On February 28, 2025, Magna Mining Inc. announced, further to its news releases dated September 12, 2024, January 9, 2025 and January 30, 2025, that it has completed its acquisition of a portfolio of base metals assets located in the Sudbury Basin from an affiliate of KGHM International Ltd., which includes the producing McCreedy West copper mine, the past-producing Levack mine, Podolsky mine and Kirkwood mine, as well as the Falconbridge Footwall (81.41%), Northwest Foy (81.41%), North Range and Rand exploration assets (collectively, the "Purchased Assets")
- subscription is required.
Summary:
The McCreedy Mine is situated along the margin of the 1.85-billion-year-old Sudbury Igneous Complex (SIC). The Levack Complex properties (McCreedy West and Levack mines) occur at the western limit of an extensively mineralized 8.5 km long portion of the North Range of the SIC known as the Levack Embayment. This area encompasses all of the major Vale Inco and Glencore past and current producing mines of the North Range (Longvack, Strathcona, Coleman, McCreedy East, Fraser, Fecunis, Craig, Levack, Onaping, McCreedy West – formerly Levack West, Boundary and Hardy).
Sudbury Breccia is a pseudotachylite-like footwall breccia that forms discontinuous belts on both the North and South ranges. The breccias are largely interpreted to have formed by comminution of footwall rocks as a result of meteorite impact and are considered to be important in the preparation of the country rocks for Cu-Ni-PGE system emplacement of which they are the primary host. Sudbury Breccia is a matrix supported fragmental rock with a black to light grey, aphanitic to fine-grained, and variably re-crystallized, quartzofeldspathic (±amphibole, biotite) matrix. Rounded, equant, footwall rock clasts from 1 mm to 30 m in diameter consist of gabbro, diabase, mafic gneiss, intermediate gneiss, granite gneiss, and granite, although exotic fragments of iron formation and quartzite have been observed locally. Sudbury Breccia occurs as veinlets and veins in fractured footwall rocks to the SIC and can form irregularly shaped masses or belts on the scale of hundreds of metres.
McCreedy West geology is typical of Sudbury North Range stratigraphy and mineralization, sharing these attributes with the neighboring Levack Mine property. The basal contact of the SIC dips southsoutheast at approximately 35° on the McCreedy West property. Granite Breccia thicknesses range from minimums of a few feet to locally more than 100 feet in “plumes”, or extensions of Granite Breccia that cross-cut basal SIC stratigraphy up into the Sublayer Norite and Mafic Norite. The Sublayer Norite displays a similar range of stratigraphic thicknesses. Both the Granite Breccia and Sublayer Norite host contactstyle Ni-rich mineralization. The footwall to the SIC is dominated by granitic gneisses and migmatites that are locally Sudbury brecciated. The Sudbury Breccia at McCreedy West locally connects to the SIC basal contact at the Middle Main Zone, but typically forms as a tabular sheet that is oriented subparallel to the base of the SIC. The Sudbury Breccia package is commonly separated from the base of the SIC by several hundred feet of relatively unbrecciated granitic gneiss and may be locally up to 1000 ft thick.
Deposit Type
There are several main types of mineral deposits in the Sudbury area:
• Contact deposits, including massive sulphide consisting of Ni, Cu, Co, Pt, Pd, and Au mineralization along the lower contact of the SIC, both within the contact sublayer and in the immediately adjacent FW Breccia.
• FW deposits, including sulphide veins and stringers containing Cu, Ni, Pt, Pd, and Au, in the brecciated FW rocks beneath the SIC.
• Structurally and/or hydrothermally remobilized sulphide Ni, Cu, Co, Pt, Pd, and Au mineralization.
• Offset dyke deposits, including massive sulphide consisting of Ni, Cu, Co, Pt, Pd, and Au mineralization associated with brecciated and inclusion-bearing phases of the quartz diorite (QD) offset dykes (i.e., inclusion-rich quartz diorite [IQD]).
• Hybrid type deposits representing combinations of the above.
