Owing to its metamorphic grade, the Borden Gold deposit is markedly different from most known Archean-aged mesothermal gold occurrences. On the basis of visual evidence, which is yet to be supported by detailed petrographic studies, it is believed that the Borden Gold deposit is most closely associated with the disseminated gold sub-class.

The gold mineralization at the Borden Gold deposit occurs as a broad zone of disseminated and fracture-controlled sulphides within a volcano- metasedimentary package of variable composition. The main sulphides are pyrite and pyrrhotite, with the former typically dominating. The mineralization generally consists of low- to moderate-grade gold, with minor silver, and is characterized by a persistent higher-grade core surrounded by a lower-grade envelope. Results to date indicate that the higher-grade core improves in grade towards the southeast where it develops into a High-Grade Zone (HGZ) with average grades typically above 2.5 g/t Au.

The northwest portions of the deposit are characterized by local silicification but lack lithological control and quartz veining; while to the southeast a well-developed hydrothermal system consisting of local quartz flooding and potassic alteration predominates and defines the HGZ. The broad mineralized zone encompasses multiple/variable host rocks, dominated by metasedimentary horizons and subordinate intrusives of acidic to intermediate composition, all of which display feldspathic, chloritic and biotitic alteration. Outcropping in the northwest parts of the deposit, the lower-grade mineralization rarely exhibits visible gold grains, while in the southeast HGZ it is much more common, particularly in the quartz-rich core. A higher-grade core is also consistently present within the lower-grade zone, locally attaining very high grades reminiscent of the HGZ.

The deposit displays continuity and is consistently intersected along strike, reaching a current length of 3.7 kilometres, while remaining open in both the northwest and southeast directions. Structurally, the deposit is described by a consistent northeast dip and, locally, a shallow southeast plunge, which is mostly evident in the HGZ. Mineralization appears to be controlled by a ductile shear zone, which appears much better developed in the HGZ. The mineralized zone is up to 120 m wide, and has been confirmed to a vertical depth of approximately 650 m.

Mining
• 15m longhole retreat – factored 24% dilution
• ~2000tpd ore @ 7gpt to mill using proven production rates
• 5x5m main haulage drifts
• Diesel trucks & tethered (electric) scoops until quick-charge battery alternate is viable.
• Battery electric equipment
• Cemented rock fill with waste backhaul from PGM for waste requirement.

Located approximately 160 kilometres west of the Porcupine mine in Chapleau, Ontario, Borden has the potential to enhance the long-term economics of Porcupine, where its ore will be processed.

Gold is recovered using a combination of gravity concentration and cyanidation techniques. The circuit consists of primary, secondary and tertiary crushing, rod/ball mill grinding, gravity concentration, cyanide leaching, carbon-in-pulp gold recovery, stripping, electro winning and refining.