The LaRonde property is located near the southern boundary of the Archean-age (2.7 billion years old) Abitibi Subprovince and the Pontiac Subprovince within the Superior Geological Province of the Canadian Shield. The most important regional structure is the Cadillac-Larder Lake fault zone, marking the contact between the Abitibi and Pontiac Subprovinces, located approximately two kilometres to the south of the LaRonde property.

The geology that underlies the LaRonde mine consists of three east-west-trending, steeply south-dipping and generally south-facing regional groups of rock formations. From north to south, they are: (i) 400 metres (approximate true thickness) of the Kewagama Group, which is made up of a thick band of interbedded wacke; (ii) 1,500 metres of the Blake River Group, a volcanic assemblage that hosts all the known economic mineralization on the property; and (iii) 500 metres of the Cadillac Group, made up of a thick band of wacke interbedded with pelitic schist and minor iron formation.

Zones of strong sericite and chlorite alteration that enclose massive to disseminated sulphide mineralization (including the ore that is mined for gold, silver, zinc and copper at the LaRonde mine) follow steeply dipping, east-west-trending, anastomosing shear zone structures within the Blake River Group volcanic units across the property. These shear zones are part of the larger Doyon-Dumagami Structural Zone that hosts several important gold occurrences (including the Doyon gold mine, the Westwood mine and the former Bousquet mines) and has been traced for over ten kilometres within the Blake River Group, from the LaRonde mine westward to the Mouska gold mine.

Mineralization
The LaRonde deposit is a gold-rich volcanogenic massive sulphide deposit. LaRonde lenses were formed mainly by sulphide precipitation from hydrothermal fluids on the seafloor and by replacement below lenses. The stacking of the LaRonde lenses is the result of successive volcanic events, intercalated by cycles of hydrothermal activity associated with reactivation of synvolcanic faults.

The gold-bearing zones at the LaRonde mine are lenses of disseminated stringers through to massive aggregates of coarse pyrite with zinc, copper and silver content. Ten zones that vary in size from 50,000 to 40 million tonnes have been identified, of which four are (or are believed to be) economic. Gold content is not proportional to the total sulphide content but does increase with copper content. Gold values are also higher in areas where the pyrite lenses are crosscut by tightly spaced north-south fractures.

These historical relationships, which were noted at LaRonde Shaft #1's Main Zone, are maintained at the Penna Shaft zones. The zinc-silver (i.e., Zone 20 North) mineralization with lower gold values, common in the upper mine, grades into gold-copper mineralization within the lower mine. The predominant base metal sulphides within the LaRonde mine are chalcopyrite (copper) and sphalerite (zinc).

The Company believes that Zone 20 North is one of the largest gold bearing massive sulphide mineralized zones in the world and one of the largest known mineralized zones in the Abitibi region of Ontario and Quebec. Zone 20 North contains the majority of the mineral reserves and mineral resources at the LaRonde mine, including 13.9 million tonnes of proven and probable mineral reserves grading 6.36 g/t gold, representing 92% of the total proven and probable mineral reserves at the LaRonde mine, 3.5 million tonnes of indicated mineral resources grading 3.58 g/t gold, representing 70% of the total measured and indicated mineral resources at the LaRonde mine, and 3.7 million tonnes of inferred mineral resources grading 5.86 g/t gold, representing 58% of the total inferred mineral resources at the LaRonde mine.

Zone 20 North extends from 700 metres below surface to at least 3,700 metres below surface, and remains open at depth. With increased access on the lower levels of the mine (i.e., below Level 245 and from the internal shaft on levels 257 and 278), the transformation from a zinc/silver orebody to a gold/copper deposit was effectively completed in 2017. The development of the West mine area, between Levels 278 and 314, provided access to a new zinc/silver rich sector beginning at the end of 2017.

Zone 20 North can be divided into an upper zinc/silver enriched gold poor zone and a lower gold/copper enriched zone. The zinc/silver zone has been traced over a vertical distance of 1,700 metres and a horizontal distance of 570 metres, with thicknesses approaching 40 metres. The gold/copper zone has been traced over a vertical distance of over 2,200 metres and a horizontal distance of 900 metres, with thicknesses varying from three to 40 metres. The zinc/silver zone consists of massive zinc/silver mineralization containing 50% to 90% massive pyrite and 10% to 50% massive light brown sphalerite. The gold/copper zone mineralization consists of 30% to 70% finely disseminated to massive pyrite containing 1% to 10% chalcopyrite veinlets, minor disseminated sphalerite and rare specks of visible gold. Gold grades are generally related to the chalcopyrite or copper content. At depth, the massive sulphide lens becomes richer in gold and copper.

