In September 2023, Bonterra Resources Inc. and Osisko Mining Inc. entered an agreement granting Osisko the right to acquire a 70% stake in specific projects by investing $30 million in exploration over three years.
By November 2023, a definitive agreement confirmed Osisko as the operator during the earn-in period. Bonterra established a subsidiary, UB Phoenix Corp. (“Subco”), to manage the assets. Osisko will hold a 70% interest in certain infrastructure, open-pit mining assets, plants, and equipment upon completing the earn-in. Until then, Bonterra retains full ownership through Subco.
In August 2024, Gold Fields Limited announced its acquisition of Osisko Mining for CAD 2.16 billion. Following the transaction's completion in October 2024, Gold Fields became the operator of the Phoenix JV project.
As of January 2025, the Phoenix JV is jointly owned by Gold Fields Limited (70%) and Bonterra Resources Inc. (30%), with Gold Fields overseeing development and operations.
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Summary:
The Properties are thought to be prospective for greenstone-hosted quartz carbonate vein gold deposits, intrusion related gold (IRGS) deposits, and volcanogenic massive sulphide (VMS) deposits (Darling and Lafontaine (2011), SGS (2019b)). The deposits at the Properties for which Mineral Resources have been estimated are characterized as Greenstone-hosted quartz carbonate veins typical of the northern portion of the Abitibi Subprovince of the Superior Province in northwestern Québec.
The Barry property is underlain by greenschist facies volcanic and intrusive rocks of tholeiitic affinity belonging to the UBGB. As there is limited outcrop exposure, the geology had to be deduced from drill holes data and geophysics. Geological mapping and diamond drilling identified a series of basaltic flows that are interpreted to cover over 90% of the Barry property. The only intrusive bodies identified on the Barry property were the quartz-feldspar porphyry in the area of the Barry I Main Zone Area and a series of gabbro sills to the north. A siltstone outcrop was identified approximately 300 m northeast of the Barry I Main Zone. Stratigraphic tops are to the southeast, as indicated by pillow facing directions. The rocks on the Barry property are overprinted by a weak to moderate northeast to southwest trending foliation (S2) that parallels regional shearing and contacts of the large granitic intrusions.
Mafic volcanic rocks are the most common rocks on the Barry property and consist of dark green, fine grained, iron-rich tholeiitic basalts. In order of decreasing abundance, these flows vary from massive, amygdaloidal, brecciated, feldspar-phyric, to locally pillow. Alteration varies from a regional chlorite alteration to carbonate, sericite, epidote plus minor silicification, hematization, biotite and actinolite alteration locally (Tessier 1996, Lariviere 1997). All these rocks vary from generally nonmagnetic to locally strongly magnetic with up to 5% disseminated magnetite crystals and less commonly stringers of magnetite.
Mafic volcanic rocks in the area of the Barry deposit are intruded by a series of porphyritic to granitic felsic dikes or sills. The quartz-feldspar porphyry varies in colour from a medium grey (fresh surface), to a reddish tint (due to hematization), to a bleached light grey (due to strong silicification). The quartzfeldspar porphyry is noted to be sill like, maintaining a general stratigraphic position within the volcanic pile, while simultaneously crosscutting the volcanic stratigraphy on surface. The thickness of this unit varies from several metres to over 125 m.
One can observe two sets of porphyritic to granitic felsic dikes or sills. The first set is foliated and exhibits 35% of feldspars and less than 5% of blue quartz-eyes. The second set of quartz-feldspar porphyry is not foliated and contains 8% to 12% of blue quartz-eyes and 50% of feldspars.
The gabbro is massive, medium to coarse grained with a dark green colour. At times, the gabbro develops a finer grained gradational contact with the basalts and varies from moderately to nonmagnetic. Drilling indicates that the gabbro is sill like and up to 20 m thick.
Gold mineralization is constrained to zones containing 5% to 15% albite-carbonate-quartz veins and their associated hydrothermally altered wall rocks (SGS, 2019a). Albite-carbonate-quartz veins are typically one centimetre to five centimetres wide, and comprise euhedral albite, carbonate, and quartz with local trace biotite ± sericite, chlorite, pyrite (fine grained anhedral, or coarse grained euhedral), pyrrhotite, rare euhedral magnetite, and fine grained visible gold as inclusions or fracture infill in pyrite, or in sharp contact with carbonate crystals in the vein. Veins locally pinch and swell or are boudinaged with biotite generally filling the cusps. Gold grades in mineralized veins and altered mafic volcanic rocks range from less than 2 g/t Au to more than 100 g/t Au.
The following alteration types have been observed on the Barry property:
• Syn-ore carbonate-quartz-pyrite alteration associated with the mineralized albite-carbonatequartz veins.
• Syn-ore biotite-calcite alteration associated with mineralized albite-carbonate-quartz veins in areas of intense foliation.
• Post-ore biotite-chlorite, carbonate, muscovite, and epidote alteration. Post-ore epidote alteration is generally found at depths greater than 25 m, where it is commonly associated with epidote-garnet veinlets, or in non-mineralized zones at shallower depths.