Endeavour Increases Resources at Its Ity Mine as Le Plaque Continues to Grow

ENDEAVOUR INCREASES RESOURCES AT ITS ITY MINE AS LE PLAQUE CONTINUES TO GROW

Resource based on only 35% of holes drilled  ·  < $20/oz discovery cost  ·  7 nearby targets confirmed

 HIGHLIGHTS:                                                      

• Le Plaque’s Indicated resource increased by 43%, ranking the deposit as Ity’s second largest and the highest grade
• Indicated resource has grown to 7.9Mt at 2.66 g/t Au for 689koz while Inferred resource stands at 0.8Mt at 2.10 g/t Au for 52koz  
• Low discovery cost of <$20 per Indicated resource ounce 
• Metallurgical tests indicate a gold recovery rate of at least 90%
• 93% of resources are in the Indicated category
• Resource estimate is expected to continue to increase as the deposit remains open at depth and in multiple directions with mineralization confirmed by step-out drilling
• Potential for the Le Plaque area to be similar to the Ity Mine Complex and host multiple deposits
• It is now estimated that the Le Plaque deposit represents only 30% of the area covered by the anomaly as reconnaissance drilling confirmed mineralization for at least seven other targets
• Further deposits are expected to be delineated as the current Le Plaque resource only incorporates 35% of the holes drilled to date
• Further exploration is scheduled for H2-2020 with 15,000 meters of drilling planned
• Mining permit for the Le Plaque deposit is targeted for Q3-2020 and an updated Le Plaque reserve estimate is expected to be published in Q3-2020  

Abidjan, July 7, 2020 – Endeavour Mining (TSX:EDV)(OTCQX:EDVMF) is pleased to announce further success from its ongoing exploration program at the La Plaque discovery, part of its flagship Ity mine in Côte d’Ivoire, with a 43% increase in Le Plaque’s Indicated resource and the confirmation of mineralization for seven additional nearby targets.

In H1-2020, exploration efforts continued to be focused on the Floleu license, located only 6km south of the processing plant, which hosts the Le Plaque discovery, with a total of 67,195 meters drilled. This amounts to 188,600 meters drilled on the license since the discovery was made in early 2018.  

To date, an important part of the drilling campaign has focused on gaining a better understanding of the area’s potential. As such, 65% of the holes drilled since 2018 were for reconnaissance, which has confirmed mineralization for at least seven targets, thereby boosting confidence in delineating further deposits. The Le Plaque deposit was the first target to be delineated and is now estimated to represent only 30% of the whole anomaly.

Drilling has resulted in a 43% increase in Le Plaque’s Indicated resource estimate to 689koz, since the last resource was published in June 2019, as shown in Table 1 below. Drilling has confirmed the Le Plaque deposit remains open at depth and in multiple directions and further resources are expected to be delineated.

At least 15,000 meters of drilling are planned for the remainder of 2020. Following these resource additions, the Le Plaque reserve estimate is expected to be published in Q3-2020 and integrated into the Ity mine plan. The permitting process is well underway, with a mining permit expected to be received in Q3-2020.

Patrick Bouisset, Executive Vice President Exploration and Growth, said: “We are very pleased with the results of the exploration program at La Plaque, as it continues to confirm its potential to be another significant discovery.

We are leveraging the same strategy of intensive reconnaissance drilling to improve our understanding of the area before ramping up to resource delineation through infill drilling that we applied to the Ity Complex prior to 2018. At that time, the priority was to quickly delineate resources to justify the construction of the CIL plant and so we focused on infill drilling to leverage the knowledge that had been acquired through previous reconnaissance drilling. This strategy resulted in the discovery of 1.6Moz of Indicated resources in 2016 and 2017 at $15/oz.

On the Floleu license, to date 65% of drill holes have been aimed at defining the global potential and making new discoveries which has led to several targets being identified, and only 35% of the drilling has been to delineate resources at Le Plaque. So far, our results have been outstanding, both in terms of the high grade nature and mineralization extension.

Looking ahead, we are excited by the upside potential of the Le Plaque deposit, which remains open at depth and in several directions, and by its neighbouring targets. We expect to continue to delineate resources and remain on track to achieve the 5-year exploration target which we set in 2016.

