Resources & Reserves

CONSOLIDATED MINERAL RESERVE ESTIMATE (EFFECTIVE DECEMBER 31, 2019)

1. The Hislop mine is a formerly producing open-pit mine acquired as part of the St Andrew Goldfields acquisition in January 2016. Hislop has not been operated by the Company since the acquisition. The Holloway mine was placed on care and maintenance effective December 31, 2016 and resumed commercial operation in the first quarter of 2019. The Cosmo mine and Union Reefs mill were placed on care and maintenance effective June 30, 2017.

Detailed footnotes related to Mineral Reserve Estimates (dated December 31, 2019) - with the exception of Detour:

1. CIM definitions (2019) were followed in the estimation of Mineral Reserves.
2. Mineral Reserves were estimated using a long-term gold price of US$1,300/oz (C$1,700/oz; A$1,765/oz).
3. Cut-off grades for Canadian Assets were calculated for each stope and included the costs of: mining, milling, General and Administration, royalties and capital expenditures and other modifying factors (e.g. dilution, mining extraction, mill recovery).
4. Cut-off grades for Australian Assets were calculated for each mining block and included the costs of: mining, milling, General and Administration, royalties and capital expenditures and other modifying factors (e.g. dilution, mining extraction, mill recovery).
5. Dilution estimates vary by mining methods and ranges from 5% to 50%.
6. Extraction estimates vary by mining methods and range from 50% to 100%.
7. Mineral Reserves estimates for Canadian Operations were prepared under the supervision of N.Vaz, P. Eng.
8. Mineral Reserves estimates for Australian Operations were prepared under the supervision of I.Holland, FAusIMM
9. Mineral Reserves are stated at a mill feed reference point.
10. Totals may not add up due to rounding.

CONSOLIDATED MEASURED & INDICATED MINERAL RESOURCES (EFFECTIVE DECEMBER 31, 2019)

CONSOLIDATED INFERRED MINERAL RESOURCES (EFFECTIVE DECEMBER 31, 2019)

Detailed footnotes related to Detour’s Mineral Reserve and Resource Estimates (dated December 31, 2019):

1. CIM definitions (2019) were followed in the calculation of Mineral Resource.
2. Mineral Resources are reported Exclusive of Mineral Reserves. Mineral Resources were calculated according to KL Gold’s Mineral Resource Estimation guidelines. 
3. Mineral Resource estimates were prepared under the supervision of Eric Kallio, P. Geo. Senior Vice President, Exploration.
4. Mineral Resources are estimated using a long-term gold price of US $1,300/oz (C$1,700/oz).
5. Mineral Resources were estimated using a range of 3.4g/t to 8.6 g/t cut-off grades for Macassa Mine, a 2.8 g/t cut-off grade for Holt Mine and Holloway Mine, a 2.5 g/t cut-off grade for Holt Near Surface, a 2.6 g/t cut-off grade for Taylor, a 2.5 g/t cut-off grade for Canamax, a 2.2 g/t cut-off grade for Hislop and a 0 g/t cut-off grade for Aquarius.
6. Totals may not add up due to rounding.

Detailed footnotes related to Mineral Resource Estimates for Australian Assets (dated December 31, 2019)

1. CIM definitions (2019) were followed in the estimation of Mineral Resource.
2. Mineral Resources are estimated using a long-term gold price of US$1,300/oz (A$1,765/oz)
3. Mineral Resources for the Australian assets are reported exclusive of Mineral Reserves.
4. Mineral Resources at Fosterville were estimated using cut-off grades 0.7 g/t Au for oxide and 1.0 g/t Au for sulfide mineralization to potentially open-pitable depths of approximately 100m, below which a cut-off grade of 3.0 g/t Au was used.
5. Mineral Resources in the Northern Territory were estimated using a cut-off grade of 0.5 - 0.7 g/t Au for potentially open pit mineralization and cut-offs of 1.5 to 2.0 g/t Au for underground mineralization.
6. Mineral Resource estimates for the Fosterville property were prepared under the supervision of Troy Fuller, MAIG.
7. Mineral Resource estimates for the Northern Territory properties were prepared under the supervision of Owen Greenberger, MAIG.
8. Totals may not add up due to rounding.

Detailed footnotes related to Detour’s Mineral Reserve and Resource Estimates (dated December 31, 2019):

1. The Company’s mineral reserve and mineral resource statement is classified in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) “CIM Definition Standards - For Mineral Resources and Mineral Reserves" adopted by the CIM Council (as amended, the “CIM Definition Standards”) in accordance with the requirements of National Instrument 43-101 “Standards of Disclosure for Mineral Projects" (“NI 43-101”). Mineral reserve and mineral resource estimates reflect the Company's reasonable expectation that all necessary permits and approvals will be obtained and maintained.
2. Mineral reserves were estimated using a gold price of US$1,000/oz and mineral resources were estimated using a gold price of US$1,200/oz at a $US/$CDN exchange rate of 1.10.
3. Mineral reserves and resources were based on a cut-off grade of 0.50 g/t Au.
4. LG fines (sourced from material grading 0.40 - 0.50 g/t Au) classified as Measured or Indicated were reported as Probable mineral reserves and included in the mine plan. Reported tonnage is defined as material scheduled to be fed from 2021 to the end of the mine as per 2018 life of mine plan.
5. Further information, including key assumptions, parameters, and methods used to estimate mineral resources and mineral reserves are described in the Technical Report on the Detour Lake operation, dated Nov 26th, 2018.
6. Mineral underground resources for 58N reported at a cut-off grade of 2.2 g/t Au, using a gold price of US$1,300 per ounce and a $US/$CDN exchange rate of 1.25 with an assumed mining dilution of 12%.
7. Mineral resources are reported exclusive of mineral reserves. Mineral resources that are not mineral reserves do not have demonstrated economic viability. Mineral resources are constrained within an economic pit shell.
8. Mineral Reserves and Mineral Resource estimates for the Detour Operation was prepared under the supervision of A. Leite, PEng , AUSIMM CP (MIN), MEng, P. Eng.
9. Totals may not add due to rounding.