• Reserves & Resources

Summary of Mineral Reserves and Mineral Resources Estimates

The following tables summarize as at December 31, 2023 the Company's estimated mineral reserves and mineral resources on its material mineral properties and select non-material mineral properties, all of which are wholly owned.

Silver-Gold Proven and Probable Reserves (as of December 31, 2023)
Tonnes
(000s)
Ag
g/t
Au
g/t
Ag Eq
g/t
Ag
oz (000s)
Au
oz (000s)
Ag Eq
Oz (000s)
Guanaceví 299 426 1.17 519 4,090 11.3 4,993
Bolanitos 99 74 2.48 273 235 7.9 865
Total Proven 398 338 1.50 458 4,326 19 5,858
Guanacevi 436 369 0.95 445 5,178 13.3 6,243
Bolanitos 360 81 1.98 239 936 22.9 2,765
Terronera 7,380 197 2.25 374 46,707 534.0 88,834
Total Probable 8,176 201 2.17 372 52,821 570 97,843
Total Proven & Probable 8,574 207 2.14 376 57,147 589 103,701
Silver-Gold Measured and Indicated Resources (as of December 31, 2023)
Tonnes
(000s)
Ag
g/t
Au
g/t
Ag Eq
g/t
Ag
oz (000s)
Au
oz (000s)
Ag Eq
Oz (000s)
Guanaceví 205 528 1.37 637 3,475 9.0 4,196
Bolañitos 79 107 2.93 342 274 7.5 873
Total Measured 284 410 1.80 555 3,749 17 5,070
Guanaceví 364 388 0.88 458 4,548 10.3 5,369
Bolañitos 710 102 2.66 314 2,400 62.8 7,427
Parral 433 271 0.00 271 3,773 0 3,773
Total Indicated 1,507 220 1.46 337 10,721 73 16,569
Total Measured & Indicated 1,791 250 1.52 371 14,470 90 21,638
Silver-Gold Inferred Mineral Resources (as of December 31, 2023)
Tonnes
(000s)
Ag
g/t
Au
g/t
Ag Eq
g/t
Ag
oz (000s)
Au
oz (000s)
Ag Eq
Oz (000s)
Guanaceví 462 498 1.05 582 7,403 15.6 8,648
Bolañitos 1,442 130 2.18 304 6,169 103.7 14,467
Terronera 1058 212 2.50 400 7,214 85.0 13,601
Parral 3,180 322 0.21 339 32,938 21.7 34,677
Total Inferred 6,142 271 1.13 360 53,725 226 71,392
Silver-Lead-Zinc Resources (as of December 31, 2023)
Tonnes
(000s)
Ag
g/t
Au
g/t
Ag Eq
g/t
Ag
oz (000s)
Au
oz (000s)
Ag Eq
Oz (000s)
Pb% Zn%
Guanaceví 363 208 0.26 229 2,421 3.1 2,670 0.78 1.32
Pitarrilla In Pit (Oxide & Transition) 133,900 87 0.00 112 375,100 0.0 483,200 0.19 0.48
Pitarrilla Underground (Sulphide) 24,800 146 0.00 264 116,500 0.0 210,700 1.01 2.14
Parral (Cometa) 180 55 1.17 149 320 6.8 860 3.20 3.30
Total Indicated 159,243 97 0.00 136 494,341 10 697,430 0.32 0.74
Guanaceví 488 132 0.16 145 2,076 2.5 2,272 1.36 2.54
Pitarrilla In Pit (Oxide & Transition) 25,600 76 - 100 63,000 - 82,700 0.14 0.48
Pitarrilla Underground (Sulphide) 9,800 115.5 - 218 36,400 - 68,600 0.93 1.8
Parral (Cometa) 880 74 1.45 190 2,100 41.0 5,376 3.27 3.24
Total Inferred 36,768 88 0.04 134 103,576 44 158,948 0.44 0.93