In the near-term, we expect the higher-grade material from Le Plaque to displace the lower-grade reserve material in the mining sequence, helping to improve the mine’s cash flow generation, whilst supporting our goal of locking in a 10-plus year mine life at Ity, with annual production of 250kozpa.”

ABOUT LE PLAQUE AREA

Le Plaque, located only 6km south of the processing plant, is a high-grade discovery made on the northern part of the wholly-owned Floleu exploration license, as shown in Figure 1 below.

Figure 1: Ity Mine Gold-in-Soil Map and Simplified Map with Exploration Targets

Given the high grade nature of the Le Plaque area, it has been the primary exploration target in the greater Ity area since March 2018. A strong focus has also been placed on understanding the potential of the wider Le Plaque area as 65% of the holes drilled (representing 40% of total meters drilled) on the license were dedicated to discovering additional targets.

During H1-2020, in addition to the Le Plaque resource definition program, a total of 543 Air Core (“AC”) holes totalling 23,186 meters were drilled on a more regional scale on the northern part of the Floleu license on a 200-meter by 50-meter northwest-southeast oriented grid. This reconnaissance drilling outlined that Le Plaque represents only 30% of the large Northern Floleu anomalous area where at least seven other targets were confirmed, as shown in Figure 2 below. Drilling on these targets is expected to start in Q4-2020, with the aim of delineating additional maiden resources in 2021.

Figure 2: Nearby Le Plaque Targets

Intercepts in the figure above are based on a minimum 2-meter length, a 0.5 g/t Au cut-off, and 1.0-meter internal dilution.

ABOUT THE LE PLAQUE DEPOSIT

As shown in Table 1 below, a maiden resource was published as part of the year-end 2018 estimate and was subsequently increased on July 8, 2019.  Since this previously announced estimate, the Le Plaque resource has increased by 43%. Due to the intensive in-fill drill program completed, 93% of the maiden resource has been classified in the Indicated category. As the mineralization starts at surface, it is amenable to open pit mining.

Table 1: Le Plaque Mineral Resource Evolution

Mineral Reserve estimates follow the Canadian Institute of Mining, Metallurgy and Petroleum ("CIM") definitions standards for mineral resources and reserves and have been completed in accordance with the Standards of Disclosure for Mineral Projects as defined by National Instrument 43-101. Reported tonnage and grade figures have been rounded from raw estimates to reflect the relative accuracy of the estimate. Minor variations may occur during the addition of rounded numbers. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. Resources were constrained by MII $1,500/oz
Pit Shell and based on a cut-off of 0.5 g/t Au. For the notes related to the December 31, 2018 resource estimate, please consult the February 23, 2018 press release available on the Company’s website. For the notes related to the June 30, 2019 resource estimate, please consult the July 8, 2019 press release available on the Company’s website.For the notes related to the June 30, 2020 resource estimate, please consult the below section entitled Le Plaque Resource Modelling.

A sensitivity analysis performed at gold prices between $1,300 and $1,700/oz demonstrates the robustness of the Le Plaque resources model due to its high grade mineralization, as shown in Table 2 below.

Table 2: Le Plaque June 2019 Mineral Resource Estimate

No Measured resources have been estimated. Mineral Reserve estimates follow the Canadian Institute of Mining, Metallurgy and Petroleum ("CIM") definitions standards for mineral resources and reserves and have been completed in accordance with the Standards of Disclosure for Mineral Projects as defined by National Instrument 43-101. Reported tonnage and grade figures have been rounded from raw estimates to reflect the relative accuracy of the estimate. Minor variations may occur during the addition of rounded numbers. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. Resources were constrained by MII $1,500/oz
Pit Shell and for sensitivity purpose by MII $1,250/oz pit shell and based on a cut-off of 0.5 g/t Au.

