The Cariboo Gold Project shares many characteristics with an orogenic gold deposit model.This class of deposit is typified by deformed and metamorphosed mid-crustal blocks and major structures, inherent products of orogenesis. Orogenic gold deposits span the entire breadth of the province of British Columbia, occurring predominantly within two main belts. The westerly belt is associated with accreted pericratonic terranes linked to Late Cretaceous to Paleocene movement on crustal-scale dextral strike-slip fault systems along the western margin of the Stikine terrane, and eastern Coast Belt (e.g., Bralorne-Pioneer, Atlin, Cassiar). The easterly belt is crudely cospatial with the Jurassic to Cretaceous accretion of the Intermontane terranes and autochthonous strata of the ancestral North American (e.g., Cariboo, Sheep Creek) (Allan, 2017). Orogenic deposits have significant economic importance, as they are known to host auriferous mineralization as high-grade vein deposits, low-grade bulk-tonnage lode deposits, and are intimately linked with substantial placer accumulations (Goldfarb et al., 2001; 2005).

Gold-bearing veins and replacement-style mineral deposits in the Cariboo Gold Project are interrelated but can be subdivided into five principal types:

1. Fault-fill shear veins in fractured early-phase quartz lenses within carbonaceous mud and siltrich, foliation sub-parallel (northwest-southeast trending) shear zones (BC Vein-style);
2. Sub-vertical, foliation-perpendicular (northeast-southwest trending) so-called axial-planar (“AXPL”) veins structurally controlled by late-stage extensional fractures preferentially formed in rheologically brittle sandstone units;
3. Foliation-oblique so-called extensional (“EXT”) veins characterized by greatest mineral potential where in association with AXPL vein systems;
4. Sulphide-replacement bodies structurally controlled by and elongate parallel to the hinges of F2 folds within calcareous sandstones and limestones (Mosquito Creek-style);
5. Fault bound sulphide-replacement bodies within calcareous siltstones (Bonanza Ledgestyle).

Vein-related Mineralization
Axial planar quartz veins are the primary source of vein hosted Au within the Barkerville trend, defining the fundamental architecture of the Mosquito Creek, Shaft, Valley, Cow Mountain, Lowhee, and KL deposits. Individual veins range in width from millimeters to several meters. Where density is high, AXPL veins form mineralized corridors extending for up to a few hundred meters along strike and down-dip within rheologically prospective units. Though often advantageous to model and describe AXPL veins as tabular bodies, their morphologies are generally more complex. They are often observed to pinch and swell in thickness with undulatory margins, and commonly network with (and/or refracture and cross-cut) earlier extensional (“EXT”) vein systems. Au-bearing EXT veins and Au-rich sulphide replacement bodies are intimately related to AXPL vein systems, both spatially and presumably in terms of mineralizing fluid dynamics.

The composition of both the AXPL and EXT veins is quartz dominant. Lesser iron carbonate usually occurs as vein-marginal or clustered intergrowths and vein-hosted sericite is also common. Pyrite is the most prevalent sulphide mineral across all deposits, with vein content ranging from trace amounts to tens of percent. Pyrite content appears to have a direct association with gold content within veins. Galena and arsenopyrite are also common veinhosted sulphides, occurring in individual veins in amounts up to several percent and locally exceeding pyrite content. Additional sulphide minerals generally occurring in trace amounts include pyrrhotite, sphalerite, chalcopyrite and (rarely) argentite. Pb-Ag-Bi sulphosalts including cosalite are found in trace amounts within veins and generally have a close association with elevated Au grades. Scheelite is also locally observed, generally as secondary fill within quartz vein vugs.

Veining can be subdivided into at least two temporally separate events. Both events are characterized by a quartz - iron carbonate ± sericite hydrothermal fluid, but they differ greatly in their Au potential. Early veins may host sulphides (mostly Py, Po, Gal, Sph ± Cpy) but tend to be barren of Au except were mineralized by later fluids. The later, Au bearing veins tend to be more sulphide rich (mostly Py, Aspy, Gal, Sph ± Arg ± Cos) and cross-cut earlier veining.

