Historical Reserves and Consolidated Grade at Limon and Libertad
B2Gold AIF 2010-2019 available on sedar.com and Calibre AIF 2020, available on sedar.com
Mineral Reserves at Limon and Libertad – December 31, 20201,2
| CATEGORY | TONNAGE (KT) |
GRADE (G/T AU) |
GRADE (G/T AG) |
CONTAINED AU (KOZ) |
CONTAINED AG (KOZ) |
|
|---|---|---|---|---|---|---|
| Limon UG | Probable | 617 | 5.14 | 8.25 | 102 | 164 |
| Limon OP | Probable | 3,389 | 4.24 | 1.22 | 462 | 133 |
| Limon Stockpile | Probable | 29 | 3.82 | 0 | 4 | 0 |
| Sub-total Limon | Probable | 4,036 | 4.38 | 2.29 | 568 | 297 |
| Libertad UG | Probable | 477 | 3.92 | 20.00 | 60 | 307 |
| Libertad OP Sources | Probable | 1,420 | 4.80 | 11.29 | 219 | 515 |
| Libertad Stockpile | Probable | 55 | 9.30 | 0 | 16 | 0 |
| Sub-total Libertad | Probable | 1,952 | 4.71 | 13.08 | 296 | 822 |
| Total Mineral Reserves | Probable | 5,988 | 4.49 | 5.81 | 864 | 1,119 |
Note 1 -Limon Mineral Reserve Notes
- CIM (2014) definitions were followed for Mineral Reserves and rounded and reported in dry tonnes.
- Underground Mineral Reserves are estimated at fully costed and incremental cut-off grades of 3.3 g/t Au and 2.2 g/t Au, respectively, for Santa Pancha 1; 3.5 g/t Au and 2.2 g/t Au, respectively, for Panteon; and 2.6 g/t Au and 1.8 g/t Au, respectively, for Veta Nueva.
- Open pit Mineral Reserves are estimated at a cut-off grade of 1.24 g/t Au, and incorporate estimates of dilution and mining losses.
- Mineral Reserves are estimated using an average long-term gold price of US$1,400 per ounce.
- A minimum mining width of 1.5 m was used for underground Mineral Reserves.
- Bulk density varies between 2.30 t/m3 and 2.41 t/m3 for all open pit Mineral Reserves; Bulk density varies between 2.47 t/m3 to 2.50 t/m3 for all underground Mineral Reserves.
- A mining extraction factor of 95% was applied to the underground stopes. Where required a pillar factor was also applied for sill or crown pillar. A 100% extraction factor was assumed for development.
Note 2 -Libertad Mineral Reserve Notes
- CIM (2014) definitions were followed for Mineral Reserves and rounded and reported in dry tonnes.
- Underground Mineral Reserves are estimated at fully costed and incremental cut-off grades of 3.05 g/t Au and 1.90 g/t Au, respectively, and incorporates 0.5 m dilution in both hanging wall and footwall.
- Open pit Mineral Reserves are estimated at a cut-off grade of 1.50 g/t Au for Pavon Norte and Pavon Central, and incorporate estimates of dilution and mining losses.
- Open pit Mineral Reserves are estimated at a cut-off grade of 0.92 g/t Au for Jabali Antena, and incorporate estimates of dilution and mining losses.
- Mineral Reserves are estimated using an average long-term gold price of US$1,400 per ounce.
- A minimum mining width of 1.5 m was used for underground Mineral Reserves.
- Open pit and underground bulk density varies from 1.70 t/m3 to 2.61 t/m3; underground backfill density is 1.00 t/m3.
- A mining extraction factor of 95% was applied to the underground stopes. Where required a pillar factor was also applied for sill or crown pillar. A 100% extraction factor was assumed for development.
Indicated & Inferred Mineral Resources at Limon and Libertad – December 31, 20203,4
| CATEGORY | TONNAGE (KT) |
GRADE (G/T AU) |
GRADE (G/T AG) |
CONTAINED AU (KOZ) |
CONTAINED AG (KOZ) |
|
|---|---|---|---|---|---|---|
| Limon UG | Indicated | 1,475 | 5.46 | 5.40 | 259 | 256 |
| Limon OP | Indicated | 4,393 | 4.45 | 1.57 | 628 | 222 |
| Limon Stockpile | Indicated | 29 | 3.82 | - | 4 | - |
| Tailings | Indicated | 7,329 | 1.12 | - | 263 | - |
| Sub-total Limon | Indicated | 13,226 | 2.71 | 1.12 | 1,154 | 478 |
| Libertad UG | Indicated | 421 | 5.72 | 28.15 | 77 | 381 |
| Libertad OP Sources* | Indicated | 2,012 | 4.41 | 12.57 | 285 | 813 |
| Libertad Stockpile | Indicated | 55 | 9.30 | - | 16 | - |
| Sub-total Libertad | Indicated | 2,488 | 4.74 | 14.93 | 378 | 1,194 |
| Total Mineral Resources | Indicated | 15,714 | 3.03 | 3.31 | 1,532 | 1,672 |
| Limon UG | Inferred | 1,149 | 5.22 | 3.90 | 193 | 144 |
| Limon OP | Inferred | 260 | 4.07 | 0.84 | 34 | 7 |
| Sub-total Limon | Inferred | 1,409 | 5.01 | 3.33 | 227 | 151 |
| Libertad UG | Inferred | 1,585 | 5.40 | 13.44 | 275 | 685 |
| Libertad OP Sources* | Inferred | 1,246 | 2.77 | 5.37 | 111 | 215 |
| Sub-total Libertad | Inferred | 2,831 | 4.24 | 9.89 | 386 | 900 |
| Total Mineral Resources | Inferred | 4240 | 4.50 | 7.71 | 613 | 1,051 |
*Includes Pavon
Note 3 –Limon Mineral Resource Notes
- Effective dates are December 31, 2020 for all El Limon deposits.
