The Gays River Deposit mineralization has long been considered a Mississippi Valley-type (“MVT”) lead-zinc deposit. Characteristics of sedimentary formations that host MVT lead-zinc mineralization include shallow-water, shelf-type carbonate rocks with reefs around the peripheries of intracratonic basins, karst structures, limestone-dolomite interfaces and proximity to a major hydrocarbon-bearing basin. The archetypical MVTs occur in the United States in several famous districts surrounding the Michigan-Illinois Basin which also has significant hydrocarbon production. Each of the districts is enormous, with resource potential of 75 million to 750 million tonnes and individual deposits in the order of 1 to 100 million tonnes.

MVTs are thought to have formed when hot, basin derived, oil field-type brines formed at depths of more than 2 km, migrated towards lower pressure areas around the basin periphery. Mineralization precipitated from the brines when they encountered porous areas like reefs, karst breccias or sedimentary traps.

Sangster and others (1998) draw on their own and others’ evidence to conclude that all Windsor Group lead-zinc deposits are epigenetic relative to their enclosing strata, exhibiting both open space filling and host-rock replacement. At the Gays River Deposit, textures (including fossils) have been preserved; representing volume-for volume replacement of original limestones by dolomite, and the sulphides are, in turn, replacements and porosity fillings within the previously altered host rocks.

Main Zone Mineralization
Nesbitt Thomson Inc. (1991) describe the high- grade mineralization as consisting of a massive sulphide zone in contact with the evaporite or trench, ranging in thickness from 0.1 m to 5.0 m and locally containing up to 78% Pb and 57% Zn. On the footwall of the massive sulphide, there is a zone of disseminated material (>7% Zn equivalent) which, in places, is up to 12 m in thickness. Locally disseminated mineralization (>2% Zn equivalent) extends up to 20 m into the footwall.

The Main Zone is essentially controlled by a sinuous paleo coastline. The main part of the deposit is shallow (generally <150 m deep), has a dip length of approximately 100 m and a strike length following the paleo-coastline over a straight-line distance of 2 km (Nesbitt Thomson Inc., 1991).

The mineralization at the Gays River Deposit consists of massive and/or disseminated ore hosted predominantly by the carbonate rocks, with extensions down into the basal breccia unit. The massive mineralization consists of fine-grained (<10-20 mm), Fe-poor, beige-colored sphalerite and medium to coarse-grained, Ag-poor galena (<10-20 ppm Ag in galena concentrates) (Kontak, 1998; Savard and Kontak, 1998), is restricted to the carbonate-evaporite contact and is 1 m to 3 m in true thickness. Disseminated mineralization, consisting of yellow to orange, millimeter-size euhedral sphalerite and millimeter- to centimeter- size euhedral galena, fills in primary porosity in the dolomitized carbonates and walls of primary cavities (Kontak, 1998).

Sphalerite and galena constitute about 99.5% of metallic minerals. Other sulphide minerals are marcasite, pyrite, and chalcopyrite, while gangue minerals include calcite, dolomite, fluorite, barite, and selenite (Patterson, 1993).

Getty Zone Mineralization
Zinc and lead sulphide mineralization are found throughout the Getty carbonate bank, along with trace amounts of iron sulphide in isolated areas. Base metal sulphides are also present to a lesser extent in carbonate matrix of the underlying conglomerate/breccia unit and within calcite or micrite filled fractures and joints present in underlying Goldenville Formation greywackes. While not extensively reported to date, galena has also been documented locally at the Scotia Mine [Main Zone] deposit in thin (<20cm thick) discordant, steeply dipping veins that generally trend north-south (B. Mitchell, personal communication, 2007).

Sphalerite is the predominant base metal sulphide phase present and is typically honey yellow to buff or beige in colour and finely crystalline. Based on drill core observations, Bryant (1975) specified the following four modes of sphalerite occurrence within the deposit, with the first being the most common:
a) disseminated mineralization showing concentrations from trace to 10% or more,
b) semi massive and massive mineralization as seams and replacements along bedding surfaces or laminae,
c) massive, porosity filling or surface coating mineralization in fossiliferous and vuggy carbonate,
d) mineralization associated with secondary calcite in small stringers and veinlets.

The Scotia Mine deposit covers a total strike length of approximately 4 kilometres, with some surface constraints in between, and a vertical distance of approximately 120 metres. All mining is from open-pit operations with an expected mine life of approximately 14 years.

The Scotia Mine mineral resources will be extracted using conventional load and haul (truck & shovel) mining methods as determined by optimized pit designs and life-of-mine schedules. Mining operations will be completed using an owner/operator of excavators, loaders, haul trucks and ancillary support equipment as well as some rental equipment. Equipment requirements have been determined based upon required production rates and haulage cycles.