A total of 51 Diamond Drilling (“DD”), 144 Reverse Circulation (“RC”) and 1 RC/DD holes totaling 25,695 meters were drilled in H2-2019 with the main results published on February 24, 2020. Additional resource infill and resource drilling down to a 25mx25m grid was conducted in H1-2020 to address the continuity of high grade mineralization. In H1-2020, a total of 34,559 meters were drilled consisting of 381 holes, comprised of 88 DD holes totaling 14,883 meters and 193 RC holes totaling 19,676 meters. The drill programs were very successful as over 72% of the drilled RC and DD Resource and extension drilled holes encountered at least one interval of mineralization of 0.5g/t Au with a minimum true width of more than two meters.

As shown in Figure 3 below, the Le Plaque deposit is now composed of four main zones (Le Plaque Main, Epsilon, Le Plaque South (Delta) and Delta Extension), all of which are open in various directions with mineralization already confirmed by step-out drilling.

Figure 3: Le Plaque Drill Map and Selected H1-2020 Intercepts (true width/grade) Per Area

Intercepts in the figure above are based on a minimum 2 meter length, a 0.5 g/t Au cut-off, and 1.0 meter internal dilution.

The Le Plaque updated resource stretches over at least 1.2km long and 0.2km wide for the Le Plaque Main and Epsilon areas, over 0.6km long and 0.3km wide for the Le Plaque South/Delta area and at least over 0.5km and 0.25km wide for Delta extension. The Le Plaque Main area remains open at depth and towards the East (Flat), the Epsilon area at depth and towards the north/northeast (Epsilon North), Le Plaque South/Delta area at depth and towards East and Delta Extension towards Southwest (Delta Extension south).

In light of the high grade (over 3 g/t Au), and sometimes very high grade (over 30 g/t Au), nature of the mineralization and its related structural complexity, including numerous mineralized intervals, an intensive RC/DD in-fill drill program was completed based on 25-meter spaced sections with 33-meter nominal spacing, generally with an angle of 50° towards the SE (N135°E), except for the Plaque Main area where drilling was orientated towards the SW (N225°E). The Le Plaque South/Delta and Delta Extension area were also covered by a 25-meter by 25-meter grid to validate the continuity of the steeply dipping high grade mineralization.

Selected best intercepts of H1-2020 include (true width uncapped):

• Le Plaque Main (Flat) and South area:
  • FL20-1227: 3.5m at 17.7 g/t Au, including 1.8m at 31.64 g/t Au
  • FL20-1233: 4.6m at 4.13 g/t Au, including 0.9m at 11.74 g/t Au
  • FL20-1236: 7.0m at 7.13 g/t Au, including 0.9m at 41.4 g/t Au
  • FL20-1232: 3.5m at 30.44 g/t Au, including 1.7m at 55.96 g/t Au
  • FL20-1238: 16.0m at 6.05 g/t Au, including 2.1m at 29.72 g/t Au and including 0.9m at 10.56 g/t Au
  • FL20-1295: 3.5m at 7.83 g/t Au, including 0.9m at 29.35 g/t Au
  • FL20-1301: 8.6m at 4.18 g/t Au, including 0.9m at 16.8 g/t Au
  • FL20-1375: 3.5m at 11.69 g/t Au, including 2.6m at 15.33 g/t Au
  • FL20-1398: 6.0m at 9.46 g/t Au, including 3.5m at 14.8 g/t Au
  • FL20-1465: 6.0m at 6.98 g/t Au, including 3.5m at 11.49 g/t Au
  • FL20-1498: 8.6m at 11.27 g/t Au, including 1.7m at 51.7 g/t Au
  • FL20-1519: 6.0m at 9.67 g/t Au, including 0.9m at 52.1 g/t Au
  • FL20-1530: 16.4m at 11.87 g/t Au, including 2.6m at 66.62 g/t Au
• Delta Extension area:
  • FL20-1246: 5.2m at 7.15 g/t Au, including 1.0m at 32.2 g/t Au
  • FL20-1248: 6.9m at 3.93 g/t Au, including 0.9m at 13.44 g/t Au
  • FL20-1255: 4.3m at 4.01 g/t Au, including 0.9m at 12.72 g/t Au; 13m at 3.55 g/t Au, including 0.9m at 15.56 g/t Au
  • FL20-1260: 7.8m at 5.7 g/t Au, including 2.6m at 10.18 g/t Au
  • FL20-1261: 6.0m at 18.42 g/t Au, including 1.7m at 59.56 g/t Au
  • FL20-1263: 9.4m at 5.94 g/t Au, including 2.3m at 15.8 g/t Au
  • FL20-1269: 18.1m at 1.16 g/t Au; 12.1m at 4.2 g/t Au, including 0.9m at 11.16 g/t Au, and including 0.9m at 18.59 g/t Au
  • FL20-1294: 2.5m at 15.04 g/t Au, including 0.9m at 40 g/t Au
  • FL20-1299: 6.5m at 11.56 g/t Au, including 1.7m at 30.95 g/t Au
  • FL20-1308: 5.2m at 11.83 g/t Au, including 0.9m at 60.5 g/t Au
  • FL20-1318: 6.0m at 16.1 g/t Au, including 0.9m at 27.18 g/t Au, and including 1.7m at 39.4 g/t Au
  • FL20-1368: 7.8m at 3.69 g/t Au, including 0.9m at 10.96 g/t Au
  • FL20-1385: 12.9m at 19.18 g/t Au, including 0.9m at 10.01 g/t Au, and including 1.7m at 79.4 g/t Au, and including 2.2m at 39.14 g/t Au
  • FL20-1408: 7.4m at 21.96 g/t Au, including 4.1m at 37.15 g/t Au
  • FL20-1509: 6.9m at 4.64 g/t Au, including 1.7m at 14.99 g/t Au
  • FL20-1537: 3.8m at 14.53 g/t Au, including 1.1m at 47.9 g/t Au