Contact Type Deposits
Mineralization includes blebby to massive accumulations of sulphide, including pyrrhotite > chalcopyrite > pentlandite concentrated within embayment depressions along the base of the SIC, both within the contact sublayer and in the immediately adjacent FW Breccia.
Footwall Type Deposits
Footwall-type deposits or “Cu-Ni-PGE Systems” are characterised by chalcopyrite-rich assemblages hosted entirely within brecciated footwall rocks to the SIC, typically either in re-crystallized Sudbury Breccia or Offset Quartz Diorite. The best-known of these deposits occur in the North Range. The most spectacular and intensely studied of these are the Cu-rich veins at the McCreedy West, Morrison Deposit at Levack Mine, McCreedy East, Coleman, Strathcona and Fraser mines in the Onaping-Levack area of the North Range. They are characterised by complex networks of veins, pods and disseminations of chalcopyrite cubanite, with minor pyrrhotite, pentlandite, millerite and magnetite.
Structurally and/or Hydrothermally Remobilized Mineralization
In some deposits, sulphide has been remobilized into shear zones and related structural traps. Important examples of this type of deposit include those at Garson, Falconbridge, Falconbridge East, and Creighton mines. Several mineralized trends at Cran Hill mimic the underlying shear fabric; because of this, these trends may fall under this deposit type.
Offset Dyke Deposits
Mineralization includes massive and semi-massive accumulations of sulphide, including pyrrhotite > chalcopyrite > pentlandite. Sulphide accumulations are associated with and are known to concentrate in structural traps such as vertical or horizontal pinches or terminations in the dyke, bends in the dyke, splays/convergences of dyke branches, along the margins or within “pressure shadows” of large blocks caught up in the dyke, and at intersections of the offset dykes with coarse mafic intrusions in the wall rock.
Mineralization
Sulphide mineralization at McCreedy West occurs as contact Ni and footwall-hosted Cu-Ni-PGE deposits with mining operations exploiting both. Contact Ni-Cu mineralization occurs along the base of SIC within Sublayer Norite and Granite Breccia-filled troughs and irregularities. These features form sulphide traps, and footwall-hosted “low-sulphide” and “sharp-walled” Cu-Ni-PGE mineralization, hosted by Sudbury Breccia. Contact Ni deposits at McCreedy West include the Intermain, East Main, Upper Main, and Lower Main zones. Each take the form of high grade pods, or sulphide concentrations, surrounded by a ubiquitous low-grade halo in the host Sublayer Norite or Granite Breccia. The contact Ni sulphide mineral assemblage is pyrrhotite-dominant, with pentlandite and chalcopyrite, ± pyrite. The footwall-hosted 700 (sharp-walled) and PM (low-sulphide) deposits have been mined at McCreedy West since 2003 and 2005, respectively. The Middle Main Zone consists of “transitional”-style mineralization physically attached to the Cu-rich footwall vein system. The footwall Cu veins at McCreedy West are particularly important because they are the only footwall veins economically exploited in the Sudbury camp to date that are physically connected to contact Ni sulphide mineralisation. The “low-sulphide” PM Zone deposit is hosted in the same Sudbury Breccia package as the 700 Complex, but further east, directly under the contact hosted Intermain. Both “sharp-walled” and “low-sulphide” Cu-Ni-PGE systems are characterized by a sulphide mineral assemblage dominated by chalcopyrite, with less common pentlandite, millerite, cubanite, and pyrrhotite. The contact zones are characterized by increased Ni, Ir, Ru and Rh compared to the footwall systems, whereas the footwall systems have considerably higher Pt, Pd, Au, Ag and Cu contents. Precious metal minerals from Cu-rich veins at McCreedy West commonly occur as large composite grains, dominated by moncheite and hessite. The most common host mineral for the precious metal grains is chalcopyrite, with some grains in amphibole, and some at silicate-sulphide grain margins.
The main mineralized zones from east to west are as follows:
• Intermain Zone
• East Main Zone
• Upper Main Zone
• Lower Main Zone
• 700 footwall-hosted (Sharp-walled) Zone
• PM (low sulphide) Zone.