- CIM (2014) definitions were followed for Mineral Resources and numbers may not add up due to rounding.
- A cut-off grade of 1.15 g/t Au is used for Limon OP, 2.40 g/t for Limon UG, 3.05 g/t for SP1 UG, 2.25 g/t for SP2 UG, 2.41 g/t for Veta Nueva UG, 3.25 g/t for Panteon UG, 0.00 g/t for Tailings, and 2.60 g/t for Atravesada UG.
- Reporting shapes were used for reporting Limon UG, SP1 UG, Veta Nueva UG, Panteon UG, and Atravesada UG.
- Mineral Resources are estimated using a long-term gold price of US$1,500/oz Au in all deposits.
- Bulk density varies between 2.30 t/m3 and 2.50 t/m3.
- Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
- Mineral Resources are inclusive of Mineral Reserves.
Note 4 – Libertad Mineral Resource Notes
- Effective dates are December 31, 2020 for all La Libertad deposits except San Antonio OP, with an effective date of August 30, 2020. The Pavon estimate has an effective date of November 12, 2019.
- CIM (2014) definitions were followed for Mineral Resources.
- A cut-off grade of 0.85 g/t Au is used for Jabali Antena OP, 0.81 g/t for Rosario OP, 0.80 g/t for Socorro OP and San Antonio OP, 2.90 g/t for San Juan UG, San Diego UG and Mojon UG, and 2.84 g/t for Jabali West UG and Jabali East UG, and 1.17 g/t Au for Pavon.
- Reporting shapes were used for reporting Jabali West UG.
- Mineral Resources are estimated using a long-term gold price of US$1,500/oz Au in all deposits except Pavón Sur, estimated using a long-term gold price of US$1,400/oz Au.
- Bulk density varies between 1.70 t/m3 and 2.57 t/m3.
- Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
- Mineral Resources are inclusive of Mineral Reserves.
- Numbers may not add up due to rounding.
The Borosi Concession Projects
Overview; Calibre Mining Corp. has outlined mineral resources in the Borosi Concessions.
(Click here for the Techncial Reports)
100% owned Eastern Borosi Project
INFERRED Mineral Resources – Eastern Borosi Project
| CATEGORY | METHOD / VEIN |
TONNAGE (000 T) |
GRADE AU (G/T) |
CONTAINED OUNCES AU (OZ) |
GRADE AG (G/T) |
CONTAINED OUNCES AG (OZ) |
GRADE AUEQ (G/T) |
CONTAINED OUNCES AUEQ (OZ) |
|---|---|---|---|---|---|---|---|---|
| Inferred | Underground | |||||||
| Blag | 740 | 3.01 | 71,500 | 117 | 2,776,000 | 4.16 | 99,000 | |
| East Dome | 513 | 2.23 | 37,000 | 219 | 3,611,000 | 4.38 | 72,500 | |
| Riscos | 1,184 | 5.73 | 218,000 | 106 | 4,046,500 | 6.77 | 258,000 | |
| Guapinol | 612 | 12.74 | 251,000 | 12 | 243,500 | 12.86 | 253,000 | |
| Vancouver | 170 | 8.54 | 46,500 | 15 | 82,000 | 8.69 | 47,500 | |
| Total Underground | 3,219 | 6.03 | 624,000 | 104 | 10,758,500 | 7.05 | 729,500 | |
| Inferred | Open Pit | |||||||
| La Luna | 1,199 | 1.98 | 76,500 | 16 | 601,000 | 2.13 | 82,000 | |
| Inferred | Total Underground and Open Pit |
4,418 | 4.93 | 700,500 | 80 | 11,359,500 | 5.72 | 812,000 |
Notes:
- CIM (2014) definitions were followed for classification of Mineral Resources.