Notes to Mineral Reserves and Mineral Resources Tables

  1. Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. There is no certainty that any or all part of the Mineral Resources will be converted into Mineral Reserves. The estimate of Mineral Resources may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues.
  2. The Inferred Mineral Resource in this estimate has a lower level of confidence than that applied to an Indicated Mineral Resource and must not be converted to a Mineral Reserve. It is reasonably expected that the majority of the Inferred Mineral Resource could be upgraded to an Indicated Mineral Resource with continued exploration.
  3. The Mineral Resources in this estimate were calculated using the Canadian Institute of Mining, Metallurgy and Petroleum (CIM), CIM Standards on Mineral Resources and Reserves, Definitions and Guidelines prepared by the CIM Standing Committee on Reserve Definitions and adopted by CIM Council.
  4. Mineral Resources are exclusive of and in addition to Mineral Reserves.
  5. Guanacevi Mineral Resource and Mineral Reserve cut-off grades are based on a 243 g/t silver equivalent for Santa Cruz Sur of Guanacevi and 243 g/t silver equivalent for Santa Cruz, 243 g/t silver equivalent for Milache and 296 g/t silver equivalent for Ocampo and Porvenir Norte of Guanaceví; Metallurgical recoveries were 86.8% silver and 91.0% gold for Guanaceví.
  6. The cutoff grade applied for resource calculation at the regional polymetallic projects at Guanacevi (Noche Buena and Buena Fe) is 202g/t silver equivalent. The silver equivalent is based on the calculated NSR for each element based on the following price assumptions US$16.29/oz for silver, US$1,195/oz for gold, US$0.82/lb for lead and US$0.90/lb for zinc.
  7. Bolañitos Mineral Resource and Mineral Reserve cut-off grades are based on 164 g/t silver equivalent for Belen, Karina and Puertecito, 156 g/t silver equivalent for La Luz Ramp, 158 g/t Silver equivalent for the Lucero Ramp and 156 g/t silver equivalent for San Miguel ramp area. Metallurgical recoveries were 86.2% silver and 90.2% gold for Bolañitos
  8. Terronera mineral reserves are reported using a silver equivalency cut-off formula AgEq (g/t) = Ag (g/t) + (Au (g/t) x 78.9474). Cut-off grade varies between 156 g/t to 200 g/t AgEq depending on mining method. Metal prices used were $1,500/oz Au and $19.00/oz Ag. Metallurgical recovery of 84.9% for silver and 79.8% for gold, transport, treatment and refining charges of $0.75/oz Ag, and NSR royalties of 2.5%. Mineral Reserves are reported based on mining costs of $30.00/t for sub-level open stoping, $49.18/t for cut and fill, and $48.00/t for shrinkage mining, and $28.46/t for process costs, and $8.49/t for G&A costs.
  9. Terronera mineral resources are constrained within a wireframe constructed at a nominal 150 g/t AgEq cut-off grade. A 150 g/t AgEq cut-off grade considers Wood’s guidance on industry consensus for long term silver and gold prices for Mineral Resource estimation, metallurgical performance, mining, processing, and site G&A operating costs, treatment and refining charges, and royalties. Mineral Resources are stated as in-situ with no consideration for planned or unplanned external mining dilution. The silver and gold ounces estimates presented in the Mineral Resource estimate table have not been adjusted for metallurgical recoveries.
  10. Parral Mineral Resources are estimated at a cut-off grade of 130 g/t AgEq for Palmilla, Veta Colorada, and San Patricio, 200 g/t Ag for Sierra Plata, and an NSR cut-off value of US$55/t for El Cometa. The NSR and AgEq values are based on estimated metallurgical recoveries, assumed metal prices and smelter terms, which include payable factors, treatment charges, penalties, and refining charges. Metal price assumptions were: US$17/oz Ag, US$1,275/oz Au, US$1.15/lb Zn, and US$1.00/lb Pb
    A minimum mining width of 1.5 m was used for Sierra Plata, and 1.75 m for all other veins.
  11. Mining recovery of 89% was applied for Guanaceví; 89.5% to 93.5% for Bolañitos, and 90% (cut and fill), 95% (longhole), 80% (shrinkage) for Terronera for Mineral Reserve Estimate calculations. Minimum mining widths were 0.8 metres for Mineral Reserve Estimate calculations.
  12. Dilution factors for Mineral Reserve Estimate calculations averaged 35.5% for Guanaceví, 37.3% for Bolañitos, and 20% for Terronera. For current operations dilution factors are based on vein width diluted to width of drive for lateral sill preparation (generally >30%) and internal stope dilution calculations and external dilution factors of 24% for cut and fill mining and 40% for long hole mining.
  13. Silver equivalent grades are based on a 80:1 silver:gold ratio and calculated including only silver and gold. Silver equivalent grades for Terronera are based on a 78:9474 silver:gold ratio and calculated including only silver and gold.
  14. Indicated and Inferred Silver-Gold Mineral Resources for "Parral" includes the Colorada, Palmilla and San Patricio areas.
  15. The Veta Colorada structure (Parral) does not contain gold on an economic scale.
  16. Price assumptions for Guanaceví and Bolañitos, are US$23/oz for silver, US$1,840/oz for gold.
  17. Figures in tables are rounded to reflect estimate precision; small differences generated by rounding are not material to the estimates.