Replacement-style Mineralization
Replacement mineralization in calcareous siliciclastic and carbonate facies rocks varies from fine to coarsely crystalline pyrite with rare arsenopyrite. This style of mineralization is thought to be the result of a reaction between the slightly acidic, Au bearing hydrothermal fluid and carbonate minerals within the host rocks which results in the simultaneous dissolution of carbonate and precipitation of gold-rich sulphide. Bonanza Ledge-style replacement mineralization is hosted in calcareous siltstone and consists entirely of fine-grained pyrite mineralized material. Sulphide content in replacement mineralized material types is generally high, ranging from 10% (replacing thin calcareous bands) to massive (replacing entire beds). Mosquito Creek-style replacement bodies in limestones and calcareous sands contain the most consistently high Au grades in the Cariboo Gold Project. These replacement bodies are thought to be both spatially and temporally related to mineralized AXPL vein systems.

Vein-related Alteration
Large veins tend to exhibit a strong silica alteration halo with associated vein halo pyrite. Stepping outward, moderate silicification persists, accompanied by moderate sericite, with pyrite present only in trace amounts. A widespread moderate silica envelope with patchy but intense silica closer to the veins is observed within high density vein corridors. Moving further from the fluid source, silicification becomes weak and sericite is present as the dominant alteration mineral. The distal-most alteration halo is characterized by iron carbonate and lesser sericite. Clay minerals (e.g., illite, smectite) and chlorite may be presented as vein forming minerals outside of mineralized corridors.

The Project consists of three main zones (Cow, Shaft, and Valley) with two smaller satellite zones (Lowhee & Mosquito). The rate of exploitation of each deposit will change over time, while the overall steady state production rate is 8,000 tpd. In 2024, production will begin at 2,000 tpd for 2.5 years and will ramp up to 8,000 tpd (pending permitting) in 2027 for 9.5 years.

The selected mining method is long hole with longitudinal retreat. Primary materials handling fleet will comprise of 10 tonne (t) scooptram Load Haul Dump (“LHD”) and 50 t haul trucks.

Pre-production of the underground workings is set to begin in 2023 with 2,000 tpd achieved in Q4 2024 and full production of 8,000 tpd at the Mine Site Complex in Q1 2027. Underground mine life
is set to last until 2035.

The long hole mining method was primarily selected due to the sub vertical geometry of mineralized vein corridors and the relatively lower cost. This method involves driving two drifts longitudinally along the mineralized vein corridors to define a stope. The top access serves as a drilling platform while the bottom access allows for mucking of drilled then blasted material. Once empty, these stopes are then backfilled with either pastefill or cemented rockfill. Stopes are mined retreating towards the access. This method allows for simultaneous mining of stopes along different vein corridors as well as along the same corridor if a pillar exists between active levels.

The minimum designed stope width for all zones is 3.7 m and the sill to sill stope height for all zones is 30 m. The maximum permissible strike length (the distance along strike that can be mined before backfilling is required) is a function of geotechnical constraints and differs by zone.

There will be three portals accessing underground ramps: The Cow portal to access the Lowhee Zone, the Island Mountain portal to access the Shaft Zone and Mosquito Zone as well as access the Main Ramp, and the Valley portal to develop the Main ramp connecting to the Island Mountain portal and access the Cow Zone and Valley Zone. The Valley portal will be used as the main services access. The zones are accessed by main ramps connecting to haulage drift and each individual zone has an internal ramp system. The Mosquito zone is further west, connected to Shaft by a 1,150 m long haulage drift.

Each zone is planned to be mined with the longitudinal retreat long hole method. Sublevels for all zones are 30 m sill to sill and a combination of Cemented Rock Fill (“CRF”) and pastefill are planned to backfill mined stopes. Stope strike lengths vary by zone based on geotechnical assessments of each zone. All zones are capped by a crown pillar (15 m for Cow and Valley and 20 m for Shaft and Mosquito) and vary in depth.

A major piece of underground infrastructure for the Project is the underground crushing system (two lines in parallel). This crusher is located below the Services Building in a location which has been identified as geotechnically favourable for long term infrastructure. Mineralized material will be brought to the crusher by underground trucks from all mining zones.

Mineralized material will ultimately be brought to surface using a vertical conveyor to be preconcentrated by sorting and flotation. The material rejected by the sorter will be transferred back underground using a wastepass raise and then subsequently used as backfill material or hauled using automated trucks to the Bonanza Ledge Waste Rock Storage Facility (“WRSF”).

The mine will include haulage drifts connecting the five separate zones, an underground garage, and pumping stations. The Valley portal will provide access for materials and the labour force.

The development schedule has been created with a combination of traditional jumbos’ development and road headers. The road headers are scheduled to provide a lateral advance of 200 m per month in single heading conditions. The jumbos will provide an average overall lateral advance of 300 m per month per jumbo crew when multiple active headings are available. Lateral development will rely on contractors for initial pre-production phase, with a handover to mine personnel with the initiation of full production.