Access to LaRonde’s underground mining operation is through the 2,250-metre-deep Penna Shaft, which was completed in March 2000 and remains the deepest single-lift shaft in the Western Hemisphere. The internal Shaft No.4 extends 823 m to 2,858 m depth to provide access to even deeper ore at the lower part of the orebody, and has been at the centre of the LaRonde mine extension project initiated in 2006.

Two mining methods are used at LaRonde: longitudinal retreat with cemented paste backfill; and transverse open stoping with paste or unconsolidated backfill. In addition, to address concerns regarding the frequency and intensity of seismic events encountered at the lower levels of the LaRonde mine, a hybrid of these two methods has been used.

Levels at the LaRonde mine are spaced at 30 metres. Stopes have an average width of 15 metres.

With the transverse open stoping method, a drawpoint is developed perpendicular to the ore above and below the stope. The sequence, which is dictated by seismicity at LaRonde, will lead to the use of cemented or uncemented fill depending on whether the stope will be exposed in the future. The transverse method is typically used is seismically active ground and when the ore is thick enough.

With the longitudinal method, a drive is developed above and below the stope in the ore parallel to the orebody. The ore is then mined in a series of stopes retreating toward the drawpoints used to gain access to the ore. Almost all of the stopes have to be filled with cemented pastefill as they are almost all exposed to future stopes. This method is typically used when the ore is of smaller width or when seismicity is not anticipated to be of significant concern.

The risk of more frequent and larger seismic events has increased as the Company mines deeper at LaRonde. Over the years, the Company has continued to adapt and manage the risk. The Company continues to adjust the mining methods, ground support and protocols to address seismic activity in the deeper portions of the mine.

Below approximately 2.8 km depth, the LaRonde mine divides into two parallel lobes called the East mine and the slightly offset West mine.

The LaRonde mine has been successful at incrementally implementing automation for its production activities and is increasingly relying on this technology. In 2021, at the LaRonde mine, 27% of the production mucking was done in automated mode with operators based on surface, compared to the Company’s initial objective of 17%. In 2022, the Company is targeting 30% of the production mucking to be done in automated mode. In addition, the Company is also testing remote production drilling.

At Zone LR11-3 (which is at the past producing Bousquet 2 mine), the dewatering of the old workings and the development continued according to plan in the fourth quarter of 2021. Production from LR11-3 is expected to begin in late 2022.

Surface facilities at the LaRonde mine include a processing plant with a daily capacity of 7,000 tonnes of ore, which has been expanded four times since 1987 from the original rate of 1,630 tonnes per day. The LaRonde mine is also the site for the Lapa mine ore processing plant (2,000 tonnes per day), which was commissioned in the second quarter of 2009 and is now used to process ore from the LaRonde Zone 5 mine.

Ore is processed at the LaRonde mineral processing complex, which includes copper and zinc flotation as well as precious metals recovery and refining. The processing plant produces doré bars containing gold and silver, as well as zinc and copper concentrates that carry valuable gold and silver credits.

The ore from the LaRonde mine requires a series of grinding, copper/lead flotation, zinc flotation and zinc tails precious metals leaching circuits, now followed by CIP recovery.

A CIL circuit was completed and began operation in April 2013 to replace the existing LaRonde precious metal Merrill-Crowe circuit.

A copper flotation circuit is utilized to improve total gold recovery. Based on laboratory tests and processing experience, increased gold recovery is obtained with the combination of copper flotation and leaching. Zinc flotation is operated periodically based on the zinc feed grade and the anticipated net smelter revenue.

Paste backfill and cyanide destruction plants operate intermittently based on underground requirements. A second paste backfill plant was commissioned in 2018 to feed the LaRonde Zone 5 mine. The tailings area has a dedicated cyanide destruction and metals precipitation plant that water passes through prior to recirculating to the mill. A biological water treatment plant addresses the presence of thiocyanate in the tailings ponds at the LaRonde mine. The plant uses bacteria to oxidize and destroy thiocyanate in the water and removes phosphate prior to its release to the environment.

The Goldex concentrate circuit consists of pulp received from the Goldex mill via truck. The material is sent to the LaRonde leaching/CIP circuit for gold recovery along with LaRonde residual pulp.