Notes on Pitarilla Resource Estimate:

  1. The classification of the current Mineral Resource Estimate into Indicated and Inferred Mineral Resources is consistent with current 2014 CIM Definition Standards - For Mineral Resources and Mineral Reserves.
  2. All figures are rounded to reflect the relative accuracy of the estimate and numbers may not add due to rounding.
  3. All Mineral Resources are presented undiluted and in situ, constrained by continuous 3D wireframe models, and are considered to have reasonable prospects for eventual economic extraction.
  4. Mineral Resources which are not mineral reserves do not have demonstrated economic viability. An Inferred Mineral Resource has a lower level of confidence than that applying to an Indicated Mineral Resource and must not be converted to a Mineral Reserve. It is reasonably expected that the majority of Inferred Mineral Resources could be upgraded to Indicated Mineral Resources with continued exploration.
  5. It is envisioned that parts of the Pitarrilla deposit (oxide and transition mineralization) may be mined using open pit mining methods. In-pit mineral resources are reported at a cut-off grade of 50 g/t AgEq within a conceptual pit shell, which has been limited to the base of the transition mineralization.
  6. The results from the pit optimization are used solely for the purpose of testing the “reasonable prospects for economic extraction” by an open pit and do not represent an attempt to estimate mineral reserves. There are no mineral reserves on the Property. The results are used as a guide to assist in the preparation of a Mineral Resource statement and to select an appropriate resource reporting cut-off grade.
  7. It is envisioned that parts of the Pitarrilla deposit (sulphide mineralization) may be mined using underground mining methods. Underground (below-pit) Mineral Resources are estimated from the bottom of the pit (base of transition mineralization) and are reported at a base case cut-off grade of 150 g/t AgEq. The underground Mineral Resource grade blocks were quantified above the base case cut-off grade, below the constraining pit shell and within the constraining mineralized wireframes. At this base case cut-off grade the deposit shows good deposit continuity with limited orphaned blocks. Any orphaned blocks are connected within the models by lower grade blocks and are included in the Mineral Resource estimate.
  8. Based on the size, shape, location and orientation of the Pitarrilla deposit, it is envisioned that the deposit may be mined using low cost underground bulk mining methods (i.e. longhole mining).
  9. High grade capping of Ag, Pb and Zn was done on 1.50 metre composite data.
  10. Bulk density values were determined based on physical test work from each deposit model and waste model.
  11. AgEq Cut-off grades consider metal prices of $22.00/oz Ag, $1.00/lb Pb and $1.30/lb Zn and considers variable metal recoveries for Ag, Pb and Zn: oxide and transition mineralization - 75% for silver, 70% for Pb and 65% for Zn; sulphide mineralization - 86% for silver, 91% for Pb and 85% for Zn.
  12. The pit optimization and in-pit base case cut-off grade of 50 g/t AgEq considers a mining cost of US$2.50/t rock and processing, treatment and refining, transportation and G&A cost of US$22.40/t mineralized material, an overall pit slope of 42° for oxide and 48° for transition and metal recoveries. The below-pit base case cut-off grade of 150 g/t AgEq considers a mining cost of US$46.50/t rock and processing, treatment and refining, transportation and G&A cost of US$30.90/t mineralized material.
  13. The estimate of Mineral Resources may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues.
  14. The database used for the current mineral resource estimate comprises data for 804 surface reverse circulation and diamond drill holes completed in the deposit area, which total 254,386 metres. The database totals 134,441 assay intervals for 188,816 metres.
  15. The mineral resource estimate is based on 19 three-dimensional (“3D”) resource models representing oxide, transition and sulphide mineralization, as well as 9 lithological 3D solids and a digital elevation surface model. The main Pitarrilla deposit generally strikes 330° to 335° and dips/plunges steeply east-northeast (-60° to -65°). The oxide mineralization in the Cordon Colorado and Javelina Creek Zones extend for 700 to 900 metres southwest and northeast of the main Breccia Ridge Zone.
  16. Silver, lead and zinc were estimated for each mineralization domain in the Pitarrilla deposit. Blocks within each mineralized domain were interpolated using 1.5 metres capped composites assigned to that domain. To generate grade within the blocks, the inverse distance squared (ID 2 ) interpolation method was used for all domains.

