Endeavour extends Karma mine life to +10 years as North Kao infill drilling adds 262koz of reserves

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North Kao Highlights:

• North Kao infill drilling confirms the continuity of the previous inferred resource and improves the grade profile
  • 314koz of resources amenable to heap leach processing converted to indicated status
  • Indicated resource grade up 53% over the previous inferred grade to 1.22 g/t Au
• 262koz were subsequently converted to reserves, extending Karma's mine life to beyond 10 years
• The North Kao mineralized structure remains open to the north and the potential exists for additional sub-parallel zones
• Following the success at North Kao, the 2017 exploration campaign will focus on other near-mill targets, such as Rambo West and Yabonsgo

Abidjan, February 23, 2017 - Endeavour Mining Corporation (TSX:EDV)(OTCQX:EDVMF) is pleased to announce that the infill drill program at its North Kao deposit, located at its Karma Gold Mine in Burkina Faso, has confirmed the continuity of the previous inferred resource, resulting in a maiden indicated resource of 314,000 ounces amenable to heap leaching and a subsequent conversion of 262,000 ounces to reserves.

Sébastien de Montessus, President & CEO, stated: "When we acquired Karma last year we were confident in its exploration potential and our ability to quickly extend its mine life. Following the conversion of resources at North Kao to reserves, Karma now meets our strategic portfolio criteria of having a minimum life of 10 years and ability to produce at an AISC below $850/oz. Looking ahead, our 2017 program will focus on the Rambo West and Yabonsgo near-mill targets, which we believe could further improve the mine's outlook."

The North Kao deposit is located within 10 kilometers of the current processing plant. Its main mineralized zone stretches over 1.4 kilometers along strike and remains open to the north. The evolution of its reserves and resources amenable to heap leaching (comprised of oxide and transition material), is summarized in the table below. 

Table 1: North Kao Reserve and Resource  (Heap Leaching)

Notes provided in Section "About the Mineral Reserves and Resources" of this Press Release. 

Infill Drilling Program  

An infill drilling program was completed in 2016 with the objective of upgrading the existing inferred resources to the indicated category. The program comprised 68 core holes (7,571 meters) and 488 reverse circulation holes (39,554 meters). The sections were spaced by 50 meters, with 35 meters between holes.

As shown in Figure 1 below, the main mineralized zone at North Kao can be followed for up to 1.4 kilometers along strike, located structurally above the mineralized zone of Kao Main, whereas multiple (up to 7 subparallel) zones were crossed in the narrow portion of the intrusion to the north. The mineralized structure remains open to the north within the sediments with potential for additional subparallel zones within the Kao intrusion.

Figure 1: North Kao Infill Drilling Program
(Showing Mineralization is Open  to the North)

Most of the mineralization occurs in the Kao Intrusion, a 2.5 kilometer long by 1.6 kilometer wide pluton of felsic composition with local porphyritic facies and centimetric aplitic veins. A minor portion occurs within clastic sediments (siltstones and argillites with andalousite porphyroblasts) close to the contact of the intrusion as it becomes narrower to the north. The mineralization is associated with northwest-trending, shallow to moderately east-dipping, anastomosed deformation and alteration zones. Alteration in the fresh rock consists of diffuse albite-carbonate-sericite-pyrite and more focused quartz-albite-carbonate veining with sericitic arsenopyrite-rich seams.

As shown in Figure 2 below, the infill drill holes targeted the base of the transition and/or the top of the bedrock, which ranges from approximately 60 meters below surface in the southern part of the grid to approximately 110 meters in the northern part.

Figure 2: North Kao Cross-Section

Upcoming Exploration Program: More Near-mill Targets

In 2017, a $4 million exploration program totaling approximately 30,000 meters has been planned to drill near-mill targets such as Rambo West and Yabonsgo, as shown in the map below.

Figure 3: Karma Near-mill Exploration Targets

About the Mineral Reserves and Resources

The mineral reserve and resource estimate for the North Kao deposit is reported in accordance with the National Instrument 43-101 and has been estimated using the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) "Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines". The mineral resource estimate is classified as "indicated" and "inferred" as defined by the CIM. Mineral resources which are not mineral reserves did not have demonstrated economic viability. The estimate of mineral reserve may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues.

The effective date of this mineral reserve and resource estimate is December 31^st, 2016, with a comparison over the previous estimate provided in the Table below. 
 

Table 2: North Kao Reserve Evolution  

Table 3: North Kao Resource Evolution  

Notes for the December 31, 2016 Reserve and Resource estimates provided in Section "About the Mineral Reserves and Resources" of this Press Release. 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. The December 31, 2015 Reserve and Resource estimates have been sourced from latest NI 43-101 TR titled «Updated feasibility study (GGI, GGII, Kao, Rambo & Nami deposits) and a Preliminary Economic Assessment (North Kao Deposit) for The Karma Gold Project Burkina Faso, West Africa», available on Sedar.

