The Meliadine gold project is located in the Archean Rankin Inlet Greenstone Belt, in the Churchill Structural Province of the northern Canadian Shield. This belt consists of mafic volcanic rocks, felsic pyroclastic rocks, sedimentary rocks and gabbro sills of about 2.7 billion years old that have been polydeformed and metamorphosed. The Meliadine trend is defined by northwest-trending rock units as well as a major fault zone known as the Pyke Fault: a high-strain zone characterized by multiple foliations and regionally important shear zones.

Seven gold deposits have been identified at the Meliadine project, of which Tiriganiaq is the most significant. The other deposits are the Discovery, F zone, Wesmeg, Normeg, Wolf and Pump. The Normeg deposit, discovered in 2012, is a southern expansion of the Tiriganiaq deposit, and extends as far as the Wesmeg deposit. Gold mineralization in these seven deposits is mostly mesothermal quartz-vein-dominated gold systems in strongly sheared and complexly folded host rocks of Archean turbidites, iron formation and volcanic rocks. Within each deposit are many gold-bearing lodes of quartz vein stockwork, laminated veins and sulphidized iron formation with strike lengths of up to 3 km. The stratigraphic units generally strike northwest-southeast, dip steeply to the north and are overturned, with the oldest units to the north. All seven deposits remain open at depth.

Mineralization in the Tiriganiaq gold deposit is strongly associated with shearing and quartz veining, which likely developed during the Proterozoic third deformation event. The most intense and consistent gold mineralization is present within both the Upper Oxide Iron Formation and proximal to the Lower Fault in the siltstones of the Tiriganiaq Formation, but minor amounts of mineralization have been reported in all rock types. Areas of intense shearing are ‘healed’ by quartz veining and there is generally little to no brittle deformation.

Gold mineralization is directly associated with syn- to post-deformational quartz veining. Vein appearance is highly variable from a several-metres-thick laminated vein along portions of the Lower Fault to wispy, apparently erratic quartz stringers and stockwork in the Tiriganiaq Formation. With some exceptions, quartz-only and quartz-ankerite veins tend to be mineralized with gold, while quartz-calcite veins are commonly barren in all lodes. This observation implies to multiple veining events.

Sulphide minerals in the Tiriganiaq gold deposit are of two distinct generations: primary and late sulphides.

Primary sulphides consist of wispy, discontinuous, bedding-parallel laminations of pyrrhotite, pyrite and chalcopyrite in oxide iron formations and black argillite. Fine-grained, web-textured sulphides in oxide iron formations close to quartz veins may represent remobilization of primary sulphides, but may alternatively signify sulphur introduced during mineralization. Gold values are generally low to absent in this sulphide assemblage, in the absence of quartz veining.

Late sulphides consist of coarse-grained (sub-centimetre-size) clots of arsenopyrite crystals and pyrrhotite associated with highly gold-bearing zones located in and close to quartz veining. The coarse arsenopyrite crystals rarely show signs of strain, having suffered little post-depositional deformation. Arsenopyrite of this type, in association with quartz veining, is a good visual indicator of elevated gold values.

Visible gold is common in all lodes in the deposit and is present in quartz veins, pyrrhotite, and along the margins and late fractures of arsenopyrite crystals.

A conventional truck/shovel operation for both pits is planned with different mining approaches for ore and waste. The mining method must be suited to Arctic conditions and provide a good daily production in waste zones. To maximize the recovery of economic material and minimize dilution in the ore zones, the method must be very selective.

A long-hole mining method was selected to mine the Tiriganiaq deposit due to the shape, thickness and orientation of the orebody. The stope height was set at 25 m to minimize drill deviation and waste rock dilution, and to maximize mine recoveries. Two variations of long-hole mining (transverse or longitudinal mining) will be utilized; the variant selected for a particular stope will depend on the thickness of the ore zone.

A long-hole mining method will also be considered for the eventual exploitation of the underground indicated and inferred mineral resources located in other deposits (F zone, Pump and Discovery) not currently include in the LOM plan but with some variations because the lodes in these deposits are generally shallower-dipping and are narrower than the Tiriganiaq lodes. Longitudinal mining would be used for these deposits. Permanent rib pillars would be left between adjacent stopes, and uncemented rockfill would be used to fill the stopes. Levels would be 20 m apart (instead of 25 m) to minimize drill-hole deviation and dilution due to the shallower dip.

The proposed process plant will treat gold ore at a nominal process rate of 3,000 tpd from Year 1 to Year 3. A process plant expansion of 2,000 tpd will increase capacity to 5,000 tpd at Year 4 due to the addition of ore from the Tiriganiaq open pit operation. The Tiriganiaq deposit will be the dominant source of process plant feed for the plant during the early years. A combination of conventional gravity concentration and cyanidation processes has been selected for the project. The process plant will consist of three separate facilities:
- a crushing facility, including primary and related material-handling facilities that can crush ore from either underground or open pit operations;
- a main processing facility including a coarse ore surge bin and related feeding and reclaim systems, single-stage grinding, gravity concentration and an intensive leaching reactor, leaching feed thickening, CIL cyanide circuit, loaded carbon acid wash, elution and reactivation, gold electrowi ........