Qualified Persons

Guanacevi and Bolanitos
The Technical Reports are entitled “NI 43-101 Technical Report: Updated Mineral Resource and Reserve Estimates for the Guanaceví Project, Durango State, Mexico” (the “ 2022 Guanacevi Report ”) with an effective date of November 5, 2022, and “NI 43-101 Technical Report: Updated Mineral Resource and Reserve Estimates for the Bolañitos Project, Guanajuato State, Mexico” (the “ 2022 Bolañitos Report ”) with an effective date of November 9, 2022 and are co-authored by Dale Mah, P.Geo., Vice President, Corporate Development of Endeavour, Don Gray, SME-RM, Chief Operations Officer of Endeavour and Richard A. Schwering, SME-RM of Hard Rock Consulting LLC. Mr. Schwering is independent of Endeavour. Both reports were filed on SEDAR and EDGAR on January 26, 2023. These authors are Qualified Persons as defined by NI 43-101 and are responsible for all sections of the Technical Reports.

Terronera Project
The 2021 feasibility study technical report entitled “NI 43-101 Technical Report on the Feasibility Study of the Terronera Project, Jalisco State, Mexico (“Technical Report”)”, prepared by Wood PLC and dated October 21, 2021 with an effective date of September 9, 2021. The Technical Report was authored in accordance with National Instrument 43-101 was filed on SEDAR and EDGAR on October 25, 2021. The FS team includes Wood PLC QPs, Tatiana Alva, P.Geo., William Bagnell, P.Eng., Alan Drake, P.Eng., Kirk Hanson, P.Eng. and Humberto Preciado, P.Eng., who are the Independent Qualified Persons for the 2021 FS and who have prepared the scientific and technical information on the Terronera project and reviewed the information that is summarized in this document. The qualified persons preparing the FS have followed industry accepted practices for verifying that the data used in the study is suitable for the purposes used. Site visits by three of the qualified persons (including Dale Mah from Endeavour and Tatiana Alva and Humberto Preciado from Wood) is part of the data verification procedures. A more detailed description of data verification undertaken by the qualified persons is included in the relevant sections of technical report.

Parral Project
The Parral Technical Report is entitled “Technical Report on the Parral Project, State of Chihuahua, Mexico”, prepared by Roscoe Postle Associates Inc. (RPA), now part of SLR Consulting Ltd. (SLR) and dated March 14, 2020. Mineral Resources disclosed in this presentation have been estimated by Mr. Jose Texidor Carlsson, P.Geo., an employee of RPA and independent of Endeavour. By virtue of his education and relevant experience, Mr. Texidor Carlsson is a “Qualified Person” for the purpose of National Instrument 43-101. The Mineral Resources have been classified in accordance with CIM Definition Standards for Mineral Resources and Mineral Reserves (May 2014).

Pitarrilla Project
The Pitarrilla Technical Report is dated November 21, 2022 and entitled “Mineral Resource Estimate for the Pitarrilla Ag-Pb-Zn Project, Durango State, Mexico” (the “2022 Pitarrilla Report”) with an effective date of October 6, 2022. The 2022 Pitarrilla Report was prepared on behalf of the Company by SGS Geological Services Inc.(“SGS”), and authored by Allan Armitage, Ph.D., P. Geo., (“Armitage”) of SGS Geological Services. Mr. Armitage is an independent Qualified Person as defined by NI 43-101 and is responsible for the Mineral Resource Estimate and all sections of the technical report.