The disclosure of a mineral reserve and resource statement for the North Kao deposit is not deemed material to Endeavour as a whole. Therefore, the Company will not be filing a technical report in respect of this mineral resource estimate.

North Kao Resource Modeling

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

The North Kao resource model was developed in the Geovia Surpac 3Dmodeling software using all the available geology information from 123 diamond drill holes totaling 18,445 meters, and 589 reverse circulation drill holes totalling 53,784 meters completed between 2007 and 2016. The geological model and assay data guided the mineralisation model. A total of 34 mineralized domains were interpreted and modeled into 3D wireframes within Geovia Surpac modeling software. The mineralized zones have an average strike of 345^o azimuth dipping 30^oNE. The drill holes gold assays were composited to 1.0 meter intervals within the mineralized wireframes and capped at 10 g/t Au. Spatial analysis of the gold mineralization using variograms indicated a good continuity of the grades along strike and down dip of the mineralised zones.

Gold grades were interpolated using inverse distance squared estimation methodology constrained by the mineralized domains. Density values of the oxidized material vary from 1.4 to 2.7 based on weathering material type while the fresh rocks density values vary from 1.6 to 2.9 based on rocktypes. The mineral resource was modelled using a 3D block model built in Geovia Surpac. Measures were conducted to validate the accuracy of the estimate, including swath plots comparison and visual review on sections.

In order to establish the reasonable prospects for eventual economic extraction, the Mineral Resources were constrained within a Whittle-optimized $1,500 pit shell, as is reported at a 0.20 g/t gold cutoff grade.

A large portion of the previously reported Sulphide inferred resource has been declassified as the Mineral Resources were constrained within a Whittle-optimized $1,500 pit shell in addition to the low confidence due to the wide drill spacing. No additional infill drilling is planned on the sulphide material as it is not considered economical with the current processing facility.

North Kao Reserve Estimation

The quantifying of modifying factors, Whittle optimization and pit design preparation was done by/under direct supervision of Michael Alyoshin, MEng, MAusIMM CP (Min), MIMMM, CEng, EUR ING. Mr. Alyoshin is Endeavour Mining's Corporate Chief Mining Eng., Strategic Projects and a Qualified Person as defined by NI 43-101.

This estimation is of Pre-Feasibility Study level of accuracy and, therefore, satisfies CIM requirements to mineral reserve reporting.

The majority of the costs parameters used in Whittle optimization are based on actual, geotechnical/ recovery information used in optimization and subsequent mine design mostly sourced from latest NI 43-101 Technical Report titled "Updated feasibility study (GGI, GGII, Kao, Rambo & Nami deposits) and a Preliminary Economic Assessment (North Kao Deposit) for The Karma Gold Project Burkina Faso, West Africa" and operational experience. Mining dilution of 22% at 0g/t was estimated using 1 meter grade shells.

The parameters used for the Reserve and Resource estimation are described below:

Table 4: North Kao Reserve and Resource parameters

Qualified Persons

This press release has been reviewed and approved by Adriaan "Attie" Roux, Pr.Sci.Nat, Endeavour's Chief Operating Officer, a Qualified Person under NI 43-101.

About Endeavour Mining Corporation

Endeavour Mining is a TSX-listed intermediate gold producer, focused on developing a portfolio of high quality mines in the prolific West-African region, where it has established a solid operational and construction track record.

Endeavour is ideally positioned as the major pure West-African multi-operation gold mining company, operating 5 mines in Côte d'Ivoire (Agbaou and Ity), Burkina Faso (Karma), Mali (Tabakoto), and Ghana (Nzema). In 2016, it expects to produce between 600koz and 640koz at an AISC of US$860 to US$905/oz. Endeavour is currently building its Houndé project in Burkina Faso, which is expected to commence production in Q4-2017 and to become its flagship low-cost mine with an average annual production of 190koz at an AISC of US$709/oz over an initial 10-year mine life based on reserves. The development of the Houndé project is expected to lift Endeavour's group production +900kozpa and decrease its average AISC to circa $800/oz by 2018, while exploration aims to extend all mine lives to +10 years.

Contact Information                

Endeavour Mining |  Executive Office | Bureau 76, 7 Boulevard des Moulins, Monaco 98000

This news release contains "forward-looking statements" including but not limited to, statements with respect to Endeavour's plans and operating performance, the mineral resource and reserve estimate, 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.  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.