Download Zgounder NI 43-101 Technical Reports
Highlights of the Zgounder Silver Mine March 2018 PEA Study:
- – A project life of 10 years with the current resources up to 2027;
- – ZMSM Internal Rate of Return of 134% pre-tax and 118% after tax;
- – ZMSM pre-tax Net Present Value of US$215.1M (discounted at 6.5%) at variable silver price from US$17.50 to US$21.50 per ounce with yearly average of US$20.50 per ounce;
- – ZMSM after-tax Net Present Value of US$200.2M (discounted at 6.5%) at variable silver price from USD$17.50 to USD21.5 USD per ounce with average of US$20.5 per ounce;
- – The extraction of 3.974Mt at 292 g/t Ag for silver production of 33.682M ounces;
- – Milling to increase to 500 tpd in 2018 then up to 2020 followed by a 2000 tpd in 2021;
- – Production increase to 1.354M ounces per year up to 4.762M ounces of silver per year;
- – Total operating cost of US $63.64 per tonne (averaged over the expected mine’s life);
- – Capex and sustaining capital requirements of US $46.9M.
The Zgounder silver deposit is located in the central Anti-Atlas on the NW flank of the Siroua massif. The Zgounder deposit is Late Neoproterozoic in age and is mainly composed of a volcano sedimentary formation attributed to the Precambrian II (PII). The formation is intruded to the West by the Askaoun granodioritic massif (later Precambrian II-III). The geology of Zgounder is divided into three formations (Demange, 1997), two with a major clastic component intercalated with volcanics (identified as the ‘blue’ and ‘brown’ formations) overlain by an acid ignimbritic volcanic complex (the ‘black formation’).
Under care and maintenance since 1990, Zgounder has been Morocco’s second most important silver mine after Imiter, and shares several of its geological, structural and age characteristics. Zones north and east of the previous underground workings promise substantial new reserves that could be exploited by open pit mining.
The mine is approximately 260 kilometres east of the major port city of Agadir (pop. 575,320), within the Proterozoic Siroua Massif of the Anti-Atlas Range.
The Zgounder mine is accessible from Agadir by well maintained paved highways (N10 and P1706) running east for 205 kilometres to Tallouine in the Taroudant province. The majority of the final 61 kilometres to the mine are traveled on a normally well paved road to the village of Askaoun. The last five-kilometre stretch to the mine is accessible via a dirt road which could be easily be upgraded.
The exploitation licence covers 16 km².
Mining Installations and Lodging
Mining installations include a cyanidation plant with a 300 t/day capacity, a chemical analysis laboratory, a crusher plant with a capacity of 300 t/h, a compressor station, an electrical power station and a machine shop. Lodging is available on site and consists of 10 housing units for engineers, geologists and managers, and 56 units for the miners and their families. There are administrative offices on site, as well as an infirmary and a mosque.
From 1982 to 1990, the Société Minière de Sidi Lahcen (SOMIL) operated the Zgounder underground silver mine and extracted 500,000 t of silver ore grading 330g/t Ag using a cut off grade of 125 g/t Ag.
The mine contains important historical resources present in ancient residues, tailings and underground workings.
* Maya is not treating the historical estimate as current mineral resources or mineral reserves
* The historical resources estimates stated above are for historical purposes only and are not compliant with CIM definition standards for Mineral Resources and Mineral Reserves, as defined under National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”). The historical resource estimates were prepared prior to the implementation of NI 43-101 and use terminology not compliant with current reporting standards. Maya has not made any attempt to re-classify the estimates according to current NI 43-101 standards of disclosure or the CIM definitions and is not treating the estimate as current mineral resources or mineral reserves as defined in NI 43-101. Historical estimates should not be relied upon. Investors are cautioned that “geological resources” are considered conceptual in nature and there is no guarantee that historic “geological resources” will be able to be converted into NI 43-101 compliant resource categories or demonstrate economic viability.
Geological and Structural Framework
The Zgounder silver deposit sits within the Proterozoic Siroua “boutonnière” or massif that occupies a transitional position between the northern mobile Panafrican belt and the southern Eburnean domain comprised in the stable West-African Craton. The Siroua massif is composed of geological assemblages belonging to the Precambrian I, II and III, each separated by major discontinuities (Figure 1). The oldest rocks of the Siroua Massif (P1) consist of gneisses and amphibolites unconformably overlain by ophiolitic complexes, volcanosedimentary units, alternating schist-sandstones and limestones, quartzites and turbidites (PII). The Zgounder deposit occurs in the PIII assemblage (Late Neoproterozoic) characterized by a felsic calc-alkaline/alkaline volcanic activity corresponding to the initiation of rifting process announcing the Infracambrian–Cambrian transgression.
The Zgounder volcanosedimentary assemblage forms a large EW-oriented monoclinal structure with a general southerly tilt (Figure 2). To the north, the assemblage rests on an andesitic basement, to the west it is intruded by the Askaoun granodioritic massif (PIII), whereas to the east it is overlain by volcanosedimentary rocks of the Ouerzazate series (PII) and Neogene phonolites. The Zgounder series is divided into three units, which are in stratigraphic order: 1) The Blue Formation (300-400 m ) consisting of sandstone, greywacke and shale with layers of tuff and quartz keratophyre followed by an orange rhyolitic unit, 2) The Brown Formation composed of 350 to 450 m of micaceous schistose sandstone overlain by a 45 m thick dolerite sill/dyke and 3), The 900 m-thick Black Formation containing at its base a felsic volcanic complex (ignimbrite, rhyolitic breccia, divitrivied rhyolite) and forming the hanging rock of the Ag-mineralization over the Brown Formation (Figure 2). To the south, the Black Formation culminates in sandstone, greywacke and conglomerate.
