The Young-Davidson Property is located within the southwestern part of the Abitibi Greenstone Belt, which is the largest preserved Archean greenstone belt in the world and one of the most continuous units of the Superior Geologic Province. The Abitibi Greenstone Belt extends for 750 km from the Grenville Province in the east to the Kapuskasing Gneiss Belt in the west, and for over 170 km from the Opatica Gneissic belt in the north to the Proterozoic Huronian sediments in the south.

The Abitibi Greenstone Belt consists of a complex and diverse array of volcanic, sedimentary, and plutonic rocks typically metamorphosed to greenschist facies grade, but locally attaining amphibolite facies grade adjacent to large plutons and along the Grenville Front.

At least five styles of gold mineralization are recognized at the Young-Davidson Project:

1. Syenite-hosted gold mineralization;
2. Mafic volcanic-hosted gold mineralization (MCM Mine);
3. Timiskaming sediment-hosted gold mineralization;
4. Ultramafic-hosted gold mineralization;
5. Hanging wall contact gold mineralization.

The syenite-hosted gold mineralization consists of a stockwork of quartz veinlets and narrow quartz veins, rarely greater than a few inches in thickness, situated within a broader halo of disseminated pyrite and potassic alteration. Visible gold is common in the narrower, glassy-textured quartz veinlets. In general, gold grades increase with quartz veinlet abundance, pyrite abundance, and alteration intensity. Mineralized areas are visually distinctive and are characterized by brick red to pink Kfeldspar-rich syenite containing two to three percent disseminated pyrite and several orientations of quartz extension veinlets and veins. The quartz veins and veinlets commonly contain accessory carbonate, pyrite, and feldspar.

The syenite-hosted gold deposits, commonly associated with quartz-monzonite to syenite stocks and dikes, has been individualized as a distinct group of gold deposits, well represented in the Abitibi Greenstone belt and particularly at the Porcupine and Kirkland Lake districts, Northern Ontario.

According to Robert (2004), the syenite-hosted gold deposits occur mainly along major fault zones, in association with preserved alluvial-fluvial, Timiskaming-type, sedimentary rocks. Robert (2004) describes the gold mineralization in these deposits as being represented by disseminated sulphide replacement zones, with variably developed stockworks of quartz-carbonate-K-feldspar veinlets within zones of carbonate, albite, K-feldspar, and sericite alteration. Syenitic intrusions are broadly contemporaneous with deposition of Timiskaming sedimentary rocks and, together with disseminated gold mineralization; they have been overprinted by subsequent regional folding and related penetrative cleavage.

The Young-Davidson deposit, also located in the Abitibi greenstone belt, can be classified as an Archean, syenite-hosted gold deposit. The gold mineralization is primarily related to quartz veinlet stockworks and disseminated pyrite mineralization, mostly enclosed within the syenite intrusion boundaries, or very close to the contacts with the enclosing rocks, and is frequently associated with broader zones of potassic alteration.

Open pit mining commenced in November 2011, and ceased in June 2014, upon depletion of the in-situ open pit Mineral Reserve. While the mining of the open pit has ceased, a sizeable stockpile of open pit ore was used to augment underground production until early 2020 but has now been depleted. Over the life of the open pit, approximately 20.9 Mt of waste rock was generated by the open pit and placed in the waste dump to the north of the pit. Commercial production was declared for the Young- Davidson open pit mine and mill effective September 1, 2012.

In October 2013, the Company commissioned the mid-shaft loading pocket and shaft hoisting infrastructure and began hoisting underground ore to surface via the Northgate shaft. Prior to October 2013, ore was being trucked to surface through the exploration ramp. On October 31, 2013, commercial production at the Young-Davidson underground mine was achieved.

The underground deposit is located approximately 210 m to 1,500 m below surface. During 2013, AuRico completed the sinking of the Northgate shaft down to the mid-shaft loading pocket to access the first eight years of mine production. The Company has since completed vertical access in the underground mine below that of the mid-shaft loading pocket, to the ultimate depth of 1,500 m. In 2017, raise boring of the Northgate shaft was completed to the ultimate depth of 1,500 m and ground supporting of the shaft was completed in 2018. Completion of the lower mine development and the tying in of the Northgate shaft extension was completed in mid-2020. In 2015 the existing MCM #3 shaft was extended to a depth of 1,500 m to provide for the hoisting of personnel, materials, and ore and waste. Commissioning of the MCM #3 shaft was completed in the first half of 2016. The mine is also accessed by a ramp, which was extended to the bottom of the mine from the existing exploration ramp and was completed in the first half of 2020. The mine design has taken into consideration the existing MCM #3 and the Northgate shafts and other existing openings for ventilation. Additional ventilation raises to surface have been established and the underground ventilation circuit continues to be upgraded as the mine deepens.