The open-pits will be mined on 5-metre-high benches with double benching being utilized on the lower, which are primarily comprised of fair to good quality. Drilling and blasting are only required for 40 percent of the total material mined over the life of mine plan, which accounts for all of the hard rock to be mined from the pits. The remaining 60 percent is largely comprised of overburden and has been proved to be free digging material based on past operations and will not require blasting. Drilling and blasting will be performed using contract services.

The Ultimate Pit Design was divided into 6 phases to optimize development sequences and production requirements. Waste has been subdivided into overburden, gypsum, and carbonate waste rock. Inferred resource material inside the Ultimate Pit Design has been included as carbonate waste rock and totals approximately 1,450,000 tonnes at 1.5% Zn and 0.7% Pb. Waste storage will consist of a combination of backfilling the mined pits and stockpiling in the waste dump. Using the Ultimate Pit Design and the pit phase sequencing, a Life-Of-Mine (“LOM”) mining schedule was developed by month and is based on operating 24 hours/day, 365 days/year.

Stockpiling & Crushing
The crushing circuit is designed for an annual operating time of 5,256 hours per annum or 60% availability. Material is hauled from the mine to stockpiles. Provision for dumping on the ROM pad for blending and rehandling into the mobile jaw crusher feed hopper is provided. Material from the mobile jaw crusher (P80: - 70mm) is crushed further by a new secondary cone crusher (P80: -40mm). The secondary crusher product then feeds a new sizing screen (6’x12’ double deck). The oversize from the new sizing screen feeds an existing cone crusher (formally the existing Secondary Crusher) to produce a final tertiary crushed product (P80: -14.5mm). The crushed material is conveyed to an existing Fine-Ore-Bin that provides approximately 10 hours of live storage. Given the milling operation is designed for an annual operating time of 8,059 hours per annum or 92% availability, this will result in excess crushed material production when the crusher is operational. The excess crushed material will allow routine crusher maintenance to be carried out without interrupting feed to the mill.

The Fine-Ore-Bin discharge area is equipped with 2 upgraded belt feeders to regulate feed at 122 t/h onto the rod mill feed conveyor.

The material handling and crushing circuit includes the following key equipment:
• Mobile Jaw Crusher
• New Secondary Cone Crusher
• New Sizing Screen
• Upgraded Conveyor Belt Drives & Pullies
• Existing refurbished Tertiary Crusher (Formally the Secondary Crusher).

Grinding Circuit
The grinding circuit consists of a rod mill followed by two ball mills in closed circuit with a new cyclone pack. The circuit is sized based on a cyclone overflow 80% passing size (P80) of 110 µm. The rod mill slurry discharges through a trommel screen into the cyclone feed pump box. The ball mills are fed by the cyclone underflow. The cyclone underflow launder is split to feed the two different sized ball mills. The ball mill discharges through a trommel and the oversize is screened out and discharged to a scats chute. Trommel undersize discharges into the cyclone feed pump box. The former regrind mill discharges through a trommel and the oversize is screened out and discharged to a scats chute. Trommel undersize is pumped to the cyclone feed pump box. Water is added to the cyclone feed pump box to obtain the appropriate density prior to pumping to the cyclones. Cyclone overflow gravitates to a new cyclone Over-Flow feed tank and then pumped to the Pb conditioner tank.

The grinding circuit includes the following key equipment:
• Existing 300 kW rod mill
• Existing 670 kW ball mill
• Existing 197 kW ball mill
• New cyclone feed pump box
• New hydrocyclones.

The Process design is comprised of the following circuits:
- Primary, secondary and tertiary crushing circuit
- Fine-Ore-Bin to buffer throughput to the grinding circuit
- Rod mill with trommel screen followed by 2 ball mills with cyclone classification (1 of the ball mills is the former re-grind mill)
- Pb and Zn flotation circuit
- Pb and Zn dewatering circuit
- Tailings discharge to tailings management facility
- Concentrate handling.

Flotation Circuit
The flotation circuit begins with the agitated Pb conditioner tank which overflows into the Pb rougher flotation cells. The Pb rougher flotation concentrate feeds the Pb 1st cleaner and the Pb rougher tails feeds the Pb scavenger flotation cells. A 3 rd cleaner concentrate feeds the final Pb concentrate pump box which feeds the Pb thickener.

The Pb scavenger concentrate and Pb cleaner tails feeds back to the Pb rougher flotation cells. The Pb scavenger tails are pumped to ........