Timok Project


Overview

Timok Project Location

The Timok copper-gold project consists of the Cukaru Peki Upper Zone and Lower Zone. Nevsun owns 100% of the Cukaru Peki Upper Zone. The Lower Zone is a joint venture with Freeport-McMoRan Exploration Corporation (Freeport).

Upper Zone Overview

The Timok project is located within the central zone of the Timok Magmatic Complex (TMC), in the Serbian section of the East European Carpathian-Balkan Arc. The TMC has one of the highest concentrations of copper enrichment in the Tethyan Belt.

The high sulphidation epithermal ("HSE") mineralization in the Upper Zone comprises massive sulphide, semi-massive, and also vein, stockwork, dissemination and hydrothermal breccia matrix sulphide hosted by strongly altered (advanced argillic and argillic) andesite. The HSE mineralization forms a single coherent zone at depths ranging from 400 to over 800 metres below surface. Pyrite is the dominant sulphide mineral, and the principal copper mineral is covellite with lesser enargite, bornite and chalcocite occurring in veins, hydrothermal breccias, disseminations and replacement. Gold is associated primarily with the copper sulphides.

The Timok project comprises the Brestovac-Metovnica, Brestovac Zapad, Jasikovo-Durlan Potok and Leskovo exploration permits that are held by Rakita d.o.o., a Serbian subsidiary of Nevsun. The exploration permits cover an area of 212.58 sq. km.

Timok Upper Zone PFS Highlights

  • 10 year mine life producing over 1.7 billion pounds of payable copper
  • Sub-level cave mining with 3.25 million tonnes per annum conventional plant producing copper concentrate
  • After tax NAV of $1.8 billion at flat $3.15 per pound copper and 8% discount rate
  • $574 million in pre-production capital with 80% IRR and under 1 year payback
  • Located in an established mining jurisdiction supportive of new mining investment

Please see the technical report for further information.

Reserves & Resources

An initial reserve for the Upper Zone was released in March 2018. The Probable Reserve for the Upper Zone is estimated to be 27 million tonnes at an average grade of 3.3% copper and 2.1g/t gold, containing 0.89 million tonnes of copper and 1.8 million ounces of gold.

 

Initial Timok Upper Zone Mineral Reserve Statement (as at March 8, 2018)

Category (all domains) Tonnes M Grade Contained Metal
% Cu g/t Au % As Cu, M tonnes Au, M ounces
Proven            
Probable 27.1 3.3 2.1 0.17 0.89 1.8
Total Proven and Probable 27.1 3.3 2.1 0.17 0.89 1.80

1) The Mineral Reserves and Resources in this news release were estimated using the Canadian Institute of Mining, Metallurgy and Petroleum (CIM), CIM Standards on Mineral Resources and Reserves, Definitions and Guidelines prepared by the CIM Standing Committee on Reserve Definitions and adopted by CIM Council.

2) Metal prices used include US$3.00/lb Cu and US$1,300/oz Au.

3) A Reserve NSR cut-off of US$35/tonne was used to optimize the SLC Ring layout.

4) Contained metal figures and totals may differ due to rounding of figures.

 

The Measured and Indicated Resource for the Upper Zone is estimated to be 29 million tonnes at an average grade of 3.7% copper and 2.4g/t gold, containing 1.1 million tonnes of copper and 2.2 million ounces of gold. The Inferred Resource for the Upper Zone is estimated to be 14 million tonnes at 1.6% copper and 0.9g/t gold containing 0.23 million tonnes of copper and 0.42 million ounces of gold. The Resource NSR value used to report the estimate is US$35 per tonne.

 

Timok Upper Zone Mineral Resource Statement (as at April 24, 2017)

Category (all domains) Tonnes
M
Grade Contained Metal
% Cu g/t Au % As Cu, M tonnes Au, M ounces
Measured 2.2 8.6 5.7 0.29 0.19 0.4
Indicated 26.6 3.3 2.1 0.2 0.87 1.8
Total Measured and Indicated 28.7 3.7 2.4 0.2 1.05 2.2
Inferred 13.9 1.6 0.9 0.06 0.23 0.42

Note: totals do not match sum of individual items due to rounding. Qualified person Martin Pittuck SRK UK

1)  Resource NSR value used to report the estimate is $US 35 per tonne

2)  All figures are rounded to reflect the relative accuracy of the estimate

3)  Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability

4)  Mineral Resource is reported on 100% basis

 

Qualified Person

The Mineral Resources were reviewed and approved by Martin Pittuck of SRK Consulting (UK) Limited, a Qualified Person under National Instrument 43-101, details of which can be found on SEDAR under the Company's profile.

