The South West, Windjammer South, Windjammer Central, Discovery, Windjammer North, and 55 deposits of the Golden Highway Project can be classified as structurally-controlled orogenic gold deposits in an Archean greenstone belt setting. The Abitibi greenstone belt of Ontario and Quebec is located in the southeastern portion of the Superior Province (Nassif et. al 2018) of the Canadian Shield. This deposit type is a significant source of gold mined in the Superior and Slave provinces. Dubè and Gosselin (2007) published an overview of greenstone hosted gold deposits in Canada. These deposits are typically quartz-carbonate vein hosted and are distributed along crustal-scale fault zones that mark convergent margins between major lithological boundaries such as those between volcano-plutonic and sedimentary domains. The Golden Highway Project is located on the DPFZ (Destor Porcupine Fault Zone), a major regional structure.

The DPFZ in northeastern Ontario, hosts the largest Archean orogenic gold camp in the world and has produced over 75 Moz of gold from the Timmins Camp alone. When combined with the adjacent Larder Lake-Cadillac Fault Zone and associated splays, this region has hosted over 200 Moz of gold (Dubé, B et al. 2017).

The greenstone-hosted quartz-carbonate vein deposits are structurally controlled, epigenetic deposits characterized by simple to complex networks of gold-bearing, laminated quartzcarbonate structure-fill veins. These veins are hosted by moderately to steeply dipping, compressional, brittle-ductile shear zones and faults with locally associated extensional veins and hydrothermal breccias. The later structures are the main host for mineralization on the Golden Highway Project.

Along the DPFZ the main host rocks are greenschist facies metamorphic rocks of dominantly mafic to ultramafic metavolcanic rocks intruded by intermediate to felsic porphyry. In the Timmins area, larger deposits are spatially associated with fluvio-alluvial conglomerate (Timiskaming conglomerate) distributed along major and deep-seated crustal fault zones DPFZ. On the Golden Highway Project, a banded iron formation transects the Timiskaming sedimentary basin and is spatially associated with gold mineralization.

The deposits are typically associated with iron-carbonate (ankerite) alteration with gold usually occurring in the quartz-carbonate pyrite vein network. Significant gold can also occur associated with the iron-rich, sulphidized, wall rock selvages or within silicified and arsenopyrite-rich replacement zones.

In the Superior Province, orogenic gold deposits are spatially associated with large scale regional deformation zones such as the DPFZ. These large-scale structures and the associated Timiskaming-type sediments are interpreted as zones of transgressive terrain accretion (Kerrich and Wyman 1990), (Nassif et al. 2018). Colvine et al.’s (1988) study of gold deposits in Ontario concluded that Archean lode gold deposits are formed at deeper crustal levels (2 to 10 km) than younger epithermal deposits.

Auriferous quartz veins cut many different rock types in the Timmins-Kirkland Lake area, including late intrusive rocks and late deformation zones such as the DPFZ. As a consequence, it is likely that gold mineralization formed late in the Archean geological history of the Timmins area (Fyon and Green, 1991). In the Timmins area, Corfu et al. (1989) have documented auriferous quartz veins cutting 2,691 to 2,688 Ma quartz-feldspar porphyry intrusions and a 2,673 +6/-2 Ma albitite dikes. At the adjacent Garrison project, Nassif et. al (2018) have concluded that north-northwest-trending extensional gold bearing quartz veins post-dated earlier sinistral trans tensional northeast-trending shear zones hosting hydrothermal mineralization dated 2,657 +/- 15Ma.

The complexity of the multiple, parallel, narrow to medium thickness mineralized structures, spatially located at depth presents challenges to underground mine design, however the mineral resource to be considered in the mine production rate, design and production schedule for the SW zone is considered suitable for the proposed mining and extraction method.

The proposed mining method for the SW zone is Longitudinal Longhole Stoping with conventional drilling and blasting. The optimal nominal mine production rate for the SW zone project is estimated to be 1,750 tonnes per day (t/d), taking into consideration the geometry of the deposits. Waste rock generated from the mine will be the main source of unconsolidated backfill.

The main decline provides access into the mine with a series of internal ramps linking one mining area to another,while crosscuts provide access into the deposits. Sills are developed in each deposit where production drilling and blasting will be carried out.

Excavated mineralized material from the mine will be transported to the processing facilities on surface with trucks, while waste material will be transported and deposited into excavated stopes to provide a working platform for the subsequent mining lift.

