Reserves & Resources
Summary of Mineral Reserves – December 31, 2022
Austral Gold Limited – Guanaco/Amancaya Mine Complex
| Category | Tonnes (000 t) |
Grades | Contained Metal | ||
| (g/t Au) | (g/t Ag) | (000 oz Au) | (000 oz Ag) | ||
Guanaco and Amancaya Mine
| Underground | |||||
| Proven | 32 | 5,81 | 14,42 | 6 | 15 |
| Probable | 116 | 5,84 | 16,94 | 22 | 63 |
| P+P | 148 | 5,83 | 16,40 | 28 | 78 |
Inesperada
| Open Pit | |||||
| Proven | - | - | - | - | - |
| Probable | 1607 | 1,05 | 14,39 | 54 | 744 |
| P+P | 1607 | 1,05 | 14,39 | 54 | 744 |
Heap Reprocessing Project
| Heap | |||||
| Proven | 10189 | 0,68 | 3,16 | 221 | 1037 |
| Probable | - | - | - | - | - |
| P+P | 10189 | 0,68 | 3,16 | 221 | 1037 |
Total
| Proven Total | 10221 | 0,69 | 3,20 | 227 | 1052 |
| Probable Total | 1723 | 1,37 | 14,56 | 76 | 807 |
| Total P+P | 11945 | 0,79 | 4,84 | 303 | 1859 |
Notes
1. Mineral Reserves followed CIM (2014) definitions and are compliant with the JORC Code.
2. Mineral Reserves are reported on a 100% ownership basis and estimated at the following cut-off grades:
Amancaya: break-even cut-off grade of 3.04 g/t AuEq, and marginal cut-off grades of 2.37 g/t AuEq and 1.37 g/t AuEq for SLS stopes and drifts, repectively.
Inesperada - pit discard cut-off grade of 0.40 g/t Au.
Heap Leach Pads - Marginal cut-off grades for Heap Reprocessing have been estimated as 0.20 g/t Au and 0.15 g/t Au for Heaps I and Heap II respectively, and at zero cut-off for Heaps III.
3. Mineral Reserves are estimated using an average long-term gold price of US$1,700/oz and silver price of US$22/oz.
4. Gold Equivalent (AuEq) for Amancaya was calculated as AuEq = Au + 0.0110 x Ag, based on prices of $1,700/oz Au and $22/oz Ag and recoveries of Au and Ag of 93% and 79%, respectively.
5. The following parameters were used for the Amancaya Mineral Reserve estimate:
A minimum mining width of 1.5 m was used for SLS stopes and 3.5 m for drifts.
Stope dilution: 0.5 m in the hanging wall and 0.5 m in the footwall (1.0 m total).
Drift dilution: 0.25 m in each of the side walls (0.5 m total).
6. Metallurgical recovery is 93% for gold and 79% for.
7. Bulk density is 2.5 t/m3.
8. The following parameters were used for the Inesperada Mineral Reserve estimate:
Dilution and mining recovery factors of 0% and 100% respectively were applied.
Metallurgical recovery is 80% for gold.
Bulk density is 2.44 t/m3.
9. The following parameters were used for the Mineral Reserve estimate for the Guanaco Heaps:
Heap Leach Pad I: maximum of 5% dilution. The average dilution over the LOM is 3.5%. Dilution grades are 0.18 g/t Au and 1.50 g/t Ag.
Heap Leach Pad II: maximum of 5% dilution. The average dilution over the LOM is 2.5%. Dilution grades are 0.13 g/t Au and 1.40 g/t Ag.
Heap Leach Pad III: All internal dilution within the heap limits was included.
10. Metallurgical recoveries for Heaps I, II, and III are 54%, 70%, and 46% for gold respectively.
11. Bulk density is 1.77 t/m3 for Heap I, 1.50 t/m3 for Heap II, and 1.70 t/m3 for Heap III.
12. Numbers may not add due to rounding.
Summary of Mineral Resources – December 31, 2022
Austral Gold Limited – Guanaco/Amancaya Mine Complex
| Category | Tonnes (000 t) |
Grades | Contained Metal | ||
| (g/t Au) | (g/t Ag) | (000 oz Au) | (000 oz Ag) | ||
Guanaco and Amancaya Mine
| Underground | |||||
| Measured | 594 | 2,77 | 13,00 | 53 | 248 |
| Indicated | 868 | 2,31 | 17,67 | 64,5 | 492,9 |
| M+I | 1448 | 2,43 | 15,67 | 113,3 | 729,5 |
| Inferred | 250 | 3,42 | 6,26 | 27,6 | 50,4 |
Inesperada
| Open Pit | |||||
| Measured | - | - | - | - | - |
| Indicated | 1682 | 1,05 | 14,38 | 57 | 778 |
| M+I | 1682 | 1,05 | 14,38 | 57 | 778 |
| Inferred | 74 | 0,91 | 12,40 | 2 | 30 |
Heap Reprocessing Project
| Heap | |||||
| Measured | 11366 | 0,67 | 3,10 | 246 | 1133 |
| Indicated | - | - | - | - | - |
| M+I | 11366 | 0,67 | 3,10 | 246 | 1133 |
| Inferred | 1907 | 0,55 | 2,64 | 34 | 162 |
Total
| Total Measured | 11961 | 0,78 | 3,59 | 299 | 1381 |
| Total Indicated | 2692 | 1,82 | 15,73 | 158 | 1362 |
| Total M+I | 14652 | 0,97 | 5,82 | 457 | 2743 |
| Total Inferred | 2383 | 1,18 | 3,93 | 90 | 301 |
Notes
1. Mineral Resources followed CIM (2014) definitions and are compliant with the JORC Code.
2. Mineral Resources are reported on a 100% ownership basis.
3. Mineral Resources are inclusive of Mineral Reserves.
4. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
5. Mineral Resources are estimated at the following cut-off grades:
Amancaya and Guanaco Underground Mineral Resources: 2.90 g/t AuEq and 1.50 g/t AuEq, respectively.
Inesperada open pit Mineral Resources: 0.38 g/t Au.
Heap Leach Pads Mineral Resources: zero cut-off grade.
6. Mineral Resources at Guanaco and Amancaya are estimated using a long term gold price of US$1,750/oz and a silver price of US$22/oz. Mineral Resources at Inesperada and Heap Leach Pads are estimated using a long term gold price of US$1,750/oz.
7. Gold equivalency (AuEq) was calculated as follows:
Guanaco: AuEq = Au + 0.0106 x Ag based on a gold and silver price of $1,750/oz and $22/oz and recoveries of gold and silver of 95% and 80%, respectively.
Amancaya: AuEq = Au + 0.0107 x Ag based on a gold and silver price of $1,750/oz and $22/oz and recoveries of gold and silver of 93% and 79%, respectively.
8. Metallurgical recoveries are 93% for gold and 79% for silver for Amancaya, 95% for gold and 80% for silver for Guanaco, 80% for gold for Inesperada, and 54%, 70%, and 46% for gold for Heaps I, II, and II, respectively.
9. A minimum mining width of 1.5 m is used for resource underground shapes for the Amancaya and Guanaco mines.
10. Bulk densities are 2.5 t/m3 for Amancaya and Guanaco, 2.44 t/m3 for Inesperada, and 1.77 t/m3 for Heap I, 1.50 t/m3 for Heap II, and 1.70 t/m3 for Heap III, respectively.
11. Numbers may not add due to rounding.