- Mineral Resources are estimated at a cut-off grade of 2.0 g/t AuEq for resources potentially mined by underground methods and 0.42 g/t AuEq for resources potentially mined by open pit methods.
- Gold equivalent values were calculated using the formula: AuEq (g/t) = Au (g/t) + Ag (g/t) / (101.8)
- Mineral Resources are estimated using a long-term gold price of US$1,500 per ounce of gold, US$23 per ounce of silver.
- A minimum mining width of 2.4 m was used for underground and 3 m for open pit.
- Bulk density is 2.65 t/m3 for Blag, East Dome, Riscos De Oro, and La Luna, and 2.60 t/m3 for Guapinol and Vancouver.
- East Dome is included in the Blag resource model and Vancouver is included in the Guapinol resource model.
- Numbers may not add due to rounding.
- Mineral Resources that are not Mineral Reserves do not have economic viability
100% owned Borosi Inferred Resources (Subject to an earn-in Agreement with Rio Tinto) (see news release here)
The Cerro Aeropuerto deposit contains gold and base metal bearing quartz veins and replacement style skarn mineralization. The NI 43-101 compliant Inferred Mineral Resource estimate for the Cerro Aeropuerto deposit is provided in the table below:
| Cerro Aeropuerto NI 43-101 Inferred Mineral Resource (April 11, 2011) | ||||||
|---|---|---|---|---|---|---|
| Tonnes | Grade (Au g/t) |
Grade (Ag g/t) |
Grade (AuEq g/t) |
Contained Au (ounces) |
Contained Ag (ounces) |
Contained AuEq (ounces) |
| 6,052,000 | 3.64 | 16.16 | 3.89 | 707,750 | 3,144,500 | 757,000 |
- CIM definition standards were followed for the resource estimate
- The 2011 resource models used Inverse Distance grade estimation within a three-dimensional block model with mineralized zones defined by wireframed solids and
- A base cutoff grade of 0.6 g/t AuEq was used for reporting mineral resources.
- Gold Equivalent (AuEq) grades were calculated using $1,058/oz Au for gold and $16.75/oz Ag for silver, and metallurgical recoveries and net smelter returns are assumed to be 100%.
- Resource Estimates for Cerro Aeropuerto are detailed in the technical report titled ‘NI 43-101 Technical Report and Resource Estimation of the Cerro Aeropuerto and La Luna Deposits, Borosi Concessions, Nicaragua’ by Todd McCracken, dated April 11, 2011.
- The quantity and grade of reported inferred resources in this estimation are uncertain in nature and there has been insufficient exploration to define these inferred resources as an indicated or measured mineral resource. It is uncertain if further exploration will result in upgrading them to an indicated or measured mineral resource category.
- Numbers may not add exactly due to rounding.
- Mineral Resources that are not mineral reserves do not have demonstrated economic viability.
100% owned Borosi Inferred Resources (Subject to an earn-in Agreement with Rio Tinto) (see news release here)
The NI 43-101 compliant Inferred Mineral Resource estimate for Primavera is provided in the table below:
| Primavera NI 43-101 Inferred Mineral Resource (January 31, 2017) | ||||||||
|---|---|---|---|---|---|---|---|---|
| Tonnes | Grade (Au g/t) |
Grade (Ag g/t) |
Grade (Cu %) |
Grade (AuEq g/t) |
Contained Au (ounces) |
Contained Ag (ounces) |
Contained Cu (pounds) |
Contained AuEq (ounces) |
| 44,974,000 | 0.54 | 1.15 | 0.22 | 0.84 | 782,000 | 1,661,000 | 218,670,000 | 1,200,000 |
- CIM definition standards were followed for the resource estimate.
- The 2016 resource models used Ordinary Kriging grade estimation within a three-dimensional block model with mineralized zones defined by wireframed solids (HG=high grade, LG= low grade, sap=saprolite).
- A base cutoff grade of 0.5 g/t AuEq was used for reporting mineral resources.
- Gold Equivalent (AuEq) grades have been calculated using $1300/oz Au for gold, $2.40/lb for Copper, and $20.00/oz Ag for silver and metallurgical recoveries are assumed to be equal for all metals.
- Resource Estimates for the Primavera project are detailed in the NI 43-101 Technical Report titled ‘Primavera Project ‘by Todd McCracken, dated January 31, 2017.
- The quantity and grade of reported Inferred resources in this estimation are uncertain in nature and there has been insufficient exploration to define these Inferred resources as an indicated or measured resource. It is uncertain if further exploration will result in upgrading them to indicated or measure mineral resource category.
- Numbers may not add exactly due to rounding.
- Mineral Resources that are not mineral reserves do not have demonstrated economic viability.
Qualified Person
Darren Hall, MAusIMM, MSME, SVP & Chief Operating Officer Calibre Mining Corp is a “qualified person” as set out under NI 43-101 has reviewed and approved the scientific and technical information in this press release.