The cut-off grade (CoG) of 2.6 g/t was established based upon input parameters including a mining cost of C$75/t mill feed and milling cost of C$40/t mill feed, and was subsequently used in the Datamine Mineable Shape Optimizer (MSO) to generate mineable stope shapes for the proposed longitudinal sublevel stoping mining method.

The life-of-mine(LOM)plan will spend 12 years mining a total of 5,394 kt of resource with a grade of 3.92g/t Au from stopes and 641 kt of resource with a grade of 4.07 g/t Au from sills,for a total of 6,035 kt of mined resource with an average grade of 3.93 g/t Au.

The LOM plan mines a total of 1,589 kt of development waste from 52 km of development.

It is estimated that the mine will require 41 pieces of mobile equipment,including eight trucks, three jumbos, six LHDs and two long hole drills.

Mining will require 143 persons in total, including 82 equipment operators, 36 maintenance crew, 15 technical services staff and ten operations management staff.

The mine design was developed to support a nominal mine production rate of approximately 1,750 t/d for the proposed mining method with unconsolidated waste rock as backfill material. The mine design was carried out in Datamine Studio UG software.

Mining commences at the bottom of each deposit with the development of sills, where production drilling, blasting and mineralized material will be extracted from the stope in a longitudinal retreat, fashion towards the crosscut. Unconsolidated waste rock will be placed from the level above during the retreat, forming the working platform for the subsequent extraction panel (i.e. mining bottom up).

All the primary underground development was designed with dimensions of 4.0 m W x 4.5 m H, with the exception of lateral developments such as levels, sills, crosscuts, remucks, safety bays and ventilation drifts, which are sized at 4.0 m W x 4.0 m H. Main ventilation shafts will be excavated with a raise bore and the remaining ventilation raises between levels will be excavated by drilling and blasting.

The main decline and a system of ramps provide access to the underground workings and productio
areas. There will only be one portal into the mine, providing access into the mine production headings and acting as the service tunnel.

In total there are 20,143 m of main decline and ramp system in the proposed mine design to access all the mineable deposits within the SW zone. The main decline and underground ramp systems are designed at a nominal -15% grade. The main decline is 1,360 m long. This connects to a series of internal ramps linking one mining area to another, totaling 2,612 m. The remaining inter-ramp system links one production level to another with at a total of 16,171 m.

Provisions for remuck and safety bays are included in the design. It is also assumed that, in certain areas, such as in the inter-ramp, the remuck bays will have multiple purposes and can be used as safety or vehicle passing bays to reduce the amount of underground development.

Currently, a provision of 10% in the LoM development cost is included to account for sumps, refuge or lunchroom, electrical and dewatering stations, explosive and fuel storage bays, ore and waste passes, and underground maintenance facilities, considering that this is preliminary economic evaluation. It is recommended that these auxiliary excavations, including secondary escape-ways or emergency exits from the mine, be considered in the mine design during future advanced stages of the project.

Crushing and Grinding Circuits
Plant feed material transported by truck from the underground mine will be either dumped directly into the primary jaw crusher feed hopper or dumped onto the nearby crusher feed stockpile. Material from the stockpile will be fed to the crusher using a front end loader.

The crushing circuit comprises single-stage jaw crusher and the design crushing rate is 109 t/h, treating a maximum lump size of 800 mm, with a product size of approximately 80% passing 125 mm. The crushed material will be conveyed onto a crushed ore stockpile that will hold 1,750 t of live capacity (one day).

The crushed ore will be fed at a controlled rate (about 77 t/h) onto the SAG mill feed conveyor which will feed the semi autogenous mill, ball mill and crusher (SABC) comminution circuit. The SAG mill in the SABC circuit will be in a closed circuit with a pebble crusher while the ball mill will be in a closed circuit with a nest of cyclones.

The selected process plant flowsheet for the on-site processing scenario will include the following unit operations:
- Single stage crushing.
- Two stages of grinding with closed circuit pebble crushing and hydrocyclone classification.
- Gravity separation and intensive leaching of the final gravity concentrate.
- Cyanide leaching and carbon adsorption using carbon-in-pulp (CIP) technology.
- Cyanide destruction of plant tailings and storage of slurry tailings.
- Loaded carbon acid wash, elution and regeneration.
- Electrowinning, refining and production of gold doré bars.

Gravity Gold Recovery
A fraction of the cyclone underflow (approximately 30%) will report to two centrifugal gravity concentrators. On average, approximately 50% of the gold in the plant feed is estimated to be recovered by the gravity circuit. An intensive leach unit will be used to solubilize the gold from the gravity concentrate, and gold in the pregnant solution ........