Reserves and Resources
PUMPKIN HOLLOW MINERAL RESERVES
Open Pit Mineral Reserves
The current mineral reserve estimate for the open pit was disclosed April 16, 2019 and the related NI 43-101 Technical Report was filed on SEDAR in April 16, 2019, with an effective date of January 21, 2019.
The tons, grades, and classification of the Mineral Reserves estimate in the Open Pit PFS mine plan are tabled below.
Confidence Category Ore (Mst) Average Ore Grades Contained Metal Cu (%) Au (oz/st) Ag (oz/st) Cu (Mlbs) Au (Koz) Ag (Koz) Proven Mineral Reserves (North) 75.4 0.65 0.002 0.070 983 151 5,302 Proven Mineral Reserves (South) 31.3 0.36 0.002 0.045 223 48 1,420 Proven Mineral Reserves (North + South) 106.6 0.57 0.002 0.063 1,206 199 6,722 Probable Mineral Reserves (North) 147.4 0.48 0.001 0.055 1,407 215 8,086 Probable Mineral Reserves (South)
131.7 0.37 0.002 0.049 977 203 6,458 Probable Mineral Reserves (North + South) 279.1 0.43 0.001 0.052 2,384 419 14,544 Proven and Probable Mineral Reserves 385.7 0.47 0.002 0.055 3,590 617 21,266 Note: Effective date of Open Pit Mineral Reserve is January 21, 2019.
CIM industry best practices were followed in the development of the Mineral Reserve- Inferred Mineral Resource was considered waste for the open pit reserve estimate.
- The cutoff 0.129% Cu for the North Pit and 0.132% Cu for the South Pit is based on the copper processing recoveries (90% for the North Pit, 88% for the South Pit) and costs. Dilution was assumed 5% and mining recovery of 98%
- Calculations used price forecast/recoveries: Cu $2.75/lb & described above, Au $1,343/toz & 67%, and Ag $19.86/toz & 56%.
- A selling cost of $0.55/lb was applied to the Cu in concentrate to account for NSR. No selling costs were applied to Au or Ag. NSR and CuEq calculations
Statement of Underground Mineral Reserve Estimate
Approximately 51% of the total Underground Measured and Indicated Mineral Resources were converted to a Mineral Reserve by the mine plan, due to the targeting of higher grade ore within the Deposits. The stated Proven and Probable Mineral Reserves estimate has been shown to be economic on the basis of reasonable cost assumptions and NSR values assigned to the resource model.
Mineral Reserve Estimate (Underground)
Category Tons Cu Au Ag (millions) % oz/st oz/st Proven 7.4 1.85 0.007 0.144 Probable 16.5 1.47 0.006 0.138 Net Reserves 23.9 1.59 0.006 0.139 Note: Effective date on the Underground Mineral Reserve is September 15, 2017
PUMPKIN HOLLOW MINERAL RESOURCES
Open Pit Mineral Resources
The current mineral resource estimate for the open pit was disclosed April 16, 2019 and the related NI 43-101 Technical Report was filed on SEDAR in April 16, 2019, with an effective date of January 21, 2019 .
The Mineral Resource estimate used as the basis for the Open Pit PFS is summarized below. Mineral Resources are subdivided into classes of Measured, Indicated and Inferred, with the level of confidence reducing with each class respectively. Mineral Resources are reported as in situ tonnage and are not adjusted for mining losses or mining recovery. The Mineral Resources reported are inclusive of those reported in Mineral Reserves. The reader is cautioned that Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
Confidence Category Ore (Mst) Average Ore Grades Contained Metal Cu (%) Au (oz/st) Ag (oz/st) Cu (Mlbs) Au (Koz) Ag (Koz) Measured Mineral Resources 134 0.561 0.002 0.064 1,508 255 8,593 Indicated Mineral Resources
419 0.417 0.001 0.051 3,492 623 21,185 Measured and Indicated Mineral Resources 553 0.452 0.002 0.054 5,000 879 29,778 Note: Effective date of Open Pit Mineral Resource is January 21, 2019.
Confidence Category Ore (Mst) Average Ore Grades Contained Metal Cu (%) Au (oz/st) Ag (oz/st) Cu (Mlbs) Au (Koz) Ag (Koz) Inferred Mineral Resources 28 0.358 0.001 0.040 197 37 1,088 CIM industry best practices were followed in the development of Mineral Resources:
- Totals may not total due to rounding.
- Cu Eq. calculated Mineral Resources were estimated at a cutoff grade of 0.12% Cu
- Resources were contained within a pit shell produced using a Cu price of $3.75/lb, Au $1,343/Troy Oz and Ag at $19.86/ Troy Oz
- Includes North, South and South-East deposits.
- Excludes materials that are oxidized, transition or volcanics.
- Columns using prices / recoveries: Cu $3.20/lb & 89.3%; Au $1,325/Oz & 67.3%; and Ag $20.01/Oz & 56.3%.
Underground Mineral Resources
The Underground Mineral Resource estimate was prepared by Tetra Tech and included in a technical report titled ‘NI 43-101 Technical Report Integrated Feasibility Study Pumpkin Hollow Project Yerington, Nevada’ with an effective date for the Underground Mineral Resource of April 15, 2015. The Underground Mineral Resource estimate was based on the results of all drilling up to the end of 2013. The 2015 and 2018 drilling has not been used to modify the current Mineral Resource estimate. Tetra Tech confirmed that there has been no material change in the current Mineral Resources estimate based on these drilling results. In addition, there has been no change in sampling protocols including drilling, sample preparation, analytical method, verification and security measures. On this basis, Tetra Tech has deemed that no revision to the current Mineral Resource estimate is required. Mineral Resources are subdivided into classes of Measured Resources, Indicated Resources and Inferred Resources, with the level of confidence reducing with each class, respectively. Mineral Resources are reported as in situ tonnage and are not adjusted for mining losses or mining recovery. The Mineral Resources reported are inclusive of Mineral Reserves. In addition to cutoff grade, the Underground Mineral Resources have been limited to the 0.5% Cu mineralized shell interpretation. The reader is cautioned that Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
Mineral Resource Underground Eastern Area
Category Cutoff Grade %/Cu Tons (millions) Grade %/Cu Contained Cu lb (millions) Grade Au oz/st Contained Au ozs (thousands) Grade Ag oz/st Contained Ag ozs (thousands) Grade Fe Contained Fe tons (millions) Measured 0.75 12.1 1.60 389 0.006 74 0.127 1,541 18.7 2.3 Indicated
0.75 41.9 1.33 1,114 0.005 217 0.112 4,716 17.6 7.4 Measured + Indicated 0.75 54.1 1.39 1,503 0.005 291 0.116 6,257 17.8 9.6 Inferred 0.75 29.2 1.09 636 0.003 87 0.064 1,875 12.8 3.7 Notes: Includes East and E2 deposts
Measured and Indicated Resources are stated as inclusive of reserves
Columns may not total due to rounding
Resources are constrained by a 0.5% Cu mineralized interpretation
Effetive date on Underground Mineral Resource is April 15, 2015