Name of the Mine

Westwood gold mine.

Location

The mine is located on the Doyon property, 40 km east of Rouyn-Noranda and 80 km west of Val d’Or, in south-western Quebec, Canada. The area is about 420 km north-west of Montreal.

Mine Owner/s

Iamgold.

Brief Description

Westwood is Iamgold’s only underground mine, and has an average resource grade of 10 g/t of gold.

Brief History

Westwood began production in the first quarter of 2013. The mine started commercial production in July 2014, producing 70 000 oz in the first two quarters, with an average diluted grade of 7.98 g/t of gold.

The most productive years to date occurred in 2017 and 2018, with production of 125 000 oz and 129 000 oz respectively.

The fallout of a government-mandated Covid-19 shutdown, from March 15 to April 15, 2020, and a seismic event on October 30 in the same year, resulted in the underground mine being placed on care and maintenance, with 437 retrenchments.

Milling operations resumed on November 4, 2020, to process stockpile material and ore from the Grand Duc satellite openpit, which is part of the Westwood operation.

The mine announced a staged recall of employees in April 2021, with underground operations in the East zone resuming in June 2021. Activities in the high-grade Central and West zones resumed only in June 2022.

Primary Metals/Minerals

Gold.

Secondary Metals/Minerals

None stated.

Geology and Mineralisation

The Westwood project is part of the Doyon-Bousquet-LaRonde (DBL) mining camp. The project is located within the southern Abitibi subprovince, in Archaean volcanic and intrusive rocks of the Bousquet Formation (2701-2696 Ma).

The project area is underlain by metavolcanics of the Blake river group and partly by metasediments of the Cadillac and Kewagama groups. Stratigraphy generally strikes east to west (100° to 110°), dips steeply to moderately (70° to 80°) towards the south and is interpreted to have a southerly facing direction. The Mooshla intrusive, a synvolcanic differentiated pluton, intrudes the volcanics in the western part of the property.

Gold-bearing volcanogenic massive sulphide (VMS) and disseminated sulphide zones occurring in the eastern part of the claims are known as the Warrenmac and Westwood showings, and are respectively to the west and east of the Bousquet fault. Rocks hosting the Warrenmac-Westwood mineralisation are lithologically and geochemically similar to the host rocks of the main sulphide lenses at the Agnico Eagle Mines’ LaRonde-Penna mine. The regional foliation strikes east to west, parallel to the stratigraphy, with dips varying from subvertical to 70° towards the south. Regional metamorphism is transitional from green schist to lower amphibolites facies.

Mineralisation observed in the DBL camp is mainly associated with units 4.2, 4.3, 4.4, 5.1 and 5.2 of the Bousquet formation. These units host gold-rich VMS-type mineralisation at the Bousquet and LaRonde deposits, and gold/sulphide vein-type mineralisation in zones 1 and 2 at Doyon.

Three distinct mineralised envelopes are identified in the Westwood area. The first two zones – Zone 2 Extension and North Corridor – consist of quartz-pyrite, chalcopyrite, sphalerite veins and veinlets within a matrix containing 2% to 10% disseminated pyrite.

The third envelope delineates the Warrenmac-Westwood mineralised corridor, located at the same stratigraphic contact on each side of the Bousquet fault. Both consist of gold-rich pyrite-sphalerite stringers or concentrations with local massive sulphide bands (5 cm to 20 cm) and minor gold-bearing sulphide-rich quartz veins/veinlets, all enveloped by a disseminated pyrite-rich alteration halo. Occasional black quartz veins with chalcopyrite traces return gold values, but not systematically. East to west subhorizontal quartz-tourmaline (pyrite) veins are also present, but rarely anomalous in gold.

Reserves

Westwood had a total reserve of 3.38-million tonnes grading 5.7 g/t of gold, containing 616 000 oz, as at December 31, 2022.

Resources

Westwood had a measured and indicated resource of about 8.47-million tonnes grading 8.7 g/t of gold, containing 2.35-million ounces as at December 31, 2022. Inferred resources were estimated at 2.7-million tonnes, grading 12.3 g/t of gold, containing 1.07-million ounces.

Type of Mine

Underground with satellite openpit deposits.

Mining Method

Longhole open stoping is the primary mining method used. Stopes are about 25 m to 30 m high with a strike varying from 12 m to 15 m in length.

Historically, mining has been conducted using bottom-up longhole open stoping methods, either in a pillarless or in a primary and secondary stope configuration. In areas of higher seismic risk the company intends to use underhand longhole open stoping (from top to bottom) for better induced stress management.

As a result, depending upon the area, either underhand or bottom-up longhole open stoping methods are employed.

Major Infrastructure/Equipment

The Doyon-Westwood property is accessible year-round using paved roads, while the nearest active railway line is located less than 10 km south of the project.

The owners refurbished the pre-existing Doyon carbon-in-pulp mill complex before operation started in 2013. Ore from the Westwood underground is hauled to the Doyon mill to be crushed and ground. The ore grinding circuit uses a semiautogenous mill and a 1 000 hp ball mill.

Prospects

In August 2020, the then Iamgold president and CEO Gordon Stothart announced that the company was pursuing a hub-and-spoke strategy at Westwood to advance assets such as the Fayolle property and the optioned Rouyn gold project, while enhancing the overall value of Westwood through incremental production growth from supplementary feed.

In 2023, Westwood gold production is projected to be at the top end of the 70 000 oz to 90 000 oz range. Production levels and unit costs are expected to continue to improve into the fourth quarter of the year, benefiting from the continued advancement of underground development providing access to more and higher-grade sequences.

Mill feed will continue to be supplemented from available satellite surface deposits, including increased proportions of comparatively higher-grade ore from the satellite Fayolle property.

Capital expenditure is expected to be about $65-million of sustaining capital in support of underground development and rehabilitation work, the renewal of the mobile fleet and fixed equipment, repairs to the Westwood mill and other capital projects.

Contact Details

Iamgold Corporation

Tel +1 416 360 4710

Email info@iamgold.com

Sources

Iamgold Corporation. Website https://www.iamgold.com

Iamgold Corporation. Westwood gold mine, Canada.

Iamgold Corporation. Iamgold Reaffirms Long-Term Production Guidance for Westwood and Files NI 43-101 Technical Report (August 5, 2020).

Iamgold Corporation. 2020 Annual Report.

Iamgold Corporation. Iamgold reports 2022 Attributable Reserves of 11.6 Million Ounces and Attributable M&I Resources of 24.1 Million Ounces (February 16, 2023)

Mining Weekly. Website https://www.miningweekly.com

Mining Weekly. Iamgold starts recalling Westwood employees (April 22, 2021).

Research Channel. Website  https://www.researchchannel.co.za

Research Channel. Westwood mine, Canada (June 03, 2016).