Lower Zone Overview

The Lower Zone is divided in ownership; currently, Nevsun owns 60.4% with Freeport-McMoRan Exploration Corporation ("Freeport") holding the remaining 39.6%. Upon completion of a feasibility study (on the Upper or Lower Zone), Nevsun will indirectly own 46% of the Lower Zone and Freeport will indirectly own 54%.

Timok (Cukaru Peki) Lower Zone Initial Mineral Resource Highlights:

  • Porphyry copper inferred mineral resource of 1.7 billion tonnes grading 0.86% copper and 0.18 g/t gold (0.96% copper equivalent)
  • Contains 14.3 million tonnes (31.5 billion pounds) of copper and 9.6 million ounces of gold at a US$25 cut off
  • Includes 1.1 billion tonnes grading 0.99% copper and 0.21 g/t Au (1.11% copper equivalent) at a US$45 cut off
  • Ranks high in grade, size and contained metal for porphyry copper deposits worldwide

Timok (Cukaru Peki) Lower Zone Resource
The Lower Zone at Timok consists of two distinct mineralization styles: first a typical porphyry copper style mineralization characterized by potassic alteration and chalcopyrite with elevated molybdenum, and second a high sulphidation style mineralization consisting of sericitic alteration with elevated arsenic and base metals (lead, zinc and bismuth). The porphyry copper mineralization is by far the most important volumetrically at over 95% of the volume at the lower cut-off.  The mineralized envelope extends above the Upper Zone on the east side with elevations ranging from approximately 500 meters below surface to just over 2,200 meters below surface.  See Figure 1 for deposit configuration and Figure 2 for a visual representation of the mineralized zones.

Table 1 provides the complete inferred mineral resource estimate.  The Lower Zone inferred mineral resource has low arsenic content, with less than 50 ppm on average and is well within the typical range for porphyry deposits.

 

Lower Zone Resource

Timok (Cukaru Peki) Lower Zone Initial Mineral Resource Highlights:

Lower Zone Resource Block Model by Zone (SRK June 19, 2018) all Inferred
Porphyry Copper
Cut-off  
US ($ / tonne) CuEq (%) Tonnes (000) Cu (%) Au (g/t) US ($ / tonne) CuEq (%) As (ppm) Cu (tonnes 000) Au (oz 000)
>55 0.83 706,000 1.12 0.24 72 1.25 49 7,907 5,346
>50 0.76 906,000 1.06 0.22 68 1.18 45 9,604 6,454
>45 0.68 1,126,000 0.99 0.21 64 1.11 44 11,147 7,540
>40 0.61 1,330,000 0.94 0.2 60 1.05 45 12,502 8,434
>35 0.53 1,483,000 0.91 0.19 58 1.01 49 13,495 9,017
>30 0.45 1,572,000 0.89 0.18 57 0.98 49 13,991 9,317
>25 0.38 1,659,000 0.86 0.18 55 0.96 50 14,267 9,566
>20 0.3 1,945,000 0.78 0.16 50 0.87 47 15,171 10,282
>15 0.23 2,286,000 0.71 0.15 45 0.79 44 16,231 10,991

Notes:

  • Results are tabulated using a dollar equivalent. Dollar equivalent is calculated using: Au per ounce = US$1,400; Cu per pound (lb) = US$3.00;
  • Recoveries: Cu = 87%; Au = 69% for Porphyry Copper Zone
  • Metal equivalent on a post recovery basis
  • Mining assumed to be by block cave
  • Modelling, resource estimation and tabulation were completed by Dr. Gilles Arseneau, PGeo of SRK Canada

 

Technical Reports