The Cariboo Gold Project (CGP) will ramp up tonnage in two phases: Phase I, starting with a 2,000 tonnes per day (“tpd”) mineral sorting and leaching flowsheet, followed by Phase II, an 8,000 tpd mineral sorting, flotation, and leaching flowsheet.

In CGP Phase I, the mineralized material will be processed in two stages at two sites. The Bonanza Ledge Site located at the current Bonanza Ledge Mine, and the Quesnel River Mill located 116 kilometres (“km”) from the Bonanza Ledge Site.

In CGP Phase II, the mineralized material will be processed in two stages at two sites. In CGP Phase II, the mineralized material will be processed in two stages at two sites. The Mine Site Complex, located in the District of Wells, British Columbia (“Wells”), and the Quesnel River Mill located 111 km west of the Mine Site Complex.

Bonanza Ledge Site
The crushing and screening circuit will be a mobile unit supplied by a sub-contractor. The unit will consist of a jaw crusher, two cone crushers, a vibrating grizzly, two screens, and the associated conveyors.

The run of mine (“ROM”) material will be dumped into a hopper that will feed onto the vibrating grizzly. The grizzly oversize will be fed to a jaw crusher and the product will be fed into the first sizing screen. The secondary cone crusher will operate in a closed circuit. The secondary cone crusher will discharge into the first sizing screen, with the screen oversize feeding the crusher, and the screen undersize feeding the second sizing screen. The targeted particle size is 40 millimeters (“mm”). The second sizing screen has two decks: the top deck will have an opening size of 45 mm, and the bottom deck will have an opening size of 15 mm. The second sizing screen oversize will feed the mineral sorters, and the undersize will be combined with the mineral sorter concentrate and fed to the tertiary cone crusher. The tertiary cone crusher, targeted particle size of 10 mm. The tertiary crusher product will be stockpiled and hauled by truck to QR Mill.

Quesnel River Mill
The grinding circuit is composed of two existing identical 3.96 metres (“m”) long by 3.05 m diameter ball mills with single-pinion 450 kilowatt (“kW”) motors, running in series and a new ball mill 350 kW in parallel of the secondary ball mill. The primary ball mill operates in open circuit is fed from the concentrate feed hopper and discharges into the cyclone feed pump box. The secondary circuit is composed of two ball mills in parallel operates in closed circuit with three new cyclones of 375 mm diameter. Two cyclones operating and one cyclone standby.

The average cyclone overflow product is designed to be a P80 of 45 microns (“µm”) at a circulating load of 200% of fresh feed. The cyclone overflow is piped to flows by gravity to the preleaching thickener. The cyclone underflow will be returned to the secondary ball mills.

Mine Site Complex
The grinding circuit will be composed of a 3.12 m long by 6.70 m diameter semi-autogenous grinding (“SAG”) mill with a 2,500 kW motor and an 8.23 m long by 4.57 m diameter ball mill with a 2,500 kW single motor. The ball mill will be operated in closed circuit with three cyclones of 720 mm diameter (two cyclones operating and one cyclone standby).

The grinding circuit will be fed by the fines from the screening circuit and mineral sorting concentrate. The production rate and availability are designed to be 230 tph and 92%.

The average cyclone overflow product is designed to be a P80 of 100 µm at a circulating load of 250% of fresh feed. The cyclone overflow gravity feed a conditioning tank prior to the flotation circuit. The cyclone underflow will be returned to the ball mill.

The Cariboo Gold Project (CGP) will ramp up tonnage in two phases: Phase I, starting with a 2,000 tonnes per day (“tpd”) mineral sorting and leaching flowsheet, followed by Phase II, an 8,000 tpd mineral sorting, flotation, and leaching flowsheet.

In CGP Phase I, the mineralized material will be processed in two stages at two sites. The Bonanza Ledge Site located at the current Bonanza Ledge Mine, and the Quesnel River Mill located 116 kilometres (“km”) from the Bonanza Ledge Site.

For the initial throughput of 2,000 tpd, a pre-concentrator, including mobile crushing and mineral sorting, will be built at the Bonanza Ledge Site. The use of the Bonanza Ledge Site will reduce the overall operation and transportation costs. The crushing operation will be a mobile unit, operated by a sub-contractor, and the crushed product will be processed in a mineral sorting circuit. The concentrate from the sorted concentrate will be trucked to the QR Mill for further comminution, ........