Form 6-K ENDEAVOUR SILVER CORP For: Dec 31

January 20, 2022 7:12 AM EST

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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16
UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of January 2022

Commission File Number: 001-33153

ENDEAVOUR SILVER CORP.
(Translation of registrant's name into English)

#1130-609 Granville Street
Vancouver, British Columbia, Canada V7Y 1G5

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

[           ] Form 20-F   [ x ] Form 40-F

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): [           ]

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): [           ]

Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes [           ] No [ x ]

If "Yes" is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b): 82- _________


SUBMITTED HEREWITH

Exhibits

Exhibit   Description
     
99.1   NI 43-101 Technical Report: Updated Mineral Resource and Reserve Estimates for the Bolañitos Project, Guanajuato State, Mexico
99.2   Consent of Qualified Person

 


SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

  Endeavour Silver Corp.
  (Registrant)
     
Date: January 20, 2022 By: /s/ Daniel Dickson
    Daniel Dickson
  Title: CEO

 



Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Table of Contents

NI 43-101 Technical Report:

Updated Mineral Resource and Reserve Estimates for the

Bolañitos Project, Guanajuato State, Mexico

 

 

Report Date:  January 2, 2022

Effective Date:  December 31, 2020 

 

 

 

Prepared by:

1130 - 609 Granville Street

Vancouver, B.C., Canada, V7Y 1G5

 

Endorsed by QP(s):

Dale Mah, P.Geo.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Table of Contents

Certificate of Qualified Persons

Dale Mah, P.Geo.
Endeavour Silver Corp.
609 Granville St, Suite 1130
Vancouver, British Columbia, Canada, V7Y 1G5
Tel: (604) 685-9775

I, Dale Mah, P,Geo, am currently employed as Vice President, Corporate Development with Endeavour Silver Corp. ("Endeavour Silver"), which has its head offices at #1130, 609 Granville Street, Vancouver, BC V7Y 1G5 Canada.

This certificate applies to the technical report titled "NI43-101 Technical Report: Updated Mineral Resource and Reserve Estimates for the Bolanitos Project, Guanajuato State, Mexico", that has an effective date of 31 December, 2020 (the "technical report").

I am a member of the Engineers & Geoscientists, British Columbia, and of the Association of Professional Engineers, Geologists and Geophysicists of Alberta. I graduated from the University of Alberta with a Bachelor of Science (Specialization) degree in Geology in 1996.

I have practiced my profession for over 25 years. In this time I have been directly involved in generating and managing exploration activities, and in the collection, supervision and review of geological, mineralization, exploration and drilling data; geological models; sampling, sample preparation, assaying and other resource-estimation related analyses; assessment of quality assurance-quality control data and databases; supervision of mineral resource estimates; project valuation and cash flow modeling.

As a result of my experience and qualifications, I am a Qualified Person as defined in National Instrument 43-101 Standards of Disclosure for Mineral Projects (NI 43-101).

I visited the Bolanitos Project most recently from 8-9 January, 2020. A personal inspection has not been conducted more recently due to the COVID-19 pandemic and travel restrictions imposed by local and foreign governments. However, once it is safe to do so, a physical site visit will take place as soon as practical.

I am responsible for Sections 1 to 27 of the technical report.

I am not independent of Endeavour Silver as independence is described by Section 1.5 of NI 43-101.

I have been involved with the Bolanitos Project since my employment commenced with Endeavour Silver in June 2016.

I have read NI 43-101 and the sections of the technical report for which I am responsible have been prepared in compliance with that Instrument.

As of the effective date of the technical report, to the best of my knowledge, information and belief, the sections of the technical report for which I am responsible contain all scientific and technical information that is required to be disclosed to make the technical report not misleading.

Dated this 2nd day of January, 2022.

"Signed" Dale Mah, P.Geo.

 
Signature of Qualified Person


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Table of Contents

Table of Contents

1. EXECUTIVE SUMMARY 1


1.1 Introduction 1
1.2 Property Description and Ownership 1
1.3 Geology and Mineralization 1
1.4 Status of Exploration 2
1.5 Mineral Resource Estimate 2
1.6 Mineral Reserve Estimate 4
1.7 Conclusions and Recommendations 5
   
2. INTRODUCTION 7


2.1 Issuer and Terms of Reference 7
2.2 Sources of Information 7
2.3 Qualified Persons and Personal Inspection 8
2.4 Units of Measure 8
   
3. RELIANCE ON OTHER EXPERTS 9
   
4. PROPERTY DESCRIPTION AND LOCATION 10


4.1 Project Location 10
4.2 Mineral Tenure, Agreements and Encumbrances 11
4.3 Permits and Environmental Liabilities 13
   
5. ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY 14


5.1 Access and Climate 14
5.2 Local Resources and Infrastructure 14
5.3 Bolañitos Mine Physiography 14
5.4 Surface Rights 15
   
6. HISTORY 16


6.1 Historical Exploration 16
6.2 Historical Production 16
6.3 Historic Mineral Resource and Reserve Estimates 16
   
7. GEOLOGICAL SETTING AND MINERALIZATION 19


7.1 Regional Geology 19
7.1.1 Stratigraphy 21
7.1.2 Esperanza Formation 22
7.1.3 La Luz Formation 22
7.1.4 Guanajuato Formation (Eocene to Oligocene) 23
7.1.5 Loseros Formation (Cenozoic) 23
7.1.6 Bufa Formation (Cenozoic) 23
7.1.7 Calderones Formation (Cenozoic) 23
7.1.8 Cedros Andesite (Cenozoic) 23
7.1.9 Chichíndaro Formation (Cenozoic) 24
7.1.10 Comanja Granite (Cenozoic) 24
7.1.11 El Capulin Formation 24
7.2 Structure 24

 


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Table of Contents

7.3 Local Geology 25
7.3.1 Alteration 27
7.4 Mineralization 28
   
8. DEPOSIT TYPES 30
   
9. EXPLORATION 32


9.1 EDR Exploration Prior to 2019 32
9.2 2020 Exploration Activities 33
   
10. DRILLING 38


10.1 Drilling Procedures 38
10.2 EDR Core Logging Procedures 39
10.3 EDR Drilling Programs and Results (2007 to 2019) 39
10.4 EDR Drilling Programs and Results (2020) 40
10.4.1 Bolañitos North Diamond Drilling Program 40
10.4.1 Plateros Diamond Drilling Program 48
10.4.1 Sangre de Cristo Diamond Drilling Program 50
10.4.1 Bolañitos South Diamond Drilling Program 53
   
11. SAMPLE PREPARATION, ANALYSES AND SECURITY 56


11.1 Methods 56
11.1.1 Production Chip Channel Samples 56
11.1.2 Exploration Sampling 56
11.2 Sample Preparation and Analysis 57
11.2.1 Exploration Drilling 57
11.3 Sample Quality Control and Quality Assurance 59
11.3.1 Production Sampling 59
11.3.2 Production Grade Control Samples 59
11.3.3 Summary of the 2017 to 2019 QA/QC Surface and Underground Exploration Programs 68
11.3.4 Surface and Underground Exploration Samples 71
11.4 Adequacy of Data 83
11.4.1 Adequacy of Mine Sampling Procedures 83
   
12. DATA VERIFICATION 84


12.1 Database Audit 84
12.1.1 Mechanical Audit 85
12.2 Certificates 85
12.3 Adequacy of Data 85
   
13. MINERAL PROCESSING AND METALLURGICAL TESTING 87


13.1 Mineralogical Analysis 87
13.2 Gravity Concentration 87
13.3 Concentrate Sale vs. Cyanide Leaching 87
13.4 Comments on Section 13 88
   
14. MINERAL RESOURCE ESTIMATES 89


14.1 Density 89
14.2 Methodology 89
14.3 Vertical Longitudinal Projection 90


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Table of Contents

14.3.1 Composite Calculations 92
14.3.2 Area and Volume Calculations 92
14.3.3 VLP Mineral Resource Classification 93
14.4 3D Block Model Method 93
14.4.1 Geologic Model 93
14.4.2 Block Model 95
14.4.3 Compositing 97
14.4.4 Capping 99
14.4.5 Variography 102
14.4.6 Estimation Parameters 105
14.4.7 Model Validation 106
14.4.8 Mineral Resource Classification 117
14.5 Bolañitos Mineral Resource Statement 117
14.5.1 VLP Mineral Resource Estimate 118
14.5.2 3D Block Model Mineral Resource Estimate 118
14.5.3 Bolañitos Mineral Resource Statement 120
   
15. MINERAL RESERVE ESTIMATES 121


15.1 CALCULATION PARAMETERS 121
15.1.1 Dilution 121
15.1.2 Reconciliation of Mineral Reserves to Production 123
15.2 Reserve Classification 123
15.3 Mineral Reserves 127
15.3.1 Factors that may affect the Mineral Reserve Estimate 129
   
16. MINING METHODS 130


16.1 Mining Operations 130
16.2 Ground Conditions 130
16.3 Mining Method 130
16.4 Mine equipment 131
16.5 Mine Production 132
   
17. RECOVERY METHODS 134


17.1 Production 134
17.2 Bolañitos Plant 134
   
18. PROJECT INFRASTRUCTURE 139


18.1 Mine Pumping 139
18.2 Mine Ventilation 139
18.3 Mine Electrical 139
   
19. MARKET STUDIES AND CONTRACTS 141


19.1 Contracts 142
   
20. ENVIRONMENTAL STUDIES, PERMITTING AND SOCIAL OR COMMUNITY IMPACT 143


20.1 Environmental Sustainability 143
20.2 Closure Plan 144
20.3 Permitting 144
20.4 Considerations of Social and Community Impacts 145


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Table of Contents

21. CAPITAL AND OPERATING COSTS 148


21.1 Capital Costs 148
21.2 Operating Costs 148
   
22. ECONOMIC ANALYSIS 149
   
23. ADJACENT PROPERTIES 150
   
24. OTHER RELEVANT DATA AND INFORMATION 151
   
25. INTERPRETATION AND CONCLUSIONS 152


25.1 December 31, 2020 Mineral Resource Estimate 152
25.2 December 31, 2020 Mineral Reserve Estimate 153
25.3 Conclusions 153
   
26. RECOMMENDATIONS 155


26.1 Exploration Program 155
26.2 Geology, Block Modeling, Mineral Resources and Reserves 155
   
27. REFERENCES 157


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Table of Contents

List of Figures

Figure 4-1  Bolañitos Project Location 10
Figure 4-2  Bolañitos Mine Claim Map 11
Figure 7-1  Regional Geology of the Bolañitos Project Area (EDR, 2016; Modified from Clark, 2009) 20
Figure 7-2  Stratigraphic Column, Eastern Guanajuato Mining District 22
Figure 7-3  Schematic Cross Section showing all known veins in the La Luz Sub-District 25
Figure 7-4  Surface Map Indicating the Location of the Veins and Mineral Concession Boundaries for the Bolañitos - Golondrinas (El Puertecito Area) Mines in the La Luz District, Guanajuato 27
Figure 7-5  Lucero Vein in the Bolañitos Mine 28
Figure 8-1  Alteration and Mineral Distributions within a Low Sulphidation Epithermal Vein System 31
Figures 9-1 & 9-2 Silver and Gold results in rock samples collected in the Ave Maria-Lourdes area. 35
Figure 9-3 Gold results in rock samples collected in the Ave Maria adit. 35
Figures 9-4 & 9-5 Silver and Gold results in rock samples collected in the La Cuesta adit. 36
Figures 9-6 & 9-7 Silver and Gold results in rock samples collected in the "terrero" located near the Villarino Shaft 37
Figures 10-1 & 10-2  DR Drilling drill rig in pad for drill hole BN-36 (Melladito) and in-house drill rig in pad for drill hole BN-51 (Melladito) 42
Figure 10-3  Longitudinal Section (looking E) showing intersection points on Melladito vein. 46
Figure 10-4  Longitudinal Section (looking E) showing intersection points on San Bernabe vein. 47
Figure 10-5  Schematic Cross Section, Melladito-Bolañitos-San Bernabe. 47
Figure 10-6  DR Drilling drill rig in station for drill hole PLU-29 (Plateros). 48
Figure 10-7  Longitudinal Section (looking NE) showing intersection points on Plateros vein. 49
Figure 10-8  Schematic Cross Section, Plateros. 50
Figure 10-9  In-house drill rig in pad for drill hole PLS06-1 (Sangre de Cristo). 51
Figure 10-10  Longitudinal Section (looking NE) showing intersection points on Sangre de Cristo vein. 52
Figure 10-11  Schematic Cross Section, Sangre de Cristo. 53
Figure 10-12  In-house drill rig in pad for drill hole AVM-04 (Ave Maria). 54
Figure 10-13  Longitudinal Section (looking NE) showing intersection points on Ave María vein. 54
Figure 10-14  Schematic Cross Section, Ave María. 55
Figure 11-1  Silver Pulp Duplicates 60
Figure 11-2  Gold Pulp Duplicates 60
Figure 11-3  Silver Reject Duplicates 61
Figure 11-4  Gold Reject Duplicates 61
Figure 11-5  Certified Standard 1802 Silver Results - Fire Assay AA Finish 62
Figure 11-6  Certified Standard 1802 Silver Results - Fire Assay Gravimetric Finish 62
Figure 11-7  Flow Sheet for Core Sampling, Sample Preparation and Analysis 72
Figure 11-8  Control Chart for Gold Assay from the Blank Samples Inserted into the Sample Stream 73
Figure 11-9  Control Chart for Silver Assay from the Blank Samples Inserted into the Sample Stream 73
Figure 11-10  Scatter Diagram of the Gold Re-Assayed ALS Samples 74
Figure 11-11  Scatter Diagram of the Silver Re-Assayed ALS Samples 75
Figure 11-12  Performance of Field Duplicates for Gold from Endeavour Silver's Bolañitos Drilling Program 76
Figure 11-13  Performance of Field Duplicates for Silver from Endeavour Silver's Bolañitos Drilling Program 76
Figure 11-14  Control Chart for Gold Assays from the Standard Reference Sample EDR-39 79
Figure 11-15  Control Chart for Silver Assays from the Standard Reference Sample EDR-39 79
Figure 11-16  Control Chart for Gold Assays from the Standard Reference Sample EDR-41 79
Figure 11-17  Control Chart for Silver Assays from the Standard Reference Sample EDR-41 80
Figure 11-18  Scatter Plot of Check Assays for Gold (ALS vs SGS) 81
Figure 11-19  Scatter Plot of Check Assays for Silver (ALS vs SGS) 81
Figure 11-20  Scatter Plot of Check Assays for Gold (SGS vs ALS) 82

 


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Table of Contents

Figure 11-21  Scatter Plot of Check Assays for Silver (SGS vs ALS) 82
Figure 14-1  VLP Showing the Belen Vein with Indicated, Inferred, and Low-Grade Resource Blocks 91
Figure 14-2  Cross Section Diagram of VLP Method 92
Figure 14-3  Cross Section (5-Meter-Thick) of Karina Vein showing Drillhole and Channel Samples, and Selected Composites 93
Figure 14-4  Cross Section (5-Meter-Thick) of Plateros Veins showing Drillhole and Channel Samples, and Selected Composites 94
Figure 14-5  Plan View of Main Bolañitos Area 94
Figure 15-1  San Miguel Vein Resource and Reserve Section 124
Figure 17-1  General View of the Bolañitos Processing Plant 134
Figure 17-2  Process Flow Sheet of the Bolañitos Plant 135
Figure 17-3  View of the Primary Crusher Circuit (left); Crushed Ore Bins (right) 136
Figure 17-4  Vibration Screen, Single 6'x16'Deck (left); Fine Crushing Circuit (right) 136
Figure 17-5  Original Ball Mill #1, size 9'6"x14' (left), Ball Mill #2, size 11'x18'7", 1000 HP Motor, and Fine Ore Bin on the back, Both Installed in 2011 (right) 137
Figure 17-6  1st Cleaner Cells (left); Flocculent Mixing System (right) 137
Figure 17-7  Filter Press (left); Concentrate Storage and Shipment Loading Area (right) 138


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Table of Contents

List of Tables

Table 1-1  Mineral Resource Estimate, Effective Date December 31st, 2020 4
Table 1-2  Mineral Reserve Estimate 5
Table 4-1  Summary of the Mineral Concessions Owned by Endeavour Silver 12
Table 4-2  Summary of the Endeavour Silver's Royalties 13
Table 4-3  Summary of Endeavour Silver's Surface Access Rights 13
Table 9-1  Assays for the Rock Sampling in the Bolañitos South Area (Ave Maria Adit) 33
Table 9-2  Assays for the Rock Sampling in the Bolañitos South Area (La Cuesta Adit) 34
Table 9-3  Assays for the Rock Sampling in the Plateros Area ("terrero" Villarin Shaft) 36
Table 10-1  Drilling Summary at Bolañitos Project (as of December, 2019) 39
Table 10-2  Bolañitos Project Exploration Drilling Activities in 2020 40
Table 10-3  2020 Drilling Summary, Melladito 41
Table 10-4  2020 Drilling Summary, San Bernabe 41
Table 10-5  2020 Drilling Results, Melladito 43
Table 10-6  2020 Drilling Results, San Bernabe 46
Table 10-7  2020 Drilling Summary, Plateros 48
Table 10-8  2020 Drilling Results, Plateros 49
Table 10-9  2020 Drilling Summary, Sangre de Cristo 50
Table 10-10  2020 Drilling Results, Sangre de Cristo 51
Table 10-11  2020 Drilling Summary, Ave Maria 53
Table 11-1  ALS Summary of Analysis Procedures 58
Table 11-2  SGS Summary of Analysis Procedures 58
Table 11-3  Summary of Control Samples Used for Exploration Programs from 2017 to 2019 68
Table 11-4  Summary of the Standard Reference Material Samples Used During the EDR's Drilling Programs (2017 to 2019) at Bolañitos 69
Table 11-5  General Rules for Standard Samples 69
Table 11-6  Summary of Analysis of Standard Reference Materials (2017 to 2019) 70

 


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Table of Contents

Table 11-7  Summary of Control Samples Used for the 2020 Exploration Program 71
Table 11-8  Comparative Table of Original vs Re-Assays values 74
Table 11-9  Reference Standards Used for Endeavour Silver's Surface & Underground Drilling Programs 77
Table 11-10  Performance Limits for Standards Used at the Bolañitos Project 77
Table 11-11  Company Protocol for Monitoring SRM Performance 78
Table 11-12  Summary of Analysis of Standard Reference Material 78
Table 12-1  Database Import Summary 85
Table 14-1  Statistical Summary of Density Data 89
Table 14-2  Summary of Veins included in the Mineral Resource Estimate 90
Table 14-3  Bolañitos Block Model Parameters 96
Table 14-4  Vein Model Volumes 97
Table 14-5  Composite True Thickness Statistics by Vein 98
Table 14-6- Capping Limits for Silver and gold by Vein 100
Table 14-7  Capped Silver Summary Statistics within Veins 100
Table 14-8  Capped Gold Summary Statistics within Veins 102
Table 14-9  Summary of Silver Variogram Parameters 104
Table 14-10  Estimation Parameters 105
Table 14-11  Silver Model Descriptive Statistical Comparison 107
Table 14-12  Silver Model Descriptive Statistical Comparison (Cont.) 109
Table 14-13  Polygonal Resource at the Bolañitos, Effective Date of December 31, 2020 118
Table 15-1  Proven and Probable Mineral Reserves, Effective Date December 31, 2020 127
Table 16-1  Bolañitos Owned Mine Equipment 131
Table 16-2  Contractor Mine Equipment 132
Table 16-3  Summary of 2020 Bolañitos Production 132
Table 18-1  Summary of the Electric Installations at the Bolañitos Project 140
Table 19-1  Average Annual High and Low London PM Fix for Gold and Silver from 2000 to 2016 (prices expressed in US$/oz) 141
Table 19-2  Contracts Held by the Bolañitos Project 142
Table 20-1  Closure Budget 144
Table 20-2  Summary of Environmental and Mining Permits for the Bolañitos Project 144
Table 20-3  Direct and Indirect Area of Influence 145
Table 21-1  Actual 2020 and Planned 2021 Capital Costs for the Bolañitos Project 148
Table 21-2  Operating Costs for the Bolañitos Mines Project 148
Table 25-1  Mineral Resource Estimate, Effective Date December 31, 2020 152
Table 25-2  Mineral Reserve Estimate, Effective Date December 31, 2020 153
Table 26-1  2021 Bolañitos Exploration Budget 155

Appendices

Appendix A - Bolañitos 2016 Exploration Results  

 


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Table of Contents

List of Acronyms

AA

Atomic Absorption

HDPE

High Density Polyethylene

AES

Atomic Emission Spectrometry

HRC

Hard Rock Consulting

EDR

Endeavour Silver Corp.

NYSE

New York Stock Exchange

FSE

Frankfurt Stock Exchange

TSX

Toronto Stock Exchange

CIM

Canadian Institute of Mining, Metallurgy and Petroleum

QA/QC

Quality Assurance/Quality Control

CMC

Compañia Minera del Cubo S.A. de C.V.

SRM

Standard Reference Material

CL

Control Limit

LL

Lower Control Limit

UL

Upper Control Limit

ID

Inverse Distance

OK

Ordinary Kriging

NN

Nearest Neighbor

CV

Coefficient Variation

MSO

Mineable Shape Optimizer

CEMEFI

Mexican Center for Philanthropy

ESR

Socially Responsible Company

HP

Horsepower

 


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Executive Summary

1. EXECUTIVE SUMMARY

1.1 Introduction

Mr. Dale Mah, P.Geo., has prepared this Technical Report (the Report) on the Bolanitos Project (Bolanitos) for Endeavour Silver Corp. (EDR). Bolanitos is located in the state of Guanajuato, Mexico. This report was prepared in accordance with the requirements and guidelines set forth in National Instrument 43-101 (NI43-101) Companion Policy 43-101CP and Form 43-101F1 (June 2011), and the mineral resources and reserves presented herein are classified according to Canadian Institute of Mining, Metallurgy and Petroleum ("CIM") Definition Standards - For Mineral Resources and Mineral Reserves, prepared by the CIM Standing Committee on Reserve Definitions and adopted by CIM Council on May 10, 2014. The mineral resource and mineral reserve estimates reported here are based on all available technical data and information as of December 31, 2020.     

1.2 Property Description and Ownership

In 2007, EDR acquired the Bolañitos mine from Industrias Peñoles S.A. de C.V. (Peñoles), the owner at the time, and Minas de la Luz, S.A. de C.V. (Minas de la Luz), the operator at the time. The acquisition included the Mina Cebada, Mina Bolañitos, Mina Golondrinas and Mina Asunción (as well as a few other currently closed mines). Minas de la Luz continued as the operator of the mines until June, 2007, when EDR assumed control. The Mina Asunción is very close to the Mina Bolañitos and the two are currently connected underground.

The Bolañitos Project is located in the state of Guanajuato, Mexico. The mine consists of three operating mines: the Bolañitos, Lucero, and Asuncion mines, which are located near the town of La Luz, about 12 km to the northeast of Guanajuato. All of the mines are readily accessed by paved and gravel roads. EDR also owns the inactive Cebada mine, located about 5 km north of the city of Guanajuato, and the inactive Golondrinas mine, which is 3.5 km to the southwest of Cebada.

1.3 Geology and Mineralization

The Bolañitos mine is located in eastern part of the Guanajuato mining district, in the southeastern portion of the Sierra de Guanajuato, which is an anticlinal structure about 100 km long and 20 km wide. Bolañitos is located on the northeast side of this structure where typical primary bedding textures dip 10° to 20° to the north-northeast. Economic mineralization at Bolañitos is known to extend as much as 250 m vertically from 2300 m to 2050 m elevation with the exception of the La Luz vein that extends 400 m vertically from 2300 m to 1900 m. 

The Guanajuato mining district is characterized by classic, high grade silver-gold, epithermal vein deposits with low sulfidation mineralization and adularia-sericite alteration. Veins in the Guanajuato district are typical of most epithermal silver-gold vein deposits in Mexico with respect to the volcanic or sedimentary host rocks and the paragenesis and tenor of mineralization. The Guanajuato mining district hosts three major mineralized fault systems, the La Luz, Veta Madre and Sierra systems. 


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Executive Summary

Of the geological formations associated with the Guanajuato district, only the Esperanza and La Luz Formations occur in the Bolañitos mine area with mineralization residing primarily within the La Luz Formation.  Mineralization is known to dissipate at the contact with the Esperanza Formation.

The Veta Madre historically was the most productive vein in the Guanajuato district, and is by far the most continuous, having been traced on the surface for nearly 25 km. The vein dips from 35° to 55º to the southwest with measured displacement of around 1,200m near the Las Torres mine and 1,700 m near La Valenciana mine. The most productive veins at Bolañitos strike parallel to the Veta Madre system.

Bolañitos mineralization is directly related to faulting. Mineralization occurs as open-space fillings in fracture zones or impregnations in locally porous wall rock. Veins which formed in relatively open spaces are the main targets for mining.

Mineralized veins at Bolañitos consist of the classic banded and brecciated epithermal variety. Silver occurs primarily in dark sulfide-rich bands within the veins, with little mineralization within the wall rocks. The major metallic minerals reported include pyrite, argentite, electrum and ruby silver, as well as some galena and sphalerite, generally deeper in the veins. Mineralization is generally associated with phyllic (sericite) and silicification alteration which forms haloes around the mineralizing structures. The vein textures are attributed to the brittle fracturing-healing cycle of the fault-hosted veins during and/or after faulting.

Economic concentrations of precious metals are present in "shoots" distributed vertically and laterally between non-mineralized segments of the veins. Overall, the style of mineralization is pinch-and-swell with some flexures resulting in closures and others generating wide sigmoidal breccia zones.

1.4 Status of Exploration

In 2020, EDR spent US $770,512 (including property holding costs) on exploration activities, including drilling, at the Bolañitos Project, focused on exploring the Bolañitos North (Melladito and San Bernabe veins), Plateros, Sangre de Cristo and Bolañitos South (Ave Maria vein) areas. A total of 45 drill holes completed with 10,458m and 2,404 samples submitted for analysis.

Field exploration conducted, mainly in the Bolañitos South and Sangre de Cristo area, and consisted of geological mapping and sampling.

1.5 Mineral Resource Estimate

The QP, Dale Mah, P.Geo. is responsible for the mineral resource estimate presented here. Mr. Mah is a Qualified Person as defined by NI 43-101 and is not independent of EDR. EDR estimated the mineral resource for the Bolañitos mine Project based on drillhole data constrained by geologic vein boundaries using Leapfrog software to audit the resource estimate in conjunction with Vulcan software. The metals of interest at Bolañitos are gold and silver.

The Bolañitos mineral resource is comprised of 37 individual veins. The mineral resources have been estimated using either a Vertical Longitudinal Projection (VLP) polygonal method (7 veins) or as 3-dimensional ("3D") block model (30 veins).


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Table of Contents

The resources based on the 2D polygonal methods are estimated by using a fixed distance Vertical Longitudinal Projection (VLP) from sample points. The VLPs are created by projecting vein geology and underground workings onto a vertical 2D long section. Resource blocks are constructed on the VLP based on the sample locations in the plane of the projection. EDR geologists review the data for sample trends and delineate areas with similar characteristics along the sample lines. The areas are then grouped based on mining requirements and the average grades and thicknesses of the samples are tabulated for each block.  Resource volumes are calculated from the delineated area and the horizontal thickness of the vein, as recorded in the sample database. The volume and density are used to determine the overall resource tonnage for each area, and the grades are reported as a length weighted average of the samples inside each resource block

The mineral resource estimate for the Bolañitos Project as of December 31st, 2020, is summarized in Table 1-1. The mineral resources are exclusive of the mineral reserves.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Executive Summary

Table 1-1  Mineral Resource Estimate, Effective Date December 31st, 2020

Classification

Tonnes

Silver Equivalent

Silver

Gold

g/t

g/t

oz

g/t

oz

Measured

34,737

265

76

84,678

2.37

2,645

Indicated

433,412

347

166

2,313,890

2.27

31,573

Measured + Indicated

468,149

341

159

2,398,568

2.27

34,218

Inferred

625,337

322

120

2,411,253

2.52

50,733

1. Measured, Indicated and Inferred resource cut-off grades were 177, 173 and 181 g/t silver equivalent at Bolañitos.

2. Mineral resources are not mineral reserves and do not have demonstrated economic viability. There is no certainty that all or any part of the mineral resources estimated will be converted into mineral reserves.

3. Metallurgical recoveries were 84.7% silver and 88.9% gold.

4. Silver equivalents are based on a 80:1 silver:gold ratio

5. Price assumptions are $16.51 per ounce for silver and $1,465 per ounce for gold for resource cutoff calculations.

6. Mineral resources are estimated exclusive of and in addition to mineral reserves.

1.6 Mineral Reserve Estimate

Mr. Dale Mah, P.Geo, of EDR is responsible for the mineral reserve estimate presented in this report. Mr. Mah is Qualified Person as defined by NI 43-101 and is not independent of EDR.  The reserve calculation for the Bolañitos Project was completed in accordance with NI 43-101 and has an effective date of December 31st, 2020.  Stope designs for reporting the reserves were created utilizing the updated resources and cutoffs established for 2020.  All of the stopes are within readily accessible areas of the active mining areas.  Ore is processed in the on-site mill and floatation process capable of processing 1,600 tpd.

EDR utilized Vulcan program to generate the stopes for the reserve mine plan.  The parameters used to create the stopes are listed below;

  • Cutoff Grades:  177, 173 and 181 g/t silver equivalent

  • Minimum Mining Width:  0.8 m.

  • Cut and Fill Stope Size:  7m W x 4m H

  • Long Hole Stope Size:  7m W x 20m H

  • External Dilution Cut and Fill:  24%

  • External Dilution Long Hole:  40%

  • Silver Equivalent:  80:1 silver to gold

  • Gold Price:  US $1,465 /oz

  • Silver Price:  US $16.51 /oz

  • Gold Recovery:  84.7%


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Executive Summary
  • Silver Recovery:  88.9%

The stopes were only created with the updated Measured and Indicated resources including internal stope dilution above the calculated cutoff and have demonstrated to be economically viable, therefore Measured and Indicated mineral resources within the stopes have been converted to Proven and Probable reserves as defined by NI 43-101.

Table 1-2  Mineral Reserve Estimate

Classification

Tonnes

(t x 1,000)

AgEq
g/t

Ag g/t

Ag (oz) *
1,000

Au g/t

Au (oz)
* 1,000

%
Dilution

Proven

76.3

243

34

83.1

2.62

6.42

34.0%

Probable

236.6

254

53

405.0

2.51

19.1

33.9%

Total Proven and Probable Reserves

312.9

251

49

488.2

2.53

25.5

33.9%

1. Reserve cut-off grades are based on 177, 173 and 181 g/t silver equivalent.

2. Metallurgical Recoveries were 84.7% silver and 88.9% gold.

3. Mining Recoveries of 95% were applied.

4. Minimum mining widths were 0.8 meters.

5. Dilution factors averaged 21.0%. Dilution factors are calculated based on internal stope dilution calculations and external dilution factors of 15% for cutand fill and 30% for long hole.

6. Silver equivalents are based on a 80:1 silver:gold ratio.

7. Price assumptions are $16.51 per ounce for silver and $1,465 per ounce for gold.

8. Mineral resources are estimated exclusive of and in addition to mineral reserves.

9. Figures in table are rounded to reflect estimate precision; small differences generated by rounding are not material to estimates.

1.7 Conclusions and Recommendations

The QP considers the Bolañitos mineral resource and reserve estimates presented herein to conform with the requirements and guidelines set forth in Companion Policy 43-101CP and Form 43-101F1 (June 2011), and the mineral resources and reserves presented herein are classified according to Canadian Institute of Mining, Metallurgy and Petroleum ("CIM") Definition Standards - For Mineral Resources and Mineral Reserves, prepared by the CIM Standing Committee on Reserve Definitions and adopted by CIM Council on May 10, 2014.  These mineral resources and reserves form the basis for EDR's ongoing mining operations at the Bolañitos Mines Project.

The QP is unaware of any significant technical, legal, environmental, or political considerations which would have an adverse effect on the extraction and processing of the resources and reserves located at the Bolañitos Mines Project. Mineral resources which have not been converted to mineral reserves, and do not demonstrate economic viability shall remain mineral resources.  There is no certainty that all or any part of the mineral resources estimated will be converted into mineral reserves.

The QP considers that the mineral concessions in the Bolañitos mining district controlled by EDR continue to be highly prospective both along strike and down dip of the existing mineralization.

EDR's Bolañitos Mines Project has an extensive mining history with well-known silver and gold bearing vein systems. Ongoing exploration has continued to demonstrate the potential for the discovery of additional resources at the project and within the district surrounding the mine.  Outside of the currently known reserve/resource areas, the mineral exploration potential for the Bolañitos Project is considered to be very good.  Parts of the known vein splays beyond the historically mined areas also represent good exploration targets for additional resource tonnage


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Executive Summary

Since EDR took control of the Bolañitos Mines Project, new mining areas have enabled EDR to increase production by providing additional sources of mill feed. EDR's operation management teams continue to search for improvements in efficiency, lowering costs and researching and applying low-cost mining techniques.

In 2021, EDR plans to drill 11,500 meters of both surface and underground drilling in the Bolañitos Project, at an estimated cost of US$1,925,000. Drilling campaigns mainly in the Bolañitos North (Melladito), San Miguel, Plateros, Belén and Bolañitos South areas.

The QP recommends that the process of converting mineral resources into reserves from 2D polygons to 3D block models be continued.  During the last couple of years, considerable progress has been made on this process with only nine veins remaining to be converted to 3D. Additional modeling efforts should be made to define the mineralized brecciated areas as they have been an important source of economic material encountered in the current operation, and could provide additional tonnage to support the mine plan.

EDR currently utilizes the exploration drilling and chip and muck samples in their resource and reserve calculations.  The QP recommends that future efforts focus on constructing block models for resource and reserve reporting utilizing only the exploration and underground drilling results.  The chip and muck samples should be used to develop the production model.  This will help keep data densities consistent in each modeling effort and will provide another level in the reconciliation process to compare modeling results.

Although the reconciliations conducted by EDR show good comparison between planned versus actual values, the reconciliation process should be improved to include the estimated tonnes and grade from the resource models. Because the LOM plan is compared to the plant production on a monthly basis, the actual physical location of the material mined may be different than the planned location.  Due to the many stopes that are mined during a day this can only be completed on an average monthly basis due to blending of stope material into the mill.  The monthly surveyed as mined areas should be created into triangulation solids and saved monthly for reporting the modeled tonnes for each month. The combination of the 3D block models and 2D and polygonal reserves makes this process difficult but considerable progress has been made during the last year to get all resources and reserves into 3D block models.  The model-predicted results versus actual can then be used to determine if dilution factors need to be adjusted, or perhaps the resource modeling parameters may require adjustment if there are large variances.  The mill production should be reconciled to the final concentrate shipments on a yearly basis and resulting adjustment factors should be explained and reported.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Introduction

2. INTRODUCTION

2.1 Issuer and Terms of Reference

Endeavour Silver Corp. ("EDR") is a Canadian based mining and exploration company actively engaged in the exploration, development, and production of mineral properties in Mexico. EDR is headquartered in Vancouver, British Columbia with management offices in Leon, Mexico, and is listed on the Toronto (TSX:EDR), New York (NYSE: EXK) and Frankfurt (FSE:EJD) stock exchanges. The company has three currently active mining properties in Mexico, the Guanaceví Property in northwest Durango State, the Bolañitos property in Guanajuato State, and the El Compas property in Zacatecas State. The Compas property has ceased mining operations since the Effective Date of this Report.

Endeavour Silver is using the provision for producing issuers, whereby the QP for this technical report is not required to be prepared by or under the supervision of an independent QP. Mr. Dale Mah, P.Geo, is employed as VP Corporate Development for Endeavour Silver and supervised the preparation of the mineral resource and reserve estimate and is not independent.

This report was prepared in accordance with the requirements and guidelines set forth in NI 43-101, NI 43-101 Companion Policy 43-101CP and Form 43-101F1 (June 2011), and the mineral resources and reserves presented herein are classified according to Canadian Institute of Mining, Metallurgy and Petroleum ("CIM") Definition Standards - For Mineral Resources and Mineral Reserves, prepared by the CIM Standing Committee on Reserve Definitions and adopted by CIM Council on May 10, 2014. The mineral resource and mineral reserve estimates reported here are based on all available technical data and information as of December 31, 2020.

2.2 Sources of Information

A portion of the background information and technical data for this study was obtained from the following previously filed NI 43-101 Technical Reports:

Hard Rock Consulting LLC (2016) NI 43-101 Technical Report: Updated Mineral Resource and Reserve Estimates for the Bolañitos Project, Guanajuato State, Mexico, effective date March 3, 2016.

Munroe, M.J. (2015). NI 43-101 Technical Report Resource and Reserve Estimates for the Bolañitos Mines Project, Guanajuato State, Mexico, effective date October 31, 2014.

Munroe, M.J. (2014). NI 43-101 Technical Report Resource and Reserve Estimates for the Bolañitos Mines Project, Guanajuato State, Mexico, effective date December 31, 2013.

Lewis, W.J., Murahwi, C. and San Martin, A.J., (2013), NI 43-101 Technical Report on the Resource and Reserve Estimates for the Guanajuato Mines Project, Guanajuato State, Mexico: unpublished NI 43-101 technical report prepared by Micon International for Endeavour Silver, effective date December 15, 2012.

Lewis, W.J., Murahwi, C. and San Martin, A.J., (2012), NI 43-101 Technical Report on the Resource and Reserve Estimates for the Guanajuato Mines Project, Guanajuato State, Mexico: unpublished NI 43-101 technical report prepared by Micon International for Endeavour Silver, effective date December 31, 2011.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Introduction

Lewis, W. J., Murahwi, C., and Leader, R. J. (2011), NI 43-101 Technical Report, Audit of the Resource and Reserve Estimates for the Guanajuato Mines Project, Guanajuato State, Mexico: unpublished NI 43-101 technical report prepared by Micon International for Endeavour Silver, effective date December 31, 2010.

Lewis, W.J., Murahwi, C., Leader, R.J. and San Martin, A.J., (2010), NI 43-101 Technical Report, Audit of the Resource and Reserve Estimates for the Guanajuato Mines Project, Guanajuato State, Mexico: unpublished NI 43-101 technical report prepared by Micon International for Endeavour Silver, effective date December 31, 2009.

Lewis, W.J., Murahwi, C., Leader, R.J. and San Martin, A.J., (2009), NI 43-101 Technical Report, Audit of the Resource and Reserves for the Guanajuato Mines Project, Guanajuato State, Mexico: unpublished NI 43-101 technical report prepared by Micon International for Endeavour Silver, effective date December 31, 2008.

Beare, M., and Sostre, M., (2008), NI 43-101 Technical Report for the Guanajuato Mines Project, Guanajuato State Mexico: unpublished NI 43-101 technical report prepared by SRK Consulting for Endeavour Silver, effective date December 31, 2007.

2.3 Qualified Persons and Personal Inspection

This report is endorsed by the following Qualified Person, as defined by NI 43-101: Mr. Dale Mah, P.Geo., VP Corporate Development of Endeavour Silver Corp.

As Qualified Persons and representative of EDR, Mr. Mah has visited the mining operations on numerous occasions. His most recent visit was conducted on January 8-9, 2020. During his visit, he viewed selected drill core, underground mining operations, visited waste rock storage facilities, toured mineral processing facilities, viewed infrastructure, and discussed aspects of mine planning, budgeting, geology, exploration and mining practices with site personnel. A personal inspection has not been conducted more recently due to the COVID-19 pandemic due to travel restrictions imposed by local and foreign governments. However, once it is safe to do so, a physical site visit will take place as soon as practical.

2.4 Units of Measure

Unless otherwise stated, all measurements reported here are in metric units, and currencies are expressed in constant 2020 U.S. dollars.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Reliance on Other Experts

3. RELIANCE ON OTHER EXPERTS

This section is not relevant to this report.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Property Description and Location

4. PROPERTY DESCRIPTION AND LOCATION

4.1 Project Location

The Bolañitos Project is located in the state of Guanajuato, Mexico, as shown in Figure 4-1. The mine consists of three operating mines: the Bolañitos, Lucero, San Miguel and Asuncion mines, which are located near the town of La Luz, about 12 km to the northeast of Guanajuato (Figure 4-1). The Bolañitos mine and the processing plant are situated approximately 5 km west of Cebada. All of the mines are readily accessed by paved and gravel roads. EDR also owns the inactive Cebada mine, located about 5 km north of the city of Guanajuato, and the inactive Golondrinas mine, which is 3.5 km to the southwest of Cebada.

Figure 4-1 Bolañitos Project Location

EDR acquired the Bolañitos mine Project in 2007 from Industrias Peñoles S.A. de C.V. (Peñoles), the owner at the time, and Minas de la Luz, S.A. de C.V. (Minas de la Luz), the operator at the time. The acquisition included the Mina Cebada, Mina Bolañitos, Mina Golondrinas and Mina Asunción (as well as a few other currently closed mines). Minas de la Luz continued as the operator of the mines until June, 2007, when EDR assumed control. The Mina Asunción is very close to the Mina Bolañitos and the two are currently connected underground.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Property Description and Location

4.2 Mineral Tenure, Agreements and Encumbrances

The Bolañitos Project consists of 26 mining concessions totaling 2,537 hectares (ha), including four operating silver (gold) mines (Bolañitos, Lucero, Asuncion and San Miguel), several past-producing silver (gold) mines, and the 1,600 t/d Bolañitos processing plant. A map of the mineral concessions belonging to the Bolañitos Project is presented in Figure 4-2, and mineral concession details are summarized in Table 4-1.

Figure 4-2 Bolañitos Mine Claim Map


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Property Description and Location

Table 4-1  Summary of the Mineral Concessions Owned by Endeavour Silver

Concession Name

Title Number

Term of Mineral Concession

Hectares

2020 Annual Taxes (pesos)

From

To

1st Half

2nd Half

La Cebada

171340

20/09/1982

19/09/2032

353.0373

60,108

60,108

El Puertecito

171537

20/10/1982

19/10/2032

441.9481

75,243

75,243

Bolañitos

171538

20/10/1982

19/10/2032

305.4762

52,011

52,011

La Paz

172120

26/09/1983

25/09/2033

413.0599

70,325

70,325

Unif. Golondrinas

188680

29/11/1990

28/11/2040

361.6543

61,574

61,574

Marion

189037

05/12/1990

04/12/2040

1.0498

189

189

Virginia

189038

05/12/1990

04/12/2040

7.1339

1,224

1,224

Ampl. a La Trinidad

190961

29/04/1991

28/04/2041

4.6061

794

794

Susy

191487

19/12/1991

18/12/2041

35.4282

6,041

6,041

Chuyita

191489

19/12/1991

18/12/2041

43.3159

7,384

7,384

Ana Rosa

191492

19/12/1991

18/12/2041

96.7364

16,477

16,477

La Trinidad

195076

25/08/1992

24/08/2042

4.4800

773

773

El Dolar

212398

04/10/2000

03/10/2050

3.1979

554

554

Lucero

238265

23/08/2011

02/08/2061

49.5060

4,799

4,799

Lucero 2

238024

12/07/2011

11/07/2061

8.0000

784

784

La Cebada 2, Fracc. 1

238982

15/11/2011

14/11/2061

95.3713

9,235

9,235

La Cebada 2, Fracc.2

238983

15/11/2011

14/11/2061

2.3183

234

234

La Cebada 1, Fracc. 2

241519

19/12/2012

18/12/2062

30.8472

2,994

2,994

La Cebada 1, Fracc. 1

241367

22/11/2012

21/11/2062

23.7041

2,303

2,303

La Cebada 1, Fracc. 3

241368

22/11/2012

21/11/2062

2.0579

209

209

La Cebada 1, Fracc. 5

241369

22/11/2012

21/11/2062

6.2726

617

617

La Cebada 1, Fracc. 4

246742

16/11/2018

15/11/2068

4.7568

65

65

Belén II

218896

23/01/2003

22/01/2053

92.6934

15,789

15,789

Ampliacion de Belén

194930

30/07/1992

29/07/2042

99.1049

16,881

16,881

Tajo de Adjuntas

231210

25/01/2008

24/01/2058

15.0000

2563

2563

Juanita

217034

14/06/2002

13/06/2052

36.5196

6227

6227

TOTAL

2537.2761

415,397

415,397

EDR has previously met all obligations of established agreements required to obtain the 100% control of all 26 concessions. Two areas retain a percentage in royalties for exploitation, and these are summarized in Table 4-2.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Property Description and Location

Table 4-2  Summary of the Endeavour Silver's Royalties

Area

Agreement

NSR

Concession Name

Title Number

Hectares

 

Belen

Sociedad Cooperativa de Producción Minera Metalurgica

2%

Belen II

218896

92.6934

Ampliación de Belen

194930

99.1049

Tajo de Adjuntas

Gilberto Rodriguez Martinez

2%

Tajo de Adjuntas

231210

15.0000

Hector Ezquivel Esparza

2%

Juanita

217034

36.5196

The annual 2020 concession tax for the Guanajuato properties is estimated to be approximately 830,794 Mexican pesos (pesos), which is equal to about US $41,540 at an exchange rate of 20.00 pesos to US $1.00.

In addition to the mineral rights, EDR has agreements with various private ranch owners that provide access for exploration and exploitation purposes. Table 4-3 summarizes the surface access rights as of December 31, 2020.

Table 4-3  Summary of Endeavour Silver's Surface Access Rights

Owner

Area Name

Validity

Term

 

 

Florentino Ortega Camarillo

Cebada - Bolañitos

15 Years

01/12/2007 - 2022

 

Benjamin Tapia Cruces

Cebada - Bolañitos

15 Years

01/12/2007 - 2022

 

Alfredo Ortega Gonzalez

Cebada - Bolañitos

15 Years

01/12/2007 - 2022

 

Cont. Y Addendum Ma. Concepción Ortega Camarillo (apoderado J. Isabel Camarillo Ortega)

Cebada - Bolañitos

10 Years

01/01/2013 - 2023

 

Ma. Elena Morales Rivera

Melladito

6 Months

10/07/2020 - 10/01/2021

 

         

4.3 Permits and Environmental Liabilities

EDR holds all necessary environmental and mine permits to conduct planned exploration, development, and mining operations at the Bolañitos Project, and is in full compliance with applicable environmental and safety regulatory standards. The QP knows of no existing or potential future significant factors or risks that might affect access, title, or the right or ability to perform work on the property.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Accessibility, Climate, Local Resources, Infrastructure & Physiography

5. ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY

5.1 Access and Climate

Primary access to the Bolañitos Project is provided by a newly constructed (2013) paved road from the city of Guanajuato. The Leon/Guanajuato international airport provides international access to the area with daily service from Los Angeles, Dallas/Fort Worth and Houston, and national access to the area from Mexico City.

The regional climate is temperate, with cool winters and mild summers. Rainfall occurs primarily during the summer season, from June to September, and typical annual precipitation is about 50 cm per year. From mid-December through January, nighttime temperatures fall to 7° to 10 °C, and daytime high temperatures in low 20 °C range are typical. Snowfall is rare but has been known to occur at the higher elevations throughout the region. Weather conditions rarely, if ever, restrict mining activity at Bolañitos, and operations can be carried out year-round.

5.2 Local Resources and Infrastructure

The capital city of Guanajuato has a population of approximately 160,000 and hosts several universities and post-secondary schools, including a mining college. Tourism is a principal industry in the area, and numerous hotels and restaurants are available as a result. The area has a rich tradition of mining and there is an ample supply of skilled personnel sufficient for both the underground mining operations and the surface facilities. Most of the work force resides in local communities or in the city of Guanajuato. Supplies required for the exploration programs and mining operations are purchased in either the city of Guanajuato or Leon.

At each of the mine sites on the Bolañitos Project, the water required for operations is supplied from dewatering of the mines. The tailings facility at the Bolañitos mine is set up to recycle as much water as possible back into the processing plant.

Power supply to the Bolañitos Project is provided by the national grid CFE (Comisión Federal de Electricidad), and telephone communications are integrated into the national land-based telephone system which provides reliable national and international direct dial telephone communications. Satellite communications also provide phone and internet capabilities at the Bolañitos mine, though the satellite phone and internet services are slow and sometimes unreliable. There is no cell phone service at any of the mines.

Additional details regarding infrastructure specific to the Bolañitos Project are provided in Section 18 of this report.

5.3 Bolañitos Mine Physiography

The state of Guanajuato is situated along the southern edge of the Central Mexican Plateau and comprises portions of the Trans-Mexican Volcanic Belt, the Mexican Plateau, and the Sierra Madre Oriental. The Bolañitos Project is located in the west central portion of the state, among a series of low mountains which are part of the Sierra Madre Occidental. Grass, small trees and shrubs along with several varieties of cacti make up most of the vegetation on the steeper hillsides, with larger trees found near springs and streams. The area is mainly devoid of trees except in the valleys and where reforestation has taken place.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Accessibility, Climate, Local Resources, Infrastructure & Physiography

Even though there is a reasonable amount of rainfall each year, most of the creeks in the area are usually dry, with the exception of man-made reservoirs surrounding the city of Guanajuato. Some cattle and/or goat grazing is carried out in the area over the scrub land. Sections of more arable land have been deforested to support small plots for growing crops.

5.4 Surface Rights

EDR has negotiated access and the right to use surface lands sufficient for many years of operation. Sufficient area exists at the Bolañitos Project for all anticipated future surface infrastructure. Details regarding surface rights for mining operations, availability of power sources, potential tailings storage areas, potential waste disposal areas, and potential processing plant sites, are discussed in the relevant sections of this report on mining methods, recovery methods and project infrastructure.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project History

6. HISTORY

The following paragraphs provide an abbreviated timeline of the history of Bolañitos Project:

  • 1968 - Fresnillo Company acquired claims and incorporated Negociación Minera Santa Lucía (now Cebada) and the Peregrina mine.

  • 1973 - The contracting company Tormex S.A. completed a photogeological study in the area of the Cebada mine holdings.

  • 1976 - Production began at the Cebada mine; between 1976 and 1995, the Cebada mine produced 1,277,216 tonnes at an average grade of 4.04 g/t gold and 372 g/t silver.

  • 2003 - Grupo Guanajuato closed the Torres, Sirena, Peregrina and Apolo mines. The Bolañitos, Golondrinas, Asunción and Cebada mines stayed in production on a break-even basis.

  • 2007 - EDR acquired the Bolañitos Project, which included, Mina Cebada, Mina Bolañitos, Mina Golondrinas and Mina Asunción (as well as a few other currently closed mines), from Peñoles, the owner at the time, and Minas de la Luz, the operator at the time. Minas de la Luz was kept on as the operator of the mines until June, 2007, when EDR assumed control.

6.1 Historical Exploration

Records from mining operations provide survey information of historical workings, while channel sample data from stopes, raises and drifts excavated on the mineralized zones provide grade information. Prior to EDR's acquisition of the Bolanitos project, there was limited historical  drilling. Several well mineralized and high-grade drill holes completed by Peñoles have not yet been followed-up, and these contribute to the remaining exploration potential for the property, which includes untested areas both along the strike of the veins and at depth below the old workings.

6.2 Historical Production

In 2006, previous operator Minas de la Luz reported production of 255,766 oz silver and 3,349 oz gold from 76,532 tonnes of ore grading 128 g/t silver and 1.62 g/t gold from the Bolañitos, Cebada and Golondrinas mines, with the Bolañitos plant operating at about 43% of its capacity.

6.3 Historic Mineral Resource and Reserve Estimates

Bolañitos Mineral resource and reserve estimates which were produced prior to EDR's involvement with the Bolañitos Project are not discussed in this report as they are historical in nature, were not completed according to modern reporting standards, and are not considered reliable or relevant to the present-day Project.

In 2016 an independent NI43/101 compliant report was commissioned from Hard Rock Mining Consultants (HRM) on the resource and reserve estimates for the Bolañitos mine. At the time the total mineral resource was comprised of 21 individual veins of which nine (9) were estimated using a Vertical Longitudinal Projection (VLP) polygonal method and twelve (12) were modelled as 3-dimensional ("3D") block model. The operational areas were included in the 3D models and were split into 2 areas based on the vein location within the deposit.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project History

The resources based on the 2D polygonal methods are estimated by using a fixed distance Vertical Longitudinal Projection (VLP) from sample points. The VLPs are created by projecting vein geology and underground workings onto a vertical 2D long section. Resource blocks are constructed on the VLP based on the sample locations in the plane of the projection. EDR geologists review the data for sample trends and delineate areas with similar characteristics along the sample lines. The areas are then grouped based on mining requirements and the average grades and thicknesses of the samples are tabulated for each block.  Resource volumes are calculated from the delineated area and the horizontal thickness of the vein, as recorded in the sample database. The volume and density are used to determine the overall resource tonnage for each area, and the grades are reported as a length weighted average of the samples inside each resource block.

The QP validated the vein models provided by EDR using Leapfrog. Ten veins were modeled by EDR using a series of cross-sectional interpretations. The sectional interpretations are based primarily on composite intercepts and are used to construct 3D vein solids in Vulcan. Cross-sections orthogonal to the strike of the vein and level plan sections were used to ensure sample selections for compositing were contained within the modeled veins.

The mineral resource estimate for the Bolañitos Project as of December 31st, 2016, is summarized in the following table. The mineral resources are exclusive of the mineral reserves.

Historic Mineral Resource Estimate, Effective Date December 31st, 2016

Classification

Tonnes

Silver Equivalent

Silver

Gold

g/t

g/t

oz

g/t

oz

Measured

89,000

329

150

427,600

2.29

6,500

Indicated

698,000

325

162

3,630,300

2.04

45,800

Measured + Indicated

787,000

325

161

4,057,900

2.07

52,300

Inferred

1,150,000

330

153

5,674,700

2.29

84,800

1. Measured, Indicated and Inferred resource cut-off grades were 162 g/t silver equivalent at Bolañitos.

2. Mineral resources are not mineral reserves and do not have demonstrated economic viability. There is no certainty that all or any part of the mineral resources estimated will be converted into mineral reserves.

3. Metallurgical recoveries were 79.6% silver and 84.5% gold.

4. Silver equivalents are based on a 80:1 silver:gold ratio

5. Price assumptions are $16.29 per ounce for silver and $1,195 per ounce for gold for resource cutoff calculations.

6. Mineral resources are estimated exclusive of and in addition to mineral reserves.

For the 2016 reserves estimation stope designs were created utilizing the updated resources and cutoffs established for 2016.  All of the stopes were within readily accessible areas of the active mining areas.  Ore is processed in the on-site mill and floatation process capable of processing 1,600 tpd.


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Bolañitos Project History

The mining breakeven cut-off grade, which includes internal stope dilution, was utilized in Datamine's MSO to generate the stope designs for defining the reserves. The cut-off is stated as silver equivalent since the ratio between gold and silver is variable and both commodities are sold.  The average cut-off grade used for the Bolañitos property is 162 g/t Ag equivalent. Silver equivalent grade is calculated as the silver grade + (gold grade * 80), taking into account gold and silver prices and expected mill recoveries.

Mineral reserves were derived from Measured and Indicated resources after applying the economic parameters, and utilizing Datamine's MSO program to generate stope designs for the reserve mine plan.  The Bolañitos Project mineral reserves were derived and classified according to the following criteria:

  • Proven mineral reserves are the economically mineable part of the Measured resource for which mining and processing / metallurgy information and other relevant factors demonstrate that economic extraction is feasible. For Bolañitos Project, this applies to blocks located within approximately 10m of existing development and for which EDR has a mine plan in place.

  • Probable mineral reserves are those Measured or Indicated mineral resource blocks which are considered economic and for which EDR has a mine plan in place. For the Bolañitos mine project, this is applicable to blocks located a maximum of 35m either vertically or horizontally from development.

The Proven and Probable mineral reserves for the Bolañitos Project as of December 31, 2016 are summarized in the following table.  The reserves are exclusive of the mineral resources reported.

Historic Mineral Reserve Estimate, Effective Date December 31st, 2016

Classification

Tonnes

(t x 1,000)

AgEq g/t

Ag g/t

Ag (oz) * 1,000

Au g/t

Au (oz) * 1,000

% Dilution

Proven

157.2

311

90

456.7

2.84

14.34

21%

Probable

238.2

245

104

798.3

1.81

13.82

20%

Total Proven and Probable Reserves

395.4

271

99

1255.0

2.22

28.17

21%

1. Reserve cut-off grades are based on a 162 g/t silver equivalent.

2. Metallurgical Recoveries were 79.6% silver and 84.5% gold.

3. Mining Recoveries of 95% were applied.

4. Minimum mining widths were 0.8 meters.

5. Dilution factors averaged 21.0%. Dilution factors are calculated based on internal stope dilution calculations and external dilution factors of 15% for cut and fill and 30% for long hole.

6. Silver equivalents are based on a 80:1 silver:gold ratio.

7. Price assumptions are $16.29 per ounce for silver and $1,195 per ounce for gold.

8. Mineral resources are estimated exclusive of and in addition to mineral reserves.

9. Figures in table are rounded to reflect estimate precision; small differences generated by rounding are not material to estimates.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Geological Setting and Mineralization

7. GEOLOGICAL SETTING AND MINERALIZATION

The following description of the geological setting for the Bolañitos Project is largely excerpted and modified from the technical reports prepared by Hard Rock Consulting (2016) and Micon (2009, 2010, 2011 and 2012). The QP has reviewed the geologic data and information available, and finds the descriptions and interpretations provided in these documents acceptable for use in this report.

7.1 Regional Geology

The mining district of Guanajuato is situated along the southern and eastern flanks of the Sierra Madre Occidental geological province, a north-northwesterly trending linear volcanic belt of Tertiary age. It is approximately 1,200 km long and 200 to 300 km in width. Rocks within the belt comprise flows and tuffs of basaltic to rhyolitic composition with related intrusive bodies. The volcanic activity that produced the bulk of the upper volcanic group ended by the late Oligocene, though there was some eruptive activity as recently as 23 Ma (early Miocene). The volcanism was associated with subduction of the Farallon Plate and resulted in accumulations of lava and tuffs on the order of 1 km thick. Later Basin and Range extensional tectonism related to the opening of the Gulf of California resulted in block faulting, uplift, erosion and the present-day geomorphology of the belt. Strata within the belt occupy a broad antiform, longitudinally transected by regional scale faults. A regional geologic map of the Bolañitos Project area is presented as Figure 7-1.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Geological Setting and Mineralization

Figure 7-1  Regional Geology of the Bolañitos Project Area (EDR, 2016; Modified from Clark, 2009)


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Geological Setting and Mineralization

The Guanajuato district is underlain by a volcano-sedimentary sequence of Mesozoic to Cenozoic age rocks. There are three main northwest trending vein systems that cut these volcano-sedimentary sequences. The vein systems from west to east are known as the La Luz, Veta Madre and La Sierra systems. These systems are generally silver-rich with silver to gold ratios from 72:1 to 214:1. They are known along strike for 10 to 25 km.

The Bolañitos mine is located in eastern part of the Guanajuato mining district, in the southeastern portion of the Sierra de Guanajuato, which is an anticlinal structure about 100 km long and 20 km wide. Bolañitos is located on the northeast side of this structure where typical primary bedding textures dip 10° to 20° to the north-northeast. Economic mineralization at Bolañitos is known to extend as much as 250 m vertically from 2300 m to 2050 m elevation with the exception of the La Luz vein that extends 400 m vertically from 2300 m to 1900 m. 

7.1.1 Stratigraphy

The stratigraphy of the Guanajuato mining district can be divided into a Mesozoic basement (Chiodi et al, 1988; Dávila and Martinez, 1987; Martinez-Reyes, 1992) and overlying Cenozoic units, as shown in Figure 7-2. The lower Mesozoic lithological units are the Esperanza and La Luz Formations which are composed of marine sedimentary rocks, weakly to moderately metamorphosed and intensely deformed by shortening. These rocks are unconformably overlain by the Tertiary Guanajuato Formation conglomerates, and the Loseros, Bufa, Calderones, Cedros and Chichíndaro Formations. The Tertiary rocks consist of continental sediments and sedimentary rocks, which generally occupy lower topographic zones, and subaerial volcanic rocks, which are principally exposed in the ranges and higher plateaus. The rocks of the Cenozoic cover have experienced only extensional deformation and in some places are gently tilted. Tertiary-aged rocks correspond to a period of tectonism accompanied by volcanism and intrusive magmatic activity.

Figure 7-2 does not depict the Peregrina intrusive, which is a floored body (laccolith) at the contact of the Bufa Formation rhyolite and the Guanajuato Formation conglomerate. The uppermost portion of the Peregrina intrusive extends into the Chichíndaro Formation rhyolite. The thickness of each unit presented graphically in the stratigraphic section represents the maximum thickness of that unit in the vicinity of the Bolañitos mine.


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Bolañitos Project Geological Setting and Mineralization

Figure 7-2  Stratigraphic Column, Eastern Guanajuato Mining District

7.1.2 Esperanza Formation

The Esperanza Formation is composed of carbonaceous and calcareous shale interbedded with arenite, limestone, and andesitic-to-basaltic lava flows, all weakly metamorphosed to phyllites, slates, and marble. The thickness of the formation exceeds 600m.

7.1.3 La Luz Formation

The La Luz Formation overlies the Esperanza Formation and consists mainly of interbedded clastic sedimentary rocks and massive and pillow tholeiitic basalts dated at 108.4 ±2 Ma. Locally, rhyolite tuffs and agglomerates are present, and some volcanogenic massive sulfide occurrences have been reported. A minimum thickness of at least 1,000 m is recognized, but the true thickness is unknown due to deformation and sub-greenschist metamorphism. Included with the La Luz Formation are the La Palma diorite and La Pelon tonalite, which form the upper part of the Guanajuato arc. Pervasive propylitic alteration is common.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Geological Setting and Mineralization

7.1.4 Guanajuato Formation (Eocene to Oligocene)

The red conglomerate characteristic of the Guanajuato Formation lies in unconformable contact with the Esperanza Formation and less frequently with the La Luz Formation andesite (Edwards, 1955). The conglomerate consists of pebbles to boulders of quartz, limestone, granite and andesite belonging to older rock units, all cemented by a clay matrix, with some interlayers of sandstone. Beds of volcanic arenites and andesitic lavas occur at the base of the conglomerate. The Guanajuato conglomerate is estimated to be between 1,500 and 2,000 m thick. Contemporaneous vertebrate paleontology and andesitic lavas (49 Ma, Aranda-Gómez and McDowell, 1998) indicate that the unit is mid-Eocene to early Oligocene in age.

7.1.5 Loseros Formation (Cenozoic)

This overlying mid-Tertiary volcanic sequence is interpreted to be within, and adjacent to a caldera. The Loseros tuff is a well-bedded, green to cream-red volcanic arenite from 10 m to 52 m thick. It is interpreted to be a surge deposit at the base of the Cubo caldera filling and Oligocene in age.

7.1.6 Bufa Formation (Cenozoic)

The Bufa Formation rhyolite is a felsic ignimbrite that is approximately 360 m thick and lies above a sharp to gradational contact. It is a sanidine-bearing rhyolite-ignimbrite with biotite as a mafic phase, and is often massive, but locally bedded. Owing to moderate welding and extensive and pervasive silicification, it is a hard rock that forms prominent cliffs east of the city of Guanajuato. It occasionally contains large lithic clasts of various types, many of which were derived from the pre-volcanic basement. At Bolañitos, the Bufa rhyolite has three mappable units: a lower breccia overlain by dense, red rhyolite porphyry, in turn overlain by a massive to bedded ignimbrite. The cliff-forming Bufa rhyolite has been dated using the K-Ar dating technique to be 37 ±3 Ma, placing it in the middle Oligocene.

7.1.7 Calderones Formation (Cenozoic)

The Calderones Formation contains a wide variety of volcanic rocks, including low- to medium-grade ignimbrites, deposits of pyroclastic flows, pyroclastic surge layers related to phreatomagmatic activity, airfall ash-rich tuffs, minor Plinian pumice layers, lahars, debris flows, reworked tuffaceous layers deposited in water, tuff-breccias and mega-breccias. Ubiquitous and characteristic chlorite alteration imparts a green to greenish blue color to almost all outcrops of the Calderones. Propylitic alteration adjacent to veins and dikes is of local importance in many outcrops.

The Calderones Formation overlies the Bufa Formation at Bolañitos with a contact marked by a megabreccia composed of large (often 5 to 10 m) fragments of the Esperanza, La Luz and Guanajuato Formations. The Calderones Formation, which exceeds 300 m in thickness at Bolañitos, is the upper caldera-filling unit above the surge deposit and the Bufa ignimbrites.

7.1.8 Cedros Andesite (Cenozoic)

Overlying the Calderones Formation is the Cedros Formation andesite, a 100 to 640-m thick unit, which consists of grey to black andesitic lava flows with interlayered red beds and andesitic to dacitic tuffs.

The Cedros Formation is entirely post-caldera and is widespread.


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Bolañitos Project Geological Setting and Mineralization

7.1.9 Chichíndaro Formation (Cenozoic)

The Chichíndaro Formation rhyolite is a sequence of domes and lava flows interbedded with poorly sorted volcanic breccias and tuffs. Fluidal porphyritic textures are characteristic in the domes and flows.

This lithologic unit is closely related to the hypabyssal Peregrina intrusion, and it ranges in thickness from 100 to 250 m. In places, the rhyolite domes contain disseminated tin and vapor-phase cavity-filling topaz distributed along the flow foliation.

The Chichíndaro rhyolite is the youngest volcanic unit in the Guanajuato mining district. Three K-Ar ages obtained from this formation (Gross, 1975; Nieto- Samaniego et al, 1996) date the unit at 32 ±1 Ma, 30.8 ±0.8 Ma and 30.1 ±0.8 Ma.

7.1.10 Comanja Granite (Cenozoic)

The Comanja granite is a unit of batholithic size, apparently emplaced along the axis of the Sierra de Guanajuato. It is Eocene in age and has been radiometrically dated at 53 ±3 Ma and 51 ±1 Ma by K-Ar in biotite (Zimmermann et al, 1990). These dates establish the youngest relative age for the Bufa formation, the youngest unit cut by the granite.

7.1.11 El Capulin Formation

The unconsolidated El Capulin Formation consists of tuffaceous sandstone and conglomerate overlain by vesicular basalt, all of Quaternary age.

7.2 Structure

The following paragraphs are modified from the summary of the structural setting of the Guanajuato mining district presented by Starling (2008), which focused on the Veta Madre but likely applies to the La Luz system that composes the Bolañitos mine.

Pre-mineralization deformation during the Laramide orogeny (~80-40 Ma) resulted in west-northwest trending pre-mineral folds and thrusts in the Esperanza Formation as observed in the Cebada mine on the Veta Madre. Early post-Laramide extension (~30 Ma) was oriented north-south to north-northeast, and controlled many vein deposits in the region (e.g., Fresnillo, Zacatecas, La Guitarra). Guanajuato appears to lie on a north-northwest-trending terrane boundary which was reactivated as a sinistral transtensional fault zone in conjunction with early-stage intermediate-sulfidation style mineralization. Subsequent (~28 Ma) regional extension to the east-northeast-west-northwest resulted in basin and range-type deformation and block faulting, and is associated with a second phase of mineralization in the Guanajuato district.

Along the Veta Madre vein system, ore shoots were controlled during early-stage mineralization by counter-clockwise jogs along the main structure and at intersections with west-northwest and northeast fault zones. These tended to generate relatively steep ore shoots plunging to the south along the Veta Madre.

During the second phase of mineralization, listric block faulting and tilting affected parts of the Veta Madre veins and new systems such as La Luz developed. The veins at La Luz appear to have formed as extensional arrays between reactivated west-northwest fault zones acting as dextral transtensional structures.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Geological Setting and Mineralization

The second phase vein systems tend to have formed sub-horizontal ore zones either reflecting fluid mixing zones or structural controls due to changes in dip of the fault surface. The overprint of two events means that in some deposits, ore shoots have more than one orientation and that there are vertical gaps in ore grade.

Randall et al (1994) first proposed a caldera structure as a conceptual geologic model for the Guanajuato mining district, citing the presence of a mega-breccia in the Calderones Formation and the distribution of the Oligocene volcanic formations described above. The hypothesis states that the caldera collapse occurred in at least two stages and the collapse was a trap-door type. The presence of a peripheral three-quarter ring of rhyolite domes intruding along bounding faults, the location of the Oligocene volcanic formations ponded within this ring, mega-breccia and topographic rim, all provide supporting evidence for this hypothesis.

Following caldera formation, normal faulting combined with hydrothermal activity around 27 Ma (Buchanan, 1980) resulted in many of the silver-gold deposits found in the district. Within the Guanajuato mining district there are three major mineralized fault systems, the La Luz, Veta Madre, and Sierra systems. Veta Madre is a north-northwest trending fault system and the largest at 25 km long. The other systems are subparallel to it. Mineralization occurs within these systems principally on normal faults oriented parallel to the main trend.

7.3 Local Geology

Of the geological formations associated with the Guanajuato district only the Esperanza and La Luz Formations occur in the Bolañitos mine area with mineralization residing primarily within the La Luz Formation. Mineralization is known to dissipate at the contact with the Esperanza Formation (Figure 7-3).

Figure 7-3 Schematic Cross Section showing all known veins in the La Luz Sub-District


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Geological Setting and Mineralization

The Veta Madre historically was the most productive vein in the Guanajuato district, and is by far the most continuous, having been traced on the surface for nearly 25 km. The vein dips from 35° to 55º to the southwest with measured displacement of around 1,200m near the Las Torres mine and 1,700 m near La Valenciana mine. The most productive veins at Bolañitos strike parallel to the Veta Madre system.

Bolañitos mineralization is directly related to faulting. Mineralization occurs as open-space fillings in fracture zones or impregnations in locally porous wall rock. Veins which formed in relatively open spaces are the main targets for mining.

There are 21 veins within the Bolañitos mine area that are included in the mineral resource estimate. These mineralized veins are known to occur from an elevation of 2300 m down to an elevation of 1900 m (Figure 7-4).


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Geological Setting and Mineralization

Figure 7-4 Surface Map Indicating the Location of the Veins and Mineral Concession Boundaries for the Bolañitos -
Golondrinas (El Puertecito Area) Mines in the La Luz District, Guanajuato

7.3.1 Alteration

The hydrothermal alteration of the wall rock is prevalent in the Guanajuato District, and is an excellent guideline in the mining prospection of Bolañitos. Alteration within the district is closely related to fractures, veins and brecciated zones. Alteration halos surrounding these zones range from a few centimeters to meters and can be divided into 4 alteration types: 1) propyllitic, 2) argillic, 3) phyllic, and 4) silicification.

Wall rock alteration at Bolañitos in general is not significantly altered at the depths of mineralization; however, breccia zones within and near the primary structures do have the typical characteristics of low sulphidation epithermal vein type alteration. Alteration encountered within the structures forms halos of phyllic (sericite) and silicification alteration. Argillic and propyllitic alteration have been identified above the mineralized level of 2300 m.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Geological Setting and Mineralization

Propyllitic alteration is the most widely distributed type and the strongest near fractures, especially in the intersections of veins. The propyllitic alteration consists of epidote, chlorite, clays and calcite. Phyllic (sericite) alteration is not as pervasive as the propyllitic alteration, and is generally encounter within or in immediate contact with the vein. The typical mineral assemblage of this type of alteration consists of pyrite, illite and sericite with occasional kaolinite and montmorillonite. Argillic alteration consists of kaolinite, montmorillonite, and halloysite. Silicification is restricted to vein and breccia zones, and typically extends only a few centimeters into the wall rock. 

7.4 Mineralization

Mineralized veins at Bolañitos consist of the classic banded and brecciated epithermal variety. Silver occurs primarily in dark sulfide-rich bands within the veins, with little mineralization within the wall rocks. The major metallic minerals reported include pyrite, argentite, electrum and ruby silver, as well as some galena and sphalerite, generally deeper in the veins. Mineralization is generally associated with phyllic (sericite) and silicification alteration which forms haloes around the mineralizing structures. The vein textures are attributed to the brittle fracturing-healing cycle of the fault-hosted veins during and/or after faulting (Figure 7-5).

Figure 7-5  Lucero Vein in the Bolañitos Mine

Economic concentrations of precious metals are present in "shoots" distributed vertically and laterally between non-mineralized segments of the veins. Overall, the style of mineralization is pinch-and-swell with some flexures resulting in closures and others generating wide sigmoidal breccia zones.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Geological Setting and Mineralization

Primary economic mineralization at Bolañitos is gold and silver. Bolañitos is postulated to be a low sulphidation system with pyrite but no arsenopyrite.

The silver-rich veins of Bolañitos contain quartz, adularia, pyrite, acanthite, naumannite and native gold. Native silver is widespread in small amounts. Much of the native silver is assumed to be supergene. Silver sulfosalts (pyrargyrite and polybasite) are commonly found at depth.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Deposit Types

8. DEPOSIT TYPES

The following description of thse mineral deposit type associated with the Bolañitos mine property is excerpted from the technical report prepared by Cameron (2012). The QP has reviewed the geologic data and information available, and finds the descriptions and interpretations provided herein reasonably accurate and suitable for use in this report.

The Guanajuato silver-gold district is characterized by classic, high grade silver-gold, epithermal vein deposits with low sulfidation mineralization and adularia-sericite alteration. The Guanajuato veins are typical of most epithermal silver-gold vein deposits in Mexico with respect to the volcanic or sedimentary host rocks and the paragenesis and tenor of mineralization.

Epithermal systems form near the surface, usually in association with hot springs, and to depths on the order of a few hundred meters. Hydrothermal processes are driven by remnant heat from volcanic activity. Circulating thermal waters rising through fissures eventually reach a level where the hydrostatic pressure is low enough to allow boiling to occur. This can limit the vertical extent of the mineralization, as the boiling and deposition of minerals is confined to a relatively narrow range of thermal and hydrostatic conditions. In many cases, however, repeated healing and reopening of host structures can occur, imparting cyclical vertical movement of the boiling zone and resulting in mineralization that spans a much broader range of elevation.

As the mineralizing process is driven by filling of void spaces and fissures, mineralization geometry is affected by the permeability and orientation of the host structures. Mineralization tends to favor dilatant zones in areas where fractures branch or change orientation, which may be driven, in turn, by wall rock competency and/or relative hardness of individual strata.

Low-sulfidation epithermal veins in Mexico typically have a well-defined, sub-horizontal ore horizon about 300 m to 500 m in vertical extent, where high grade ore shoots have been deposited by boiling hydrothermal fluids. The minimum and maximum elevations of the mineralized horizons at the Bolañitos mine have not yet been established precisely, but historic and current production spans an elevation range from 1900 to 2300 m.

Low-sulfidation deposits are formed by the circulation of hydrothermal solutions that are near neutral in pH, resulting in very little acidic alteration with the host rock units. The characteristic alteration assemblages include illite, sericite and adularia that are typically hosted either by the veins themselves or in the vein wall rocks. The hydrothermal fluid can travel along discrete fractures creating vein deposits, or it can travel through permeable lithology such as poorly welded ignimbrite flows, where it may deposit its load of precious metals in a disseminated fashion. In general, disseminated mineralization is found some distance from the heat source. Figure 8-1 illustrates the spatial distribution of the alteration and veining found in a hypothetical low-sulphidation hydrothermal system.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Deposit Types

Figure 8-1  Alteration and Mineral Distributions within a Low Sulphidation Epithermal Vein System


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Exploration

9. EXPLORATION

9.1 EDR Exploration Prior to 2019

Exploration activities conducted by EDR in recent years prior to 2019 are summarized in the following paragraphs, and are discussed in greater detail in the technical reports prepared by Munroe (2013, 2014) and HRC (2015, 2016). Exploration field activities carried out during 2017 to 2019, which have not been included in previous technical reports, are also summarized below.

During 2013, EDR completed 6,728 m of drilling in 47 underground diamond drill holes at the Bolañitos Project. A total of 2,638 samples were collected and submitted for assays.  EDR completed 15,337 m of drilling in 51 surface diamond drill holes at the Bolañitos Project.  A total of 4,379 samples were collected and submitted for assays.  EDR also conducted geological mapping, trenching, soil geochemical and sampling programs in La Luz (San Antonio de los Tiros, La Paz and Plateros), Belen (Ericka and Ana) and Bolañitos South (San Cayetano and Emma) areas. A total of 1,233 samples were collected and submitted for assays.

In 2014, EDR did not conduct any underground exploration drilling at the Bolañitos Project, but completed 28,167 m of drilling in 87 surface diamond drill holes. A total of 7,949 samples were collected and submitted for assays.  EDR also conducted geological mapping and sampling programs in Bolañitos South (San Antonio, Lourdes, Margaritas, La Cuesta, and Laura). A total of 685 samples were collected and submitted for assays.

In 2015, EDR spent US $1,453,473 (including property holding costs) on exploration activities, including drilling, at the Bolañitos Project. Geological mapping and sampling were conducted at Bolañitos North (Bolañitos, San Ignacio, San Miguel & Realejo Veins), Bolañitos South (San Antonio), and Ana Rosa and Belen (Erika, Ana, Edith and Perla). These activities were mainly conducted to complete the delineation of the Bolañitos North structures, and to investigate possible targets of interest in the South West part of Belen and in the Ana Rosa claim (located at SW of la Luz town).

In 2016, EDR conducted a drilling program with the objective to test the La Luz (San Antonio de los Tiros area), San Cayetano and Emma veins at the Bolañitos Project. A total of 2,528 meters completed in 9 holes. Geological mapping and sampling were conducted in the Bolañitos South (La Loba-Margaritas zone) area.

During 2017, the EDR drilling program included a total of 28 drill holes with 7,287 meters and 2,080 samples collected and submitted for assays. No exploration field activities carried out during the year.

In 2018, EDR did not conduct geological mapping in the Bolañitos Project, but completed 11,242m of drilling in 55 holes and 3,727 samples collected and submitted for assays.

In 2019, exploration field activities carried out by EDR in the Bolañitos Project, including drilling. Little geological mapping and sampling conducted in the Bolañitos South area, over the Lourdes and San Antonio veins, 40 rock samples collected in the area. The drilling program included a total of 8,670 meters in 54 holes and 3,145 samples collected and submitted for analysis.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Exploration

9.2 2020 Exploration Activities

In 2020, EDR spent US $770,512 (including property holding costs) on exploration activities, primarily drilling, at the Bolañitos Project. During the year, field exploration carried out, mainly focused on the Bolañitos South and Sangre de Cristo areas.

In addition, a total of 45 drill holes completed in the Bolañitos North (Melladito and San Bernabé veins), Plateros, Sangre de Cristo and Bolañitos South (Ave María vein) areas, for a total of 10,458 meters.

Bolañitos South

Geological mapping and sampling carried out by EDR in the Bolañitos South area. Exploration activities conducted over the traces of the Ave Maria, Lourdes and La Cuesta veins.

A total of 54 rock samples were collected and submitted for analysis. Individual assay results are presented in Tables 9-1 and 9-2.

Sample locations are shown on Figures 9-1 to 9-6.

Table 9-1  Assays for the Rock Sampling in the Bolañitos South Area (Ave Maria Adit)

Sample ID

Width
(m)

Structure

Description

Au
(g/t)

Ag
(g/t)

BOL-2651

0.50

Veta Lourdes/Soc. Ave María

Veta de cuarzo , textura Bx - bandeado , oxidos de Fe

0.48

<5

BOL-2652

0.50

Veta Lourdes/Soc. Ave María

Veta de cuarzo , textura Bx - bandeado , oxidos de Fe y puntos de color negro

1.38

<5

BOL-2653

0.40

Veta Lourdes/Soc. Ave María

Veta de cuarzo , textura Bx - bandeado , oxidos de Fe

0.77

<5

BOL-2654

0.60

Veta Lourdes/Soc. Ave María

Veta de cuarzo , textura Bx-Bn , oxidos de Fe y puntos negros , posibles sulfuros

4.45

<5

BOL-2655

0.60

Veta Lourdes/Soc. Ave María

Veta de cuarzo , textura Bx-Bn , oxidos de Fe y puntos negros , posibles sulfuros

2.64

<5

BOL-2656

0.90

Veta Lourdes/Soc. Ave María

Zona de alteracion con vetillas de cuarzo cristalino y oxidos de Fe

0.15

<5

BOL-2657

1.50

Veta Lourdes/Soc. Ave María

Zona de alteracion con vetillas de cuarzo cristalino y oxidos de Fe

0.36

<5

BOL-2658

1.50

Veta Lourdes/Soc. Ave María

Zona de alteracion con vetillas de cuarzo cristalino y oxidos de Fe

0.21

<5

BOL-2659

1.50

Veta Lourdes/Soc. Ave María

Zona de alteracion con vetillas de cuarzo cristalino y oxidos de Fe

0.11

<5

BOL-2660

1.50

Veta Lourdes/Soc. Ave María

Zona de alteracion con vetillas de cuarzo cristalino y oxidos de Fe

0.09

<5

BOL-2661

1.50

Veta Lourdes/Soc. Ave María

Veta de cuarzo cristalino , textura Bx y con oxidos de Fe

0.21

<5

BOL-2662

1.10

Veta Lourdes/Soc. Ave María

Veta de cuarzo cristalino , textura Bx y con oxidos de Fe

0.31

<5

BOL-2663

0.60

Veta Lourdes/Soc. Ave María

Veta de cuarzo cristalino , textura Bx y con oxidos de Fe

0.76

<5

BOL-2664

0.60

Veta Lourdes/Soc. Ave María

Veta de cuarzo cristalino , textura Bx y con oxidos de Fe

1.53

<5

BOL-2665

0.40

Veta Lourdes/Soc. Ave María

Veta de cuarzo cristalino , textura Bx y con oxidos de Fe

0.11

<5

BOL-2666

0.40

Veta Lourdes/Soc. Ave María

Veta de cuarzo cristalino , textura Bx y con oxidos de Fe

1.50

<5

BOL-2667

0.60

Veta Lourdes/Soc. Ave María

Veta de cuarzo cristalino , textura Bx y con oxidos de Fe

0.85

<5



Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Exploration

Table 9-2  Assays for the Rock Sampling in the Bolañitos South Area (La Cuesta Adit)

Sample ID

Width
(m)

Structure

Description

Au
(g/t)

Ag
(g/t)

BOL-2668

0.50

Bajo La Cuesta

Sw2 QzCca en Andesita La Luz, leve Sil, traz de arcillas y de FeO

0.10

5

BOL-2669

0.50

Bajo La Cuesta

Sw2 QzCca en Andesita La Luz, leve Sil, traz de arcillas y de FeO

0.04

2

BOL-2670

0.60

Veta La Cuesta

Vn de QzCca blanco, hilos mm de mate obscuro

0.34

78

BOL-2671

1.00

Alto La Cuesta

Vlleo intenso de QzCca en andesita La Luz con fuerte Sil, Py y Py Ox

0.13

2

BOL-2672

0.40

Bajo La Cuesta

Andesita La Luz, traz de arcillas Prop M

0.05

2

BOL-2673

0.50

Veta La Cuesta

Vn de QzCCa blanco, traz de arcillas

2.58

91

BOL-2674

0.40

Alto La Cuesta

Andesita La Luz con vlleo intenso de QzCca, roca con fuerte Sil

0.16

33

BOL-2675

0.50

Bajo La Cuesta

Andesita La Luz, Sil W, Prop M, escaso mm vlleo de Qz

0.01

0

BOL-2676

0.50

Bajo La Cuesta

Andesita La Luz, Sil W, Prop M, mm ramaleo de Py

0.11

3

BOL-2677

0.90

Veta La Cuesta

Vn de QzCCa con traz de FeO y arcillas

0.44

92

BOL-2678

1.00

Veta La Cuesta

Vn de QzCca con fragmentos de roca

0.25

27

BOL-2679

0.80

Veta La Cuesta

Vn de QzCca con traz de FeO

0.05

8

BOL-2680

0.80

Alto La Cuesta

Andesita La Luz con Sil W con escaso mm vlleo de CcaQz

0.04

2

BOL-2681

0.30

Bajo La Cuesta

Ansita la Luz con Sil M y Ox Q

1.63

148

BOL-2682

0.50

Veta La Cuesta

Veta Qz Cca, traz de Ox

0.09

52

BOL-2683

0.60

Veta La Cuesta

Veta de QzCca blanca

1.19

173

BOL-2684

0.40

Bajo La Cuesta

Andesita La Luz, Sil W, Ox W, mm vlleo y traz de arcillas

0.03

1

BOL-2685

0.20

Falla

Arcilla + roca deleznable, Ox y escaso mm vlleo

0.10

3

BOL-2686

0.50

Veta La Cuesta

Vn de QzCCa blanco

0.04

18

BOL-2687

0.50

Alto La Cuesta

Vetilleo intenso de Qz, traz FeO en andesita La Luzx

0.31

7

BOL-2688

0.30

Bajo La Cuesta

vlleos moderados de Qz, en andesita La Luz Sil W propM

0.09

13

BOL-2689

0.30

Falla

Zona de falla, material arcilloso con Ox

0.07

8

BOL-2690

0.60

Veta La Cuesta

Vn de Qz traz Sul, Ox en fracturas

0.34

78

BOL-2691

0.30

Veta La Cuesta

Brecha de QzCca con fragmentos de roca, arcillas moderadas

0.07

32

BOL-2692

0.30

Alto La Cuesta

Andesita La Luz con Sil fuerte, mm vlleo de Qz y OX

0.02

1

BOL-2693

0.40

Bajo La Cuesta

Andesita La Luz, Sil M escaso mm vlleo

0.01

1

BOL-2694

0.50

Veta La Cuesta

Veta de Qz blanco, fracturas rellenas de Ox traz Sul

0.13

24

BOL-2695

0.35

Veta La Cuesta

Veta Bx con fragmentos de roca

0.09

9

BOL-2696

0.50

falla

zon arcillos + roca argilizada con Prop y mm vlleos escasos

0.04

3

BOL-2697

0.40

Veta La Cuesta

Vn QzCCa blanco con FeO rellenando fracturas

0.24

102

BOL-2698

0.50

Alto La Cuesta

Andesita prop M-Sil M con mm vlleos de Qz, fracturas rellenas d Ox

0.11

47

BOL-2699

0.35

Bajo HW La Cuesta

escasos vlleos de Qz en andesita La Luz con Opx y arcillas

0.36

4

BOL-2700

0.70

Bajo HW La Cuesta

vlleo inteso de Qz en roca Prop/Sil

0.12

3

BOL-2701

0.35

HW Veta La Cuesta

Veta de CcaQz con FeO

0.10

45

BOL-2702

0.60

Bajo HW La Cuesta

Andesita La Luz con moderados vlleos de QzCca

0.05

1

BOL-2703

0.60

HW Veta La Cuesta

Veta de QzCca blanco, mm fracturas rellenas de Ox y arcillas

0.11

58

BOL-2704

0.40

Alto HW La Cuesta

Andesita La Luz Prop M

0.06

4



Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Exploration

Figures 9-1 & 9-2 Silver and Gold results in rock samples collected in the Ave Maria-Lourdes area.

Figure 9-3 Gold results in rock samples collected in the Ave Maria adit.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Exploration

Figures 9-4 & 9-5 Silver and Gold results in rock samples collected in the La Cuesta adit.

9.2.1 Sangre de Cristo

Field exploration activities carried out in the southeast projection on surface of the La Luz-Plateros veins, in the Sangre de Cristo area. A total of 14 rock samples collected in "terrero" near the Villarin Shaft.

Sample locations are shown on Figures 9-6 and 9-7, and individual assay results are presented in Table 9-1.

Table 9-3  Assays for the Rock Sampling in the Plateros Area ("terrero" Villarin Shaft)

Sample ID

Description

Au (g/t)

Ag (g/t)

BOL-2710

Muck Material

0.98

91

BOL-2711

Muck Material

0.40

7

BOL-2712

Muck Material

0.16

40

BOL-2713

Muck Material

1.88

84

BOL-2714

Muck Material

0.53

64

BOL-2715

Muck Material

0.64

80

BOL-2716

Muck Material

1.10

195

BOL-2717

Muck Material

3.39

157

BOL-2718

Muck Material

0.48

39

BOL-2719

Muck Material

0.40

45

BOL-2720

Muck Material

0.51

89

BOL-2721

Muck Material

0.27

37

BOL-2722

Muck Material

0.55

19

BOL-2723

Muck Material

0.40

59



Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Exploration

Figures 9-6 & 9-7 Silver and Gold results in rock samples collected in the "terrero" located near the Villarino Shaft


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

10. DRILLING

Diamond drilling at the Bolañitos Project is conducted under two general modes of operation: one by the exploration staff (surface exploration drilling) and the other by the mine staff (production and underground exploration drilling). Production drilling is predominantly concerned with definition and extension of the known mineralized zones in order to guide development and mining. Exploration drilling is conducted further from the active mining area with the goal of expanding the resource base. Drilling results from both programs were used in the mineral resource and mineral reserve estimates presented in this report.  To date, all drilling completed at the Bolañitos Project has been diamond core.

10.1 Drilling Procedures

Surface drillholes are generally oriented to intersect the veins as close to perpendicular as possible. The drillholes are typically drilled from the hanging wall, perpendicular to, and passing through the target structure into the footwall, and no drilling is designed for intercepts with angles less than about 30° to the target. Drillholes extend an average of 50 m beyond the target zone. 

Underground drillholes are typically drilled from the hanging wall, and are ideally drilled perpendicular to structures, but oblique intersection is required in some instances due to limitations of the drill station. Underground positive angled holes (up holes) are generally drilled from the footwall using the same criteria. All holes are designed to pass through the target and into the hanging or footwalls. Both surface and underground drillholes are typically HQ to NQ in size.

On the drill site, the drill set-up is surveyed for azimuth, inclination and collar coordinates, with the drilling subject to daily scrutiny and coordination by EDR geologists. Since 2010, surface holes are surveyed using a Reflex multi-shot down-hole survey instrument normally at 50 m intervals from the bottom of the hole back up to the collar. At underground drill stations, azimuth orientation lines are surveyed in prior to drilling. Inclination of underground holes is collected using the Reflex EX-Shot® survey device prior to starting drilling.

The survey data obtained from the drillholes are transferred to databases in Vulcan® and AutoCAD®, and are corrected for local magnetic declination, as necessary. Information for each drillhole is stored in separate folders.

Drill core is collected daily and is transported to the core logging facility under EDR supervision. The core storage facilities at Bolañitos are well protected by high level security fences, and are under 24-hour surveillance by security personnel to minimize any possibility of tampering with the dill cores.

When assay results are received from the laboratory, they are merged into an Excel® spreadsheet for importation and interpretation in Vulcan and AutoCAD® software. The starting and ending point of each vein and/or vein/vein breccia intercept is determined from a combination of geology notes in the logs and assay results. Using approximate vein and drillhole orientation information a horizontal width is calculated for the intercept to be used as part of a Vertical Longitudinal Projection ("VLP").


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

The center point of the intercept, horizontal width, and gold and silver assay values are plotted on VLPs of each vein. These are used to guide further drilling, interpret mineralization shoots, and as the basis of polygonal resource estimation.

10.2 EDR Core Logging Procedures

As the core is received at the core facility, geotechnical data is logged manually on paper sheets and entered into Excel®. The core is then manually logged for geological data and marked for sampling. Geological data and sample information are entered directly into Excel® spreadsheets.

10.3 EDR Drilling Programs and Results (2007 to 2019)

Since acquisition of the Bolañitos Project in 2007, and prior to the 2020 exploration campaign, EDR had completed 706 diamond drill holes totaling 204,222 m (Table 10-1). Holes were drilled in both surface and underground drill stations, and 52,090 samples were collected and submitted for assay.

Table 10-1  Drilling Summary at Bolañitos Project (as of December, 2019)

Project Area

Number of
Holes

Total Metres

Number of
Samples Taken

Cebada

34

12,598

2,852

Bolañitos Sy.stem

121

30,079

9,588

Lucero System

160

44,288

10,561

La Joya/Lana

85

26,977

5,606

Belen

55

14,544

3,719

La Luz System

169

51,378

12,882

Bolañitos South (inc. Golondrinas)

70

20,781

6,002

Siglo XX

12

3,577

880

Total

706

204,222

52,090

EDR's drilling exploration programs through 2016 are well described in previous technical reports (HRC 2015, 2016; Munroe 2013, 2014; Micon 2008, 2009, 2010, 2011, 2012; SRK 2007). To provide continuity, a brief description of the 2017, 2018 and 2019 exploration programs (which are not included in previous technical reports) is provided in the following paragraphs.

In 2017, surface and underground drilling carried out in the Bolañitos Project. Underground drilling focused on the La Luz (San Vicente area, between the elevations 1,900 to 2,150 masl) and Plateros (below level 2169) veins, totaling 3,845m in 16 drill holes and 1,214 samples collected. Surface drilling carried out in the Bolañitos South (to test the San Cayetano vein) and Siglo XX areas, a total of 12 drill holes completed with 3,442 m and 866 samples submitted for analysis.

During 2018, EDR carried out both surface and underground drilling programs at the Bolañitos Project. Surface drilling mainly focused to test the Bolañitos vein in La Herradura area, in addition, drilling carried out in the San Miguel vein and two infill drill holes in the Belén area, a combined of 4,196 m drilled in 16 drill holes and 1,270 samples sent for analysis. The underground drilling program included 39 holes drilled in the Plateros (below level 2169), Bolañitos (Santa María, Bolañitos and San José veins), Lucero (Lucero and Cecilia veins) and La Luz (Refugio and Asunción areas), totaling 7,045 m and 2,457 samples submitted for analysis.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

In 2019, surface and underground drilling carried out by EDR in the Bolañitos Project. Surface drilling conducted in the San Miguel area, to continue defining the San Miguel and San Ignacio (shallow part) veins, and in the Bolañitos North area, with the objective to determine the possible definition of a a mineralized body over the Melladito vein, between the San Pablo and San Ramón Shafts, totaling 3,855 m in 23 holes and 1,388 samples submitted. The underground drilling program included 4,815 m in 31 drill holes and 1,757 samples collected, the objective was to define the extension to depth of the Lana, Karina, Daniela, Bolañitos (south of Santa Rosa shaft, between levels 134 and 200 of the Bolañitos mine) and Plateros veins near the active mine workings, and to test the north projection of San Miguel vein in the Palomas adit area.

10.4 EDR Drilling Programs and Results (2020)

In 2020, EDR carried out surface and underground drilling programs in the Bolañitos North (Melladito and San Bernabé veins), Plateros, Sangre de Cristo and Bolañitos South (Ave María vein) areas at the Bolañitos Project and included a total of 10,458 m in 45 drill holes.

Table 10-2 sumarrizes the drilling activities carried out by EDR in the Bolañitos Project.

Table 10-2  Bolañitos Project Exploration Drilling Activities in 2020

Project Area

Number of
Holes

Total Metres

Number of
Samples Taken

Melladito

28

6,953

1,585

San Bernabe

3

686

117

Plateros

3

360

208

Sangre de Cristo

6

1,561

275

Ave María

5

898

219

Total

45

10,458

2,404

Surface and underground diamond drilling was conducted using one DR Drilling México (DR Drilling) drill rig and one in-house VERSA Kmb-4 drill rig. DR Drilling is a contract drilling company and is independent of EDR.

10.4.1 Bolañitos North Diamond Drilling Program

Surface drilling at the Bolañitos North area mainly focused on the definition of the Melladito vein and a few drill holes to test the San Bernabé vein.

The program included a total of 7,638.70 m in 31 holes and 1,702 samples collected and submitted for assays. Details of the holes drilled in the Bolañitos North area are shown in Tables 10-3 & 10-4.

Figures 10-1 and 10-2 show photographs of the DR Drilling and in-house drill rigs placed in surface pads to test the Melladito vein.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

Table 10-3  2020 Drilling Summary, Melladito

HOLE

AZIMUTH

DIP

DIAMETER

TOTAL DEPTH
(m)

START DATE

FINISH DATE

BN-35

267 º

-46 º

NQ

278.00

20/01/2020

28/01/2020

BN-36

286 º

-55 º

NQ

281.00

28/01/2020

04/02/2020

BN-37

253 º

-55 º

NQ

287.00

05/02/2020

12/02/2020

BN-38

253 º

67 º

NQ

318.50

13/02/2020

21/02/2020

BN-39

277 º

-66 º

NQ

330.50

22/02/2020

04/03/2020

BN-40

296 º

-64 º

HQ

350.70

16/05/2020

28/05/2020

BN-41

281 º

-72 º

HQ

359.70

28/05/2020

05/06/2020

BN-42

313 º

-63 º

HQ

395.50

07/06/2020

15/06/2020

BN-43

247 º

-63 º

HQ

350.70

16/06/2020

23/06/2020

BN-44

312 º

51 º

HQ

189.50

23/06/2020 - 03/07/2020

27/06/2020 - 07/07/2020

BN-45

230 º

-65 º

HQ

167.70

28/06/2020

02/07/2020

BN-46

250 º

-75 º

HQ

190.40

08/07/2020

12/07/2020

BN-47

267 º

-48 º

HQ

254.55

13/07/2020

19/07/2020

BN-48

286 º

-64 º

HQ

167.70

20/07/2020

23/07/2020

BN-49

276 º

-65 º

HQ-NQ

218.50

24/07/2020

30/07/2020

BN-50

253 º

-47 º

HQ-NQ

260.35

30/07/2020

05/08/2020

BN-51

252 º

-60 º

HQ-NQ

189.60

06/08/2020

10/08/2020

BN-52

246 º

-71 º

HQ-NQ

257.90

11/08/2020

18/08/2020

BN-53

235 º

-78 º

HQ-NQ-BQ

323.95

19/08/2020

26/08/2020

BN-54

264 º

-64 º

HQ-NQ

233.25

27/08/2020

31/08/2020

BN-55

268 º

-74 º

HQ-NQ

281.90

01/09/2020

08/09/2020

BN-56

285 º

-74 º

HQ-NQ-BQ

365.50

10/09/2020

18/09/2020

BN-57

230 º

-74 º

HQ-NQ-BQ

353.50

18/09/2020

25/09/2020

BN-58

304 º

-44 º

HQ-NQ

152.20

27/09/2020

02/10/2020

BN-62

288 º

-49 º

HQ-NQ

131.00

02/12/2020

07/12/2020

BN-63

221 º

-53 º

HQ-NQ

120.50

07/12/2020

11/12/2020

BN-64

266 º

-60 º

HQ

51.75

12/12/2020

13/12/2020

BN-65

356 º

-80 º

HQ

91.60

14/12/2020

18/12/2020

Total

6,952.95

 

 

Table 10-4  2020 Drilling Summary, San Bernabe

HOLE

AZIMUTH

DIP

DIAMETER

TOTAL DEPTH
(m)

START DATE

FINISH DATE

BN-59

270 º

-45 º

HQ-NQ

170.50

03/10/2020

08/10/2020

BN-60

291 º

-53 º

HQ-NQ

281.55

08/10/2020

13/10/2020

BN-61

263 º

-65 º

HQ-NQ

233.70

14/10/2020

19/10/2020

Total

685.75

 

 



Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

   

Figures 10-1 & 10-2 DR Drilling drill rig in pad for drill hole BN-36 (Melladito) and in-house drill rig in pad for drill hole BN-51 (Melladito)

The drilling campaign over the Melladito vein carried out with the objective to continue defining and extend the mineralized body discovered in 2019, located between the San Pablo and San Ramón Shafts. In addition, some drill holes to test the Melladito vein at north of the Providencia Shaft (between level 115 and Mina Grande adit). By the end of the year, four addional drill holes completed in the area between the San Pablo and Santa Rosa Shafts and between the Levels 42 and 134 of the Bolañitos mine.

The Melladito main mineralized zone measures up to 200 m long by more than 250 m deep.

Drilling along the San Bernabe vein highlighted by hole BN-59; the results are shown in Table 10-6. The other two drill holes with negative results.

Drilling results are summarized in Tables 10-5 and 10-6; and the Melladito and San Bernabe veins intercepts are shown on the longitudinal sections in Figures 10-3 and 10-4.

Figure 10-5 depict typical cross-section showing some of the holes drilled to test the Melladito and San Bernabe veins in the Bolañitos North area.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

Table 10-5  2020 Drilling Results, Melladito

Drill Hole
ID

Structure

Mineralized Interval

Assay Results

From (m)

To (m)

Core Length
(m)

True Width
(m)

Silver (g/t)

Gold (g/t)

BN-35

Melladito Vein

215.60

217.40

1.80

1.76

191

0.57

Melladito Composite

216.30

217.40

1.10

1.08

306

0.73

Including

217.00

217.40

0.40

0.39

470

0.77

BN-36

Melladito Vein

243.10

249.90

6.80

6.21

13

1.58

Melladito Composite

243.10

247.80

4.70

4.29

18

2.06

Including

247.35

247.80

0.45

0.41

5

4.62

BN-37

Melladito Vein

223.50

229.00

5.50

5.06

9

1.16

Melladito Composite

225.00

226.80

1.80

1.66

5

2.03

Including

225.50

226.15

0.65

0.60

7

2.44

Fw Melladito Vein

267.00

267.45

0.45

0.36

82

32.30

Fw Melladito Composite

267.00

268.65

1.65

1.32

34

13.13

Including

267.00

267.45

0.45

0.36

82

32.30

BN-38

Melladito Vein

255.60

258.50

2.90

2.39

5

0.22

Melladito Composite

255.60

257.10

1.50

1.24

6

0.23

Including

256.70

257.10

0.40

0.33

4

0.30

BN-39

Melladito Vein

251.60

252.50

0.90

0.82

828

1.86

Melladito Composite

251.60

252.80

1.20

1.09

626

1.46

Including

252.00

252.50

0.50

0.45

1395

2.91

Fw Melladito Vein

268.50

278.25

9.75

8.22

13

2.07

Fw Melladito Composite

268.50

274.35

5.85

4.93

13

2.39

Including

272.25

273.35

1.10

0.93

16

3.50

BN-40

Melladito Vein

273.95

274.75

0.80

0.66

4

0.76

Melladito Composite

272.80

274.75

1.95

1.61

79

0.64

Including

272.80

273.95

1.15

0.95

132

0.57

Fw Melladito Vein

291.10

299.40

8.30

5.22

5

3.35

Fw Melladito Composite

292.40

299.40

7.00

4.41

5

3.88

Including

294.50

295.20

0.70

0.44

14

12.90

BN-41

Melladito Vein

276.90

277.20

0.30

0.23

108

0.64

Melladito Composite

276.90

277.90

1.00

0.78

34

0.22

Including

276.90

277.20

0.30

0.23

108

0.64

Fw Melladito Vein

317.20

321.45

4.25

2.62

8

1.06

Fw Melladito Composite

318.00

319.50

1.50

0.92

7

1.46

Including

318.00

319.00

1.00

0.62

8

1.59

BN-42

Melladito Vein?

294.65

302.70

8.05

6.03

15

2.82

Melladito Composite

296.90

302.70

5.80

4.34

8

3.70

Including

298.15

298.70

0.55

0.41

10

7.82

Fw Melladito Vein

335.55

337.85

2.30

1.32

5

2.41

Fw Melladito Composite

334.55

337.85

3.30

1.89

5

2.12

Including

336.85

337.85

1.00

0.57

6

3.76

BN-43

Melladito Vein

229.55

231.75

2.20

1.89

23

0.36

Melladito Composite

229.80

231.00

1.20

1.03

32

0.52

Including

230.60

231.00

0.40

0.34

13

1.03

BN-44

Melladito Vein

59.00

60.10

1.10

0.85

77

0.18

Including

59.40

60.10

0.70

0.54

103

0.21

San Ignacio Vein

144.65

158.25

13.60

2.47

130

0.19

San Ignacio Composite

151.00

158.25

7.25

1.51

163

0.23

Including

154.45

154.75

0.30

0.06

784

1.34



Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

Drill Hole
ID

Structure

Mineralized Interval

Assay Results

From (m)

To (m)

Core Length
(m)

True Width
(m)

Silver (g/t)

Gold (g/t)

BN-45

Melladito Vein

58.45

68.55

10.10

6.49

50

0.12

Melladito Composite

60.40

63.55

3.15

2.02

110

0.10

Including

63.15

63.55

0.40

0.26

253

0.15

Melladito Composite

67.55

69.10

1.55

1.00

260

0.28

Including

68.55

69.10

0.55

0.35

660

0.66

San Ignacio Vein

111.25

114.35

3.10

2.57

357

1.90

Including

111.25

112.05

0.80

0.66

1085

3.73

BN-46

Melladito Vein

115.60

116.40

0.80

0.51

21

0.23

Melladito Composite

115.60

117.00

1.40

0.90

20

0.15

Including

116.10

116.40

0.30

0.19

8

0.39

Fw Vein

131.50

132.10

0.60

0.48

707

1.51

Fw Vein Composite

131.50

132.60

1.10

0.88

391

1.15

Including

131.80

132.10

0.30

0.24

790

1.74

BN-47

Melladito Vein

88.80

95.10

6.30

5.84

205

0.88

Melladito Composite

86.95

95.10

8.15

7.56

213

0.73

Including

93.25

93.70

0.45

0.42

713

1.13

San Ignacio Vein

168.65

171.50

2.85

2.05

477

2.08

San Ignacio Composite

167.45

174.50

7.05

5.07

243

1.48

Including

171.10

171.50

0.40

0.29

615

4.30

BN-48

Melladito Vein

114.60

116.35

1.75

1.44

32

0.30

Melladito Composite

114.60

115.95

1.35

1.11

39

0.31

Including

114.60

115.00

0.40

0.33

106

0.64

BN-49

Melladito Vein

119.25

121.50

2.25

1.72

5

0.13

Melladito Composite

118.15

119.70

1.55

1.19

7

0.25

Including

118.15

119.25

1.10

0.84

6

0.27

BN-50

Hw Melladito Vein

172.35

175.55

3.20

3.03

201

0.55

Hw Melladito Composite

174.30

175.55

1.25

1.18

506

0.89

Including

175.10

175.55

0.45

0.43

1390

2.01

Melladito Vein

179.35

184.75

5.40

5.28

62

1.96

Melladito Composite

180.05

182.80

2.75

2.69

110

3.37

Including

180.30

180.90

0.60

0.59

236

8.47

Bolañitos Vein

237.50

237.80

0.30

0.25

3460

15.95

Bolañitos Composite

237.50

238.35

0.85

0.70

1226

5.70

Including

237.50

237.80

0.30

0.25

3460

15.95

BN-51

Melladito Vein

185.30

186.00

0.70

0.60

89

0.83

Melladito Composite

184.40

186.00

1.60

1.37

89

0.59

Including

184.40

184.90

0.50

0.43

154

0.51

Old Working (Melladito)

186.00

189.60

3.60

3.09

Old Working

BN-52

Melladito Vein

213.65

215.25

1.60

1.36

807

0.72

Melladito Composite

212.50

215.70

3.20

2.71

491

0.51

Including

214.75

215.25

0.50

0.42

2220

1.74

BN-53

Melladito Vein

241.00

241.80

0.80

0.58

2

0.17

Melladito Composite

241.00

242.70

1.70

1.22

2

0.20

Including

241.80

242.70

0.90

0.65

3

0.23

Fw Melladito Vein

286.70

288.20

1.50

0.76

40

1.07

Including

287.60

288.20

0.60

0.30

11

2.01

BN-54

Old Working (Melladito)

226.50

233.25

6.75

6.28

Old Working

Melladito (Stockwork sample)

227.80

228.30

0.50

0.47

2

0.04

Melladito (Muck sample)

229.20

229.50

0.30

0.28

3

0.03

Melladito (Muck sample)

230.70

231.20

0.50

0.47

451

1.34

BN-55

Old Working (Melladito)

278.40

281.90

3.50

2.92

Old Working

Melladito (Muck sample)

278.40

278.55

0.15

0.13

15

0.06

Melladito (Muck sample)

279.10

279.45

0.35

0.29

9

0.04



Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

Drill Hole
ID

Structure

Mineralized Interval

Assay Results

From (m)

To (m)

Core Length
(m)

True Width
(m)

Silver (g/t)

Gold (g/t)

BN-56

Melladito Vein

273.55

276.45

2.90

2.16

3

0.29

Melladito Composite

275.30

276.45

1.15

0.85

1

0.50

Including

275.30

275.80

0.50

0.37

1

0.71

Fw Melladito Vein

325.60

326.65

1.05

0.54

1

0.77

Fw Melladito Composite

323.25

326.10

2.85

1.47

3

2.24

Including

323.25

323.75

0.50

0.26

11

9.87

BN-57

Melladito Vein

284.40

285.30

0.90

0.66

4

3.07

Melladito Composite

283.10

288.20

5.10

3.73

4

3.89

Including

287.50

288.20

0.70

0.51

21

20.40

Fw Melladito Vein

297.50

305.45

7.95

4.09

3

0.69

Fw Melladito Composite

300.70

302.75

2.05

1.06

4

2.01

Including

300.70

301.60

0.90

0.46

5

3.09

BN-58

Hw Melladito Vein

45.95

50.25

4.30

3.80

9

0.13

Hw Melladito Composite

48.45

49.65

1.20

1.06

15

0.22

Including

49.45

49.65

0.20

0.18

29

0.53

Melladito Vein

51.70

53.65

1.95

1.71

277

0.96

Melladito Composite

52.00

54.85

2.85

2.49

218

0.83

Including

52.60

53.00

0.40

0.35

723

1.90

Bolañitos Vein

114.70

116.75

2.05

1.50

127

25.12

Bolañitos Composite

114.70

120.85

6.15

4.50

55

12.76

Including

116.20

116.75

0.55

0.40

171

43.50

BN-62

Hw Melladito Vein

48.70

54.30

5.60

4.23

116

1.05

Hw Melladito Composite

52.65

54.30

1.65

1.25

354

2.27

Including

54.00

54.30

0.30

0.23

1928

10.28

Melladito Vein

58.65

64.75

6.10

5.09

177

1.98

Including

61.35

61.75

0.40

0.33

539

5.86

Bolañitos Vein

81.90

84.35

2.45

1.76

3

0.66

Bolañitos Composite

81.00

84.35

3.35

2.41

19

1.19

Including

84.05

84.35

0.30

0.22

5

4.23

BN-63

Melladito Vein

48.00

50.60

2.60

1.56

13

0.66

Melladito Composite

46.85

48.70

1.85

1.11

8

1.27

Including

46.85

48.00

1.15

0.69

10

1.61

Bolañitos Vein

74.35

78.70

4.35

2.24

7

1.10

Bolañitos Composite

77.10

78.70

1.60

0.82

6

1.91

Including

78.25

78.70

0.45

0.23

10

3.15

BN-64

Hw Melladito Vein

41.95

43.25

1.30

0.97

1044

8.09

Including

41.95

42.30

0.35

0.26

1974

14.18

Hw Melladito Vein

45.00

46.25

1.25

0.87

115

2.33

Including

45.00

45.40

0.40

0.28

146

1.97

Old Working (Melladito)

48.05

51.75

3.70

2.57

Old Working

BN-65

Hw Melladito Vein

74.85

78.70

3.85

1.44

15

2.14

Hw Melladito Composite

74.85

77.60

2.75

1.03

15

2.64

Including

76.45

77.60

1.15

0.43

14

5.41

Melladito Vein

82.70

87.20

4.50

2.52

88

4.06

Including

84.75

85.50

0.75

0.42

105

5.27

Old Working (Melladito)

87.20

90.90

3.70

2.07

Old Working

Melladito (Muck sample)

90.90

91.60

0.70

0.39

3

0.09



Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

Table 10-6  2020 Drilling Results, San Bernabe

Drill Hole
ID

Structure

Mineralized Interval

Assay Results

From (m)

To (m)

Core Length
(m)

True Width
(m)

Silver (g/t)

Gold (g/t)

BN-59

San Bernabé Vein

106.55

110.15

3.60

2.68

12

7.91

Including

108.60

109.20

0.60

0.45

19

9.96

BN-60

San Bernabé Vein

168.95

169.55

0.60

0.42

9

0.36

San Bernabé Composite

168.95

170.55

1.60

1.13

4

0.17

Including

168.95

169.55

0.60

0.42

9

0.36

BN-61

San Bernabé Vein

170.20

171.00

0.80

0.44

<2

0.52

San Bernabé Composite

169.20

171.00

1.80

0.98

<2

0.24

Including

170.20

171.00

0.80

0.44

<2

0.52

Figure 10-3 Longitudinal Section (looking E) showing intersection points on Melladito vein.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

Figure 10-4 Longitudinal Section (looking E) showing intersection points on San Bernabe vein.

Figure 10-5 Schematic Cross Section, Melladito-Bolañitos-San Bernabe.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

10.4.1 Plateros Diamond Drilling Program

At the end of 2020, EDR carried out an underground drilling program in the Plateros area, at south of the current mine workings, using one DR Drilling drill rig (Figure 10-6).

A total of 360 meters completed in 3 drill holes and 208 samples submitted for analysis. Table 10-7 show the details of the holes drilled in the Plateros area.

Table 10-7  2020 Drilling Summary, Plateros

HOLE

AZIMUTH

DIP

DIAMETER

TOTAL DEPTH
(m)

START DATE

FINISH DATE

PLU-29

60 º

-21 º

NQ

105.00

28/11/2020

08/12/2020

PLU-31

108 º

0 º

NQ

112.50

09/12/2020

12/12/2020

PLU-32

133 º

-9 º

NQ

142.50

12/12/2020

18/12/2020

Total

360.00

 

 

Figure 10-6 DR Drilling drill rig in station for drill hole PLU-29 (Plateros).

Underground drilling with the objective to verify the extent of possible mineralization in the deep part of Plateros and southeast of the current mine workings, between the elevations 1,975 and 2,025 masl.

Several structures intercepted along the holes, significant results include: Plateros PL1 vein in hole PLU-29, and Sangre de Cristo vein in hole PLU-32.

The summary of the results of the underground drilling carried out in the Plateros area during 2020 are shown in Table 10-8. The impacts of the Plateros vein are shown in the longitudinal section in Figure 10-7, as well as the typical cross section in Figure 10-8.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

Table 10-8  2020 Drilling Results, Plateros

Drill Hole
ID

Structure

Mineralized Interval

Assay Results

From (m)

To (m)

Core Length
(m)

True Width
(m)

Silver (g/t)

Gold (g/t)

PLU-29

Plateros (PL1)

35.35

37.10

1.75

1.70

3

1.30

Plateros (PL1) Composite

36.00

37.10

1.10

1.07

3

1.41

Including

36.00

37.10

1.10

1.07

3

1.41

Plateros (PL2)

39.00

40.00

1.00

0.97

<2

0.27

Sangre de Cristo Vein

44.00

44.60

0.60

0.58

<2

0.14

Sangre de Cristo Composite

44.00

45.00

1.00

0.97

<2

0.15

Including

44.60

45.00

0.40

0.39

<2

0.16

PLU-31

Plateros (PL1)

42.60

46.10

3.50

1.80

3

0.43

Plateros (PL1) Composite

42.60

44.70

2.10

1.08

3

0.55

Including

43.50

43.85

0.35

0.18

3

1.32

Plateros (PL2)

49.70

53.65

3.95

2.08

2

0.14

Plateros (PL2) Composite

50.45

52.15

1.70

0.89

2

0.18

Including

51.50

52.15

0.65

0.34

3

0.25

Sangre de Cristo Vein

60.65

61.50

0.85

0.44

<2

0.32

Sangre de Cristo Composite

60.00

61.50

1.50

0.77

<2

0.27

Including

60.65

61.50

0.85

0.44

<2

0.32

PLU-32

Plateros (PL1)

76.60

78.60

2.00

0.65

86

0.10

Plateros (PL1) Composite

76.90

80.20

3.30

1.07

57

0.13

Including

76.90

77.75

0.85

0.28

143

0.14

Plateros (PL2)

80.20

86.40

6.20

2.02

7

0.03

Plateros (PL2) Composite

81.25

84.00

2.75

0.90

14

0.04

Including

82.90

84.00

1.10

0.36

27

0.03

Sangre de Cristo Vein

88.10

107.85

19.75

6.27

68

0.09

Sangre de Cristo Composite

103.50

106.80

3.30

1.05

392

0.47

Including

105.60

106.80

1.20

0.38

756

0.85

Figure 10-7 Longitudinal Section (looking NE) showing intersection points on Plateros vein.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

Figure 10-8 Schematic Cross Section, Plateros.

10.4.1 Sangre de Cristo Diamond Drilling Program

In 2020, surface diamond drilling carried out in the Sangre de Cristo vein area, using one in-house drill rig (Figure 10-9).

Six drill holes completed with 1,561.25 meters and 275 samples collected and sent for assays to the laboratory. Details of the holes drilled in the Sangre de Cristo area are in Table 10-9.

Table 10-9  2020 Drilling Summary, Sangre de Cristo

HOLE

AZIMUTH

DIP

DIAMETER

TOTAL DEPTH
(m)

START DATE

FINISH DATE

PLS05-2

45 º

-55 º

HQ-NQ-BQ

311.00

20/10/2020

27/10/2020

PLS05-3

45 º

-81 º

HQ-NQ

230.70

27/10/2020

02/11/2020

PLS06-1

63 º

-45 º

HQ-NQ

239.45

03/11/2020

09/11/2020

PLS06-2

63 º

-60 º

HQ-NQ

214.10

10/11/2020

14/11/2020

PLS06-3

90 º

-56 º

HQ-NQ

199.00

24/11/2020

28/11/2020

PLS07-1

86 º

-66 º

HQ-NQ-BQ

367.00

15/11/2020

23/11/2020

Total

1,561.25

 

 



Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

Figure 10-9 In-house drill rig in pad for drill hole PLS06-1 (Sangre de Cristo).

At the end of 2020, surface drilling carried out along the Sangre de Cristo vein, which corresponds to the possible southeast extension of La Luz-Plateros, with the objective to determine the possible existence of a mineralized body in the area between the Villarino and Sangre de Cristo shafts and between surface and the Santa Brigida Level of the Sangre de Cristo historic mine workings.

Significant results for the Sangre de Cristo vein include: PLS05-3, PLS06-1 and PLS06-3.

Table 10-10 shows the summary of the results of the surface drilling carried out in the Sangre de Cristo area. Figure 10-10 shows the impacts of the Sangre de Cristo vein in the longitudinal section, and a typical cross section is shown in Figure 10-11.

Table 10-10  2020 Drilling Results, Sangre de Cristo

Drill Hole
ID

Structure

Mineralized Interval

Assay Results

From (m)

To (m)

Core Length
(m)

True Width
(m)

Silver (g/t)

Gold (g/t)

PLS05-2

Sangre de Cristo Vein

106.85

107.80

0.95

0.81

11

0.04

Including

106.85

107.50

0.65

0.56

15

0.04

PLS05-3

Sangre de Cristo Vein

183.20

183.60

0.40

0.20

354

2.02

Sangre de Cristo Composite

183.20

184.60

1.40

0.70

102

0.61

Including

183.20

183.60

0.40

0.20

354

2.02

PLS06-1

Sangre de Cristo Vein

196.75

203.00

6.25

6.06

39

0.23

Sangre de Cristo Composite

199.30

200.20

0.90

0.87

114

0.55

Including

199.65

200.20

0.55

0.53

135

0.45

Old Working (Sangre de Cristo)

203.00

206.20

3.20

3.10

Old Working

Muck sample

205.60

206.20

0.60

0.58

<2

0.05

PLS06-2

Hw Sangre de Cristo

204.55

205.15

0.60

0.53

19

0.07

Old Working (Sangre de Cristo)

206.55

214.10

7.55

6.67

Old Working

Muck sample

206.55

207.75

1.20

1.06

33

0.13

Muck sample

210.75

211.65

0.90

0.79

124

0.03

Muck sample

213.30

214.10

0.80

0.71

<2

0.06



Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

Drill Hole ID

Structure

Mineralized Interval

Assay Results

From (m)

To (m)

Core Length (m)

True Width (m)

Silver (g/t)

Gold (g/t)

PLS06-3

Sangre de Cristo Vein

125.30

127.65

2.35

1.97

200

0.21

Sangre de Cristo Composite

125.30

126.75

1.45

1.22

283

0.30

Including

125.60

126.00

0.40

0.34

942

0.77

PLS07-1

Sangre de Cristo Projection

232.55

232.85

0.30

0.22

<2

0.04

Sangre de Cristo Composite

231.55

232.85

1.30

0.94

<2

0.01

Including

232.55

232.85

0.30

0.22

<2

0.04

Sangre de Cristo Projection

244.55

244.85

0.30

0.22

<2

0.01

Sangre de Cristo Composite

244.55

245.85

1.30

0.94

<2

0.01

Including

244.55

244.85

0.30

0.22

<2

0.01

Figure 10-10 Longitudinal Section (looking NE) showing intersection points on Sangre de Cristo vein.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

Figure 10-11 Schematic Cross Section, Sangre de Cristo.

10.4.1 Bolañitos South Diamond Drilling Program

During 2020, surface diamond drilling carried out in the Bolañitos South area, with the objective to test the Ave Maria vein, located in the northwest part of the El Puertecito EDR claim. A total of 898.30m drilled in five holes, using one in-house drill rig (Figure 10-12), 219 samples collected and submitted for analysis.

Details of the holes drilled to test the Ave Maria vein are shown in Table 10-11.

Table 10-11  2020 Drilling Summary, Ave Maria

HOLE

AZIMUTH

DIP

DIAMETER

TOTAL DEPTH
(m)

START DATE

FINISH DATE

AVM-01

37 º

-47 º

HQ/NQ

51.00

02/03/2020

04/03/2020

AVM-02

48 º

-83 º

HQ, NQ

192.50

05/03/2020

12/03/2020

AVM-03

45 º

-45 º

HQ, NQ

229.00

13/03/2020

21/03/2020

AVM-04

48 º

-60 º

HQ-NQ

181.20

23/03/2020

29/03/2020

AVM-05

48 º

-71 º

HQ-NQ

244.60

29/03/2020

04/04/2020

Total

898.30

 

 



Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

Figure 10-12 In-house drill rig in pad for drill hole AVM-04 (Ave Maria).

The Ave María vein was tested along 400m long, between the elevations 2,075 and 2,225 masl. The results were not positive with only one intercept over the Ave Maria vein with values of interest in hole AVM-03.

The Ave Maria veins intercepts are shown on the longitudinal section in Figure 10-13 and typical cross-section in Figure 10-14.

Figure 10-13 Longitudinal Section (looking NE) showing intersection points on Ave María vein.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Drilling

Figure 10-14 Schematic Cross Section, Ave María.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Sample Preparation, Analyses and Security

11. SAMPLE PREPARATION, ANALYSES AND SECURITY

The sample data relied upon during completion of the mineral resource and reserve estimates presented in this report are from diamond drill core and underground chip channel samples.

11.1 Methods

11.1.1 Production Chip Channel Samples

Bolañitos employs standardized procedures for collecting underground grade control chip samples, and these procedures are documented in a detailed, illustrated manual. Chip channel sampling is carried out daily in accessible stopes and development headings by mine sampling technicians. Samples are located by measuring with a tape from known survey points. The samples are taken perpendicular to the veins at 3m to 5m intervals along drifts. Sample locations are cleaned and marked with two parallel, red spray paint lines to guide the sampling. Chip samples are collected on all vein faces in drifts, crosscuts, raises, and stopes. On faces and raises they are taken perpendicular to the dip of the vein to approximate true width. Stopes are sampled across the roof (back) following the profile of the working.

The entire chip sample is divided into a number of discrete samples based on the geology (lithology). The simplest configuration is a single vein where the chip sample would be divided based on one sample of the wall rock on each side of the vein, and one sample of the vein. In more complex configurations, if there is more than one vein present, or it is divided by waste rock, then each of the vein sections is sampled separately. The chip samples are cut approximately 10 cm wide and 2 cm deep using a hammer and chisel. The rock chips are collected in a net, placed on a canvas, and any fragments larger than 2.5 cm are broken with a hammer. The maximum sample length is generally 1.5 m and minimum sample length is generally 0.2 m, though a few samples are taken over as narrow a width as 0.1 m.

The samples are sealed in plastic bags with a string and sent to the laboratory at Bolañitos. Samples which tend to be large, representing long sample intervals, can be too large for the bags provided and are reduced in size at the sample site to 1-2kg by quartering. Care is taken to collect all of the fines for the selected quarters. The samples are sealed in plastic bags and transported to the geology storage facility on surface. From there the samples are taken to the laboratory at the Bolañitos mine site by contracted transporter. Sample locations are plotted on stope plans using CAD software. The sample numbers and location data are recorded in a spreadsheet database. Upon receipt of assays, technicians and geologists produce reports used for day-to-day monitoring and grade control.

11.1.2 Exploration Sampling

EDR's exploration staff are responsible for regional and mine exploration within the Bolañitos mining district, including the management, monitoring, surveying, and logging of surface and underground diamond drilling.

Regardless of which program the core comes from, the process is the same. Core from diamond drilling is placed in boxes which are sealed shut at the drill site. EDR personnel transport the core to the core facility. Sample handling at the core facility follows a standard general procedure, during which depth markers are checked and confirmed; the outside of the boxes are labeled with interval information; core is washed and photographed; and the recovery and modified rock quality designation (RQD) are logged for each drillhole.


Endeavour Silver Corp. NI 43-101 Technical Report
Bolañitos Project Sample Preparation, Analyses and Security

All of EDR's surface and underground exploration drillholes are processed at the exploration core facility.

A cutting line is drawn on the core with a colored pencil, and sample tags are stapled in the boxes or denoted by writing the sample number with a felt tip pen.

The core is split using a diamond saw.

11.2 Sample Preparation and Analysis

Mine production sampling including plant feed samples, concentrate and doré, are sent to EDR's in-house, ISO-certified Bolañitos assay laboratory. The laboratory is set up in a single facility at the Bolañitos mine with separate enclosed sections for sample preparation, fire assay with gravimetric finish, and atomic absorption facilities. The facilities are located within the Bolañitos mine compound and operate 24 hours per day.

11.2.1 Exploration Drilling

During 2020, all samples of rock and drill core are bagged and tagged at the Guanajuato core facility. From January to October, samples were sent to the ALS preparation facility in Zacatecas, Mexico, and after preparation, the samples are shipped to the ALS laboratory in Vancouver, Canada,