves.