Technical Report On The Avino Property, Durango, Mexico

The following excerpt is from the company's SEC filing.

The Avino Mine (the Property or the Project), near Durango, Mexico, is Avinos principal asset and is the subject of this technical report, which includes a current resource estimate on the Avino and San Gonzalo veins, as well as the previously reported estimate on the oxide tailings (Tetra Tech 2012). Avino holds a 96.5996% interest in the Property through its subsidiary company called Compaa Minera Mexicana de Avino (CMMA). Avino commenced development, including drilling and bulk sampling, on the San Gonzalo vein in 2010 and this work is ongoing. This marks the resumption of activity on the Property since 2001, when low metal prices and the closure of a key smelter caused the mine to close after having been in operation continuously for 27 years. Between 1976 and 2001, the mine produced approximately 497 t of silver, 3 t of gold, and 11,000 t of copper (Slim 2005) as well as an apparently undocumented amount of lead.

This report includes a summary of material information concerning a preliminary economic assessment (PEA) conducted on part of the Property by Tetra Tech and filed in 2012. The PEA is preliminary in nature and includes Inferred Mineral Resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves. Furthermore, there is no certainty that the resource estimate will be realized.

The majority of the information has been sourced from data provided by Avino, Avino internal reports, Slim (2005d), and Gunning (2009). The majority of the information was provided in English, but some information was written in Spanish and subsequently translated into English.
1.2
Property Description and Location


The Property is located in Durango State in North Central Mexico, within the Sierra Madre Silver Belt, 82 km northeast of Durango City (Figure 1.1). The current Property is comprised of 23 mineral concessions, totalling 1,103.934 ha. Of these, 22 mineral concessions, totalling 1,005.104 ha, are held by CMMA (Avinos Mexican subsidiary company), by Promotora Avino SA de CV, and by Susesion de la Sra. Elena del Hoyo Algara de Ysita. Ownership proportions are summarized in Table 1.1.
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Figure 1.1
General Property Location Map
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Table 1.1
Summary of Property Ownership
Company
Relationship to
Avino Silver and
Gold Mines Ltd.
Effective Ownership of
Avino Mine Property
(%)
CMMA
Subsidiary
96.60
Promotora Avino, S.A. de C.V.
Subsidiary
2.68
Total Effective Ownership of Avino Mine Property
-
99.28
Estate of Ysita
Non-controlling interest
0.72
Total
-
100.00


Through its subsidiary company, Avino entered into an agreement (the Agreement) on February 18, 2012 with Minerales de Avino, Sociedad Anonima de Capital Variable (Minerales), whereby Minerales has indirectly granted to Avino the exclusive mining and occupation rights to the La Platosa concession.The La Platosa concession covers 98.83ha and hosts the Avino vein and Elena Toloso Zone (ET Zone).

Pursuant to the Agreement, Avino has the exclusive right to explore and mine the concession for an initial period of 15 years, with the option to extend the agreement for another 5 years.In consideration of the grant of these rights, Avino must pay to Minerales the sum of US$250,000 by the issuance ofcommon shares of Avino.Avino will have a period of 24 months for the development of mining facilities.Avino has also agreed to pay to Minerales a royalty equal to 3.5% of net smelter returns (NSRs), at the commencement of commercial production from the concession.

All concessions are current and up to date based on information received.Mineral concessions in Mexico do not include surface rights and Avino has entered into agreements with communal landowners (Ejidos) of San Jose de Avino, for the temporary occupation and surface rights of the concessions.
1.3
Geology and Mineralization


The Property is located within the Sierra de Gamon, on the east flank of the Sierra Madre Occidental.The area is a geological window into the Lower Volcanic series and consists mainly of volcanic flows, sills, and tuffaceous layers of andesite, rhyolite, and trachyte.Individual rock units vary from 300 to 800 m in thickness.Andesitic rocks outcrop over most of the region with other rock types occurring more sparsely to the north (Slim, 2005d).

A large monzonitic intrusion is observed in the region in the form of dykes and small stocks, which appear to be linked to the onset of the Avino vein mineralization.Other post-mineralization dykes of intermediate to felsic composition outcrop in various areas and appear to cause minor structural displacements.A number of thin mafic sills are also found in various parts of the region and are related to recent volcanism.
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Regionally, the Avino concession is situated within a 12 km north-south by 8.5 km caldera, which hosts numerous low sulphidation epithermal veins, breccias, stockwork and silicified zones. These zones grade into a near porphyry environment, particularly in the Avino Mine area. The caldera has been uplifted by regional north trending block faulting (a graben structure), exposing a window of andesitic pyroclastic rocks of the lower volcanic sequence, a favourable host rock, within the caldera. This sequence is overlain by rhyolite to trachytes with extensive ignimbrite layers forming the upper volcanic sequence and is intruded by monzonite bodies. The basal andesite-bearing conglomerate and underlying Paleozoic basement sedimentary rocks (consisting of shales, sandstones and conglomerates) have been identified on the Avino concession in the south-central portion of the caldera, covering the Guadalupe, Santiago, San Jorge, the San Gonzalo Trend, Malinche, Porterito and Yolanda areas. A northerly trending felsic dyke, probably a feeder to the upper volcanic sequence, transects the Property and many of the veins. The Aguila Mexicana low temperature vein system, with significant widths but overall low precious metal values, trends north-northwest, similar to the felsic dyke and with similar continuity across the property. The two structures may occupy deep crustal faults that controlled volcanism and mineralization, with the felsic dyke structure controlling the emplacement of the Avino, Nuestra Senora and El Fuerte-Potosina volcanic centres and the Aguila Mexicana controlling the Cerro San Jose and El Fuerte-Potosina volcanic centres (Paulter 2006).

Silver- and gold-bearing veins crosscut the various lithologies and are generally oriented north-northwest to south-southeast and northwest to southeast. The rocks have been weathered and leached in the upper sections, as a result of contact with atmospheric waters. The oxide tailings material is primarily from this source, whereas the sulphide tailings are predominantly from material sourced at depth from the underground workings. In Mexico, these types of deposits can have large lateral extents, but can be limited in the vertical continuity of grades.

The valuable minerals found during the period of mining of the oxide zone were reported to be argentite, bromargyrite, chalcopyrite, chalcocite, galena, sphalerite, bornite, native silver, gold and native copper. The gangue minerals include hematite, chlorite, quartz, barite, pyrite, arsenopyrite and pyrrhotite. Malachite, anglesite, and limonite are common in the quartz zones of the weathered parts of the oxide material.
1.3.1
Avino Vein


The Avino vein was the primary deposit mined during the 27 years of open pit and underground production prior to 2001. It is 1.6 km long and 60 m wide on the surface. To date, the deepest level mined was at the 2,070 m level (330 m below surface).
1.3.2
San Gonzalo Vein


The San Gonzalo vein system, including the crosscutting Angelica vein, is located 2 km northeast of the Avino vein. It constitutes a strongly developed vein system over 25 m across, trending 300 to 325/80 northeast to 77 south. It is characterized by banded textures and open-space filling and has an average width of 2 m. The silica-pyrite or iron oxide-sericite alteration with additional stockworking extends across 300 m, south of the main San Gonzalo vein. The vein was mined historically and underground workings extend over an area approximately 150 m along strike and 136 m in depth. The age of the tailings associated with the vein is unclear.
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1.3.3
Oxide and Sulphide Tailings


The tailings are situated approximately 500 m west-southwest of the main shaft to the old underground workings. The oxide tailings (at the bottom of the pile) are primarily derived from weathered and oxidized rocks close to the surface on the Property, whereas the sulphide tailings (at the top of the pile) are predominantly derived from material sourced at depth from the underground workings. At this time, it is not clear what the real nature of the chemical difference between the two is, but they are distinctly different in colour. The sulphide tailings, in the absence of any definitive sampling data penetrating the depth of the pile, are an exploration target at best.
1.4
Resource Estimates


The Avino system and San Gonzalo system mineral resources were modelled and estimated using Datamine software version 3.20.6140.0. The reported mineral resource was interpolated using ordinary kriging (OK) and capped grades. Avino mineralization included the interpolation of silver, gold and copper, while San Gonzalo mineralization included the interpolation of silver and gold. Reported cut-offs utilize a silver equivalent (Ag_Eq) calculation where the total metal value is converted into an in situ silver resource. For reporting purposes, a base-case Ag_Eq cut-off of 100 g/t is used for the Avino system and an Ag_Eq cut-off of 150 g/t is used for the San Gonzalo system. Current cut-offs used for financial projections by Avino, based on recent market prices, include 80 g/t for the Avino system and 120 g/t for the San Gonzalo system.

The oxide tailings mineral resource was estimated using Geovariance Isatis software and OK interpolation with uncapped grades. The assay values for this estimate are based on 28 drillholes which were completed on the tailings by CMMA in 1990, and include 407.75 m of drilling and 383 assays of both gold and silver. A specific gravity of 1.605 was used based on the global average for the oxide tailings reported by Slim (2005d). For reporting purposes, a silver cut-off of 50 g/t was used; an Ag_Eq value was not calculated for the oxide tailings. This mineral resource was estimated by Mr. Mike OBrien, and has an effective date of July 24, 2012. It was originally disclosed by Tetra Tech (2012), but is considered current.

provides the base case values for all current mineral resources for the Avino Mine, including the Avino and San Gonzalo systems and the oxide tailings.
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Table 1.2
Summary of Mineral Resources for the Avino Mine
Resource
Category
Deposit
Cut-off
Ag_Eq*
Tonnes
Contained Metal
Grade
Ag_Eq
(oz)
Ag
(oz)
Au
(oz)
Cu
(t)
Ag_Eq
(g/t)
Ag
(g/t)
Au
(g/t)
Cu
(%)
Measured
San Gonzalo System
150
71,416
914,791
759,801
3,288
N/A
398
331
1.432
N/A
Total Measured - All Deposits
-
71,416
914,791
759,801
3,288
N/A
-
-
-
-
Indicated
Avino System
100
4,253,968
23,838,629
10,835,338
72,207
30,914
174.3
79.2
0.528
0.727
Indicated
San Gonzalo System
150
222,407
2,763,069
2,043,514
15,263
N/A
386
286
2.134
N/A
Total Indicated - All Deposits
-
4,476,375
26,601,698
12,878,852
87,470
30,914
-
-
-
-
Inferred
Avino System
100
3,220,896
16,262,944
7,068,831
75,858
17,719
157
68.3
0.733
0.55
Inferred
San Gonzalo System
150
1,085,276
10,494,843
8,158,834
49,549
N/A
300.8
233.8
1.42
N/A
Inferred
Oxide Tailings
50*
2,340,000
N/A
6,660,000
39,530
N/A
N/A
91.3
0.54
N/A
Total Inferred - All Deposits
-
6,646,172
26,757,787
21,887,665
164,937
17,719
-
-
-
-
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1.5
Mineral Processing, Metallurgical Testing and Recovery Methods
1.5.1
Avino Vein


Avino is not conducting mining activity on the Avino vein. No mineral processing methods or metallurgical testing is underway or proposed for the Avino vein.

Prior to the mine shutting down in 2001, Avino operated a 1,000 t/d processing plant producing a copper concentrate that was sold to a smelter in San Luis Potosi. The plant consisted of a conventional three-stage crushing circuit with the tertiary crusher in closed circuit with a screen. Fine crushed material was fed to a ball mill and classified with a cyclone. The fines from the cyclone reported to the flotation circuit where typical flotation reagents for copper minerals were used. The concentrate from the rougher and scavenger circuits were upgraded in a cleaner circuit with the final concentrate reporting to a thickener, vacuum filter and dryer. The concentrate was dried to approximately 8% moisture and then shipped to the smelter. Flotation tailing was pumped to the permitted tailings impoundment where decant water is reclaimed for process use.
1.5.2
San Gonzalo Vein


Avino is currently conducting mining activity on the San Gonzalo vein, including processing of San Gonzalo vein material at the mine plant.

The process plant consists of crushing and grinding facilities, followed by a flotation process circuit to recover and upgrade silver and gold from the feed material. Common reagents were used within the flotation circuit. The flotation concentrate is thickened, filtered to 9.9% moisture content, and sent to the concentrate stockpile for subsequent shipping to customers.
1.5.3
Oxide Tailings


Tetra Tech used the estimated grade values and test work results as reported by MineStart Management Inc. (MMI) and Process Research Associates Ltd. (PRA), who conducted the metallurgical tests.

Tetra Tech investigated gravity separation, flotation, cyanide leach, carbon-in-pulp, and heap leach processing options. Using the recoveries and process conditions resulting from these tests, the capital costs to construct a processing plant using selected process options were developed while the operating costs associated with each option were determined and a financial model compiled. A heap leach operation indicated the best financial alternative.
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1.6
Mining Methods
1.6.1
Avino Vein


Avino is not currently conducting mining activity on the Avino vein.In addition, no mining methods are currently proposed for any potential mining activity on the Avino vein.
1.6.2
San Gonzalo Vein


Avino is currently conducting mining activity on the San Gonzalo vein. Both cut-and-fill and shrinkage stoping are used to feed the mill which is currently configured to accommodate 230 t/d of dry material from San Gonzalo. A contractor is used for haulage. More information can be found in Section 16.2.
1.6.3
Oxide Tailings


This tailings mineral resource will be mined through surface methods and without blasting. A truck/front-end loader arrangement has been selected and will operate one 8 h shift per day, 365 d/a for the 4.7-year life of this Project.

Initially the oxide tailings will be processed without having to move the sulphide tailings, which covers a portion of the oxide tailings. Not all of the sulphide tailings need to be removed to gain access to the oxide tailings. Approximately 0.5 Mt/a of oxide tailings will be sent to the heap leach pad.
1.7
Environmental


Environmental settings, permits and registrations, and environmental management strategies that may be required for the Project are summarized in Section 20.0. Permits and authorizations required for the operation of the Project may include an operating permit, an application for surface tenures, a waste water discharge registration, a hazardous waste generator's registration, and an Environmental Impact Assessment (EIA) or Evaluacin de Impacto Ambiental. Acid-base accounting (ABA) tests have indicated that mild acid generation may already have started on the tailings dam. A gap analysis and additional tests to further characterize current conditions of the tailings should be completed to properly design a tailings management plan.
1.8
Capital and Operating Costs
1.8.1
Avino Vein


Avino is not currently conducting mining activity on the Avino vein.No capital or operating costs have been proposed for any potential mining activity on the Avino vein.
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1.8.2
San Gonzalo Vein


The actual capital expenditures to date on the San Gonzalo vein are summarized in Table 1.3.The capital expenditures (in US dollars) have been broken down by year and area.
Table 1.3
Capital Costs for the San Gonzalo Vein
2011
2012
2013
Total
Mine
695,411
338,474
1,527,106
2,560,991
Mill
270,760
184,451
160,399
615,610
Development
2,881,768
1,841,757
176,360
4,899,885
Geological
-
90,660
169,441
260,101
Total
-
-
-
8,336,587


Mine and mill capital costs were attributed to equipment purchases.Development was for the construction of the haulage ramp and installation labour and geological for engineering services.
Table 1.4
Operating Costs for the San Gonzalo Vein
Description
Q4 2012
Q1 2013
Total Cost
Cost per tonne
Processed
Total Milled Tonnes Q4 2012 and Q1 2013
-
-
-
39,262
Direct Costs
-
-
-
-
Mining
910,095
1,621,393
2,531,488
64
Milling
168,806
374,031
542,837
14
Geological
178,394
189,715
368,109
9
Total Direct Costs
1,257,295
2,185,139
3,442,434
88
General and Administrative (G&A)
127,393
86,941
214,334
5
Total Operating Costs
1,384,688
2,272,080
3,656,768
93


The mine and milling costs included operating and maintenance labour together with the associated consumable supplies.Power was included in the milling costs.The geological component was mostly technical labour.
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1.8.3
Oxide Tailings


Tetra Tech (2012) developed the capital cost estimate (CAPEX) for the Project based on the treatment of 1,370t/d, or 500,000t/a of oxide tailings.A total cost of US$29.1million, including contingency, was estimated as the CAPEX for the Project (Table 1.5).
Table 1.5
CAPEX Summary
Item/Description
Cost
(US$)
Direct Costs
Mining, Agglomeration, and Pad Loading
3,293,320
Process Facilities
3,905,528
Reagents/Auxiliary Services
501,750
Buildings
932,763
Leach Pad and Infrastructure
7,414,974
Power Supply and Distribution
1,457,296
Total Direct Costs
17,505,632
Indirect Costs
Engineering, Procurement, Construction Management, Quality Assurance and Vendor Representatives
2,658,728
Freight and Construction Indirects
3,146,235
Contingency
5,828,000
Total Indirect Costs
11,632,964
Total CAPEX
29,138,596


Table 1.6 gives the overall estimated cost summary for the processing facility and the G&A costs based on 1,370t/d, with an availability of 90% and 365 operating days per year.

The annual operating cost estimate (OPEX) for the process facilities is estimated to be US$6.3million or US$12.74/t of tailings treated at a processing rate of 1,370t/d.An incremental increase in the G&A OPEX is estimated to be US$752,656, or US$1.51/t of tailings treated.
Table 1.6
OPEX Summary
Description
Personnel
Annual Cost
(US$)
UnitCost
(US$/t Treated)
Process Manpower
Maintenance Labour
7
175,104
0.35
Operations Labour
35
545,832
1.09
Laboratory
7
139,536
0.28
Subtotal
49
860,472
1.72
table continues
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Description
Personnel
Annual Cost
(US$)
UnitCost
(US$/t Treated)
Process Supplies
Operating Supplies
-
4,582,421
9.16
Maintenance Supplies
-
450,000
0.90
Power Supply
-
479,947
0.96
Subtotal
-
5,512,368
11.02
Total Process OPEX
49
6,372,840
12.74
G&A Costs
G&A Staff
11
262,656
0.53
G&A Expenses
-
490,000
0.98
Total G&A OPEX
11
752,656
1.51
Total OPEX
60
7,125,496
14.25
1.9
Economic Analysis
1.9.1
Avino Vein
1.9.2
San Gonzalo Vein
1.9.3
Oxide Tailings
54.5% internal rate of return (IRR)
1.6-year payback
US$38.6million net present value (NPV) at an 8% discount rate.


The PEA is preliminary in nature and includes Inferred Mineral Resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves.Furthermore, there is no certainty that the resource estimate will be realized.Mineral resources that are not mineral reserves and have not demonstrated economic viability.
1.9.4
Sulphide Tailings
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1.10
Recommendations


Tetra Techs recommendations are summarized below.These recommendations are not required for continued mine development on the Property, and therefore a cost estimate for this work is not provided.The recommendations cover a variety of concerns noted by Tetra Tech regarding database management, quality assurance/quality control (QA/QC), health and safety, and environmental factors.
1.10.1
Geology


Tetra Tech recommends a single, compiled database be maintained, containing all drillhole and channel sample data for both veins. Additional detailed recommendations related to this database are provided in Section 26.1.1.

Geology data for the mine is not currently being stored in a digital format, and the geology interpretation is inconsistent and at times incorrect. Specific recommendations for improving geology data capture and interpretation are provided in Section 26.1.2.

Tetra Tech recommends that a multi-shot, non-magnetic instrument (Reflex Gyro or Reflex Maxibor) be used for downhole surveys on all future drillholes on the Property. Survey measurements should be collected at least every 10 m down the hole, and all drillholes should be cemented following completion.

Tetra Tech recommends that all future specific gravity analyses be completed using the water displacement method, which is generally more accurate than caliper measurement. Additional detailed recommendations are provided in Section 26.1.4.

Tetra Tech recommends QA/QC samples be included in all drilling and channel sampling completed on the Property, according to industry best practices. Additional detailed recommendations are provided in Section 26.1.5.

For the confidence in the Inferred Mineral Resource of oxide tailings to be improved, a drilling campaign should be carried out with suitable equipment (sonic drilling is recommended to recover unconsolidated material with variable moisture content). At the same time, the overlying deposit of sulphide tailings should be drilled. To achieve a nominal drill collar spacing of 50 m by 50 m, 90 holes with an average length of 20 m would be required for a total of 1,800 m of drilling.
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Additional surface drilling on the Avino and San Gonzalo veins is not currently planned by Avino. Drilling on the San Gonzalo vein using Avinos underground diamond drill is planned as drift development progresses, with the goal of further definition of the San Gonzalo vein and in particular of high grade areas.

A resource estimate for the sulphide tailings should be completed for mine planning purposes, in addition to an updated oxide tailings resource estimate, following the drilling program recommended above.

Both the Avino and San Gonzalo veins contain mineral resources estimated at a classification level of Indicated or higher.As such, further drilling would not be required to include these resources in economic analyses at a prefeasibility or feasibility level.Further drilling would be required in order to include any Inferred resources in these studies, however.
1.10.2
Process


For the next phase of the study, Tetra Tech recommends that Avino submit representative samples from both the Avino and San Gonzalo veins for further metallurgical tests.

Based on the conclusions within the components of this technical report, it is recommended that the following tasks could be executed for verifying the material within the tailings:
drill the surface of both tailings dam areas to determine the volumes and bulk density of each of the oxide and sulphide tailings material
take sufficient amounts of samples from both oxide and sulphide tailings to obtain representative samples for assay and metallurgical test work to confirm the grade of the deposit and the recovery of silver and gold from the heap leach process
use the metallurgical results from the test work program to confirm/define the duration of leaching on the pad, the reagent consumption values and the silver and gold precipitation efficiencies
use the metallurgical results from the metallurgical test work program to develop a heap leach flowsheet
based on accurate assay and reproducible metallurgical test work data, prepare an economic analysis for the retreatment of the oxide tailings dam material, the sulphide tailings dam material, and for the treatment of both oxide and sulphide tailings material.
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The suitability and/or the possibility of refurbishing the existing equipment at the Avino Mine plant site needs to be evaluated more closely.The general availability of used equipment from other locations in the Durango district, or in Mexico, would need to be investigated.

The option of whether the sulphide tailings should be re-treated on the heap or relocated and dumped elsewhere, while possibly being treated for environmental remediation, is not known at this stage.The absence of reliable sulphide tailings dump metallurgical information makes quantification difficult.A detailed trade-off study should be undertaken to determine whether the re-treatment of this material would contribute to the profitability of the Project.
1.10.3
Environmental


Government agencies should be consulted prior to the permitting process to determine if current permits for the San Gonzalo Mine can been revised.The cost of expropriating agricultural land for the leach pad, and the cost of water which would have to be redirected to the heap leach project but which is currently used for agricultural purposes has not been assessed.Once the mine plan, site layout and tailings management plan are further along and have definitive locations, the cost of these factors should be addressed.The cost for monitoring environmental effects post mine closure needs to be estimated.

A detailed trade-off study should be undertaken to characterize current conditions of the sulphide tailings and to determine whether the re-treatment of this material would contribute to the profitability of the Project.

There is potential for the water from the underground workings to be acid producing (Slim 2005d).Treatment of water from the underground workings was initiated in 2012 following the construction of a water treatment plant.
1.10.4
Mining


Tetra Tech has numerous recommendations related to mining of the Avino and San Gonzalo veins, including many with health and safety implications.These are provided in detail in Section 26.4.
1.10.5
Project Development


Tetra Tech recommends that a PEA be completed for the entire Property, including a resource estimate for the sulphide tailings and an updated estimate for the oxide tailings.
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2.0
INTRODUCTION


Avino is a Canadian-based mining and exploration company listed on the TSXV and NYSE, trading under the symbol ASM.Avino has precious metal properties in Mexico and Canada and has a head office located at 900-570 Granville Street, Vancouver, BC, Canada, V6C 3P1.

Tetra Tech has been retained by Avino to produce a new technical report on the Avino Property.The primary purpose of this new report is to disclose two new mineral resource estimates for the Avino vein and San Gonzalo vein portions of the Property.The report also includes a summary of curent information previously disclosed in a Tetra Tech report filed in 2012, comprising a mineral resource estimate and preliminary economic assessment on the oxide tailings portion of the Property.This report has been prepared in accordance with National Instrument 43-101 and Form 43-101F.
2.1.1
Units of Measurement


All units of measurement used in this technical report and resource estimate are in metric, and currency is expressed in US dollars, unless otherwise stated.
2.2
Effective Dates
2.3
Information and Data Sources


The majority of the information has been sourced from data provided by Avino, Avino internal reports, Slim (2005d), and Gunning (2009).The majority of the information was provided in English, but some information was written in Spanish and subsequently translated into English.

In preparation of this report, various historical engineering, geological and management reports compiled about the Project or site were reviewed and supplemented by direct site examinations and investigations.All the data files reviewed for this study were provided by Avino in the form of hard copy documents, .pdf reports, .xls files, email correspondence, and personal communication with management and personnel from Avino.Work completed by Avino includes several decades of open pit and underground mining, drilling and sampling, trenching, metallurgical testing, and geophysical surveying.
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Gunning, D.2009.Resource Estimate on the San Gonzalo Vein A Part of the Avino Mine, Durango, Mexico, for Avino Silver and Gold Mines Ltd.Prepared by Orequest.Effective date August 31, 2009.
Slim, B.2005d.A Tailings Resource.Prepared for Avino Silver & Gold Mines Ltd.Report prepared by Bryan Slim, MineStart Management Inc.October 25, 2005.
Huang, J. and Tan, G.2005.Metallurgical Test Work on Avino Tailings, Durango, Mexico.Report to Brian Slim, MineStart Management Inc.Prepared by Process Research Associates Ltd.March 28, 2005.
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3.0
RELIANCE ON OTHER EXPERTS


In preparation of this report, Tetra Tech has relied upon others for information, and disclaims responsibility for information derived from reports pertaining to mineral tenure, property ownership, surface rights, environment, royalties, and social issues, as discussed in the following sections:
mineral tenure, property ownership, royalties and surface rights and discussed in Sections 4.2 and 4.3
environmental and and social issues are discussed in Section 20.0 and in greater detail in Tetra Techs previous report (Tetra Tech 2012).
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4.0
PROPERTY DESCRIPTION AND LOCATION
4.1
Location


The Property is located in Durango State in North Central Mexico, within the Sierra Madre Silver Belt on the eastern edge of the Sierra Madre Occidental mountain range. The nearest major center is the city of Durango, 82 km to the southwest of the Property. The Property is within the municipality of Pnuco de Coronado between the towns of Pnuco de Coronado and San Jos de Avino. The Property is located at latitude N 24 53', longitude W 104 31', 14 km northwest of Highway 40D.
4.2
Property Ownership


In 1968, Avino Mines and Resources Ltd. acquired a 49% interest in CMMA and Minera San Jos de Avino SA, which together held mineral claims totalling 2,626 ha (6,488 ac). Avino Mines and Resources Ltd. retained Vancouver based Cannon-Hicks & Associates Ltd. (Cannon-Hicks), a mining consulting firm, to conduct the exploration and development of the Property. Cannon-Hicks exploration activities included surface and underground sampling and diamond drilling (VSE 1979).

In early 1970, Avino Mines and Resources Ltd. signed a letter of intent with Denison Mines Ltd. for the future development of the Avino Mine. However, the agreement was never signed.

In May 1970, Avino Mines and Resources Ltd. signed a formal agreement with Selco Mining and Development (Selco), a division of Selection Trust Company. Due to other commitments, Selco abandoned its interest in the Project in 1973 (VSE 1979).

In October 1973, Avino Mines and Resources Ltd. signed a new agreement with S.G.L. Ltd. and Sheridan Geophysics Ltd. Under the terms of the agreement, S.G.L. Ltd. was to provide up to $500,000 plus the management to erect a production plant. The agreement provided for the return of the capital from first cash flow, plus a management fee and interest payment together with an option to convert a portion of the advanced funds to common shares. The agreement with S.G.L. Ltd. was terminated in mid-1976.
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4.3
Mineral Concessions and Agreements


The current Property is comprised of 23 mineral concessions, totalling 1,103.934 ha (Figure 4.3). Of these, 22 mineral concessions totalling 1,005.104 ha, are held by CMMA (Avinos Mexican subsidiary company), Promotora Avino SA de CV, and Susesion de la Sra. Elena del Hoyo Algara de Ysita. Ownership proportions and mineral concessions are summarized in Table 4.1 and Table 4.2, respectively.
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Company
Relationship to
Avino Silver and Gold Mines Ltd.
Effective Ownership of
Avino Mine Property
(%)
CMMA
Subsidiary
96.60
Promotora Avino, S.A. de C.V.
Subsidiary
2.68
Total Effective Ownership of Avino Mine Property
-
99.28
Estate of Ysita
Non-controlling interest
0.72
Total
-
100.00
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Table 4.2
Mineral Concessions Avino Property
Concession
Name
Concession
No.
Location
Hectares
(ha)
Date
Acquired
Expiration
Date
Cost
(US$/ha)
Payment
(US$)
Agrupamiento San Jose (Purisma Chica)
155597
Pnuco
136.708
30/09/1971
29/09/2021
124.74
17,052.91
Agrupamiento (San Jose)
164985
Pnuco
8
13/08/1979
12/8/2029
124.74
997.92
Agrupamiento San Jose (El Trompo)
184397
Pnuco
81.547
13/10/1989
12/10/2039
124.74
10,172.12
Agrupamiento San Jose (Gran Lucero)
189477
Pnuco
161.468
5/12/1990
4/12/2040
124.74
20,141.57
Agrupamiento San Jose (San Carlos)
117411
Pnuco
4.451
5/2/1961
16/12/2061
124.74
555.16
Agrupamiento San Jose (San Pedro Y San Pablo)
139615
Pnuco
12
22/06/1959
21/06/2061
124.74
1,496.88
Aguila Mexicana
215733
Pnuco
36.768
12/3/2004
29/06/2044
70.88
2,606.12
Ampliacion La Malinche
204177
Pnuco
6.01
18/12/1996
17/12/2046
124.74
749.72
Ampliacion San Gonzalo
191837
Pnuco
5.85
19/12/1991
18/12/2041
124.74
729.67
Avino Grande Ix
216005
Pnuco
19.558
2/4/2002
1/4/2052
70.88
1,386.24
Avino Grande Viii
215224
Pnuco
22.882
14/02/2002
13/02/2052
70.88
1,621.85
El Caracol
215732
Pnuco
102.382
12/3/2002
28/04/2044
70.88
7,256.84
El Potrerito
185328
Pnuco
9
14/12/1989
13/12/2039
124.74
1,122.66
Fernando
205401
Pnuco
72.129
29/08/1997
28/08/2047
124.74
8,997.33
La Estela
179658
Pnuco
14
11/12/1986
12/12/2036
124.74
1,746.36
La Malinche
203256
Pnuco
9
28/06/1996
27/06/2046
124.74
1,122.66
Los Angeles
154410
Pnuco
23.713
25/03/1971
24/03/2021
124.74
2,957.96
Negro Jose
218252
Pnuco
58
17/10/2002
16/10/2052
70.88
4,111.04
San Gonzalo
190748
Pnuco
12
29/04/1991
28/04/2041
124.74
1,496.88
San Martin De Porres
222909
Pnuco
30
15/09/2004
14/09/2054
70.88
2,126.40
Santa Ana
195678
Pnuco
136.182
14/09/1992
13/09/2042
124.74
16,987.38
Yolanda
191083
Pnuco
43.458
29/04/1991
28/04/2041
124.74
5,420.91
Total
-
-
1,005.106
-
-
-
-
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On February 18, 2012, through its subsidiary company CMMA, Avino re-entered into an agreement (the Agreement) with Minerales, whereby Minerales has indirectly granted to Avino the exclusive mining and occupation rights to the La Platosa concession. The La Platosa concession covers 98.83 ha and hosts the Avino vein and ET Zone.

Pursuant to the Agreement, Avino has the exclusive right to explore and mine the concession for an initial period of 15 years, with the option to extend the agreement for another 5 years. In consideration of the grant of these rights, Avino must pay to Minerales the sum of US$250,000, by the issuance of common shares of Avino. Avino will have a period of 24 months for the development of mining facilities.

Avino has agreed to pay to Minerales a royalty equal to 3.5% of NSRs, at the commencement of commercial production from the concession. In addition, after the development period, if the minimum monthly processing rate of the mine facilities is less than 15,000 t, then Avino must pay to Minerales in any event a minimum royalty equal to the applicable NSR royalty based on processing at a minimum monthly rate of 15,000 t. In the event of a force majeure, Avino shall pay the minimum royalty as follows:
first quarter: payment of 100% of the minimum royalty
second quarter: payment of 75% of the minimum royalty
third quarter: payment of 50% of the minimum royalty
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fourth quarter: payment of 25% of the minimum royalty
in the case of force majeure still in place after one-year of payments, payment shall recommence at a rate of 100% of the minimum royalty and shall continue being made as per the quarterly schedule.


Minerales has also granted to Avino the exclusive right to purchase a 100% interest in the concession at any time during the term of the Agreement (or any renewal thereof), upon payment of US$8 million within 15 days of Avino's notice of election to acquire the Property. The purchase would be completed under a separate purchase agreement for the legal transfer of the concession. This agreement replaces all other previous agreements.

During the month of May of each year, Avino must file assessment work made on each concession for the immediately preceding calendar year. During the months of January and July of each year, Avino must pay in advance the mining taxes which are based on the surface of the concession and the number of years that have elapsed since it was issued.

Consistent with the mining regulations of Mexico, cadastral surveys have been carried out for all the listed mineral concessions as part of the field staking prior to recording (Slim 2005d). It is believed that all concessions are current and up to date. Mineral concessions in Mexico do not include surface rights. Avino has entered into agreements with communal land owners (Ejidos) of San Jos de Avino, for the temporary occupation and surface rights of the concessions.

A current title opinion dated April 4, 2012, has been prepared by Juan Manuel Gonzlez Olguin of the Mexican law firm Bufete Gonzlez Olguin SC. Based on the review of legal opinion, issued title certificates and the unhindered residence on the Property, Tetra Tech has verified that Avino owns the concessions through its Mexican subsidiary company, CMMA, and that there is no indication of any encumbrances at the site. Furthermore, the legal document prepared by Jess Bermdez Fernndez, dated February 18, 2012, delineating the terms of the agreement on the La Platosa concession has been sourced for information.
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5.0
ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY
5.1
Topography, Elevation and Vegetation


The average elevation of the Property is approximately 2,200masl.Local relief is estimated to be roughly 100m ranging from the bottom bench of the tailings to the top of the open pit.
5.2
Accessibility and Local Resources


The Property is easily accessible by road and is an important part of the local community from which skilled workers are available. Access is provided by Highway 40, a four-lane highway leading from Durango, past the airport and on to the city of Torreon in Coahuila. Successive turn-offs for the Property are at Francisco I Madero, Ignacio Zaragoza, and San Jos de Avino (Slim 2005d). The Avino mineral concessions are covered by a network of dirt roads which provide easy transport access between all areas of interest on the Property and the mill at the main Avino Mine (Gunning 2009).

The nearest major city is Durango, with a population of approximately 465,000. Durango is a major mining center in Mexico where experienced labour and services can be obtained. The two towns nearest the mine are Pnuco de Coronado and San Jos de Avino, where the majority of the employees lived while working at the mine when it was in operation. Pnuco de Coronado has a population of approximately 12,000, and San Jos de Avino is a small center with a population of less than 1,000.
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5.3
Climate and length of Operating Season


The climate is temperate and semi-arid. In the region, the mean annual rainfall is 580.6 mm and the average annual temperature is 16.9C. July and January average temperatures are 21.8C and 11.3C, respectively (www.worldclimate.com Durango). The majority of the rainfall occurs between June and September. In the winter months, frost can occur.
5.4
Infrastructure
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6.0
HISTORY
6.1
Avino Mine, 1555-1968


The Avino deposit was originally discovered around 1555 by the Spanish conquistador, Don Francisco de Ibarra. In 1562, Francisco de Ibarra, was appointed governor of the newly formed province of Nueva Vizcaya, in the Viceroyalty of Nueva Espaa (New Spain) and, in 1563, founded the town of Durango. Francisco de Ibarra led several expeditions in search of silver deposits in the region and is recognized as having established Minas de Avino, present day Avino Mine; San Martn, Durango; and Pnuco, Sinaloa. Mining operations at the Avino Mine are said to have commenced in 1562-1563 and have been in production until the early 1900s. Operations at the Avino Mine continued up to the onset of the War of Independence (1810) when operations were interrupted but continued through to the early 1900s.

In 1880, the mines were taken over by Avino Mines Ltd., a company controlled by American and English interests. With aid of new industrial technology the Avino mine developed into a more efficient mining operation. By 1908, the Avino Mine was considered one of the largest open pit mines in the world and equipped with one of the largest lixification smelters (Gallegos 1960; Bannon 1970; VSE 1977; Slim 2005d).

During the outbreak of the Mexican Revolution in 1910, proceeds from the mine supplied funds to the revolutionary forces. Since much of the fighting occurred in and around Durango and the risk posed by brigands hiding in the mountains was high, the mine was abandoned in 1912.

Between 1912 and 1968, the mine was worked intermittently on a very small scale (Avino Annual Report 1980). There is no known historical record of production from the Avino Mine during this period.
6.1.1
San Gonzalo Deposit


The history of the San Gonzalo deposit is not well known. Shallow workings from an old mine are present in the San Gonzalo vein, and consist of small underground workings which were originally accessed by a five-level vertical shaft. These workings were sampled by M. Evans in 1954. The workings are accessible through a raise that was driven in 2012 which is being used for ventilation. No attempts have been made to duplicate the results of the 1954 sampling. The limits of past workings have been taken from old maps but are assumed to be reasonably accurate (Gunning 2009).
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7.0
GEOLOGICAL SETTING AND MINERALIZATION
7.1
Regional Geology


The Property Is located within the Sierra de Gamon, on the east flank of the Sierra Madre Occidental. The area is a geological window into the Lower Volcanic series and consists mainly of volcanic flows, sills, and tuffaceous layers of andesite, rhyolite, and trachyte. Individual rock units typically vary from 300 to 800 m in thickness. Andesitic rocks outcrop over most of the region with other rock types occurring more sparsely to the north (Slim 2005d).

A large monzonitic intrusion is observed in the region in the form of dykes and small stocks, which appear to be linked to the onset of the Avino vein mineralization. Other post-mineralization dykes of intermediate to felsic composition outcrop in various areas and appear to cause minor structural displacements. A number of thin mafic sills are also found in various parts of the region and are related to recent volcanism.

Higher areas of the Sierra Madre Occidental surrounding the mine are composed of rhyolites and ignimbrites of the Upper Volcanic Series, with thicknesses approaching 1,500 m.

The Avino district has been affected by a number of tectonic events, some possibly related to the Laramide orogenic event. Other tectonic events in the region appear to be associated with later igneous events, both extrusive and intrusive, causing the formation of various systems of pre-mineralization faulting. These fault systems usually produced normal displacement of the pre-existing rocks, and generally strike northwest-southeast. Additional normal fault systems are also observed in the region, striking northeast-southwest and dipping towards the south.

Post-mineralization faulting has produced the present rough topography. One of the most significant regional features of the district is the Avino Fault which strikes northwest 20 southeast and dips southeast and appears to cut off the mineralization, juxtaposing the Upper and Lower Volcanic series.
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7.2
Property Geology and Mineralization


The Avino concession is located within a 12km (north-south) by 8.5km (east-west) caldera.The Property contains numerous low-sulphidation epithermal veins, breccias, stockwork, and silicified zones that grade into a near porphyry environment, particularly in the Avino Mine area.The caldera has been uplifted by regional north-trending block faulting (a graben structure), exposing a window of andesitic pyroclastic rocks of the lower volcanic sequence within the caldera.The lower volcanic sequence is overlain by the upper volcanic sequence, consisting of rhyolite to trachyte flows and extensive ignimbrites and intruded by monzonite bodies.The basal andesite-bearing conglomerate and underlying Paleozoic basement sedimentary rocks (consisting of shales, sandstones and conglomerates) have been identified on the Avino concession in the south-central portion of the caldera, covering the Guadalope, Santiago, San Jorge, the San Gonzalo Trend, Malinche, Porterito and Yolanda areas.A northerly trending felsic dyke, possibly a feeder to the upper volcanic sequence, transects the Property and many of the veins.The Aguila Mexicana low temperature vein system, with significant widths but overall low precious metal values, trends north-northwest at a similar orientation to the felsic dyke and with similar continuity across the Property.The two structures may occur along deep crustal faults that controlled volcanism and mineralization, with the felsic dyke structure controlling the emplacement of the Avino, Nuestra Senora and El Fuerte-Potosina volcanic centres and the Aguila Mexicana structure controlling the Cerro San Jose and El Fuerte-Potosina volcanic centres (Paulter 2006).

Silver- and gold-bearing veins cross-cut the various lithologies and are generally oriented north northwest-south southeast and northwest-southeast (Figure 7.1 and Figure 7.2).The rocks have been weathered and leached in the upper sections, as a result of contact with atmospheric waters; the oxide tailings material (Section 7.2.3) is primarily from this source, whereas the sulphide tailings are predominantly from material sourced at depth, below the leached zone.In Mexico, these types of deposits can have large lateral extents, but can be limited in the vertical continuity of grades.

In the oxide zone, mineralization is primarily hosted by the minerals argentite, bromargyrite, chalcopyrite, chalcocite, galena, sphalerite, bornite, native silver, gold, and native copper.Other minerals present in mineralized areas, but not hosting the metals of interest, include hematite, chlorite, quartz, barite, pyrite, arsenopyrite and pyrrhotite.Malachite, anglesite and limonite are common in the quartz zones of the weathered parts of the oxide material.
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Figure 7.1
General Map of Property Geology
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Figure 7.2
Plan Map of San Gonzalo Veins and Other Nearby Veins
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7.2.1
Avino Vein


The Avino vein is 1.6 km long and 60 m wide on the surface. To date, the deepest level accessed was at the 2,070 m level (330 m below surface).

The Avino vein is the most striking and important example of the epithermal mineralization of the district whose structures are normally weathered and leached in their upper section as a result of contact with atmospheric waters producing a band of oxide minerals and zones of supergene enrichment to a depth of about 70 m.

In the oxide portion of the Avino vein, the common minerals encountered include hematite, limonite, anglesite and copper carbonate in white or green, somewhat chloritized, quartz zones. The common primary and secondary minerals encountered are argentite, bromargyrite, chalcopyrite, chalcocite, galena sphalerite, bornite, native silver, free gold, and native copper. Other minerals present in mineralized areas include quartz, pyrite, chlorite, barite, arsenopyrite, pyrrhotite and specularite.

Higher silver values, which appear to be found at or near the surface, are reported to decrease overall with depth, except at vein intersections where higher values are more persistent. The same can be said for gold, although the higher values start just below the onset of silver mineralization, at or near the surface. In contrast, higher copper values coincide with vein intersections and may increase with depth.

The Avino vein has been followed longitudinally for more than 1,300 m and vertically for more than 600 m. It strikes north 66 east with an east-west splay, and dips to the south and southeast at 60 to 70. Steeply dipping, acicular high grade zones within the vein and stock-work zones are frequently found in the upper part of the vein, as well as at its intersections with a number of lateral veins. An example of a higher grade area of mineralization encountered with major lateral vein intersecting the Avino was the El Hundido, which exceeded 40 m in thickness. In the lower areas of the vein and mine, mineralized cross-veins, branch-veins, and stockwork zones have been found in the footwall at San Luis and at El Hundido, and are assumed to persist with depth. The hanging wall of the Avino vein is andesite, while the footwall is a monzonite intrusive with andesite sections. A post-mineralization fault parallel with the vein occurs in the hanging wall at a distance of several metres in the area of San Luis, while in the central part of El Hundido, this fault is located at the contact with the vein over a distance of about 300 m, up to the area of Santa Elena and San Antonio. From that point, and proceeding toward the El Chirumbo Mine, this fault cuts the vein between the face at San Carlos to the face exposed at the underground ramp. The fault then enters the footwall where it remains until a point about 30 m east of the west face of the Chirumbo area, producing a downward displacement of the vein of between 50 to 100 m.

At Chirumbo, the fault largely replaces the vein due to strong leaching by post-mineralization circulating of water in the gouge. On the east face at Chirumbo, the fault again enters the hanging wall; in this zone the vein is composed of branches and stockwork and to the east of this point the fault crosses the vein numerous times.
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The deposit is epithermal and made up of veins and dependent stockwork structures, mainly in the hanging wall and often associated with vein intersections. Four vein systems have been described which, in decreasing order of importance, are:
system striking east-west, dipping south at 60 to 70, including the Avino Vein and its possible extension in the Cerro de San Jose
system striking north 60 to 70 west, dipping 60 to 80 southwest, comprising the following important veins: El Trompo, San Juventino, San Jorge, Platosa, Los Reyes, Potosina, El Fuerte, and Conejo
system striking north 20 to 30 west, dipping between 60 to 80 to either the southwest or northeast, comprising the following significant veins: San Gonzalo, Aguila Mexicana, and La Calcita, as well as the Stockwork La Potosina, and the Stockwork El Fuerte
systems striking north 60 to 80 east, dipping 60 to 80 southeast, comprising the following veins: Santiago, Retana, Nuestra Senora, and San Pedro and San Pablo.
Propylitic alteration is most common in andesite, giving the andesite a greenish tint.
Argillaceous alteration appears mainly in the upper parts of the veins and manifests itself as a whitening of the country rock due to alunite and montmorillonite clays.
Silicification, chloritization, and pyritization alteration is observed in the hanging wall and footwall, and is more prominent closer to the vein.
7.2.2
San Gonzalo Vein


The San Gonzalo vein is located approximately 1.4 km northeast of the eastern modelled extent of the Avino vein. The San Gonzalo vein system constitutes a strongly developed vein system over 25 m wide, trending 300 to 325/80 northeast to 77 south. It is characterized by banded textures and open-space filling. The main vein has an average width of 2 m, but the silica-pyrite or iron oxide-sericite alteration with additional stock working extends across 300 m, south of the main San Gonzalo vein to the Los Angeles vein. The San Gonzalo vein appears to be related to the Los Angeles vein and the two are separated by a suspect offset fault (Figure 7.1 and Figure 7.2). The San Gonzalo is a typical narrow vein precious metal deposit with some erratic values and extends approximately 2 km to the northwest to the Santa Ana-Malinche area (Gunning 2009).
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The Cerro San Jose-La Estella-San Gonzalo Cerro San Jose represents a distinct hydrothermal centre with similar characteristics to the Avino system which include the following (Paulter 2006):
occur on a topographic high
strong to intense silicification and brecciation
easterly trending stockwork system similar to the trend of the Avino vein
similar temperatures of formation to Avino
presence of an intersecting northwesterly trending vein system (la Estella at San Jose and San Juventino at Avino)
emplacement along a northerly trending, deep crustal fault zone (defined by the Aguila Mexicana Vein at Cerro San Jose and the felsic dyke at Avino).
7.2.3
Oxide and Sulphide Tailings


The Avino tailings dam is located approximately 500 m west-southwest of the main shaft to the old underground workings and 2.5 km southwest of the San Gonzalo vein. An orthogonal view of the tailings dam is shown in Figure 7.3.
Lower oxide bench (referred to as Phase 1.1 in Section 14.3).
Upper oxide bench (referred to as Phase 1.2 in Section 14.3).
Upper bench or sulphide bench (referred to as Phase 2 in Sections 14.3 and 14.4).


The oxide tailings are primarily derived from weathered and oxidized rocks close to the surface on the Property, whereas the sulphide tailings are predominantly derived from material sourced at depth from the underground workings, below the weathered/leached zone. At this time, it is not clear what the real nature of the chemical difference between the two is, but they are distinctly different in colour.

The oxide tailings (both the upper and lower benches) have been analyzed in greater details than the sulphide tailings, and are included in the current mineral resource for the oxide tailings (Section 14.3). The sulphide tailings, in the absence of any definitive sampling data penetrating the depth of the pile, are an exploration target at best (Section 14.4). Figure 7.4 shows a photograph of the tailings dam illustrating the clear division between the three benches.
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Figure 7.3
Orthogonal View of Tailings Pile (Looking Roughly to the North)
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Figure 7.4
Photograph of the Tailings Deposit (Viewed from the Northeast)
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8.0
DEPOSIT TYPES


Regionally, the Property is situated within a 12km by 8.5km caldera that hosts numerous low- to intermediate-sulphidation silver-gold epithermal veins, breccias, stockwork and silicified zones, grading into a near porphyry environment in the Avino Mine area.

The historic mining on the Property was on the Avino vein, a silver-gold-copper rich epithermal vein. The San Gonzalo vein, however, has a much lower copper content than the Avino vein and is more equivalent to other silverlead-zinc deposits of the Sierra Madres.

Low-sulphidation vein systems are commonly characterized by low concentrations of sulphide minerals, alteration mineralogy dominated by quartz-adularia-sericite, and a lack of extensive wall-rock alteration. Conversely, high-sulphidation vein systems are commonly characterized by sulphur saturation leading to the presence of native sulphur and sulphide minerals, quartz-alunite alteration, and extensive wall-rock alteration. The Mexican silver deposits are usually within the intermediate sulphidation range, rather than either of the end member classifications.

In Mexico, and particularly within the Mexican Silver Belt, these types of deposits can have large lateral extents, but may be limited vertically. There are many silver-gold mines in Mexico, some of which form large mining districts, and others which exploit multiple veins over limited vertical horizons which are sometimes only 100 m in depth (Gunning 2009).

On the Property, the oxide tailings have been predominantly sourced from earlier open pit operations and the sulphide tailings have been predominantly sourced from later underground workings.
Avino Silver & Gold Mines Ltd.
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9.0
EXPLORATION
9.1
Early Exploration (Prior to Mine Closure), 1968 to 2001


Exploration on the Property has been ongoing since before production commenced in 1976, and the majority of the work focused on the main Avino vein and surrounding area. The following is a summary of significant exploration work conducted either by Avino, or on behalf of Avino, until the mine closed in 2001.

Pre-production exploration was carried out by CMMA and others, and covered 2,500 m of drifting and cross-cuts, as well as 8,000 m of surface and underground diamond drilling. Extensive rehabilitation was completed involving Selco, including connecting three of the old possibly pre-1900 underground mine workings.

In 1970, a contract was signed with Selco, who spent more than US$1 million in exploration and feasibility studies before returning the Property back to CMMA in 1972, reportedly because of low metal prices. The majority of the documentation examined covered feasibility work and was related to investigations of old underground workings that were likely developed in the late 1800s. A contract was signed in October 1973 with S.G.L. Ltd. and Sheridan Geophysics Ltd., under which a new 500 t/d plant was completed in May 1974.

Since 1992 exploration in/for the mine has been limited to traditional underground mine development with associated sampling and planning for production feed. In the late 1990s it appears that development was not kept up as company monthly reports showed decreasing historical reserve allocations for production and mill feed.

The only recorded property exploration, apart from limited prospecting, is documented in the 1993 report by Servicios Administratos Luismin, SA de CV, the engineering branch of Ca Minera de San Luis Exploration. The study reported on detailed analysis and sampling of the then known showings on the Property with the emphasis on the Avino vein and Potosina/El Fuerte area. The extensive underground sampling programme carried out by Luismin provided later direction for underground mining. The report made recommendations for follow-up for drilling and underground development for the main Avino vein, as well as trenching and drilling recommendations for the Potosina/El Fuerte area. It is believed that these recommendations were never implemented for the prospective areas. Additionally, the report included a property-scale geological mapping and lithogeochemical sampling programme which was contoured and coloured for gold, silver, copper, lead, zinc, arsenic, antimony and mercury.
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All mineralization, with the exception of the Nuestra Senora and Potosina/El Fuerte area radiate outwards in a west to north-west direction from the Cerro San Jose. The Cerro San Jose is a silicified and partly hornfelsed body of volcanic rock probably overlying an intrusive stock, which could have been the source of most mineralization on the Property.
Mineralization in all radiating structures is described as being strongest 2 to 3 km from Cerro San Jose. This resembles many of the gold deposits in Nevada where the source of mineralization is a near surface acid-intrusive but with mineralized bodies lying 1 to 5 km away along high angle faults.
The two strongest and widest structures appear to be the Avino and Aguila Mexicana veins.
The Avino vein has three main mineralized zonesSan Luis, Elena Tolosa (La Gloria/Hundido) and Chirumbo areaswhich rake to the west and are open at depth. While silver values decrease with depth, gold appears to increase.
The existence of other mineralization cutting the Cerro San Jose mineralization in the Nuestra Senora and Potosina/El Fuerta areas could offer the potential for bulk mineable stockwork zones.


Assay values from outcrop sampling of surface-mapped veins towards the San Jose hill ranged from lows of 2 g/t silver and trace gold over a true thicknesses from 0.1 to 2.3 m up to a high of 755 g/t silver with a corresponding 1.5 g/t gold over 0.45 m.

No systematic sampling, trenching or drilling on either the outcrops or the veins is known to have occurred during the program undertaken in 1993.
9.2
Recent Exploration (Post Mine Closure), 2001 to Present


Since mine closure in 2001, Avino has intermittently conducted exploration work on the Property, with the intention of expanding and better defining known areas of mineralization. Historic near-to-surface mining activities are being relied upon for guidance, and modern techniques are being employed to integrate, manage and interpret results. Included in the list of exploration activities is an induced polarization (IP) geophysical survey, 1,500 soil samples, satellite imagery, mapping, trenching, tailings investigations, bulk sampling, and underground channel sampling.
9.2.1
Tailings Investigations (Oxides), 2003 and 2004


Two specific mineralogical assessments were conducted in 2003 and 2004 on samples from the tailings on the Property. The purpose of the program was to provide data for independent investigation of the 1990 drilling results on the oxide tailings (discussed in Section 10.0) in terms of verifying assay grades and volumes, as well to examine the metallurgical characteristics of the material. The results and implications of these findings are discussed further in Section 13.0. The 2004 sample composites assays are given in Table 9.1 and sample locations are illustrated in Figure 9.1, relative to the drill fences of the 1990/1991 drillholes.
Avino Silver & Gold Mines Ltd.
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Technical Report on the Avino Property, Durango, Mexico
Table 9.1
2004 Sample Composites Assays
Area
Composite
No.
Ag (ppm)
Multi/ICP
Au (g/t)
FA/AA
Lower Bench
1
82.03
0.34
3
99.80
0.33
5
134.08
0.53
6
122.18
0.28
7
103.88
0.31
8
96.75
0.36
9
105.28
0.33
10
87.73
0.26
Middle Bench
1
83.40
0.48
2
105.33
0.59
3
78.83
0.42
4
103.05
0.59
5
72.55
0.40
6
77.70
0.61
Note: ICP inductively coupled plasma
FA fire assay
AA atomic absorption
Figure 9.1
Plan View Location Map of Samples from Oxide Tailings
Avino Silver & Gold Mines Ltd.
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Technical Report on the Avino Property, Durango, Mexico


The 2004 tailings field-work was under the direction of MineStart and excavation of the sample pits was under contract to Desarrollos Rod Construcciones of Durango. Local casual labour were hired as needed.

Given the hydraulic deposition of the tailings, four important factors required examination: anomaly characteristics of the samples and total population, assay comparison by fence, examination of downstream decrease in assays and factors arising from the downstream construction.

Comparison of the 2004 assays with those from 1990 show consistency in assay values and provide confidence in the 1990 sampling and assaying program.

The preliminary investigations in 2003 showed the need for a sampling of the oxide tailings to validate the assay results of the 1990 drilling and to carry out metallurgical characterization, the latter requiring large samples. In deciding on test pitting, the costs, timing and sample size were important. Backhoes were available locally and could be mobilized within a few days whereas drills would have to be brought in from up to 500 km away, for minimum contracts in excess of the project needs and with limited immediate availability. Backhoe sampling was chosen.

The sampling exercise carried out in 2004, using shallow (4 m deep) backhoe trenches and hand-dug pits, represented a local corroboration of the previous sampling but cannot be considered to constitute a representative random sampling of the oxide tailings for the following reasons:
The positions of the sampling pits and trenches were sketched on previous maps but were not surveyed, unlike the drillhole collars from the 1990 campaign.
Full sections through the tailings were not obtained and access was limited to the eastern portion of the oxide tailings; thus the sampling is vertically and laterally biased to represent only the topmost 4m of the easternmost oxide tailings.


The trench sampling material (Z-series) from the 1993 campaign is also likely to be non-representative as samples were taken in the surficial zone in the vicinity of the middle bench wall of the tailings heap, where cycloning of the material to aid the construction of the wall will have produced significantly coarser material than in the rest of the tailings deposit. Furthermore, these trench samplings also do not cover the full thickness of the upper (second) phase of the oxide tailings, so they cannot be considered fully representative of material, even on a local scale.

Consequently, it was decided to use only the drillhole assay data (excluding the Z-series trenches) from the 1990 campaign for the oxide tailings resource estimate (Section 14.2), as it represents unbiased vertical profiles through the entire oxide tailings and has positional control.
Avino Silver & Gold Mines Ltd.
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Technical Report on the Avino Property, Durango, Mexico
9.2.2
Tailings Sampling (Sulphides), 2005


Some sampling was carried out in 2005 by means of hand-dug pits on the upper bench of sulphide tailings. The silver and gold values generally ranged from 40.0 to 100.0 g/t and 0.3 to 0.6 g/t, respectively. While these values give a general idea of the potential grade of the sulphide tailings, they are not considered to be representative of the sulphide tailings, even at a local scale.
9.2.3
Bulk Sample Program of San Gonzalo Vein, 2011


Avino completed a 10,000 t bulk sample program at the San Gonzalo deposit following a comprehensive review of the data and discussions with Tetra Tech. The bulk sample feed grade was 261 g/t silver and 0.9 g/t gold. Silver and gold recoveries were stated to be 76% and 59%, respectively, and 232 dry tonnes of flotation concentrate were produced. Results are summarized in Table 9.2.
Table 9.2
San Gonzalo Bulk Sample
Weight
(t)
Assay (g/t)
Contents (kg)
Contents (oz)
Recovery (%)
Au
Ag
Au
Ag
Au
Ag
Au
Ag
Feed
10,519*
0.9
261
9.35
2,746.75
300.9
88,311.70
100
100
Concentrate
232
23.8*
8,998*
5.52
2,087.53
177.5
67,116.90
59
76
Tail
10,287
0.4
64
3.83
659.22
123.4
21,194.80
41
24
Source: Avino 2011
Note:
*These figures have been reconciled to the weighed feed tonnage and the final concentrate assays.They also have been rounded for clarity.
9.2.4
Underground Channel Sampling of San Gonzalo and Angelica Veins, 2010-Present


Underground channel sampling began in 2010 and has continued to the present. Channel sampling is currently being conducted on the San Gonzalo and Angelica veins, coinciding with drift development. Results are current to March 19, 2013 and include results from levels 1 through 4 of the San Gonzalo mine, as well as ramps and off-shoots into the Angelica vein.

Table 9.3 summarizes the number and lengths of channels by level. Table 9.4 summarizes the assay results by level. Figure 9.2 shows the location of all channels, colour coded by grade, included in the current resource estimate (Section 14.2), within the San Gonzalo vein (green solid) and Angelica vein (purple solid) wireframes.
Avino Silver & Gold Mines Ltd.
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Technical Report on the Avino Property, Durango, Mexico
Table 9.3
Summary of San Gonzalo and Angelica Channel Samples, By Level
Number of
Channels
Strike
Length of
Vein Covered
(m)
Total
Channel
Length
(m)*
Average
Channel
Length
(m)
Max
Channel
Length
(m)
Level 1
120
225
82.01
0.68
1.51
Level 2
223
285
585.54
2.63
10.77
Level 2 Ramp
43
75
58.48
1.36
1.75
Level 3
217
280
618.99
2.85
6.85
Level 4
265
400
673.61
2.54
5.60
Total
868
1,265
2,018.66
-
-
Table 9.4
Summary of San Gonzalo and Angelica Channel Assay Results, By Level
Ag
Au
Cu
Pb
Zn
Level 1
Number of Assays
433
433
433
433
433
Maximum Grade (ppm)
3,170.0
10.86
3,263
14,500
13,400
Mean Grade (ppm)
171.2
0.44
207
1,348
1,088
Level 2
Number of Assays
861
861
861
861
861
Maximum Grade (ppm)
5,522.9
9.88
7,160
117,200
106,000
Mean Grade (ppm)
170.0
0.57
426
3,247
5,255
Level 2 Ramp
Number of Assays
115
115
115
115
115
Maximum Grade (ppm)
5,962.0
13.95
6,141
22,900
12,300
Mean Grade (ppm)
285.9
1.09
453
3,738
1,176
Level 3
Number of Assays
726
726
726
726
726
Maximum Grade (ppm)
5,348.4
9.47
41,000
89,000
138,600
Mean Grade (ppm)
141.9
0.49
595
2,265
4,993
Level 4
Number of Assays
1,025
1,025
1,025
1,025
1,025
Maximum Grade (ppm)
14,768.4
185.20
12,300
91,500
154,900
Mean Grade (ppm)
395.8
1.90
542
4,276
7,997
All
Number of Assays
3,160
3,160
3,160
3,160
3,160
Maximum Grade (ppm)
14,768.4
185.20
41,000
117,200
154,900
Mean Grade (ppm)
238.3
0.97
476
3,092
5,355
Avino Silver & Gold Mines Ltd.
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Figure 9.2
Channel Samples, Colour Coded by Grade, Within the San Gonzalo and Angelica Vein Wireframes
Note:
Looking south southwest.
Green solid = San Gonzalo vein; purple solid = Angelica vein.Assay colours indicated by cutoffs in legend.Easting and elevation values in metres.
Avino Silver & Gold Mines Ltd.
9-7
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico
10.0
DRILLING


Drilling activities performed by Avino since acquisition of the Property are summarized below. Drillhole assay results have been previously reported (except ET-12-07 to ET-12-09; Appendix A) by Gunning (2009) and Tetra Tech (2012) and are not disclosed here.
10.1
Early Drilling (Prior to Mine Closure), 1968 to 2001
10.1.1
Avino Vein


Between 1968 and 2001, at least 25 diamond drillholes, ranging in length from 132.20 to 575.20 m, are reported to have been drilled from surface into the Avino vein. Included in this total are 10 holes that were drilled by Selco in 1970 when they were re-habilitating some of the old underground workings to provide access for sampling (Slim 2005d). No further information on these drillholes was available to Tetra Tech and they are not included in the resource estimate for the Avino vein (Section 14.1).
10.1.2
Oxide Tailings, 1990 to 1991


Between November 10 and December 5, 1990 and March 8 and May 30, 1991, Avino completed six trenches and 28 vertical drillholes in the tailings (Table 10.1) along 7 fences at a spacing of roughly 50 m by 50 m (Figure 10.1) (Benitez Sanchez 1991). Drilling was completed transversely to the drainage pattern of the tailings. Cut at 1 m vertical increments, 461 samples were assayed for silver and gold at the mine assay lab and occasional moisture contents were reported. Assay results from these drillholes have been previously reported (Tetra Tech 2012). Although the Z-series trenches are included in Table 10.1 and Figure 10.1, they are not included in the oxide tailings resource estimate (Section 14.3) as they are not considered representative of the tailings at a local scale (see Section 9.2.1).
Table 10.1
Summary of 1990/1991 Holes
Hole
ID
Easting
(m)
Northing
(m)
Elevation
(m)
Assay
Length
(m)
Measured
Length
(m)
A1
570205
2712340
2,204
5.0
5.00
A2
570184
2712306
2,203
7.0
7.25
A3
570192
2712267
2,203
8.0
8.00
A4
570167
2712236
2,203
9.0
9.00
A5
570175
2712197
2,203
15.0
16.25
A6
570152
2712167
2,202
18.0
18.00
table continues
Avino Silver & Gold Mines Ltd.
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Hole
ID
Easting
(m)
Northing
(m)
Elevation
(m)
Assay
Length
(m)
Measured
Length
(m)
A7
570159
2712128
2,201
16.0
16.00
A8
570149
2712094
2,200
8.0
8.00
Z1*
570197
2712411
2,218
9.0
9.50
Z2*
570176
2712365
2,218
16.0
16.00
Z3*
570165
2712317
2,217
13.0
13.25
Z4*
570153
2712269
2,217
13.0
13.50
Z5*
570142
2712221
2,216
13.0
13.00
Z6*
570135
2712175
2,215
14.0
14.00
B1
570132
2712365
2,217
10.0
10.00
B2
570114
2712318
2,217
19.0
19.25
B3
570101
2712268
2,216
26.0
26.75
B4
570079
2712207
2,216
23.5
23.50
B5
570082
2712140
2,214
18.0
18.00
C1
570085
2712383
2,218
8.5
8.75
C3
570077
2712354
2,217
15.0
15.00
C4
570049
2712250
2,216
24.0
24.00
C5
570028
2712164
2,216
14.0
14.00
C6
570017
2712117
2,216
10.0
10.00
D1
570029
2712373
2,218
13.0
13.00
D2
570018
2712329
2,217
19.0
19.25
D3
570003
2712273
2,218
19.5
19.50
D4
569961
2712167
2,216
6.0
6.00
E1
569977
2712369
2,217
13.0
13.25
E2
569960
2712311
2,216
18.5
18.50
E3
569952
2712267
2,216
12.0
12.00
F1
569936
2712401
2,216
18.5
18.50
F2
569926
2712364
2,216
16.0
16.00
F3
569915
2712324
2,216
15.0
15.00
Avino Silver & Gold Mines Ltd.
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Technical Report on the Avino Property, Durango, Mexico
Figure 10.1
Plan View of 1990 Hole Locations
Avino Silver & Gold Mines Ltd.
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Technical Report on the Avino Property, Durango, Mexico
10.2
Recent Drilling (Post Mine Closure), 2001 to Present


A total of 98 drillholes have been completed on the Avino and San Gonzalo veins, totalling 26,147.32 m. Additional exploration holes have been drilled elsewhere on the Property, but those drilling results are not considered material. Most holes were surveyed downhole using a Tropari single-shot magnetic instrument. Of those holes for which downhole surveys were completed, the majority contain three or fewer measurements, typically at the collar and near the end of hole, and sometimes part-way down the hole. Many holes were not surveyed to within 10 m of the end of the hole.
10.2.1
Avino Vein (Including ET Zone) and Nearby Veins


Since 2001, Avino has drilled 34 holes below Level 12, where mining ceased, for a total of 11,523.2 m of drilling. Drilling has targeted the ET Zone in particular. There were 5 holes completed in 2006 (2,166.85 m), 12 holes in 2007 (3,906.5 m), 8 holes in 2008 (2,186.7), and 9 holes in 2012 (3,263.15 m). No drilling has been completed on the Avino Vein since 2012. Collar coordinates for all drillholes included in the Avino vein resource estimate (Section 14.1) are provided in Table 10.2. Assay results from all drillholes up to and including ET-12-06 have been previously reported (Tetra Tech 2012). Assay results from drillholes ET-12-07 to ET-12-09 are provided in Appendix A. A location map of Avino vein drillholes is provided in Figure 10.2.

Tecmin Servicios, S.A. de C.V., was contracted for the 2007 and 2008 drilling programs at the ET Zone of the Avino vein. Since the Avino deposit strikes approximately east-west and dips at 60 to 70 to the south, holes are generally oriented from south to north at various bearings and dip angles in order to intersect the structure at a target depth. Holes were drilled using Avino's Longyear 44 core rig at thin wall NQ diameter.
Table 10.2
Drillholes Completed from 2006 to 2012 on the Avino Vein
Hole
ID
Azimuth
()
Dip
()
Depth
(m)
Easting
(m)
Northing
(m)
Elevation
(m)
CH-06-03
338
-50
453.75
571013
2712796
2,208
ET-06-01
337
-55
431.20
570271
2712262
2,187
ET-06-02
340
-50
416.70
570337
2712309
2,190
ET-06-03
339
-48
421.15
570457
2712361
2,194
ET-06-04
340
-50
444.05
570501
2712468
2,215
ET-07-01
001
-69
298.60
570176
2712453
2,222
ET-07-02
358
-75
311.90
570206
2712467
2,224
ET-07-03
336
-71
349.50
570344
2712498
2,226
ET-07-04
331
-56
318.70
570440
2712511
2,226
ET-07-05
333
-65.5
351.50
570440
2712510
2,226
ET-07-06
336
-55
320.05
570520
2712524
2,225
ET-07-07
330
-56.5
304.85
570585
2712569
2,230
ET-07-08
346
-69
399.70
570584
2712569
2,231
table continues
Avino Silver & Gold Mines Ltd.
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Hole
ID
Azimuth
()
Dip
()
Depth
(m)
Easting
(m)
Northing
(m)
Elevation
(m)
ET-07-09
336
-62
328.55
570629
2712604
2,235
ET-07-10
338
-62
308.65
570645
2712650
2,245
ET-07-11
337
-69
329.80
570682
2712654
2,241
ET-07-12
337
-48
284.70
570735
2712654
2,234
ET-08-01
329
-45
221.45
570807
2712712
2,236
ET-08-02
330
-54
234.50
570341
2712549
2,244
ET-08-03
333
-64
265.10
570341
2712549
2,244
ET-08-04
337
-65
358.65
570579
2712568
2,231
ET-08-05
338
-66
371.10
570658
2712629
2,240
ET-08-06
338
-59
292.45
570676
2712654
2,243
ET-08-07
343
-70
174.40
570747
2712656
2,234
ET-08-08
344
-45
269.05
570906
2712766
2,227
ET-12-01
332
-62
288.15
570354
2712501
2,226
ET-12-02
335
-53
360.90
570507
2712472
2,214
ET-12-03
335
-61
367.75
570507
2712471
2,214
ET-12-04
335
-64
373.75
570544
2712497
2,216
ET-12-05
336
-62
369.20
570566
2712508
2,218
ET-12-06
336
-70
396.10
570589
2712523
2,219
ET-12-07
336
-64
327.60
570678
2712594
2,227
ET-12-08
336
-72
384.35
570678
2712594
2,227
ET-12-09
336
-72
395.35
570646
2712555
2,222
10.2.2
San Gonzalo and Nearby Veins


At San Gonzalo, Avino drilled 40 holes in 2007 (9,222.9 m), 6 in 2008 (1,782.65 m), and 18 in 2011 (3,618.57 m), for a total of 64 drillholes and 14,624.12 m of drilling. No drilling has been completed on the San Gonzalo vein since 2011. All holes were of thin wall NQ size core diameter and were completed using Avinos Longyear 44 core rig. Additional holes also explored the nearby Guadalupe, San Juventino, San Lucerno, Mercedes, San Jorge, and Yolanda veins.

According to Gunning (2009), the collars for 2007 and 2008 drillholes were marked by concrete monuments and the collars have been surveyed. A check of the coordinates with a handheld global positioning system (GPS) revealed a possible 10 m constant error which may simply mean that all of the mine coordinates are not precisely Universal Transverse Mercator (UTM). However, this could also indicate the existence of a small surveying error on the Property.

In 2011, a total of 69 holes totalling 9,943 m were drilled principally in the following locations: San Gonzalo (18 holes), La Potosina (9 holes), Guadalupe (23 holes), San Juventino (3 holes), San Lucero (5 holes), Mercedes (1 hole), San Jorge (3 holes), Yolanda (2 holes). With the exception of the San Gonzalo vein, all of these locations are considered targets for further exploration.
Avino Silver & Gold Mines Ltd.
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Collar coordinates for all drillholes included in the San Gonzalo resource estimate (Section 14.2) are provided in Table 10.3. Assay results from these drillholes have been previously reported (Gunning 2009; Tetra Tech 2012). A location map of drillholes on the San Gonzalo vein is provided in Figure 10.3.
Table 10.3
Drillholes Completed from 2007 to 2011 on the San Gonzalo Vein
Hole
ID
Azimuth
()
Dip
()
Depth
(m)
Easting
(m)
Northing
(m)
Elevation
(m)
SG-07-01
050
-60
386.80
571713
2713982
2297
SG-07-02
038
-48
323.70
571714
2713983
2297
SG-07-03
074
-43
315.00
571714
2713981
2297
SG-07-04
053
-49
312.70
571651
2714059
2276
SG-07-05
059
-69
137.00
571650
2714058
2276
SG-07-06
055
-58
387.20
571650
2714058
2276
SG-07-07
044
-44
281.55
571578
2714117
2281
SG-07-08
043
-55
383.70
571578
2714116
2281
SG-07-09
038
-45
106.60
571677
2714137
2277
SG-07-10
053
-58
162.90
571677
2714136
2277
SG-07-11
015
-49
158.60
571676
2714135
2277
SG-07-12
089
-53
175.45
571678
2714133
2277
SG-07-13
055
-49
160.55
571770
2713993
2315
SG-07-14
054
-53
295.20
571716
2713971
2297
SG-07-15
218
-49
96.20
571689
2714268
2296
SG-07-16
219
-54
99.85
571552
2714354
2285
SG-07-17
252
-55
69.80
571428
2714421
2268
SG-07-18
218
-65
238.05
571765
2714318
2293
SG-07-19
257
-66
344.90
571763
2714320
2293
SG-07-20
215
-67
247.40
571650
2714345
2281
SG-07-21
038
-53
294.00
571713
2713979
2297
SG-07-22
218
-54
232.50
572007
2714128
2343
SG-07-23
216
-70
303.45
572007
2714128
2343
SG-07-24
217
-53
124.40
571969
2714077
2351
SG-07-25
216
-65
190.45
571969
2714078
2351
SG-07-26
216
-69
395.40
572033
2714172
2337
SG-07-27
218
-55
237.75
572078
2714077
2345
SG-07-28
218
-74
319.50
572078
2714078
2345
SG-07-29
221
-43
103.55
572033
2714010
2356
SG-07-30
221
-64
158.40
572034
2714010
2356
SG-07-31
218
-43
71.85
571954
2714056
2352
SG-07-32
223
-70
407.95
572122
2714135
2330
SG-07-33
211
-43
130.60
572069
2714009
2353
SG-07-34
210
-58
183.05
572069
2714010
2353
SG-07-35
211
-68
272.15
572069
2714010
2353
SG-07-36
215
-41
102.15
572050
2713959
2358
table continues
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Hole
ID
Azimuth
()
Dip
()
Depth
(m)
Easting
(m)
Northing
(m)
Elevation
(m)
SG-07-37
219
-53
154.35
572115
2713975
2351
SG-07-38
221
-66.5
214.15
572115
2713975
2351
SG-07-39
220
-73
128.05
572120
2713898
2353
SG-07-40
220
-74
516.05
571899
2714211
2321
SG-08-01
035
-51
210.05
571776
2713974
2314
SG-08-02
215
-57
269.05
571964
2714167
2335
SG-08-03
215
-70
331.95
571964
2714168
2335
SG-08-04
215
-63
269.95
572029
2714121
2343
SG-08-05
035
-55
475.25
571701
2713893
2285
SG-08-06
048
-64
226.40
571679
2714137
2277
SG-11-01
215
-59
100.95
571981
2714009
2357
SG-11-02
215
-63
141.15
571995
2714030
2355
SG-11-03
215
-44
98.45
572020
2713994
2357
SG-11-04
212
-54
176.50
571969
2714079
2351
SG-11-05
040
-43
151.40
571892
2713832
2317
SG-11-06
189
-44
122.32
571732
2714379
2274
SG-11-07
030
-68
74.00
572030
2713946
2358
SG-11-08
037
-67
125.35
572043
2713888
2360
SG-11-09
181
-48
71.10
571585
2714366
2278
SG-11-10
201
-61
78.40
571240
2714538
2235
SG-11-11
201
-61
91.95
571329
2714397
2274
SG-11-12
218
-71
312.15
571811
2714288
2305
SG-11-13
218
-71
345.40
571847
2714258
2310
SG-11-14
209
-61
330.50
571939
2714214
2326
SG-11-15
211
-68
363.45
572030
2714172
2337
SG-11-16
209
-62
334.25
572092
2714173
2331
SG-11-17
210
-70
383.10
571836
2714336
2306
SG-11-18
218
-71
318.15
571765
2714321
2293
10.2.3
Specific Gravity Results


Bulk density samples were analyzed from all 2006-2012 drilling programs on both the Avino and San Gonzalo veins. Analytical procedures are discussed in Section 11.8 and a review of the data and Qualified Person (QP) opinion is discussed in Section 12.2 and 12.5.1, respectively. Table 10.4 summarizes the results of these specific gravity measurements.
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Table 10.4
Summary of Specific Gravity Results
Number of Samples
Average SG
All Rock Types
Average SG - Veins
Average SG Country Rock
All Samples
262
2.64
2.67
2.61
San Gonzalo Vein
152
2.62
2.67
2.59
Avino Vein
110
2.66
2.68
2.64
Avino Silver & Gold Mines Ltd.
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Figure 10.2
Plan View Map Illustrating the Location of Drillholes on the Avino Vein
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Figure 10.3
Plan View Map Illustrating the Location of Drillholes on the San Gonzalo Vein
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11.0
SAMPLE PREPARATION, ANALYSES, AND SECURITY
11.1
Drilling and Trenching of Oxide Tailings, 1990 to 1991


The oxide tailings were sampled prior to institution of NI 43-101 and associated QA/QC requirements, and as such no QA/QC measures were utilized during the 1990-1991 program. As a result, the resource estimate for the oxide tailings in Section 14.3 is all classified as Inferred. Twenty-eight holes were drilled and six trenches completed, from which a total of 461 samples were collecting for assaying. The analyses were completed in the on-site laboratory, which is described in Section 11.7 and was visited during the site visit, as summarized in Section 12.4.

Avinos current on-site, non-certified, laboratory facility consists of sample preparation, crushing and pulverizing, a fire assay and an AA section. However, the procedures and facilities used in 1990 to 1991 may be different from the current sample analysis procedures. As a result of the uncertainty associated with these analyses, two separate verification exercises have been completed. Slim (2005d) collected numerous samples from across the oxide tailings, and the results of this verification are discussed in Section 11.2. In 2012, Mr. OBrien, QP, of Tetra Tech collected numerous verification samples from the oxide tailings, and these results are discussed in Section 12.3.2.
11.2
Tailings Investigations (Test Pits in Oxide Tailings), 2004


The sampling method and approach adopted by Slim (2005d) on the test pits in the oxide tailings incorporated the following steps:
1.
A backhoe was used to excavate sample pits to a depth of 4m.Hand samples were taken at 1m vertical increments from the sidewalls of each pit.
2.
The sample mass collected from each sampling point generally amounted to between 2 and 5kg.
3.
The sampling program was ostensibly based on the 1990 CMMA sampling program.Fourteen sample pits were excavated to a depth of 4m and generated 86samples.
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The samples were air-freighted to PRA in Vancouver, British Columbia, from Durango, Mexico. The samples had been initially bagged and sealed with identification tags attached. The samples were allotted new identification numbers, and were subsequently un-bagged and dried. The dry samples were individually mixed and blended, and then split into four one-quarter fractions as directed by Slim (2005d). One fraction was used to determine the head grade assay, while another quarter was used to create composite samples used for the subsequent metallurgical test work program. Instructions were followed with the compositing of the samples, and the test work program. Excess sample was archived for future test work or analyses. For analytical techniques employed during the test work program, the standard fire assay (with AA spectrophotometric finish) was initially used for the silver analyses. However, this method is not very accurate for silver values of less than 100 g/t. Subsequently, the inductively coupled plasma spectroscopy method (ICP-MS), which uses multi-acid digestion, was used for silver. This method also resulted in analyses being obtained for other elements of interest (e.g. copper, zinc, lead, etc.). The standard fire assay method was used for gold analyses. Cyanide and lime concentrations were measured using standard titrimetric methods. Total sulphur was measured using a standard Leco furnace, and sulphide sulphur assays were measured using the standard wet chemical gravimetric analysis (Slim 2005d).

The PRA labs (part of Inspectorate labs) in Nevada and British Columbia are International Organization for Standardization (ISO) 9001:2008 certified, full service laboratories that are independent of Avino. Tetra Tech did not independently verify nor compare the results of the sampling program.
11.3
Drilling Program, San Gonzalo, 2007, 2008, and 2011


For the drilling programs at San Gonzalo, core is sawed at Avino's core storage facility at the secure mine site. Samples of vein material, usually from a few centimeters to 1.5 m, are placed and sealed in plastic bags, which are collected by personnel from Inspectorate Labs in Durango at the mine site facilities. Samples are prepared in Durango, and pulps are sent to the Inspectorate facility in Sparks, Nevada for analysis.

Sample preparation in Durango involves the initial drying of the entire sample. Two-stage crushing is used to create a product which is at least 80% minus 10 mesh. A Jones riffle splitter is then used to separate a nominal 300 g portion of the sample. This 300 g sub-sample is then pulverized to more than 90% passing a 150-mesh screen. Inspectorate Labs states that they use sterile sand to clean the pulverizer between samples (Gunning 2009).

Gold analyses are by 30 g fire assay with an AA finish. Silver, zinc, and lead are analyzed as part of a multi-element inductively coupled argon plasma package using a four-acid digestion with over-limit results for silver being reanalyzed with assay procedures using fire assay and gravimetric. Avino employs a rigorous quality control program that includes standardized material, blanks, and core duplicates. However, for the 2007 program, Avino did not perform any independent QA/QC and relied on the internal QA/QC procedures completed by the labs (Gunning, 2009).

Avino used a series of standard reference materials (SRMs), blank reference materials (blanks) and duplicates as part of their QA/QC program during analysis of assays from San Gonzalo vein drillholes. Tetra Tech compiled and reviewed these results in Section 12.1.4.
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11.4
Drilling Programs, ET Zone of the Avino Vein, 2006, 2007, 2008 and 2012


Sample lengths of NQ drill core were diamond sawed into halves by mine staff and shipped to Inspectorate Labs in Durango for preparation into pulps and rejects. Pulps were analyzed at Inspectorate Labs in Sparks, Nevada. Gold and silver were analyzed by fire assay using aqua regia leach and AA finish. Other elements are reported from a 29-element ICP-MS package. Inspectorate Labs in Nevada and British Columbia are ISO 9001:2008 certified, full service laboratories that are independent of Avino. Sample preparation and analysis and QA/QC procedures are as described in Section 11.3.

Avino used a series of standard reference materials (SRMs), blank reference materials (Blanks) and duplicates as part of their QA/QC program during analysis of assays from Avino vein drillholes. Tetra Tech compiled and reviewed these results in Section 12.1.4.
11.5
Underground Channel Sampling of San Gonzalo Vein, 2010 to Present


Samples from channels cut across the San Gonzalo vein were assayed by Inspectorate Labs. Samples were crushed and ground in Durango with pulps assayed in Richmond, British Columbia using fire assay and AA finish for gold, four acid digestion and AA for most silver with fire assay and gravimetric finish for very high silver. Base metals were analyzed via aqua regia digestion and ICP-MS. Inspectorate Labs in Durango and British Columbia are ISO 9001:2008 certified, full service laboratories that are independent of Avino. Sample preparation and analysis and QA/QC procedures are as described in Section 11.3.

For the 2011 bulk sampling program of San Gonzalo, samples were obtained from channels cut across the vein, and were assayed by Inspectorate Labs. Samples were crushed and ground in Durango with pulps assayed in Richmond, British Columbia using fire assay and AA finish for gold, four acid digestion and AA for most silver with fire assay and gravimetric finish for very high silver. Base metals were analyzed via aqua regia digestion and ICP-MS for base metals. Inspectorate Labs in Nevada and British Columbia are ISO 9001:2008 certified, full service laboratories that are independent of Avino.

Samples from 2012 and 2013 underground channel sampling of the San Gonzalo vein are shipped to Inspectorate Labs for analysis for gold, silver, arsenic, bismuth, copper, molybdenum, lead, antimony, zinc, and mercury. Samples are crushed and ground in Durango with pulps assayed in Reno, Nevada using fire assay and AA finish for gold, four acid digestion and AA for most silver with fire assay and gravimetric finish for very high silver, and aqua regia digestion and ICP-MS for base metals. Inspectorate Labs in Nevada and British Columbia are ISO 9001:2008 certified, full service laboratories that are independent of Avino. Sample QA/QC procedures are as described in Section 11.3.
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11.6
Avino Laboratory


The Avino laboratory has fire assay, AA and sieving analysis equipment. Head grade assay data comparisons (Figure 11.1) suggest that recent gold assay results from the Avino laboratory are consistently slightly higher than those from the SGS laboratory in Durango. Silver analyses are similar overall, with slightly higher grades reported from the Avino laboratory at low silver values (below approximately 80 ppm) but with slightly lower grades reported at high silver values.
11.7
Specific Gravity Samples


Avino completed specific gravity measurements on drillcore from both the Avino and San Gonzalo veins. All measurements were completed by Avino staff on the mine site. Two different methods were employed to obtain these specific gravity values: caliper volume calculation (CV) and water displacement (WD). The procedures followed for each method are summarized below.

A total of 262 samples were measured for bulk density, 110 from the Avino vein and 152 from the San Gonzalo vein. Tetra Tech provides recommendations regarding specific gravity sampling procedures in Section 26.1.4 and a QP opinion in Section 12.5.1.
11.7.1
Caliper Volume Calculation Method


The CV method of determining the specific gravity of drillcore samples involved the following procedures, based on the methodology outlined by Lipton (2001):
Each measurement involves pieces of whole core with the ends neatly cut perpendicular to the core axis.
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The core diameter is determined using a pair of vernier calipers, and the diameter should be measured at several points along the length of core and averaged.
The core length is measured using a tape measure.
The mass is determined by weighing the core; weighing should be completed once the core is dried.
The dry bulk density is calculated by: density = mass/volume where volume = x (average core diameter/2)2 x core length.
11.7.2
Water Displacement Method
The mass is determined by weighing the core; weighing should be completed once the core is dried.
A graduated cylinder, of an appropriate size to completely submerse the core, is used to determine the volume.The volume of water in the graduated cylinder is measured prior to submersing the core.
The core is then submersed in water in the graduated cylinder and the total volume is measured.
The difference in the volume of water before and after sample submersion is the volume of the sample.
The dry bulk density = mass/volume.
11.8
QP Opinion


Tetra Tech is not aware of any drilling, sampling or recovery factors affecting the reliability of the samples.It is Tetra Techs opinion that the sample preparation, security and analytical procedures followed by Avino are adequate for the purpose of this study and technical report.
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12.0
DATA VERIFICATION
12.1
Avino and San Gonzalo Vein Drillhole Database Verification


Tetra Tech compiled the drillhole data provided by Avino on a hole-by-hole basis, including drillhole collar, survey, lithology, and assay data. A variety of partially-compiled data sources were provided to Tetra Tech at various times during development of this study, indicating that the technical database on the Avino mine site is poorly-organized and inconsistently managed. Although many of the drillholes have been previously disclosed by Gunning (2009) and Tetra Tech (2012), the lack of a compiled and unified database and inconsistent data management has resulted in an overall low confidence in the data as provided. As a result, Tetra Tech verified the collar and assay data from at least 10% of all drillholes and channel samples included in the current, compiled database. Survey data could not be verified. Lithology data could not be verified due to inconsistent and conflicting geology data (see Section 12.1.3).

The San Gonzalo underground channel samples were provided to Tetra Tech in the form of AutoCAD plan and section views and in spreadsheets containing only assay results; 3D location coordinates and from-to values for each channel sample were not provided. The location of channel samples was compiled by Tetra Tech using the plan and section views provided by Avino. Each channel was treated as a drillhole and digitized with collar and survey information, as indicated on the plan and section views. This data was cross-referenced with the assay data provided by Avino, and a unique channel identifier, including from-to values for each assay sample, was assigned for each channel in the database. Following data compilation, more than 10% of all assays from these channels were verified against the laboratory assay certificates; these results are included in the verification results discussed in Section 12.1.1.

The QP opinion of the reliability of the Avino drillhole data is discussed in Section 12.5.1 and detailed recommendations are provided in Section 26.1.
12.1.1
Collar and Assay Data


The overall rate of significant errors was less than 1% for gold, silver, copper, lead, and zinc. Table 12.1 summarizes the validation results and Table 12.2 documents errors observed. The most frequent errors in the assay database are related to inconsistent application of rounding parameters and an inconsistent approach to below detection limit values, which are considered to be minor errors that do not impact the overall confidence in the database.
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Database
Description
Unit
Collar Table
Number of Records
490
Number of Records Reviewed
55
Validation Percentage
11.2%
Errors Found
6
Errors Found (>1 m difference)
1
Error Rate
10.9%
Rate of Significant Errors
1.8%
Assay Table
Number of Records (Au, Ag, Cu, Pb, Zn)
31,385
Number of Records Reviewed
5,765
Validation Percentage
18.4%
Errors Found
34
Errors Found (> 1 decimal place)
1
Error Rate
0.6%
Rate of Significant Errors
0.0%
Database
Drillhole/
Channel
Sample
ID
Item
Error
Collar
ET-08-05
N/A
Elevation
Value in database 2239.836; value in log 2284.991.
Collar
ET-12-08
N/A
Easting
Value in database 570678.266; value in log 570678.469.
Collar
ET-12-08
N/A
Northing
Value in database 2712593.838; value in log 2712593.381.
Collar
ET-12-08
N/A
Elevation
Value in database 2226.767; value in log 2226.776.
Collar
SG-07-28
N/A
Northing
Value in database 2714077.851; value in log 2714077.012.
Collar
SG-08-03
N/A
Elevation
Value in database 2335.066; value in log 2335.766.
Assay
SG-07-01
150678
Ag
Value in database 1342; value in certificate 1342.4.
Assay
SG-11-02
157262
Ag
Value in database 170; value in certificate 170.4.
Assay
L4-L-0
165979
Ag
Value in database 36; value in certificate 36.4.
Assay
L4-L-1 O
165981
Ag
Value in database 4; value in certificate 4.3.
Assay
L4-L-1 O
165982
Ag
Value in database 23; value in certificate 23.3.
Assay
L4-L-2 O
165983
Ag
Value in database 6; value in certificate 5.8.
Assay
L4-L-2 O
165984
Ag
Value in database 18; value in certificate 18.4.
Assay
L4-L-2 O
165985
Ag
Value in database 8, value in certificate 7.7.
Assay
L4-L-3 O
165987
Ag
Value in database 496; value in certificate 495.7.
Assay
L4-L-3 O
165988
Ag
Value in database 14; value in certificate 13.7.
Assay
L4-L-4 O
165989
Ag
Value in database 50; value in certificate 50.3.
Assay
L4-L-4 O
165990
Ag
Value in database 26; value in certificate 25.8.
Assay
L4-L-4 O
165991
Ag
Value in database 250; value in certificate 250.3.
Assay
L4-L-5O
165992
Ag
Value in database 51; value in certificate 51.4.
Assay
L4-L-5 O
165993
Ag
Value in database 323; value in certificate 322.6.
Assay
L4-L-5 O
165994
Ag
Value in database 273; value in certificate 273.3.
table continues
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Database
Drillhole/
Channel
Sample
ID
Item
Error
Assay
L4-L-6 O
165995
Ag
Value in database 111; value in certificate 110.7.
Assay
L4-L-6 O
165996
Ag
Value in database 1799; value in certificate 1799.3.
Assay
L4-L-6 O
165997
Ag
Value in database 289; value in certificate 289.3.
Assay
L4-L-6 O
165998
Ag
Value in database 66; value in certificate 65.8.
Assay
L4-L-60 P
166873
Au
Value in database 7.597; value in certificate 7.579.
Assay
L-4-L-147-O
169156
Zn
Value in databse 1900; value in certificate 19000


A previous validation exercise was completed for assay results from post-2009 drilling by Tetra Tech (2012). Original assay certificates were compared against the data as reported by Avino. Assay results from drillholes SG-11-13 to SG-11-17, and ET-12-01 to ET-12-09 were verified. For all metals in the database (gold, silver, copper, lead, zinc, and bismuth), the error incidence was less than 1%. Table 12.3 documents these errors.
Hole
Number
Sample
Number
From
(m)
To
(m)
Error
ET-12-05
162686
345.10
345.50
Value entered as 4.8g/t Au, should be 48.1g/t Au;
Value entered as 350g/t Ag, should be 1,811.3g/t Ag
ET-12-05
162687
345.50
345.80
Value entered as 2.8g/t Au, should be 28.3 g/t Au
ET-12-02
162463
276.85
277.3
Value entered as 101.1g/t Ag, should be 101.8g/t Ag
ET-12-06
162720
Standard
Value entered as 1.02 ppm Pb, should be 10,200ppm Pb
ET-12-05
162694
354.8
355.8
Value entered as 2,600ppm Zn, should be 26,000ppm Zn


Drillhole SG-08-01 was excluded from resource estimation of the San Gonzalo vein (Section 14.2) because the vein intersection is inconsistent with the vein intersections of nearby drillholes and underground workings. It is possible that the collar location of SG-08-01 was incorrectly surveyed, but this cannot be confirmed by Tetra Tech.
12.1.2
Downhole Survey Data


Downhole survey data exists for 87 of the 98 drillholes completed in the Avino and San Gonzalo veins. Most drillholes have three or fewer downhole survey points, which is less frequent than typical industry practice. Many of these holes contain a survey data point at the collar and near the end of hole, and sometimes part-way down the hole. However, 26 of the 87 holes for which downhole survey data exists were not surveyed to within 10 m of the end of the hole. All measurements were completed by a magnetic survey method, which is not recommended in general, and particularly not in locations with extensive underground infrastructure such as those present on the Property. Given the abundance of historical infrastructure on the Property and the potential for any drillholes to intersect active workings, downhole survey measurements should be collected at a frequency of at least every 10 m and all drillholes should be cemented following completion.
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Downhole survey data for hole SG-07-06 was disregarded below 50m depth due to an unrealistic kink in the drillhole orientation below this depth, which could be due to an instrument malfunction or to magnetic interference.
12.1.3
Geology Data and Interpretation
To Tetra Techs knowledge, routine photography of drillcore and underground drifts is being completed. A digital photographic record is kept of all drillcore and underground drifts for future reference, and to facilitate consistent core logging and geology interpretation.
Geology logs for both the Avino and San Gonzalo veins have not been entered into a digital format. Although digital cross-sections exist for all holes, these were not created from a geology database and in many instances it appears that the depths of lithology contacts on these sections are only approximate (see point 3 below).
From-to depths of drillcore intersections are frequently inconsistent between data sources. The most common example of this is inconsistent depths of geological contacts between geological sections created by Avino and paper drillhole logs.
Rock type names are frequently inconsistent from one data source to another (such as between paper core logs, cross sections, and lithology comments for assay intervals and density samples). For example, Tetra Tech observed numerous instances of the same interval in a drillhole called both an andesite and an intrusion in different data sources. Photography (point 1 above) would facilitate more consistent logging.
Rock type names are frequently applied incorrectly, and a primary cause of this appears to be that the distinction between rock names for volcanic and intrusive rocks is not clear. An example frequently observed is the rock type name andesitic intrusion, which is incorrect. If the rock unit appears to be an extrusive volcanic rock, the term andesite is appropriate. If the rock appears to be an intrusive igneous rock and is of intermediate composition, then the term diorite should be used. Mis-application of volcanic (i.e. extrusive) versus intrusive igneous rock terminology has lead to an inconsistent geological interpretation of the mine geology.
The information on the regional and property geology (Slim 2005d; Paulter 2006) suggests a greater diversity in the chemical composition of volcanic and intrusive rocks than is reflected in any of the Avino mine geology logs or sections. The mine geology also does not appear to correlate distinct lava flows, volcaniclastic units, or intrusive phases. Further work is warranted in establishing the stratigraphy on the Property, and particularly within the mine areas. Establishing this should improve the confidence of correlations between drillholes and may help identify additional targets for exploration on the Property.
Avino Silver & Gold Mines Ltd.
12-4
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Technical Report on the Avino Property, Durango, Mexico
12.1.4
Review of Drillhole Quality Assurance/Quality Control Samples


Avino used a number of SRMs, blank reference materials (blanks) and duplicates as part of their QA/QC program. QA/QC samples were submitted in the sample stream during all 2006 to 2012 drilling programs on both the Avino and San Gonzalo veins, although not in a consistent manner. These results were reviewed by Tetra Tech and are discussed below.

The rate of QA/QC sample insertion is slightly below recommended industry standards on the Avino vein (close to 5% of total samples), but significantly below industry standards on the San Gonzalo vein (less than 3% of total samples). Based on the information provided to Tetra Tech, it also does not appear that industry standard plots of SRM, blank, and duplicate results (see below) are being constructed and reviewed by Avino on a routine basis.

A total of 76 standards were analyzed during the 2006, 2007, 2008, 2011, and 2012 drilling programs. Avino used five laboratory-certified standards for their 2007, 2008, 2011, and 2012 drilling programs, and the results of these standards are discussed below. Although standards were also analyzed during the 2006 drilling program, a variety of different standards were used and these miscellaneous results are not discussed further here.

A rough sinusoidal pattern is observed for most standards, which is indicative of laboratory calibration drift and suggests that more frequent instrument calibration should be completed by the Inspectorate laboratory used by Avino.

Overall, there does not appear to be any systematic bias in sample grades, although one low grade SRM (Cu136) showed a slight bias to higher silver and copper grades. This same bias was not observed with the other SRMs and is therefore not considered representative of a general analytical bias. This may, however, suggest a lower degree of analytical accuracy at low silver and copper grades.

There were 13 Cu119 SRMs used through all drilling programs. The Cu119 SRM is from WCM Minerals of Burnaby, British Columbia and has reported results of 0.5060.0269% copper and 158.38811.343 g/t silver (within two standard deviations). This SRM is not ideal for the Project because it is not certified for gold, one of the primary metals of economic interest in the Avino mine. SRM Cu119 results are shown in Figure 12.1 for silver and Figure 12.2 for copper.
Avino Silver & Gold Mines Ltd.
12-5
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Technical Report on the Avino Property, Durango, Mexico


Silver values for SRM Cu119 were generally within the acceptable limits, with two marginal fails above the accepted value and one marginal fail below. The copper results show more variability, with several high and low failures. It appears that instrument calibration drift is more evident with the copper results. Overall, SRM Cu119 indicates a lack of analytical bias.

There were 14 Cu136 SRMs used through all drilling programs. An additional two SRMs labelled as CU136 were excluded because of apparent sample mis-labelling. The Cu136 SRM is from WCM Minerals of Burnaby, British Columbia and has reported results of 0.0690.0042% copper, 29.12.185 g/t silver, and 2.2780.140 g/t gold (within two standard deviations). SRM Cu136 results are shown in Figure 12.3 for silver, Figure 12.4 for gold, and Figure 12.5 for copper.
Avino Silver & Gold Mines Ltd.
12-6
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Technical Report on the Avino Property, Durango, Mexico


SRM Cu136 has numerous silver and copper fails above the acceptable limits, which is a concern. Other standards do not show a similar failure pattern, which suggests that it is not an overall analytical bias with the instrument. However, this is a lower grade standard than others used in this QA/QC program, and it is possible that the instrument may not be accurately calibrated at lower grades, or that sample contamination during preparation is most evident in lower grade samples.

Four failures are noted for gold, however there is no consistent bias with the gold results. Rather, the gold results show a rough sinusoidal pattern.
Avino Silver & Gold Mines Ltd.
12-7
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Technical Report on the Avino Property, Durango, Mexico


There were 12 CDN-GS-5G SRMs used through all drilling programs. The CDN-GS-5G SRM is from CDN Resource Laboratories in Langley, British Columbia and has reported results of 101.87.0 g/t silver and 4.770.40 g/t (within two standard deviations). SRM CDN-GS-5G results are shown in Figure 12.6 for silver and Figure 12.7 for gold.

One high and one low silver failure was noted for SRM CDN-GS-5G, but there is no apparent analytical bias for this SRM. All gold values were within the accepted range.
Avino Silver & Gold Mines Ltd.
12-8
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Technical Report on the Avino Property, Durango, Mexico


There were 11 CDN-GS-1P5D SRMs used through all drilling programs. The CDN-GS-1P5D SRM is from CDN Resource Laboratories in Langley, British Columbia and has reported results of 1.470.15 g/t gold (within two standard deviations). This SRM is not ideal for the Project because it is not certified for silver, the primary metal of economic interest in the Avino mine. SRM CDN-GS-1P5D results are shown in Figure 12.8 for gold.
Avino Silver & Gold Mines Ltd.
12-9
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Technical Report on the Avino Property, Durango, Mexico


There were 12 CDN-ME-6 SRMs used through all drilling programs. The CDN-ME-6 SRM is from CDN Resource Laboratories in Langley, British Columbia and has reported results of 1017.1 g/t silver, 0.270.028 g/t gold, 0.6130.034% copper, 1.020.08% lead, and 0.5170.040% zinc (within two standard deviations). SRM CDN-ME-6 results are shown in Figure 12.9 for silver, Figure 12.10 for gold, Figure 12.11 for copper, Figure 12.12 for lead, and Figure 12.13 for zinc.

Failures for SRM CDN-ME-6 include three for silver, one for gold, two for copper, 4 for lead, and 2 for zinc. Most failures are marginal however, and there is no apparent analytical bias for any element. All elements appear to show a rough sinusoidal pattern.
Avino Silver & Gold Mines Ltd.
12-10
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Technical Report on the Avino Property, Durango, Mexico
Avino Silver & Gold Mines Ltd.
12-11
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Technical Report on the Avino Property, Durango, Mexico


A total of 49 blanks were analyzed during the 2007, 2008, 2011, and 2012 drilling programs. Two different materials were used as blanks. No blank was used for the 2006 drilling program, a locally-sourced basalt was used for the 2007 and 2008 drilling programs, and a laboratory-certified blank was used for the 2011 and 2012 drilling programs.

For the 2007 and 2008 drilling programs, Avino used a locally-sourced basalt as blank material. A total of 26 basalt blanks were analyzed. To Tetra Techs knowledge, no expected results were determined for this basalt material. As a result, the blank analysis below applies arbitrary reasonable upper limits for the analyses in order to gain some idea of lab performance on the three primary metals of economic importance in the Avino mine (silver, gold, and copper). For gold, the same upper limit is applied as reported for the CDN-BL-9 blank (0.01 g/t). For silver, an upper limit of three times the detection limit was used, or 0.3 g/t. For copper, an arbitrary upper limit of 0.005% (50 ppm) was used, or roughly the average background level of copper in the earth (Emsley 2003).

The results for the basalt blank are shown in Figure 12.14 for silver, Figure 12.15 for gold, and Figure 12.16 for copper. Six silver samples failed, or 23% of all blanks. Three gold samples failed, or 11% of all samples. For copper, 13 samples failed or 50% of all samples. Although the upper failure limits applied to the basalt are arbitrary, they are reasonable values which any blank (for these three elements of interest) should be below. Therefore, this basalt is not a good source of blank material for the Avino mineralization and should not be used for future QA/QC studies. Nonetheless, the plots below do provide some idea of lab contamination; overall, it does not appear that a systematic bias is present due to contamination.
Avino Silver & Gold Mines Ltd.
12-12
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Technical Report on the Avino Property, Durango, Mexico


If a locally-sourced blank is used, a more appropriate material should be selected that contains less than three times the detection limit of any elements of economic interest. In addition, the material should first be sent to a number of laboratories to provide an upper limit for acceptable analyses.
Avino Silver & Gold Mines Ltd.
12-13
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Technical Report on the Avino Property, Durango, Mexico


One laboratory-certified blank was used during the 2011 and 2012 drilling programs on both the Avino and San Gonzalo veins. The blank is CDN-BL-9, from CDN Resource Laboratories in Langley, British Columbia, it is derived from granite material, and it has a reported upper limit for gold of 0.01 g/t. A total of 23 CDN-BL-9 blanks were analyzed. This blank is only certified for gold, which is not ideal because silver is the primary metal of economic interest in the Avino mine. In order to gain some idea of the performance of the lab on silver and copper, the same arbitrary upper limits were used as applied to the basalt blank (0.3 g/t silver and 0.005% copper).

The results for the CDN-BL-9 blank are shown in Figure 12.17 for silver, Figure 12.18 for gold, and Figure 12.19 for copper. For silver, seven failures were noted, or 30% of all blanks. One gold sample failed, or 4% of all samples. There were no copper failures. Although the upper failure limits applied for silver and copper are arbitrary, they are reasonable values which any true blank (for these elements) should be below. Therefore, CDN-BL-9 is not a good source of blank material for silver (even without certification by the laboratory). If a laboratory-certified blank is used, it should at minimum be certified for gold and silver, the primary metals of economic interest in the Avino mine.
Avino Silver & Gold Mines Ltd.
12-14
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Technical Report on the Avino Property, Durango, Mexico
Avino Silver & Gold Mines Ltd.
12-15
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Technical Report on the Avino Property, Durango, Mexico


Field duplicates were collected from 33 samples from both the Avino and San Gonzalo veins. The results of duplicate samples are shown in Figure 12.20 (silver), Figure 12.21 (gold), Figure 12.22 (copper), Figure 12.23 (lead), and Figure 12.24 (zinc). In some cases, very high grade samples were excluded from the graph in order to allow better resolution of the lower-grade results. An incorrect original sample for a duplicate is apparent in one instance.

The target results are 90% within a 20% relative difference of the original sample. For the elements shown below, 73% of gold analyses, 76% of silver analyses, 85% of copper analyses, 91% of lead analyses, and 91% of zinc analyses are within the 20% relative difference window. There does not appear to be a consistent trend in the samples that fall outside of this window. The number of samples that are outside this window therefore likely reflects the inherent variability in element distribution within the deposit.
Avino Silver & Gold Mines Ltd.
12-16
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Technical Report on the Avino Property, Durango, Mexico
Avino Silver & Gold Mines Ltd.
12-17
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Technical Report on the Avino Property, Durango, Mexico
12.2
Avino and San Gonzalo Vein Bulk Density


A limited number of specific gravity measurements were originally collected by Avino from drillholes in the Avino and San Gonzalo Veins. These measurements were not representative of the veins spatially or by drilling program, and Tetra Tech requested additional specific gravity measurements be completed on drillcore from both veins. These additional measurements were completed by Avino in 2013. These new measurements are part of the specific gravity database discussed in more detail in Section 10.2.3, Section 11.7 and Section 14.5.

Table 12.4 shows a comparison of the maximum, minimum, and mean results for specific gravity samples from the San Gonzalo vein, from the Avino vein, and from all samples.
Deposit
Maximum Value
Minimum Value
Average Value
% Difference (Max-Min)
% Difference (Max-Mean)
% Difference (Mean-Min)
San Gonzalo Vein
3.23
2.0
2.62
62
23
31
Avino Vein
3.38
2.1
2.66
69
27
27
All
3.38
2.0
2.64
69
28
32


The 2013 specific gravity measurements included some samples that were measured by a CV method, and some by a WD method (see Section 11.7). As part of this exercise, Tetra Tech also requested that Avino complete duplicate measurements on whole drillcore by each method. These duplicate measurements were reviewed by Tetra Tech as a check on the reliability of the procedures followed on site. Table 12.5 shows the results from these duplicate measurements. The results show good agreement between the CV and WD methods, with an overall slight bias to lower values using the CV method.
Avino Silver & Gold Mines Ltd.
12-18
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Technical Report on the Avino Property, Durango, Mexico
Drillhole
Depth
(m)
CV
Density
(g/cm3)
WD
Density
(g/cm3)
%
Difference
(WD-CV)
SG-07-01
334.90
2.55
2.56
0.3
SG-07-07
272.10
2.77
2.79
0.9
SG-07-16
85.00
2.60
2.63
1.1
SG-07-28
295.00
2.58
2.61
1.2
SG-07-36
45.05
2.55
2.55
-0.3
SG-07-40
512.00
2.69
2.68
-0.3
SG-08-06
200.00
2.60
2.58
-0.7
SG-11-04
155.25
2.55
2.54
-0.5
SG-11-16
332.15
2.48
2.49
0.4
ET-07-05
280.00
2.66
2.66
0.1
ET-12-01
200.00
2.60
2.64
1.7
ET-12-09
390.45
2.63
2.64
0.5
Average
-
-
-
0.3


Tetra Tech also reviewed the results by rock type and by analytical method, including previously collected results that were all completed using the CV method. Table 12.6 shows these results, indicating an overall good agreement between results obtained from both the CV and WD methods. However, this comparison does show a slight bias with the CV method yieleding consistently lower average densities.
Deposit
Number of
Samples
(VC)
Number of
Samples
(WD)
Average
Density VC
(g/cm3)
Average
Density WD
(g/cm3)
%
Difference
(WD-CV)
San Gonzalo Vein
113
39
2.62
2.64
0.8
Avino Vein
69
41
2.63
2.71
3.0
All
182
80
2.62
2.67
1.9


Based on this review, Tetra Tech recommends that Avino use the WD method for future specific gravity measurements, as outlined in Section 26.1. A QP opinion of the reliability of the Avino specific gravity data is discussed in Section 12.5.1.
Avino Silver & Gold Mines Ltd.
12-19
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico
12.3
Oxide Tailings Drillhole Database


Tetra Tech compiled the assay data used in the oxide tailings resource estimate by referring to original mine sections (Tetra Tech 2012) and verification of this data is described below. The 1:1,000 scale plans drafted for this exercise were scanned and used to verify the positions of the old drillholes. A transposition error on one collar elevation in mine coordinates was observed and subsequently corrected (drillhole E3 was incorrectly recorded at an elevation of 2,275 m, and was corrected to 2,257 m).
local mine grid X+ 560421.245 = X UTM
local mine grid Y+ 2707618.312 = Y UTM
local elevation - 41.306 = elevation amsl.


Since the trenches (named with Z-series) from the 1990 to 1991 program represent incomplete surface sampling of an unrepresentative part of the pile (at the wall where the outlets for the hydraulic emplacement of the material were sited), these data were not used in the oxide tailings resource estimate.
12.3.1
Assay Verification of 1990/1991 Drillholes in Oxide Tailings


The drillholes in the oxide tailings were completed prior to institution of NI 43-101 and related QA/QC requirements. The analyses were completed in the Avino Mine laboratory and no original assay certificates have been produced or preserved. The database and mine sections were therefore compared with the original hand-written data collected from the mine laboratory. These assay sheets from the mine laboratory show good agreement with the mine sections and resulting database used by Tetra Tech for estimation of the oxide tailings in Section 14.1. Tetra Tech verified 54% of drillholes in this database (15 of 28 drillholes) and 58% of both silver and gold assays (444 of 766 values) used for this estimation (excluding the Z-series trenches). Only two errors were noted in the database, as documented in Table 12.7, yielding an error incidence of less than 1%. An additional discrepancy noted during this verification exercise was a mistake in the hole number sequence along the C-C line on the original plan view map (Figure 10.1, Section 10). The original mine sections and assay sheets skip hole C2 and include the drillhole numbers C1 and C3 to C6, whereas the plan view map lists the C-series drillholes sequentially from C1 to C5. The database used for estimation matches the mine sections and original assay sheets, and therefore no hole C2 exists in the database. The original mine sections are provided in Tetra Tech (2012). Also included in Appendix A are the original hand-written assay sheets for all drillholes that were verified (the assay sheets also includes assay data for other, unrelated material which was being processed around the same time as the oxide tailings material).
Avino Silver & Gold Mines Ltd.
12-20
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Technical Report on the Avino Property, Durango, Mexico
Hole
Number
From
(m)
To
(m)
Error
E2
14
15
Ag value entered as 97g/t, should be 87g/t
C4
18
19
Ag value entered as 119g/t, should be 113 g/t


In order to verify the reliability of the assay data from the oxide tailings sampling, Tetra Tech collected numerous verification samples (as described in Section 12.3) with the goal of evaluating:
the presence and grade of silver and gold in the tailings
the reliability of the Avino Mine laboratory; to address this, the same samples were analysed at the mine as well as two external labs.
12.3.2
Oxide Tailings Verification Samples


During a site visit conducted on June 7 and 8, 2012, Michael F. OBrien visited the tailings heaps and supervised the collection of eight samples from the oxide tailings (3 to 4 kg each). The samples were collected from gulleys that had eroded into the tailings pile and provided a vertical section through the tailings. It is believed that while such samples cannot provide a statistically representative reflection of overall grade, they do provide some insight into the grade of the tailings near surface. The eight samples were each split into three separate sub-samples, which were submitted in turn to the Avino Mine laboratory together with SGS laboratories in Durango and Vancouver.

Statistical analysis of the three sets of results demonstrates that there is good correlation between the three labs, as exhibited by linear comparison plots in Figure 12.25 to Figure 12.29, and in correlation coefficient matrices in Table 12.8 to Table 12.12. Assay results from the verification samples are presented in Table 12.13; assay certificates for these results were previously disclosed by Tetra Tech (2012).

Silver values performed excellently, as did two of the three base metals. Zinc values from the Avino lab came back lower than at the two SGS labs, but displayed the same trend. As noted in Section 11.7, gold values from the Avino laboratory came back slightly higher than from the SGS labs. It should be noted that gold assays have a high intrinsic variance compared to other metals, hence the lower correlation numbers for those values, although they are well within normally expected variation. The variance and relative standard error (RSE) for each of the five metals are:
silver: variance = 12.43 (g/t)2, RSE = 3.01%
gold: variance = 0.011 (g/t)2, RSE = 9.16%
Avino Silver & Gold Mines Ltd.
12-21
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Technical Report on the Avino Property, Durango, Mexico
lead: variance = 440,534 ppm2, RSE = 5.24%
zinc: variance = 53,990 ppm2, RSE = 16.91%
copper: variance = 6,088 ppm2, RSE = 3.79%.
Avino Silver & Gold Mines Ltd.
12-22
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Technical Report on the Avino Property, Durango, Mexico
Avino Silver & Gold Mines Ltd.
12-23
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Technical Report on the Avino Property, Durango, Mexico
Avino Silver & Gold Mines Ltd.
12-24
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Technical Report on the Avino Property, Durango, Mexico
Avino Ag
(g/t)
SGSD Ag
(g/t)
SGSV Ag
(g/t)
Avino Ag (g/t)
1
-
-
SGSD Ag (g/t)
0.963
1
-
SGSV Ag (g/t)
0.984
0.986
1
Avino Au
(g/t)
SGSD Au
(g/t)
SGSV Au
(g/t)
Avino Au (g/t)
1
-
-
SGSD Au (g/t)
0.612
1
-
SGSV Au (g/t)
0.808
0.703
1
Avino Pb
(ppm)
SGSD Pb
(ppm)
SGSV Pb
(ppm)
Avino Pb (ppm)
1
-
-
SGSD Pb (ppm)
0.948
1
-
SGSV Pb (ppm)
0.989227101
0.968924309
1
Avino Zn
(ppm)
SGSD Zn
(ppm)
SGSV Zn
(ppm)
Avino Zn (ppm)
1
-
-
SGSD Zn (ppm)
0.940
1
-
SGSV Zn (ppm)
0.984
0.955
1
Avino Cu
(ppm)
SGSD Cu
(ppm)
SGSV Cu
(ppm)
Avino Cu (ppm)
1
-
-
SGSD Cu (ppm)
0.999
1
-
SGSV Cu (ppm)
0.998
0.999
1


The sampling exercise did provide the opportunity to review the artificial sedimentary deposit that comprises the Avino oxide tailings and supported the previous assumptions of the tailings, such as regarding the oxide tailings as two superimposed units with slightly different chemical and particle size characteristics and pronounced horizontal continuity. The source data and plans prepared more than 20 years ago after the initial drilling campaign were examined at the mine and found to be of professional standard and provide support for their use in the estimation of the oxide tailings. The overall homogeneity of the material, horizontal continuity and relatively high confidence in the volume and tonnage, mitigate any uncertainty in the historical data set.
Avino Silver & Gold Mines Ltd.
12-25
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Technical Report on the Avino Property, Durango, Mexico
Avino Silver & Gold Mines Ltd.
12-26
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Technical Report on the Avino Property, Durango, Mexico
Table 12.13
Results of Verification Samples
Avino Laboratory Results
SGS Durango Results
SGS Vancouver Results
Sample
Number
Ag
(g/t)
Pb
(ppm)
Zn
(ppm)
Cu
(ppm)
Au
(g/t)
Sample
Number
Ag
(g/t)
Pb
(ppm)
Zn
(ppm)
Cu
(ppm)
Au
(g/t)
Sample
Number
Ag
(g/t)
Pb
(ppm)
Zn
(ppm)
Cu
(ppm)
Au
(g/t)
162185
35
2,812
243
826
0.82
165019
44
2,660
421
907
0.63
165019
41
2,880
431
854
0.65
162188
47
2,125
292
848
0.91
165020
43
2,400
553
1,020
0.62
165020
42
2,640
559
997
0.65
162189
38
2,928
460
2,356
0.62
165021
39
2,660
751
2,610
0.59
165021
38
2,790
726
2,430
0.50
162190
70
8,298
498
993
0.65
165022
69
6,650
779
1,120
0.57
165022
67
6,690
791
1,060
0.49
162191
62
7,398
441
878
0.54
165023
58
7,540
868
1,030
0.51
165023
58
6,140
695
953
0.56
162192
85
8,821
724
951
0.77
165024
92
7,070
1,220
1,060
0.47
165024
79
6,850
1,100
1,000
0.51
162193
76
7,700
553
1,062
0.72
165025
73
8,260
1,250
1,230
0.53
165025
69
6,560
960
1,110
0.54
162194
57
5,689
791
523
0.45
165026
56
5,890
1,380
583
0.47
165026
52
5,530
1,340
569
0.37
Avino Silver & Gold Mines Ltd.
12-27
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Technical Report on the Avino Property, Durango, Mexico
12.4
Site Visit


Michael F. OBrien conducted a site visit on June 7 and 8, 2012. During this visit, Mr. OBrien visited the tailings heaps and verified the location of walls and the extent of the oxide and sulphide tailings. Mr. OBrien supervised the collection of eight samples from the oxide tailings; a Garmin GPSMAP 60CSx GPS was used to verify locations. The underground, open-pit, and dump sampling sections of the mine were visited to gain familiarity with the geography and deposits of the Avino and San Gonzalo veins. The San Gonzalo mine was toured down to the level 3 ramp to level 4. The Avino underground workings were flooded at the time of the site visit, and only the portal area could be visited. The core shed was visited, where Mr. OBrien observed the data capture and specific gravity measurement procedures followed by mine staff. Mr. OBrien also visited the Avino Mine laboratory, and observations related to the lab are presented in Section 11.6.
12.5
Tetra Tech Conclusions and Opinion


The drill dataset has been produced within a brownfield property. All data used for this study is obtained from work carried out by staff of the current issuer, which has owned the Property continuously since the start of this work.
12.5.1
Avino and San Gonzalo Veins


A single, compiled database containing all relevant drilling information does not exist for the Property. A variety of partially-compiled data sources were provided to Tetra Tech, indicating poorly-organized and inconsistent database management. In order to verify that the assay data provided by Avino is reliable, Tetra Tech verified the collar and assay data from at least 10% of all drillholes and channel samples included in the current database (as compiled by Tetra Tech). This verification exercise yielded results within an acceptable error rate for collar and assay data.

Based on the data verification completed by Tetra Tech, it is evident that the data collected by Avino is reliable. However, the data management needs to be better organized. The data, as provided by Avino, was only usable for the purpose of this study after extensive data compilation and verification by Tetra Tech.

Downhole survey data is currently not being collected to industry standards by Avino. However, the location of the Avino and San Gonzalo vein intersections observed in drillholes can be verified by both surface and underground mapping, providing confidence in the location, orientation, and true width of both veins.
Avino Silver & Gold Mines Ltd.
12-28
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Technical Report on the Avino Property, Durango, Mexico


Overall confidence in the Avino geology interpretation and database is low. However, the vein intersections were more consistently identified and logged, and the veins of interest are confirmed by assays and surface and underground mapping. Therefore, despite Tetra Techs concerns with the geological identification and interpretation on the mine, the lithology database is considered appropriate for this study because the lithology units modelled and included in the resource estimates in Section 14.1 and Section 14.2, the Avino and San Gonzalo veins, were confirmed by separate data sources.

Based on a review of specific gravity data from drillholes in the Avino and San Gonzalo veins, Tetra Tech concludes that future bulk density measurements should be completed using a water displacement method. The frequency at which specific gravity measurements are collected should also be increased. A comparison of the two measurement techniques used for these SG samples indicates that the results are acceptable for this study.

The rate of QA/QC sample insertion is slightly below recommended industry standards on the Avino vein, but significantly below industry standards on the San Gonzalo vein. Based on the information provided to Tetra Tech, it also does not appear that industry standard plots of standard, blank, and duplicate results (as in Section 12.3) are being constructed and reviewed by Avino on a routine basis. However, QA/QC samples were collected, albeit inconsistently, from all 2006 to 2012 drilling programs and Tetra Tech reviewed the results of these samples. This review found no evidence of systematic laboratory bias, indicating that the assay results are reliable.
12.5.2
Oxide Tailings


The identified grade pattern is similar in character to other tailings deposits, such as overall homogeneity and a pronounced horizontal continuity.

Verification samples taken by Mr. OBrien have confirmed the presence of gold and silver mineralization at grades similar to those obtained in the original tailings drilling campaign, with a low silver bias consistent with the superficial position of the samples in the zone most likely to have suffered surface leaching. The verification samples also confirm that the mine lab assays are not materially different from those of external labs.
12.5.3
QP Opinion


It is Tetra Techs opinion that the assay, sample location, vein lithology, and specific gravity data from the Avino and San Gonzalo veins are reliable to support the purpose of this technical report and a current mineral resource on both veins.
Avino Silver & Gold Mines Ltd.
12-29
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico


While it has been difficult to verify the oxide tailings drill dataset, the fact pattern identified in Section 12.5.2. suggests to Tetra Tech that it is reasonable to rely on the oxide tailings drill database to support the purpose of this technical report and a current mineral resource.
Avino Silver & Gold Mines Ltd.
12-30
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico
13.0
MINERAL PROCESSING AND METALLURGICAL TESTING
13.1
Avino Vein


Historical smelter receipts (pre-2001) and recent discussions with concentrate trading firms have suggested bismuth would be an element of concern in the concentrate. There are plans for metallurgical test work with the objective of reducing the bismuth content in the concentrate in order to improve on the smelter return.
13.2
San Gonzalo Vein


No current metallurgical testwork has been performed. Production decisions are being made without mineral reserves or any studies of economic viability that have been prepared in accordance with NI 43-101. Avino is basing its economic decisions on the net proceeds of a bulk sample program described in Section 9.3.2 and on the basis of results of the current operations.
Avino Silver & Gold Mines Ltd.
13-1
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico
13.3
Oxide Tailings


Tetra Tech has disclosed mineral processing and metallurgical testing methods and results for the oxide tailings portion of the Property. These were disclosed in the technical report entitled Technical Report on the Avino Property, dated July 24, 2012, and summarized below.

Tetra Tech used the estimated grade values and test work results as reported by MMI and PRA, who conducted the metallurgical tests. From these Tetra Tech reviewed all available data and developed different mining and processing flowsheets during the evaluation of the property. Much of the previous data could not be validated and, therefore, could not be used in the review. The MMI technical report indicated that an economic evaluation of the tailings deposit could not be completed at this stage since the deposit could only be classified as an inferred resource. MMI had arrived at this conclusion based on their acknowledgement that their study was limiting with respect to the sampling of the tailings dam and incomplete metallurgical characterization. However, a conceptual financial model was developed by Tetra Tech using the estimated grade values and test work results as reported by MMI and PRA, who conducted the metallurgical tests. Additionally, Tetra Tech investigated gravity separation, flotation, cyanide leach, carbon-in-pulp (CIP), and heap leach processing options. Using the recoveries and process conditions resulting from these tests, the capital costs to construct a processing plant using selected process options were developed while the operating costs associated with each option were determined and a financial model compiled. A heap leach operation with a four-year mine life indicated the best financial alternative.
13.4
Sulphide Tailings


Avino is not conducting mining activity on the sulphide tailings. No mineral processing methods or metallurgical testing is underway or proposed for the sulphide tailings.
Avino Silver & Gold Mines Ltd.
13-2
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico
14.0
MINERAL RESOURCE ESTIMATES
14.1
Resource Summary


The following tables provide a synopsis of the reported mineral resources reported in this section. Table 14.1 summarizes the base case values for all current mineral resources on the Property. A more detailed summary is also provided for the Avino vein (Avino vein and cross-cutting vein in Table 14.2) and the San Gonzalo vein (San Gonzalo vein and Angelica vein in Table 14.3). The reporting cut-off for the Avino vein is 100 g/t Ag_Eq and the cut-off for the San Gonzalo vein is 150 g/t Ag_Eq. These cut-offs were determined by Avino based on actual mining scenarios and a silver price of $20/oz. Current cut-offs used for financial projections by Avino, based on recent market prices, include 80 g/t for the Avino vein and 120 g/t for the San Gonzalo vein.
Avino Silver & Gold Mines Ltd.
14-1
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico
Contained Metal
Grade
Resource
Category
Deposit
Cut-off
Ag_Eq*
Tonnes
Ag_Eq
(oz)
Ag
(oz)
Au
(oz)
Cu
(t)
Ag_Eq
(g/t)
Ag
(g/t)
Au
(g/t)
Cu
(%)
Measured
San Gonzalo Vein
150
71,416
914,791
759,801
3,288
N/A
398
331
1.432
N/A
Total Measured - All Deposits
-
71,416
914,791
759,801
3,288
N/A
-
-
-
-
Indicated
Avino Vein
100
4,253,968
23,838,629
10,835,338
72,207
30,914
174.3
79.2
0.528
0.727
Indicated
San Gonzalo Vein
150
222,407
2,763,069
2,043,514
15,263
N/A
386
286
2.134
N/A
Total Indicated - All Deposits
-
4,476,375
26,601,698
12,878,852
87,470
30,914
-
-
-
-
Inferred
Avino Vein
100
3,220,896
16,262,944
7,068,831
75,858
17,719
157
68.3
0.733
0.55
Inferred
San Gonzalo Vein
150
1,085,276
10,494,843
8,158,834
49,549
N/A
300.8
233.8
1.42
N/A
Inferred
Oxide Tailings
50*
2,340,000
N/A
6,660,000
39,530
N/A
N/A
91.3
0.54
N/A
Total Inferred - All Deposits
-
6,646,172
26,757,787
21,887,665
164,937
17,719
-
-
-
-
Metal
Grade
Resource
Category
Cut-off
Ag Eq
Volume
(m3)
Tonnes
Density
Ag_Eq
(oz)
Ag
(oz)
Au
(oz)
Cu
(t)
Ag_Eq
(g/t)
Ag
(g/t)
Au
(g/t)
Cu
(%)
Indicated
50
3,156,176
8,485,813
2.689
33,698,095
14,645,088
105,279
45,384
123.5
53.7
0.386
0.535
80
2,113,760
5,673,771
2.684
27,938,365
12,390,900
86,867
36,874
153.2
67.9
0.476
0.650
100
1,584,648
4,253,968
2.684
23,838,629
10,835,338
72,207
30,914
174.3
79.2
0.528
0.727
150
863,528
2,327,430
2.695
16,205,941
7,697,377
46,408
20,369
216.6
102.9
0.620
0.875
200
405,792
1,105,097
2.723
9,474,178
4,522,283
27,828
11,718
266.7
127.3
0.783
1.060
250
218,048
596,569
2.736
5,820,374
2,792,304
16,552
7,243
303.5
145.6
0.863
1.214
Inferred
50
3,316,272
8,982,925
2.709
29,258,352
12,407,216
130,031
33,978
101.3
43.0
0.450
0.378
80
1,742,616
4,710,633
2.703
20,488,097
8,718,189
97,196
22,668
135.3
57.6
0.642
0.481
100
1,193,320
3,220,896
2.699
16,262,944
7,068,831
75,858
17,719
157.0
68.3
0.733
0.550
150
519,704
1,399,366
2.693
8,967,681
4,229,254
29,878
10,670
199.3
94.0
0.664
0.763
200
204,560
552,562
2.701
4,338,265
2,289,307
7,375
5,539
244.2
128.9
0.415
1.002
250
71,344
195,258
2.737
1,802,917
1,022,743
2,284
2,197
287.2
162.9
0.364
1.125
Avino Silver & Gold Mines Ltd.
14-2
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico
Metal
Grade
Resource
Category
Ag_Eq
Cut-off
Volume
(m3)
Tonnes
Density
Ag_Eq
(oz)
Ag
(oz)
Au
(oz)
Ag_Eq
(g/t)
Ag
(g/t)
Au
(g/t)
Measured and
50
163,400
425,764
2.606
4,076,578
3,124,273
20,199
297.8
228.2
1.476
Indicated
100
134,112
349,348
2.605
3,901,468
2,987,063
19,396
347.4
265.9
1.727
120
126,688
329,323
2.599
3,830,639
2,927,804
19,150
361.8
276.5
1.809
150
113,264
293,822
2.594
3,677,861
2,803,315
18,550
389.3
296.8
1.964
200
89,704
231,583
2.582
3,325,495
2,528,182
16,912
446.6
339.6
2.271
250
76,672
197,530
2.576
3,079,688
2,339,140
15,708
484.9
368.3
2.473
Inferred
50
560,128
1,476,184
2.635
11,899,790
9,281,947
55,527
250.7
195.6
1.170
100
512,920
1,352,355
2.637
11,615,072
9,055,601
54,289
267.1
208.3
1.249
120
488,944
1,289,240
2.637
11,391,021
8,880,117
53,259
274.8
214.2
1.285
150
412,200
1,085,276
2.633
10,494,843
8,158,834
49,549
300.8
233.8
1.420
200
296,232
779,484
2.631
8,811,481
6,824,184
42,153
351.6
272.3
1.682
250
209,536
551,401
2.632
7,148,532
5,508,613
34,785
403.2
310.7
1.962
Avino Silver & Gold Mines Ltd.
14-3
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico
14.2
Data


Drillhole data for the Avino and San Gonzalo resource estimates was supplied by Avino to Tetra Tech, who verified and compiled it into .csv files (see Section 12.1).Wireframes (.dxf files) of the topography and an out-of-date model of the San Gonzalo vein were also supplied by Avino.Drillhole data was imported into Datamine software (version 3.20.6140.0) and subsequently verified by standard internal Datamine processes.These .csv files contain collar, survey, logging and assay data collected by Avino and collated and confirmed by Tetra Tech.Data includes underground face sampling, reverse circulation (RC), and diamond drill core.Most samples were obtained from diamond drill core.

Wireframes supplied by Avino assisted in modelling the deposit.These wireframes were imported and verified in Datamine software prior to implementation into the block model.These wireframes include, but are not limited to:
surface topography
San Gonzalo vein (last updated in 2007).


Additional wireframes were created by Tetra Tech based on cross-section and plan view images (provided by Avino) of the Avino, San Gonzalo, and Angelica veins, as well as the underground workings of both the Avino and San Gonzalo mines. These images included geological interpretations of the position and extent on individual mineralized veins. These were also imported into Datamine software, but were, in this situation, used as a guide in developing an independent interpretation by Tetra Tech of the main zones of mineralization for the resource estimate.
14.3
Avino Vein
14.3.1
Geological Interpretation


The Avino vein was separated into two geological units; a relatively continuous mineralized vein system, and a zone of surrounding mineralized breccia.
14.3.2
Wireframing


The Avino vein and the surrounding system are interpreted as part of a low- to intermediate-sulphidation system of silver-gold epithermal veins, breccias, stockworks, and silicified zones. This interpretation was applied in the modeling described below.

Solid wireframe models of the main mineralized lithologies were created in Datamine Studio 3 (version 3.21.7164). Drillhole data received from Avino was imported from comma-separated-values (.csv) tables containing collar, assay, lithology, and downhole survey data. A digital terrain model (DTM) was created from a contour map provided by Avino. In addition to this, a geology plan map and drill sections were provided by Avino.
Avino Silver & Gold Mines Ltd.
14-4
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico


For the main Avino vein, drillhole lithologies, sectional and plan geological maps, and modeled underground workings were sufficient to model the mineralized zone.A halo of higher-grade material was noted adjacent to the Avino vein lithology.This was frequently logged as a quartz stockwork or breccia.It is inferred, based on geometry, that this material would have been mined with the Avino vein in the previously mined material.This material was also modeled separately from the Avino vein at depth using the available drillhole data.In some instances, material was included or excluded in this model based on assay grade and not lithology.A secondary vein, which is noted at surface and in the upper mining areas to cross-cut the main Avino vein, was also modeled.Similarly to the quartz stockwork zone, this vein was in some instances modeled based on grade as opposed to lithology.
Designation
Strike
()
Dip
()
Strike
Length
(m)
Down-dip
Extension
(m)
Width
(m)
Main Avino Vein
~70
(E-NE)
-65 to -70
~1,300
~550
~10 to 20
(up to 40)
Quartz Stockwork/Breccia
~70
(E-NE)
-65 to -68
~1,050
up to ~350
Variable
(0 to 30)
Avino Cross-cut Vein
~100
(E-SE)
-56 to -45
~700
~450
~4 to 10
Avino Silver & Gold Mines Ltd.
14-5
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico
Note:
Looking down to the west-northwest.Main Avino vein in red, quartz stockwork/breccia in blue, Avino cross-cut vein in pink, underground mine workings in green, topography in light yellow transparent mesh, and drillhole traces.


To test the validity of these models, and to determine the ideal method for treating the wireframe boundaries, contact profiles were generated, and are discussed in Section 14.2.3.
14.3.3
Contact Profiles


Contact profiles were generated to test the validity of the wireframe models and to determine the ideal method for treating wireframe boundaries.The mineralized domains displayed strong, hard contacts with the wallrock in silver and copper profiles (as shown in Figure 14.2).Note that in this figure, elevated silver values appear at distances greater than 15m from the contact; this is not because the wallrock contains abundant silver at this distance, but rather that this far away from the main vein only mineralization (and not all barren material) is sampled.The contacts of gold mineralisation are softer than silver, but average grade data still showed that the populations were clearly statistically distinct.Between the main Avino vein and the adjacent/surrounding mineralized quartz stockwork/breccia, the silver and copper contacts were slightly softer
Avino Silver & Gold Mines Ltd.
14-6
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico


(Figure 14.3), though still mostly acting as a hard boundary.As these two units are geologically distinctive (vein versus breccia), they were treated as a hard boundary for grade interpolation.All contacts between mineralized and wallrock populations were treated as hard boundaries in estimation.
Avino Silver & Gold Mines Ltd.
14-7
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico
14.4
San Gonzalo Vein
14.4.1
Geological Interpretation


The San Gonzalo vein, like the Avino vein, represents a geologically continuous mineralized vein system. Unlike the Avino vein, the San Gonzalo vein does not have a notable contiguous breccia envelope.
14.4.2
Wireframing


The San Gonzalo vein and the surrounding system is interpreted as part of a low- to intermediate-sulphidation system of silver-gold epithermal veins, breccias, stockworks, and silicified zones.This interpretation was applied in the modeling described below.

Solid wireframe models of the main mineralized lithologies were created in Datamine Studio 3.Drillhole data from Avino was imported from .csv tables containing collar, assay, lithology, and downhole survey data.A DTM was created from a contour map provided by Avino.In addition to this, drill sections were provided by Avino.This data, combined with the wireframe model of the underground workings, was utilized in the creation of the grade domains.
Avino Silver & Gold Mines Ltd.
14-8
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico


For the main San Gonzalo vein, drillhole lithologies and assay grades, sectional geological maps, and modeled underground workings were used to model the mineralized zone.A secondary vein, the Angelica vein, which is noted in the upper mining areas to cross-cut the main San Gonzalo vein, was also modeled using the same information as that applied to the main San Gonzalo vein.
Designation
Strike
()
Dip
()
Strike
Length
(m)
Down-dip
Extension
(m)
Width (m)
Main San Gonzalo Vein
~295 (W-NW)
to ~320 (NW)
-73 to -80
~700
~450
~2 to 8
Angelica Cross-cut Vein
~100 (E-SE)
-80
~350
~220
~1 to 8
Avino Silver & Gold Mines Ltd.
14-9
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico
Note:
Looking down to the east-northeast.Main San Gonzalo vein in red, Angelica vein in blue, underground mine workings in green, topography in light yellow transparent mesh, and drillhole traces.
14.4.3
Contact Profiles


Contact profiles were generated to test the validity of the wireframe models and to determine the ideal method for treating wireframe boundaries. The mineralized domains displayed strong, hard contacts with the wallrock in silver and copper profiles, with only slight to moderate increases approaching the contact (as evidenced in Figure 14.5). For gold the contacts were less conspicuous, but average grade data still showed that the populations were statistically distinct. All contacts between mineralized and wallrock populations were treated as hard boundaries in estimation.
Avino Silver & Gold Mines Ltd.
14-10
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico
14.5
Exploratory Data Analysis
14.5.1
Raw Data Assays and Statistics


Table 14.6 tabulates the raw drillhole assay and length statistics for the Avino mineralization. They are tabulated as a total and also by domain. Assayed metals include silver, gold, copper, zinc, and lead. Metals considered in the Avino resource estimate include silver, gold, and copper.
Avino Silver & Gold Mines Ltd.
14-11
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico


Table 14.7 tabulates the raw drillhole assay and length statistics for the San Gonzalo mineralization. It is tabulated as a total and also by domain (4 and 5). Assayed metals considered in the San Gonzalo resource estimate include silver, gold, copper, zinc, and lead. Unlike Avino, San Gonzalo data includes face samples (4f) in domain 4. Data without face samples are also presented (4dh).
Avino Silver & Gold Mines Ltd.
14-12
1251920100-REP-R0001-02
Technical Report on the Avino Property, Durango, Mexico
Table 14.6
Avino Raw Data Statistics
Domain
Field
N
Records
N
Samples
Minimum
Maximum
Mean
Variance
Standard
Deviation
Standard
Error
Skewness
Kurtosis
1, 2
and 3
Ag_gt
1,623
1,592
0
1811.3
37.06
6441.29
80.26
2.01
10.99
188.97
Au_gt
1,623
1,592
0
48.054
0.2625
2.3509
1.5333
0.0384
23.65
665.57
Cu_pct
1,623
1,592
0.0009
10.31
0.4014
0.5080
0.7127
0.0179
6.8924
73.2701
Zn_pct
1,623
1,592
0
2.5
0.0733
0.0194
0.1391
0.0035
9.8863
136.0172
Pb_pct
1,623
1,592
0
2.28
0.0412
0.0155
0.1245
0.0031
8.9404
115.6834
LENGTH
1,623
1,623
0.04
16.4
1.2448
0.6792
0.8241
0.0205
9.2797
134.3613
1
Ag_gt
767
767
0.3
1811.3
52.41
10188.52
100.9382
3.6447
9.5419
137.14
Au_gt
767
767
0.0025
48.054
0.3630
4.6337
2.1526
0.0777
17.53
350.7454
Cu_pct
767
767
0.0021
10.02
0.5788
0.6893
0.8302
0.0300
5.4219
46.8048
Zn_pct
767
767
0
2.5
0.0902
0.0332
0.1822
0.0066
8.6847
91.4761
Pb_pct
767
767
0
2.28
0.0596
0.0258
0.1606
0.0058
7.4944
77.6199
LENGTH
767
767
0.05
2.5
1.2946
0.1337
0.3657
0.0132
-1.5445
1.9204
2
Ag_gt
749
725
0
1034.9
21.20
2506.68
50.07
1.8594
13.29
241.98
Au_gt
749
725
0
4.31
0.1402
0.1339
0.3660
0.0136
6.9956
62.7635
Cu_pct
749
725
0.0009
10.31
0.2537
0.3185
0.5643
0.0210
10.8615
162.9471
Zn_pct
749
725
0
0.678
0.0569
0.0057
0.0753
0.0028
2.6637
11.0782
Pb_pct
749
725
0
1.21
0.0231
0.0056
0.0751
0.0028
8.8347
107.9050
LENGTH
749
749
0.04
13.7
1.1924
0.8858
0.9412
0.0344
7.6261
80.3417
3
Ag_gt
107
100
0.6
271.1
34.36
2586.09
50.85
5.0854
2.8984
9.0494
Au_gt
107
100
0.0025
6.72
0.3777
0.7153
0.8458
0.0846
5.0857
31.5475
Cu_pct
107
100
0.0025
0.6228
0.1119
0.0083
0.0912
0.0091
2.5720
9.3318
Zn_pct
107
100
0.0021
0.589
0.0614
0.0083
0.0911
0.0091
3.1453
11.7254
Pb_pct
107
100
0.001
0.2726
0.0321
0.0027
0.0522
0.0052
2.8027
8.2988
LENGTH
107
107
0.05
16.4
1.2551
3.1064
1.7625
0.1704
6.4956
49.9188
Avino Silver & Gold Mines Ltd.
14-13
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Technical Report on the Avino Property, Durango, Mexico
Domain
Field
N
Records
N
Samples
Minimum
Maximum
Mean
Variance
Standard
Deviation
Standard
Error
Skewness
Kurtosis
4 and 5
Ag_gt
3,535
3,426
0
14,768.4
243.1
503,925
709.877
12.128
9.504
129.2
Au_gt
3,535
3,426
0.0025
185.2
1.0224
20.188
4.493
0.077
26.12
925.8
Cu_pct
3,535
3,426
0.00005
4.1
0.0513
0.021
0.144
0.002
15.69
356.6
Zn_pct
3,535
3,426
0.0068
35.5
0.5744
2.351
1.533
0.026
9.003
126.8
Pb_pct
3,535
3,426
0.000411
14.6
0.3361
0.742
0.862
0.015
6.890
66.01
LENGTH
3,535
3,535
0
10.2
0.6847
0.154
0.392
0.007
10.33
206.2
4
Ag_gt
3,143
3,038
0
14,768.4
251.3
531,849
729
13.231
9.5
128.2
Au_gt
3,143
3,038
0.0025
185.2
1.0861
22.5583
4.7496
0.0862
24.9
834.5
Cu_pct
3,143
3,038
0.00005
3.74
0.0450
0.0131
0.1144
0.0021
16.1
420.2
Zn_pct
3,143
3,038
0.0068
35.5
0.5422
2.4206
1.5558
0.0282
9.38
133.5
Pb_pct
3,143
3,038
0.000411
14.6
0.3477
0.8133
0.9018
0.0164
6.68
61.26
LENGTH
3,143
3,143
0
10.2
0.6795
0.1611
0.4014
0.0072
10.8
211.0
5
Ag_gt
390
386
0.25
5,523
179
282,065
531
27.03
7.427
62.37
Au_gt
389
385
0.005
16.320
0.516
1.333
1.154
0.059
8.839
104.139
Cu_pct
390
386
0.0013
4.1
0.0998
0.0786
0.2804
0.0143
9.963
122.8
Zn_pct
390
386
0.0103
13.14
0.8194
1.7101
1.3077
0.0666
4.723
30.99
Pb_pct
390
386
0.0039
4.7
0.2451
0.1770
0.4208
0.0214
5.093
38.29
LENGTH
390
390
0.05
1.75
0.7269
0.0912
0.3019
0.0153
0.6512
0.3156
4dh
Ag_gt
273
264
0
3,623
168
129,852
360
22.18
5.32
38.33
Au_gt
273
264
0.0025
24.85
1.2209
9.7298
3.1193
0.1920
5.26
31.06
Cu_pct
273
264
0.0005
3.74
0.0703
0.0689
0.2625
0.0162
10.97
143.7
Zn_pct
273
264
0.0068
35.5
0.9054
10.3085
3.2107
0.1976
7.47
64.79
Pb_pct
273
264
0.0008
14.6
0.5291
2.6907
1.6403
0.1010
5.46
33.57
LENGTH
273
273
0.2
10.2
0.9539
1.0553
1.0273
0.0622
6.48
46.90
table continues
Avino Silver & Gold Mines Ltd.
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Technical Report on the Avino Property, Durango, Mexico
Domain
Field
N
Records
N
Samples
Minimum
Maximum
Mean
Variance
Standard
Deviation
Standard
Error
Skewness
Kurtosis
4f
Ag_gt
2,880
2,782
0.05
14,768
257
566,454
753
14.27
9.3466
122.5
Au_gt
2,880
2,782
0.0025
185.2
1.0331
23.55
4.8532
0.09
25.35
836.4
Cu_pct
2,880
2,782
0.00005
4.1
0.0502
0.0182
0.1350
0.0026
15.75
372.8
Zn_pct
2,880
2,782
0.007
15.49
0.5682
1.7476
1.3220
0.0251
6.1940
47.62
Pb_pct
2,880
2,782
0.000411
11.72
0.3236
0.5981
0.7734
0.0147
6.0065
49.05
LENGTH
2,880
2,880
0
2
0.6611
0.0692
0.2630
0.0049
0.9094
1.3655
Avino Silver & Gold Mines Ltd.
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Technical Report on the Avino Property, Durango, Mexico
14.5.2
Outlier Management and Capping Strategy


When dealing with skewed populations, as well as outliers to the distribution, it is common practice in the industry to restrict the influence of high assays through top-cutting or capping. Capping was implemented on the raw assay data prior to sample length compositing. Capping limits were chosen as a function of the continuity-discontinuity of the high-grade tail of the metals histograms.

Avino and San Gonzalo mineralization are geographically separated. Thus, for the purposes of capping, they are considered separately. The following histograms form the basis for the capping strategy.

The high-grade tail population of length-weighted sample assays forms a cohesive group until just over 250 g/t silver. Afterwards, the population becomes increasing irregular. Thus, it was considered that samples are capped at 700 g/t silver (Figure 14.6).
Avino Silver & Gold Mines Ltd.
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Technical Report on the Avino Property, Durango, Mexico
Avino Silver & Gold Mines Ltd.
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Technical Report on the Avino Property, Durango, Mexico


The Avino vein gold histogram high-grade tail clearly disaggregates just above 9g/t (Figure 14.7).Thus, a gold cap of 9g/t was applied to the data.
Avino Silver & Gold Mines Ltd.
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Technical Report on the Avino Property, Durango, Mexico


Similarly, the copper histogram high-grade tail disengages immediately above 6% copper (6,000ppm) (Figure 14.8).Thus, a cap was applied at 6% for copper.
Avino Silver & Gold Mines Ltd.
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Technical Report on the Avino Property, Durango, Mexico


The San Gonzalo mineralization was estimated for both zinc and lead as well as copper, gold and silver.Unlike the Avino vein drillhole sample population, the San Gonzalo vein also has a significant number of underground face samples in the main San Gonzalo vein (domain 4).As shown in Table 14.8, face samples were included in the capping strategy as there are an order of magnitude more face samples than drillhole samples in the dataset.Statistics indicate datasets are comparable.
Type
Field
N
Records
N
Samples
Minimum
Maximum
Mean
Variance
Standard
Deviation
Skewness
Kurtosis
DDH
Ag_gt
273
264
0
3,623
168.2
129,852
360.3
5.319
38.334
Au_gt
273
264
0.003
24.85
1.221
9.730
3.119
5.258
31.057
Cu_pct
273
264
0.001
3.740
0.070
0.069
0.263
10.97
143.70
Zn_pct
273
264
0.007
35.500
0.905
10.308
3.211
7.470
64.788
Pb_pct
273
264
0.001
14.600
0.529
2.691
1.640
5.464
33.569
Face
Ag_gt
3,196
3,098
0.050
14,768
249.1
534,459
731.1
9.432
125.7
Au_gt
3,196
3,098
0.003