The Zgounder shales-sandstones strike N90°E and dip strongly to the south forming the southern flank of an anticline generated by NS-compression. There are four types of faulting and fracturing present at Zgounder;1) an EW-oriented system corresponding to the opening and filling of fractures with argillaceous material and to subvertical fractures, 2) a NS-oriented system with a northward reject, 3) a NNE-NNW-oriented system dipping 60 to 75°E and 4) a subhorizontal system oriented NNE-SSW which generated a staircase collapse of the Brown Formation toward the north (Figures 3 and 4).
The silver mineralization occurs in three, often superposed, genotypes: 1) Mm-thick beds of well-crystallized, finely disseminated pyrite associated with quartz and other sulphides found in chloritized and tuffaceous pelitic layers of the Brown Formation with low silver grades (5 to 25 g/t Ag) (Figure 5), 2) Native silver veinlets associated with proustite (Ag₃AsS₃), argentite (Ag₂S) and filling micro-fractures discordant with the stratitification and suggesting a stockwork-type mineralization and 3), Native silver dissemination with sulphide veinlets (sphalerite, galena, argentite and cinabar) in brecciated sandstone-shale layers and spotted by nodules and flakes of chlorite and/or carbonate microlithes. The paragenetic sequence shows two successive stages: an early Fe-As stage (silver-bearing pyrite and arsenopyrite), followed by an Ag-bearing polymetallic (Zn, Pb, Cu, Hg; sphalerite and chalcopyrite) stage. Native silver is by far the most common silver mineral and forms an amalgam with Hg. Tension gashes originally trapped the silver mineralization within a NNE-oriented shear zone affecting the Brown Formation shale-sandstone beds containing anomalous Ag values. These were then transposed by EW-oriented structures forming isolated Ag-mineralized lenses and fissures (Figure 4).
900 – 1200 Zgounder was first explored and exploited for silver principally in shallow oxidized zones (Figure 6).
1978 The BRPM/PNUD estimated the residues of ancient workings to contain 66,000 t @ 325g/t Ag
1982-1990 The Société Minière de Sidi Lahcen (SOMIL) operated an underground mine and a plant with an ore throughput capacity of approximately 75-80,000 t/yr. 500,000 t of ore grading 330g/t Ag were treated during this period using a cut off grade of 125 g/t. SOMIL undertook 15,383 metres of drilling, 9,220 metres of underground drifts and adits, as well as 1,200 m of raises and ore passes (Figure 7).
1990 The BRPM pursued underground exploration and sunk 10 drill holes to find the western continuation of the mineralization.
1997 The BRPM undertook an exploration campaign consisting of mapping and sampling the mineralized structures followed by a drilling program totaling 1800 m of core. New silver mineralized zones were defined at the base of the sandstone-shale beds of the Brown Formation. ACA Howe International undertook the sampling of surface rocks and tailings. ACA Howe International verified the available core left after the 1997 campaign and collected rock samples from key surface areas of the mine. ACA Howe estimated that there was at least 500,000 t present in the recent tailings. The upper tailings averaged 250 g/t Ag (9 m-thick) and the lower tailings (12 m-thick) 109 g/t Au.
2002-2004 The Compagnie Minière de Touissit carried out extensive surface and underground work. 6,228 m of underground and surface drilling were directed to find new silver-rich zones, adding 1128 of new drifts, galleries and ore shoots and performing 14,636 m of underground percussion drill holes. The work enabled the definition of new historical reserves in the southern (357,400 t @ 468.3 g/t Ag) and northern (449,625 t @ 375.9 g/t Ag) sectors of the Zgounder mine.
2009 A pre-feasibility study put out by MANAGEM evaluated the operational investment costs as well as the infrastructure and milling rehabilitation costs related to reopening the Zgounder mine.
2011 In April, participation in the international tender organized by L’Office National des Hydrocarbures et des Mines (ONHYM) for the total or partial acquisition of the Zgounder mine.
In September, the Corporation and the ONHYM agreed to negotiate a convention in order for Maya to acquire 85% of the Zgounder Silver Deposit.
2012 The convention for Zgounder silver deposit was signed on January 6th.
- Complete rehabilitation of mine site and mill at Zgounder;
- Completion of the Environmental Impact Study;
- Creation of Zgounder Millennium Silver Mining (85% Maya / 15% ONHYM);
- Closing of 12-month loan agreement of US$3.5M;
- Initial NI43-101 compliant silver resources estimate for Zgounder silver mine;
- Zgounder Millennium Silver Mining obtained cyanide permitting (March 2014);
- Filing of NI43-101 Preliminary Economic Assessment on SEDAR (March 2014);
- Closing of a convertible debentures financing for $10 M (April 2014);
- Filing of NI43-101 Pre-Feasibility Study on SEDAR (May 2014);
Sources: SGS Canada Inc. Geostat (2011), A C A Howe International (1999) and Compagnie Minière de Touissit (2004).