(See Orvana’s Annual Information Form dated December 29, 2022 for the fiscal year-ended September 31, 2022, pages 21-25)
Cautionary Notes to Investors - Mineral Reserves and Resources Estimates
In accordance with applicable Canadian securities regulatory requirements, all mineral reserve and mineral resource estimates of the Company disclosed have been prepared as at September 30, 2022 in accordance with Canadian National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101"), classified in accordance with Canadian Institute of Mining Metallurgy and Petroleum's "CIM Standards on Mineral Resources and Reserves Definitions and Guidelines" (the "CIM Guidelines").
Pursuant to the CIM Guidelines, mineral resources have a higher degree of uncertainty than mineral Reserves as to their existence as well as their economic and legal feasibility. Inferred mineral resources, when compared with measured or indicated mineral resources, have the least certainty as to their existence, and it cannot be assumed that all or any part of an inferred mineral resource will be upgraded to an indicated or measured mineral resource as a result of continued exploration. Pursuant to NI 43-101, inferred mineral resources may not form the basis of any economic analysis, including any feasibility study. Accordingly, readers are cautioned not to assume that all or any part of a mineral resource exists, will ever be converted into a mineral Reserve, or is or will ever be economically or legally mineable or recovered.
In fiscal 2020, Orovalle engaged an independent engineering firm, Roscoe Postle Associates Inc. (“RPA”), to complete mineral reserves and resources estimates and a life-of-mine-plan (“LOMP”) update, which were published in the “Technical Report on Orovalle Operation, Asturias, Spain” dated November 30, 2020 by: (i) Rick C. Taylor, P.Eng., of RPA, in respect of the estimated mineral reserves and the life of mine plan, and (ii) John Makin, P.Geo., of RPA, in respect of the estimated mineral resources. Each of Messrs. Taylor and Makin is a Qualified Person within the meaning of NI 43-101. The full text of the Orovalle 43-101 Report is available for viewing on SEDAR at www.sedar.com.
Since the Orovalle 43-101 Report, the Company has updated the mineral reserves and resources. The updated mineral resource estimates for El Valle as at September 30, 2022 were prepared by Orovalle under the supervision of Ms. Guadalupe Collar, European geologist and the Chief of Geology of Orovalle, based on updating resource block models incorporating drilling results from July 1, 2021 to June 30, 2022 and accounting for production depletion up to September, 2022.
Mineral Resource estimates were based on robust cut-off grade. Isolated areas with ore above cut-off grade were removed from the Measured + Indicated Mineral Resources estimate (the tonnage is approximately 0.1 million tonnes), also during fiscal 2022 Orovalle’s geotechnics made a review of areas not subject to being mined due to geotechnical risks from previous mining, and this material has also been excluded from the Measured + Indicated Mineral Resources estimate (with an estimated impact of 2.4 million tonnes).
Mineral resource estimates are summarized in the following tables:
SUMMARY OF MINERAL RESOURCES INCLUSIVE OF MINERAL RESERVES
SEPTEMBER 30, 2022 - Orovalle Minerals S.L. – Orovalle Operation
Measured Mineral Resources
|
Zone |
Tonnage (000 t) |
Grade (g/t Au) |
Grade (g/t Ag) |
Grade (% Cu) |