The underground mine has been designed for low operating costs using large modern equipment, gravity movement of ore and waste through raises, shaft hoisting, minimal ore, and waste re- handling, high productivity bulk mining methods, and paste backfill. The mining method employed is a combination of transverse and longitudinal stoping, followed by paste backfill, on 30 m sub- levels. Below the 9,400 m level sub-levels are being developed on 35 m intervals. Given the significant orebody widths, it is expected that approximately 90% of the remaining Mineral Reserves will be transversely mined. The mine operates scoop trams to load, haul and transfer stope production to the ore pass system from where it is hoisted to the surface via two 24.5 tonne skips in the Northgate shaft.

With the commissioning of the lower mine, the Northgate shaft hoisting capacity is approximately 10,500 tpd of ore and waste.

At the current design production rates of 2.92 million tonnes per year (8,000 tpd) at full production (post-2021), the underground will have a minimum mine life of approximately 15 years based on the current Mineral Reserve.

Lateral development of the underground mine will average approximately 11,000 m per year including capital, operating, and ore categories for the first ten years of the underground mine operation. In the last five years of the underground mine life, the development requirements drop off sharply as the mine is close to being fully developed.

The average underground hourly mining personnel requirements at 8,000 tpd are estimated to be approximately 380 persons. The mine operates seven days a week with two 10.5 hour shifts per day working five days on and four days off followed by four days on and five days off schedule. The mine is fully owner-operated with only diamond drilling and raising being contracted.

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The Young-Davidson mill can be considered a standard flotation/CIL gold mill. The mill was commissioned during Q1 of 2012 and the first gold pour occurred on April 30th, 2012. Ore is currently sourced from two sources, the underground mine and from low grade surface stockpiles, produced by the open pit between 2011 and 2014.

The cyclone overflow feeds a trash screen prior to feeding the flotation conditioner. The flotation conditioner overflows into the first flotation cell. The flotation circuit is comprised of four tank cells.

The flotation concentrate is pumped to the concentrate thickener. Thickener underflow is pumped to the regrinding circuit. The thickened concentrate is pumped to the regrinding circuit, comprising a vertical tower mill, where the solids are reduced to a size distribution with a nominal P80 target of 15 µm, operated in closed circuit with a cyclone cluster. The cyclone underflow returns to the tower mill box while the cyclone overflow flows directly to the concentrate CIL circuit.

The flotation tailings are pumped to the flotation tailings thickener. The flotation tailings thickener underflow is pumped to the combined CIL circuit. Thickener overflows from both thickeners report to the mill process water tank for reuse.

The flotation concentrate from the regrind circuit reports to a pre-leach tank. The slurry overflows from the pre-leach tank into a series of four CIL tanks providing a total of 48 hours of retention time.

The loaded carbon extracted from the first tank of the concentrate CIL tank is pumped to the carbon stripping circuit for carbon elution.

The flotation tailings, along with the previously leached flotation concentrate are fed to the combined CIL circuit consisting of five leach tanks providing an overall retention time of 24 hours. The combined leach circuit tailings report to the cyanide destruction circuit.

The carbon elution circuit has been sized for processing 4 t/d of carbon. The loaded carbon is pumped from the first flotation concentrate leach tank across a loaded carbon screen. The loaded carbon flows by gravity into the acid wash vessel where the loaded carbon is rinsed by a solution of hydrochloric acid followed by neutralization. The loaded carbon is transferred by a recessed impeller pump to the elution vessel. The stripped carbon is reactivated in an electric kiln and reused in the CIL circuit.

The carbon stripping circuit elutes the precious metals into the pregnant solution. The pregnant solution feeds the electrowinning circuit. Pregnant solution is pumped through the electrowinning circuit to produce sludge on the cathodes containing the precious metals. The cathodes are washed, dewatered and dried. The dried cathode sludge is melted in an electric induction furnace and poured into doré bars.

The combined leach circuit tailings report to the cyanide destruction circuit using the SO2/air process and copper sulphate solution. The treated tailings slurry is pumped to the tailings impoundment area for settling or to the paste fill plant and a portion of the reclaim water is sent back to the process plant as process water.