Copper Cliff
Location, Access, Description
The Copper Cliff property is located in Eeyou-Istchee James Bay Government, Northern Québec, Canada (NTS 32G16), approximately 4.5 km southeast of Chibougamau, along the north shoreline of Lac aux Dorés. It consists of 7 contiguous claims covering a total area of 90.91 hectares in McKenzie township. The Project is easily accessible in vehicle by all-weather gravel roads connecting to regional highway #167.
The claims have been stacked by Globex and then transferred in 2012 to Chibougamau Independent Mines (CIM), a subsidiary of Globex ; TomaGold optioned the property from CIM in 2023 (as well as several other properties of CIM ; see the General Map of Globex’s assets in the Chibougamau area), and Globex will retain a 3% Gross Metal Royalty (GMR) on it.
The Copper Cliff former mine located immediately northwest of the property has a total estimated production of 1,273,819 t of ore grading 1.83% Cu (±Ag ±Au) between the late 1960s and 1974 (DPV 368).
Geology and Mineralization
The Copper Cliff property is located in the Superior Province of the Canadian Shield. The Abitibi Sub-province is known for its prolific and diverse rich mineral deposits; total gold production of the Abitibi Greenstone Belt (AGB) since the beginning of the 20th century is estimated at over 210 million ounces (Moz) Au (Dumas, 2024).
The Chibougamau region hosts some of the eldest rocks of the AGB; the area is dominated by a stacking of Archean mafic volcanic rocks intercalated with a few felsic units and some sedimentary units, intruded by two large batholiths : the anorthosite Doré Lake Complex, and the Chibougamau Pluto composed of tonalite and granodiorite. These two intrusions played a major role as regional mineralized features, and the vast majority of mines in the Lake Chibougamau area are located within or near these two intrusions. Regional metamorphism is at the greenschists grade.
The property area is mostly underlain by anorthosite and gabbroic anorthosite of the Lac Doré mafic to ultramafic intrusive Complex adjacent to the Lac Chibougamau Batholith, located further to the SE. The Copper Cliff property covers an area of altered gabbroic anorthosite associated to the Lac Doré Complex. The rock formations present within property limits are dominated by variably sericitized, massive anorthosite and anorthositic gabbro, always coarse grained.
The Chibougamau Mining District is located in the northeastern part of the Abitibi Greenstone Belt and hosts a variety of deposit styles; Leclerc et al. (2012) documented volcanogenic massive sulphide (“VMS”) deposits, magmatic Fe-Ti-V and Ni-Cu ± PGE mineralization, early polymetallic (Au-Ag-Cu-Zn-Pb) vein deposits (to which the Property mineralization might belong), Chibougamau-type Cu-Au-veins, shear zone-hosted Au deposits, and Opemiska-type Cu-Au veins. Total production of the Chibougamau mining camp since the beginning of the 20th century is estimated at 1,624.9 Mlbs Cu and 3.22 Moz Au (Houle, 2019).
Mineral production from the Chibougamau Mining Camp was derived largely from mesothermal Cu-Au veins. Most of the past producing mines are located within the anorthositic gabbro phase of the Lac Doré Complex. When the Chibougamau Pluton intruded the bedrock, the Lac Doré anorthosites were fractured and filled with metal-bearing hydrothermal fluids. Mineralization on the Copper Cliff property consists of disseminations and stringers of pyrite with little chalcopyrite in mafic dykes and chloritized bands of anorthosite. Mineralization is also often associated with quartz-carbonate veins in the anorthosite (GM71931).
History
Discovery of metallic mineralization in this area dates back to 1906 with the discovery of sulphide mineralization by John Kokko at the future Kokko Creek mine. Numerous exploration programs (mapping, sampling, geophysics, rock stripping, diamond drilling…) have been undertaken by successive owners ; more details about the history of exploration on the property is presented in CIM 2019 work report by Amrhar (2020).
The Copper Cliff mine (Cu ±Ag ±Au) located in the direct vicinity of the property, has been in production from the late 1960s to 1974. Remaining historical Resource of 52,600 t grading 1% Cu and 860 ppb Au were estimated after the mine closure (DPV 727).
Several diamond drilling programs have been done on the Copper Cliff property prior to its acquisition by Globex. A total of 18,736 linear metres in 94 DDH have been documented in Quebec public data (Sigéom); most of the drilling was fairly shallow and dates back to 1988 and earlier.
Recent developments :
In 2019, CIM undertook one (1) single 460.94 m long DDH on the Copper Cliff property in order to follow-up on historical intersections. Hole CCF-19-01 intersected anorthosites hosting anomalies up to 3.36 g/t Au and 0.55% Cu over 0.95 m in a black chloritized interval with disseminated pyrite-chalcopyrite stringers and bands, and 2.95 g/t Au with 0.53% Cu over 1.41 m in a quartz-carbonate vein (GM71931).
In 2021, CIM requested the services of NOVATEM to fly a very-high resolution airborne magnetic survey over several of its properties in the Chibougamau area (GM72456), including the Copper Cliff claims.
TomaGold optioned two (2) blocks of properties from CIM in 2023, including the Copper Cliff claims (CIM Press Release dated August 14, 2023). No work appears to have been carried out by TomaGold on the property at this time.
Resources and Potential
Historical work in the area identified a regional favorable context for several commodities including gold, silver, copper and zinc. The property potential is supported by favourable geological and structural setting and the presence of well-documented metallogenic and litho-tectonic elements such as the layered anorthositic Lac Doré Complex, and other structures and alteration. This potential is attested by the presence of several former mines in the direct vicinity of the Copper Cliff property (Copper Cliff, Québec-Chibougamau Goldfields, Kokko Creek, Copper Rand, Cedar Bay…); Cu was the principal commodity extracted with minor quantities of Zn, Ag and Au.
Future exploration work on the Copper Cliff property should begin with refreshing and resampling old trenches as recommended by Amrhar (2020). Airborne chargeability and resistivity survey may also help to highlight the presence of faults and shear zones. Then follow-up with ground IP on the identified structures should be considered before thinking of rock stripping and DDH.