The 25,506-ha land package that makes up Agnico Eagle's Kirkland Lake project was formerly owned by a succession of junior exploration companies.
Agnico Eagle is focusing on the Upper Beaver and Upper Canada deposits, which are near each other. Probable mineral reserves have been estimated at Upper Beaver of 8.0 million tonnes grading 5.43 g/t gold and 0.25% copper (containing 1.4 million ounces of gold and 19,980 tonnes of copper) as of December 31, 2020, and there are substantial indicated and inferred mineral resources. At the Upper Canada deposit, there are indicated mineral resources of 10.4 million tonnes grading 2.15 g/t gold (containing 722,000 ounces of gold) and inferred mineral resources of 18.6 million tonnes grading 3.11 g/t gold (containing 1.9 million ounces of gold) at underground and open pit depths.
Recent exploration activity at the project focused on conversion drilling of shallow and deep mineral resources at the Upper Beaver deposit. During 2020, 103 holes or branches were drilled, totalling 28,300 metres at the Kirkland Lake project, mostly at Upper Beaver.
The combined indicated mineral resources at the property’s Anoki and McBean deposits have been estimated at 1.9 million tonnes grading 5.33 g/t gold (containing 320,000 ounces of gold) as of December 31, 2020, and there are additional inferred mineral resources, all at underground depths. At the Amalgamated Kirkland (AK) deposit, the underground mineral resource estimate includes indicated mineral resources of 1.3 million tonnes grading 6.51 g/t gold (containing 265,000 ounces of gold) as of December 31, 2020, as well as inferred mineral resources.
Geology
The properties lie within the southern Abitibi Greenstone Belt of the Superior Province of the Canadian Shield, approximately 110 km west of Agnico Eagle's LaRonde mine. The area is underlain by an east-west-trending linear Timiskaming assemblage comprised of volcanic and sedimentary rocks as well as synvolcanic intrusion emplacements consisting typically of diorite, syenite, quartz-feldspar porphyries and monzonite. The assemblage, deposited in a sub-aerial to shallow marine arc-rift environment, is typically bound to the south by the Larder-Cadillac Break (LCB) – which is a major east-trending, south-dipping regional structure that juxtaposed Tisdale mafic to ultramafic rocks (south of the fault) against much younger Timiskaming sedimentary rocks. The LCB lies within the Larder Cadillac Deformation Zone (LCDZ), which is a wide structural zone cutting across several lithologies.
Mineralization
There are three main deposits on the properties:
- The Upper Beaver deposit's gold-copper mineralization is mainly hosted in the Upper Beaver alkalic intrusive complex and the surrounding basalts it intruded, and is associated with disseminated pyrite and chalcopyrite, and magnetite-sulphide veining associated with strong magmatic-hydrothermal alteration. The mineralization occurs as elongated tabular bodies that strike northeast, dip steeply northwest and plunge 65 degrees to the northeast. The mineralization has been defined along a 400-metre strike length from surface to a depth of 2,000 metres and it remains open at depth.
- The Upper Canada deposit lies approximately 6 km southwest of the Upper Beaver property, and 1.6 km north of the main LCDZ, within a 300- to 400-m-wide strongly altered deformation corridor. Host rocks are primarily volcanic (trachyte) tuffs and sediments that have been intruded by syenite bodies. Gold mineralization is associated with intensely altered shear zones with fine pyrite and ancillary sulphide mineralization. En-echelon higher-grade lenses are present within a broader envelope of lower grade mineralization.
- The AK (Amalgamated Kirkland) deposit consists of lode-style gold mineralization hosted by altered and pyritic Timiskaming volcanic and sedimentary rocks. The deposit is hosted in one of many northeast-trending structures that lie between the Kirkland Lake Main Break and the LCDZ. The gold mineralization is of two types: gold-bearing quartz and quartz breccia veins, and gold within pyrite-altered host rocks.
Exploration
In 2021, the Company plans to drill 36,500 metres at Upper Beaver in a program that will include additional shallow drilling to test an open pit concept and further deep drilling to convert mineral resources to mineral reserves. An internal technical evaluation at Upper Beaver that will include an updated mineral reserve and mineral resource estimate incorporating drill results from 2020 and 2021 is expected to be completed by the end of 2021.
Elsewhere on the Kirkland Lake property in 2021, the Company plans to drill 15,700 metres in a regional exploration program that will include Upper Canada and Bidgood as targets.