On March 28, 2018, Agnico Eagle acquired 100% of interest in the project, giving Agnico Eagle 100% ownership of Canadian Malartic Corporation’s interest of the Kirkland Lake properties (Upper Beaver is part of Kirkland Lake exploration properties).
Summary:
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.
Mineralization at Upper Beaver, as described by Queenston (Kontack, Dube and Benham, unpublished):
- Occurs both in flat and steeply dipping zones;
- Is of replacement-type with rare vein-type mineralization;
- Is associated with minor to pervasive alteration which includes feldspar, epidote, carbonate, sericite, silica and magnetite with trace hematite; and
- Has an element association of Cu, Au, or Au-Cu with associated molybdenum.
Queenston classifies the mineralization as three main groups of zones (from south to north):
- South Contact Zones;
- Beaver North Zones; and
- North Basalt Zones.
The South Contact Zones disseminated mineralization consists of two, relatively flat-lying zones. These occur below and south of the mine workings in the Upper Tisdale contact area, marked by the roll in the stratigraphy from a north-westerly to north-easterly strike. Gold and copper contents increase where steeply dipping quartz-chalcopyrite-quartz veins and stringers intersect the flat-lying disseminated zones. The host is mafic breccia and volcaniclastic conglomerate with variable silica, epidote and calcite alteration, along with magnetite, chalcopyrite, pyrite, pyrrhotite, and visible gold.
The Beaver North Zones include a series of east-northeast striking, north-dipping, fracture, vein and stringer systems containing chalcopyrite, magnetite, pyrite and visible gold. They occur below and north of the mine workings near the south contact of the large (600 m) syenite plug. The fracture systems crosscut a variety of rock types and are tentatively named by their position in the stratigraphy when first identified as: Syenite Zones, North Contact Zone (the basalt/syenite contact area), Porphyry Zones (associated with feldspar porphyry), Syenite Breccia Zones, and Lower Gauthier Zone (in Upper Tisdale assemblage rocks).
The North Basalt Zones are located at the north contact of the 600 m, syenite plug. They are also characterized by a series of fractures and stringers with chalcopyrite and magnetite crosscutting syenite to mafic syenite and basalt.