Le Plaque’s geology consists of a granodiorite batholith intruded into a sequence of Birimian skarn altered metasediments (impure marbles, metasiltstones and sandstones) and dioritic intrusions. The mineralization is structurally controlled and associated with deformation corridors displaying few meters-thick ductile and brittle-ductile shears with silica-sericite alteration, quartz veining and sulfides (pyrite, with lesser sphalerite and chalcopyrite and local trace galena or pyrrhotite), mostly within the granodiorite, and along contacts between lithological units.

The previous mineral resource estimate released on July 8, 2019 was centred on the WNW-ESE trending Le Plaque Main and the NNE-SSW trending Epsilon contact zones between the granodiorite and skarn domains and in the granodiorite-hosted NNE-SSW trending shears in Le Plaque South area (Delta structural corridor). Following positive results obtained in late 2019, the H1-2020 drilling has been targeting additional mineralized splays in the granodiorite in Le Plaque South/Delta and Le Plaque Flat areas as well as strike extensions, most notably a 500-meter long extension of the mineralization in the granodiorite domain toward the south (Delta Extension), as shown in Figure 4.

Figure 4: Delta Extension H1-2020 Best selected Intercepts Map

As shown in Figure 5 and 6 below, the Northern part of Delta Extension mineralization is associated with a set of en-echelon north-northeast-trending, steeply west-northwest-dipping shearing structures entirely hosted within the granodiorite, while in its central part, it can be very high grade and closely associated with a blind and thick dioritic intrusive. Delta Extension remains clearly open at depth and towards south, and should extend at least a further 400 meters as demonstrated by positive step out drilling recently performed.

Figure 5: Section A – Delta Extension Northern Part

Figure 6: Section B – Delta Extension Central Part

Drilling will resume in the Le Plaque area with at least 15,000 meters of additional drilling expected to be completed before year-end. The aim is to extend its mineralization and delineate additional resources.  

UPDATED ITY MINE RESOURCES

The updated Le Plaque resource estimate has increased Ity’s Measured and Indicated resources by 6%, as presented in Table 3 below, while adding higher-grade material.

Table 3: Ity Mine Mineral Resource Evolution

Mineral Reserve estimates follow the Canadian Institute of Mining, Metallurgy and Petroleum ("CIM") definitions standards for mineral resources and reserves and have been completed in accordance with the Standards of Disclosure for Mineral Projects as defined by National Instrument 43-101. Reported tonnage and grade figures have been rounded from raw estimates to reflect the relative accuracy of the estimate. Minor variations may occur during the addition of rounded numbers. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. Resources were constrained by MII $1,500/oz
Pit Shell and based on a cut-off of 0.5 g/t Au. For the notes related to the December 31, 2019 resource estimate, please consult the March 9, 2020 press release available on the Company’s website. For the notes related to the June 30, 2020 resource estimate, please consult the below section entitled Le Plaque Resource Modelling. The Ity Mine Mineral Resource is inclusive of Ity Mine depletion since December 31, 2019. The updated Mineral Resource is current as of December 31, 2019.

NEXT STEPS

• An Ity mine reserve update, inclusive of the updated Le Plaque resource, is expected to be published in Q3-2020
• Due to the success achieved, and as the Le Plaque deposit still remains open at depth and in various directions, a follow-up 15,000-meter drilling campaign is expected to begin after the rainy season with the aim of further resource delineation and is expected to be continued into 2021
• Exploration is also ongoing on other targets within the Ity mining permit, for which an update will be published later in the year 
• Mining permit for the Le Plaque area is expected to be received in Q3-2020

LE PLAQUE RESOURCE MODELLING

The statistical analysis, geological modelling and resource estimation were prepared by
Kevin Harris, CPG.
Mr. Harris is Endeavour Mining's V.P. Resource Manager and a Qualified Person as defined by NI 43-101.

The Le Plaque resource model was developed in Geovia’s Surpac software. A total of 49 mineralized zones were defined from the current drilling data and geologic interpretations across La Plaque.  The gold assays from the drill holes were composited to 1.0 meter intervals within the mineralized wireframes and capped at from 10 to 40 g/t Au based on the statistics of each mineralized zone.  Spatial analysis of the gold distribution within the mineralized zone using variograms indicated a good continuity of the grades along strike and down dip of the mineralized zones and were used to establish ordinary kriging parameters.

The density was measured in 5,069 core samples within the various rock types then averaged within the model by the weathered zones. The laterite density is 1.55, the saprolite is 1.50, the transition is 2.40, and the fresh rock is 2.80.

The gold grade was estimated with the ordinary kriging method constrained within the mineralized domains.  The grade was estimated in multiple passes to define the higher confidence areas and extend the grade to the interpreted mineralized zone extents.  The grade estimation was validated with visual analysis by comparison with the drilling data on sections, comparing with inverse distance squared estimation, and with swath plots comparing the block grades with the composites.

The mineralized domains were classified as indicated and inferred resource classifications depending on the sample spacing, number samples, confidence in mineralized zone continuity, and geostatistical analysis.  Indicated classification was generally applied to blocks within the mineralized zoned defined by a minimum of seven samples from at least three drill holes with a 50-meter search.  Inferred classification is defined by a minimum of three samples within a 75-meter search from two drill holes.

The resource was constrained by a $1,500 pit shell and 0.50 g/t cut-off grade.  A $1,300/oz and $1,700 was also created to determine price sensitivity. The Whittle pit shell optimization assumed a base mining cost of $2.67 per tonne, and an adjusted ore mining cost of $3.20/tonne for oxide, $3.74/tonne for transition, and $4.01/tonne for fresh rock, mining recovery of 95%, mining dilution of 10%, pit slope of 40o, gold recovery of 94.6% in oxide, 93.2% in transition and 81% in fresh rock, and processing and G&A cost of $15.85 per tonne in oxide, $16.79 in transition and $17.61 in fresh.

ASSAYS AND QUALITY ASSURANCE/QUALITY CONTROL / DRILLING AND ASSAY PROCEDURES

The RC and AC drill program samples were collected on a 1-meter interval using dual tube, a percussion hammer. The material passes through a cyclone which is thoroughly cleaned after every sample by flushing the hole. Samples were split at the drill site using a single chute riffle splitter with both bulk and laboratory sample weights and moisture recorded. Representative samples for each interval were collected with a spear, sieved into chip trays and retained for reference.

Drill core (PQ, HQ and NQ size) samples are selected by Endeavour geologists and sawn in half with a diamond blade at the project site. Half of the core is retained at the site for reference purposes. Sample intervals are generally 1 meter in length.

