The Westwood Project is located on the Doyon property, 2.5 kilometres east of the former Doyon Gold Mine in the Bousquet Township, approximately 40 kilometres east of Rouyn-Noranda and 80 kilometres west of Val d’Or in southwestern Québec, Canada. This area is approximately 420km northeast of Montreal. The Westwood Project covers 1,925 hectares and consists of 120 titles, one mining lease, one surface lease and three tailings leases. The Westwood Project is held 100% by IAMGOLD.
The Doyon-Westwood property is accessible year-round via paved roads.
The 120 km separating Rouyn-Noranda from Val-d’Or is scattered with producing and past-producing mining projects such as: Mouska, Doyon, Bousquet, LaRonde and Lapa.
Communications are via fast network links and water supply facilities are available to the Westwood Project. The nearest active railway line is located less than 10 km south of the project.
Westwood began production in the first quarter of 2013. The mine commenced commercial production in July 2014, producing 70,000 ounces in the first two quarters, with an average diluted grade of 7.98 grams of gold per tonne.
The Westwood Project is part of the Doyon-Bousquet-LaRonde (DBL) mining camp. The project is located within the southern Abitibi Sub-Province, in Archaean volcanic and intrusive rocks of the Bousquet Formation (2701-2696 Ma). The DBL mining camp hosts two world class deposits: the Doyon and LaRonde-Penna mines and is by far the largest Au-Cu-Zn-Ag producing district in Québec.
The Westwood Project area is underlain by meta-volcanics of the Blake River Group and partly by meta-sediments of the Cadillac and Kewagama Groups. Stratigraphy generally strikes east-west (100-110°), dips steeply to moderately (70-80°) 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 VMS and disseminated sulphide zones occurring in the eastern part of the claims are known as the Warrenmac and Westwood showings, respectively to the west and to the east of the Bousquet Fault. Rocks hosting the Warrenmac-Westwood mineralization are lithologically and geochemically similar to the host rocks of the main sulphide lenses at the LaRonde-Penna mine. The regional foliation strikes east-west, parallel to the stratigraphy, with dips varying from sub-vertical to 70° towards the south. Regional metamorphism is transitional from greenschist to lower amphibolites facies.
Mineralization 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 mineralization at the Bousquet and LaRonde, deposits and gold-sulphide vein-type mineralization in Zones 1 and 2 at Doyon.
Three distinct mineralized 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 vein systems are orientated 085-095°/60-70°S, which is slightly discordant to the regional foliation in both strike and dip. These zones are located within felsic volcanic units #4.3 and #4.4, and associated with a proximal sericite-pyrite-garnet alteration assemblage.
The third envelope delineates the Warrenmac-Westwood mineralized corridor, which is 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 (5-20cm) 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-west sub-horizontal quartz-tourmaline (pyrite) veins are also present but rarely anomalous in gold. The Federal Government is in the final stages of an important multidisciplinary study that aims to better understand the geological and hydrothermal evolution of the DBL camp. The goal is to determine whether the Westwood mineralized zones represent a transitional system and hydrothermal link between the syn-magmatic Au-Cu veins of the Doyon deposit to the west, and the volcanogenic sulphide veins, stockworks and disseminations of the Bousquet 1 mine to the east.
Westwood is currently IAMGOLD’s only underground mine, and has an average resource grade of 10 grams of gold per tonne.
With our ongoing focus on production efficiency and cost reduction, we are reviewing life-of-mine profiles with production ranging
from 165,000 to 180,000 ounces at average cash costs between $630 and $690 per ounce. Westwood is estimated to have a mine
life of roughly 20 years in all the mining scenarios under consideration.
Ore processing utilizes the pre-existing Doyon carbon-in-pulp (“CIP”) mill complex.
Ore from the Westwood underground is hauled to the Doyon mill (two kilometres away) to be crushed and ground. The ore grinding circuit utilizes a SAG mill and a 1,000 HP ball mill.
Because of its legacy, where the Doyon mill had the capacity to process more than 1 million tonnes per year in the 1990’s, the existing gold recovery circuit has more capacity than required to recover the annual gold production from Westwood, which is expected to peak at about 850,000 tonnes per year. Consequently, Westwood continues to seek opportunities to find additional ore to process in the region surrounding its operation.
Following the production interruption in 2015 and based on the revised life-of-mine plan, 2016 efforts will be focused on underground development to expand the number of mining areas, remedial work in the affected zones and development activities providing access to production blocks for future years. Throughout 2016, the mill will operate on a reduced schedule due to the low level of mining, with ramp-up to full capacity over the next four years. The Company plans to continue to implement cost improvement initiatives focused on improving development productivity.