Contained Metal (000 oz Au) |
Contained Metal (000 oz Ag) |
Contained Metal (000 lb Cu) |
Boinás Oxide |
1,363 |
4.43 |
6.97 |
0.36 |
194 |
305 |
10,768 |
Boinás Skarn |
1,245 |
2.62 |
14.51 |
0.64 |
105 |
581 |
17,636 |
Carlés |
396 |
3.49 |
6.19 |
0.41 |
44 |
79 |
3,573 |
La Brueva |
- |
- |
- |
- |
- |
- |
- |
Total |
3,004 |
3.56 |
9.99 |
0.48 |
343 |
965 |
31,977 |
Indicated Mineral Resources
|
Zone |
Tonnage (000 t) |
Grade (g/t Au) |
Grade (g/t Ag) |
Grade (% Cu) |
Contained Metal (000 oz Au) |
Contained Metal (000 oz Ag) |
Contained Metal (000 lb Cu) |
Boinás Oxide |
2,980 |
4.41 |
4.32 |
0.32 |
422 |
414 |
20,714 |
Boinás Skarn |
634 |
2.81 |
16.08 |
0.61 |
57 |
327 |
8,539 |
Carlés |
1,239 |
3.33 |
7.26 |
0.36 |
133 |
289 |
9,757 |
La Brueva |
- |
- |
- |
- |
- |
- |
- |
Total |
4,853 |
3.92 |
6.61 |
0.37 |
612 |
1,031 |
39,011 |
Measured + Indicated Mineral Resources
|
Zone |
Tonnage (000 t) |
Grade (g/t Au) |
Grade (g/t Ag) |
Grade (% Cu) |
Contained Metal (000 oz Au) |
Contained Metal (000 oz Ag) |
Contained Metal (000 lb Cu) |
Boinás Oxide |
4,343 |
4.42 |
5.15 |
0.33 |
617 |
719 |
31,482 |
Boinás Skarn |
1,879 |
2.68 |
15.04 |
0.63 |
162 |
908 |
26,175 |
Carlés |
1,635 |
3.37 |
7.00 |
0.37 |
177 |
368 |
13,330 |
La Brueva |
- |
- |
- |
- |
- |
- |
- |
Total |
7,857 |
3.78 |
7.90 |
0.41 |
956 |
1,996 |
70,988 |
Inferred Mineral Resources
|
Zone |
Tonnage (000 t) |
Grade (g/t Au) |
Grade (g/t Ag) |
Grade (% Cu) |
Contained Metal (000 oz Au) |
Contained Metal (000 oz Ag) |
Contained Metal (000 lb Cu) |
Boinás Oxide |
1,752 |
4.26 |
6.44 |
0.31 |
240 |
363 |
12,062 |
Boinás Skarn |
225 |
2.41 |
16.01 |
0.64 |
17 |
116 |
3,172 |
Carlés |
730 |
3.27 |
5.41 |
0.27 |
77 |
127 |
4,316 |
La Brueva |
201 |
3.81 |
14.85 |
0.09 |
25 |
96 |
397 |
Total |
2,908 |
3.83 |
7.50 |
0.31 |
358 |
701 |
19,948 |
Notes:
- CIM (2014) definitions were followed for Mineral Resources.
- Mineral Resources are estimated at gold equivalent ("AuEq”) cut-off grades of 2.38 g/t for Boinás oxides, 2.11 g/t for Boinás skarns and 2.12 g/t for Carlés. AuEq cut-offs are based on recent operating results for recoveries, off-site concentrate costs and on-site operating costs. AuEq cut-off grades of 2.38 g/t was used for La Brueva.
- Mineral Resources are estimated using a long-term gold price of US$1,700 per ounce; copper price of US$3.25 per pound; and a silver price of US$ 20 per ounce. A US$/Euro exchange rate of 1/1 was used.
- Mineral Resources are inclusive of Mineral Reserves.
- A crown pillar of 75 m is excluded from the Mineral Resource below El Valle TSF.
- A crown pillar of 42 m is excluded from the Mineral Resource below Boinás East open pit.
- A crown pillar of 55 m is excluded from the Mineral Resources below topography in Carles West.
- Unrecoverable material in exploited mining areas has been excluded from the Mineral Resources.
- A no-mining sterilization zone of 10 meters below already mined stopes in Boinás has been excluded from the Mineral Resources.
- A no-mining sterilization zone of 5 meters around waste filled stopes in Boinás has been excluded from the mineral resources.
- Areas of mineral blocks in Carlés and Boinas have been removed from the Mineral Resource report to ensure RPEEE.
- Numbers may not add due to rounding.
- El Valle mineral resources estimates were prepared under the supervision G. Collar, European Geologist, a qualified person for the purposes of NI 43-101, who is an employee of Orovalle and thus not independent of the Company.
