Musselwhite mine is a fly-in/fly-out operation on the southern shore of Opapimiskan Lake in northwestern Ontario, Canada, 480 kilometres north of Thunder Bay. The nearest town is Pickle Lake, 103 kilometres by air to the south. The property is compromised of a combination of leases and mining claim units covering a total area of 17,548 hectares, entirely on traditional First Nations land.
The Musselwhite mine is located within the Weagamow – North Caribou Greenstone Belt of the Sachigo Subprovince, part of the Archean Superior Province. The stratigraphy in the immediate mine vicinity is dominated by mafic volcanics, chemical sediments and felsic volcanics. External to the supracrustal sequences are a series of undifferentiated gneisses and granitoids. All lithologies within the immediate mine area have been metamorphosed at mid to upper amphibolite facies. Although the mine scale deformation is considered to form part of a progressive deformation event, it is possible to differentiate four local deformation events.
Mineralization is predominantly hosted within meta-chemical sediments (banded iron formations) and in particular within garnet-magnetite-grunerite facies meta-banded iron formations (locally termed the Northern Iron Formation). The location of mineralization is controlled by the intersection of shear zones and folded meta-banded iron formations. These geological controls result in mineralized shoots, which plunge at approximately 15 degrees to grid north, have a down dip extent of up to 150 metres, down plunge continuation in excess of 1.5 kilometres, and across-lithology width of up to 10 metres. Mineralized zones are characterized by abundant pyrrhotite, quartz flooding and, rarely, visible gold.