Hudbay Minerals Inc., through its wholly owned subsidiary, Copper Mountain Mine (BC) Ltd., holds a 100% interest in the Copper Mountain Mine.
On March 27, 2025, Hudbay announced that it acquired the remaining 25% ownership interest from Mitsubishi Materials Corporation, consolidating full ownership of the operation.
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Summary:
The Copper Mountain (CM) deposit is an example of an alkalic porphyry deposit, in which copper–gold mineralization is spatially and genetically associated with multiple pulses of volumetrically restricted, and compositionally varied, alkaline porphyry intrusions.
Mineralization
The bulk of the known copper mineralization at Copper Mountain occurs in a northwesterly trending belt of Nicola Group rocks, approximately 5 km long and 2 km wide, that is bounded in the south by the CMS and in the west side by the northernly trending Boundary Fault system. Here copper mineralization occurs as structurally controlled, multidirectional veins and vein stockworks, with peripheral disseminations. Mineralization had been subdivided into four types, as follows: 1) disseminated and stockwork chalcopyrite, bornite, chalcocite, and pyrite in altered Nicola Group volcanic rocks and LHIC rocks; 2) bornite-chalcopyrite associated with pegmatite-like veins (coarse masses of orthoclase, calcite, and biotite; 3) magnetite-(±hematite)-chalcopyrite replacements and/or veins); and 4) chalcopyrite-bearing magnetite breccias (Fahrni et al., 1976; Klue et al., 2020; Preto, 1972; and Stanley et al., 1995). All mineralization types can be found in each pit area, but each pit is unique with respect to the relative quantities and character of mineralization type.
Disseminated and stockwork chalcopyrite–bornite–chalcocite-(±pyrite) mineralization formed much of the core of the deposit in the southern area of the CM Main Pit (formerly known as Pit 3). In the highestgrade areas that were mined underground, bornite and chalcopyrite veins have locally been replaced on their margins by minor amounts of bladed specular hematite, digenite, chalcocite, and epidote. These replacements are interpreted to be a late hydrothermal overprints on the bornite-chalcopyrite bearing veins, possibly during collapse and cooling of the magmatic hydrothermal system.
Bornite-chalcopyrite mineralization associated with “pegmatite-like” veins are either barren of sulphides or contain chalcopyrite and magnetite with either bornite or, less commonly, pyrite. Historically, these have been subdivided into several different groups, based upon mineralogy: 1) barren veins; 2) bornite–chalcopyrite–(magnetite) bearing veins; and 3) chalcopyrite–pyrite–(magnetite)–bearing veins. Sulphide-absent pegmatite-textured veins occur locally across the mine area. In contrast, the distribution of the sulphide-bearing pegmatite-textured veins defines an “inner” bornite–chalcopyritebearing zone and an “outer” chalcopyrite–pyrite-bearing zone. The inner zone is situated along the northern contact of the CMS within the Nicola Group (in the vicinity of the historical Pits 1 and 3); however, these veins do not penetrate more than 1 m into the CMS (Stanley et al., 1995).
Magnetite–hematite–chalcopyrite replacements and veins primarily existed in the historical Virginia Pit (now known as the CM North zone), and within prospects hosted by the LHIC. They are commonly dilatant, planar, and occur in “sheeted” parallel sets, but in some cases form crackle zones a few metres wide. They are mineralogically similar to the chalcopyrite–pyrite-bearing pegmatite-textured veins, but carry significantly higher gold grades (Stanley and Lang, 1993) relative to other mineralized zones to the east. Chalcopyrite precipitated after pyrite and magnetite within these veins and native gold has been observed associated with chalcopyrite over-grown by pyrite. Gangue calcite, is typically interstitial to magnetite and sulphides.
Magnetite filled breccias with potassically altered clasts of Nicola Group volcanic and LHIC dykes occur within the Ingerbelle Pit and the north side of the CM Main Pit. They occur as elongate bodies along faults, or as roughly circular bodies at fault intersections. These breccias are mineralized with chalcopyrite and pyrite and are bounded by a higher-grade zone of copper–gold mineralization. The breccias include stockworks on their margins, crackle breccias, and clast-supported partially-milled breccias in their cores. The alteration mineralogy of these breccias is closely associated with magnetite–sulphide veins, and are interpreted to be a different structural representation of the hydrothermal event that formed the magnetite–sulphide veins (Stanley et al, 1995).