MINERAL RESERVES – SEPTEMBER 30, 2022
Orovalle Minerals S.L. – Orovalle Operation
|
Category (g/t Au) |
Tonnage (000 t) |
Grade (g/t Au) |
Grade (g/t Ag) |
Grade (% Cu) |
Contained Metal (000 oz Au) |
Contained Metal (000 oz Ag) |
Contained Metal (000 lbs Cu) |
Proven |
1,067 |
3.21 |
6.19 |
0.33 |
110 |
212 |
7,777 |
Probable |
1,694 |
3.21 |
3.60 |
0.27 |
175 |
196 |
9,960 |
Proven and Probable |
2,761 |
3.21 |
4.60 |
0.29 |
285 |
408 |
17,737 |
Proven
|
Category (g/t Au) |
Tonnage (000 t) |
Grade (g/t Au) |
Grade (g/t Ag) |
Grade (% Cu) |
Contained Metal (000 oz Au) |
Contained Metal (000 oz Ag) |
Contained Metal (000 lbs Cu) |
Boinás Skarn |
281 |
2.03 |
9.46 |
0.50 |
18 |
86 |
3,107 |
Boinás Oxides |
657 |
3.75 |
5.08 |
0.26 |
79 |
107 |
3,786 |
Carlés |
129 |
2.98 |
4.71 |
0.31 |
12 |
20 |
883 |
Total |
1,067 |
3.21 |
6.19 |
0.33 |
110 |
212 |
7,777 |
Provable
|
Category (g/t Au) |
Tonnage (000 t) |
Grade (g/t Au) |
Grade (g/t Ag) |
Grade (% Cu) |
Contained Metal (000 oz Au) |
Contained Metal (000 oz Ag) |
Contained Metal (000 lbs Cu) |
Boinás Skarn |
151 |
1.91 |
12.16 |
0.50 |
9 |
59 |
1,671 |
Boinás Oxides |
1,324 |
3.47 |
2.63 |
0.26 |
148 |
112 |
7,487 |
Carlés |
219 |
2.57 |
3.54 |
0.17 |
18 |
25 |
802 |
Total |
1,694 |
3.21 |
3.60 |
0.27 |
175 |
196 |
9,960 |
Notes:
- Based on the application of CIM (November 29, 2019) definitions and guidelines were followed for Mineral Reserve estimation.
- Mineral Reserves are based on the application of AuEq break-even cut-off grades by zone, consisting of 3.06 g/t AuEq for Boinás oxides (D&F), 2.39 g/t AuEq for Boinás skarns (SLS), and 2.26 g/t AuEq for Carlés skarn (SLS).
- Additional Reserves were added based on application of stope break-even cut-off grades by method, consisting of 2.53 g/t AuEq for Boinás oxides (D&F), 2.12 g/t AuEq for Boinás skarns (SLS), and 2.69 g/t AuEq for Boinás skarns (D&F).
- Some Reserves were included based on the application incremental cut-off grades by method, consisting of 2.25 g/t AuEq for Boinás oxides (D&F), 1.55 g/t AuEq for Boinás skarns (SLS), and 2.10 g/t AuEq for Boinás skarns (D&F).
- AuEq cut-offs are based on recent operating results for recoveries, off-site concentrate costs, and on-site operating costs. AuEq factors are based on metal prices, metallurgical recoveries, metal payables, and selling costs.
- Mineral Reserves are estimated using average long term prices of US$1,600/oz Au, US$18/oz Ag, and US$3.00/ lb Cu. A US$/€ exchange rate of 1.00/1.00 was used.
- A minimum mining width of 4 m was used.
- Crown pillars of 75 m and 42 m in Boinas are excluded from the Mineral Reserves below the El Valle TSF and Boinás East open pits, respectively and in Carles 55 m in CW.
- A no-mining sterilisation zone of 10 m below mined out stopes and 5 m around waste filled stopes has been applied.
- El Valle Mineral Reserves estimates were prepared under supervision of Brian William Buss, P. Eng., QP, a qualified person for the purposes of NI 43-101, who is an independent consultant of the Company.
- Numbers may not add due to rounding.