All samples are transported by road to Bureau Veritas in Abidjan or to SGS. Each laboratory sample is secured in poly-woven bags ensuring that there is a clear record of the chain of custody. On arrival samples are weighed and crushed to 2mm (70% passing), pulverize entire sample to 75μm (85% passing). Samples are analysed for gold using standard fire assay technique with a 50-gram charge and an Atomic Absorption (AA) finish. Blanks, field duplicates and certified reference material (CRM’s) are inserted by Endeavour geologists in the sample sequence for quality control and to ensure there are a suite of QC samples in each fire assay batch.

The sampling and assaying are monitored through the implementation of a quality assurance – quality control (QA-QC) program. This QA-QC program was audited by International consultant, independent from Endeavour Mining, in 2019 and consequently designed to follow industry best practices.

Full drill results are available by clicking here. 

QUALIFIED PERSONS

The scientific and technical content of this news release has been reviewed, verified and compiled by
Silvia Bottero, Professional Natural Scientist l, VP Exploration Côte d’Ivoire for Endeavour Mining.
Silvia Bottero has more than 18 years of mineral exploration and mining experience and is a "Qualified Person" as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects ("NI 43-101"). The resource estimation was completed by Kevin Harris, CPG, VP Resources for Endeavour Mining and "Qualified Person" as defined by National Instrument 43-101.

CONTACT INFORMATION

ABOUT ENDEAVOUR MINING CORPORATION

Endeavour Mining is a TSX listed intermediate African gold producer with a solid track record of operational excellence, project development and exploration in the highly prospective Birimian greenstone belt in West Africa. Endeavour is focused on offering both near-term and long-term growth opportunities with its project pipeline and its exploration strategy, while generating immediate cash flow from its operations.

For more information, please visit www.endeavourmining.com.

Corporate Office: 5 Young St, Kensington, London W8 5EH, UK   

This news release contains "forward-looking statements" including but not limited to, statements with respect to Endeavour's plans and operating performance, the estimation of mineral reserves and resources, the timing and amount of estimated future production, costs of future production, future capital expenditures, and the success of exploration activities. Generally, these forward-looking statements can be identified by the use of forward-looking terminology such as "expects", "expected", "budgeted", "forecasts", and "anticipates". Forward-looking statements, while based on management's best estimates and assumptions, are subject to risks and uncertainties that may cause actual results to be materially different from those expressed or implied by such forward-looking statements, including but not limited to: risks related to the successful integration of acquisitions; risks related to international operations; risks related to general economic conditions and credit availability, actual results of current exploration activities, unanticipated reclamation expenses; changes in project parameters as plans continue to be refined; fluctuations in prices of metals including gold; fluctuations in foreign currency exchange rates, increases in market prices of mining consumables, possible variations in ore reserves, grade or recovery rates; failure of plant, equipment or processes to operate as anticipated; accidents, labour disputes, title disputes, claims and limitations on insurance coverage and other risks of the mining industry; delays in the completion of development or construction activities, changes in national and local government regulation of mining operations, tax rules and regulations, and political and economic developments in countries in which Endeavour operates. Although Endeavour has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking statements, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements. Please refer to Endeavour's most recent Annual Information Form filed under its profile at www.sedar.com for further information respecting the risks affecting Endeavour and its business. AISC, all-in sustaining costs at the mine level, cash costs, operating EBITDA, all-in sustaining margin, free cash flow, net free cash flow, free cash flow per share, net debt, and adjusted earnings are non-GAAP financial performance measures with no standard meaning under IFRS, further discussed in the section Non-GAAP Measures in the most recently filed Management Discussion and Analysis.

Attachments

• Figure 1 Ity Mine Gold-in-Soil Map and Simplified Map with Exploration Targets
• Figure 2 Nearby Le Plaque Targets
• Figure 3 Le Plaque Drill Map and Selected H1-2020 Intercepts
• Figure 4 Delta Extension H1-2020 Best selected Intercepts Map
• Figure 5 Section A – Delta Extension Northern Part
• 200707 - NR - Le Plaque Resources Update Vf