The Dumont Project is entirely owned and operated by Magneto Investments Limited Partnership ("Magneto").
Nion Nickel Inc. owns the Dumont Project through its 100% ownership of Magneto.
Waterton Global Resource Management, Inc. is the advisor to the two private funds (Waterton Precious Metals Fund II Cayman, LP and Waterton Mining Parallel Fund Onshore Master, LP) which jointly own 100% of Nion Nickel and Magneto Investments L.P.
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Summary:
Magmatic nickel-copper-platinum group element (PGE) deposits occur as sulphide concentrations associated with a variety of mafic and ultramafic magmatic rocks. The magmas originate in the upper mantle, and an immiscible sulphide phase occasionally separates from the magma as a result of the processes occurring during emplacement into the crust. The sulphide phase generally partitions and concentrates nickel, copper and PGE elements from the surrounding magma. The heavy sulphide droplets once concentrated and separated from the magma tend to sink towards the base of the magma, and form concentrated pockets or layers of sulphides that crystallize upon cooling to form mineral deposits.
The Dumont mineral deposit comprises olivine + sulphide cumulates that comprise differentiated layers of the Dumont sill, an Archean komatiitic intrusion contained within the Archean Abitibi Greenstone Belt of northwestern Quebec. As such, it is usually classified (Naldrett, 1989) with its most analogous counterpart, the Mt. Keith mineral deposit located in the Agnew-Wiluna Greenstone Belt within the Archean Yilgarn craton of West Australia.
Both the Dumont and Mt. Keith deposits have undergone pervasive serpentinization and local talc-carbonate alteration due to metamorphism to mid-upper greenschist facies. At Dumont, this alteration history has resulted in liberation of much of the nickel from nickel silicates (olivine) and consequent upgrading of the primary magmatic nickel-sulphide and formation of nickel-alloy minerals through partitioning of nickel. However, the Dumont deposit is differentiated from the Mt. Keith deposit by the abundance of the nickel-iron alloy awaruite and by the restricted extent of talc-carbonate alteration, which is limited to the basal contact of the intrusion and occurs outside the resource envelope. Also, the Dumont deposit has not been subjected to the extensive supergene weathering alteration present at Mt. Keith.
Disseminated Nickel Mineralization
Nickel-bearing sulphides and a nickel-iron alloy are enriched (grades > 0.35% nickel) in stratiform bands within the dunite subzone and are also broadly disseminated at lower concentrations throughout the dunite and lower peridotite subzones. The number and thickness of these bands varies from place to place in the deposit. Nickel sulphide and alloy concentrations decrease gradationally away from the centre of these bands toward the interband zones where mineralization continues at lower concentrations. The total nickel contained in these rocks occurs in variable proportions in sulphides, alloy and silicates depending on primary magmatic nickel mineralogy and the degree of serpentinization of the rock.
Nickel Mineralogy
Disseminated nickel mineralization is characterized by disseminated blebs of pentlandite ((Ni,Fe)9S8), heazlewoodite (Ni3S2), and the ferronickel alloy, awaruite (Ni2.5Fe), occurring in various proportions throughout the sill. These minerals can occur together as coarse agglomerates, predominantly associated with magnetite, up to 10,000 µm (10 mm), or as individual disseminated grains ranging from 2 to 1,000 µm (0.002 to 1 mm). Nickel can also occur in the crystal structure of several silicate minerals including olivine and serpentine.
The observed mineralogy of the Dumont deposit is a result of the serpentinization of a dunite protolith, which locally hosted a primary, disseminated (intercumulus) magmatic sulphide assemblage. The serpentinization process whereby olivine reacts with water to produce serpentine, magnetite and brucite creates a strongly reducing environment where the nickel released from the decomposition of olivine is partitioned into low-sulphur sulphides and newly formed awaruite. Nickel also occurs in remnant olivine and newly formed serpentine with the concentration of nickel in these minerals being dependent on the degree of serpentinization of the rock.
Millerite (NiS) is rare but can be present in lesser amounts near host rock contact zones and in major fault zones. It typically occurs as fine secondary overgrowths, characteristically overprinting pentlandite and heazlewoodite in intercumulus blebs.
Nickel Mineralization Assemblages
Mineralized zones containing pentlandite, awaruite, and heazlewoodite, are classified into the following mineralization assemblages; sulphide dominant, alloy dominant and mixed.
Sulphide Mineralization Assemblage
The sulphide mineralization assemblage occurs in higher-grade bands (grades > 0.35% nickel) that are subparallel to the dip of, and principally in the centre of, the sill. Sulphide mineralization is dominated by pentlandite (Pn) and/or heazlewoodite (Hz) with lesser awaruite (Aw). Pentlandite and heazlewoodite occur as medium to coarse-grained blebs occupying intercumulus spaces in a primary magmatic texture, sometime exhibiting secondary overgrows within magnetic blebs. These blebs are often intimately associated with magnetite ± brucite ± chromite ± awaruite, in intercumulus spaces. Where awaruite is present with sulphides, it often observed to be a secondary overgrowth on pentlandite within the primarily textures intercumulus magnetite blebs. Up to three sulphide bands are found within the dunite where it is the thickest in the central southeast region of the sill.
Alloy Mineralization Assemblage
The alloy mineralization assemblage is characterized by the presence of awaruite with little to no sulphides. Awaruite occurs as fine grains (generally <1 mm) associated with small intercumulus magnetite or chromite blebs. Awaruite can also be observed as a secondary overgrowth on serpentine within the pseudomorphed grain. Alloy mineralization zones occur where primary sulphides are not present and serpentinization is near complete.
Mixed Mineralization Assemblage
The mixed mineralization assemblage typically represents a transition from sulphide to alloy or sulphide (pentlandite) to sulphide (heazlewoodite) mineralization. The mixed mineralization assemblage contains varying amounts of sulphide (pentlandite and heazlewoodite) along with similar quantities of awaruite. Mineralization can occur as coarse sulphide-magnetite blebs associated with awaruite or as finely disseminated discrete grains.