Paleoproterozoic Ni-Cu-Co sulphide mineralization, Suluk occurrence, Gibson-MacQuoid Lake area, western Churchill Province, Northwest Territories

The recently discovered Ni-Cu-Co Suluk occurrence is interpreted to be Paleoproterozoic and represents the first recognition of a gabbro-associated magmatic sulphide deposit type in the Western Churchill Province. Archean tholeiitic metavolcanic rocks of the Gibson-MacQuoid greenstone belt that host the occurrence were reworked during Paleoproterozoic thermotectonism. A recrystallized and altered composite gabbroic intrusion is spatially associated with and inferred to be genetically related to the nickel-copper occurrence. Massive sulphide is irregular in form, concordant with the foliation in the enveloping tholeiitic metavolcanic rocks and is composed of massive nickeliferous pyrrhotite-pentlandite that contains abundant wallrock xenoliths. This magmatic nickel sulphide event in the Western Churchill Province is correlated with extensive mafic magmatism and associated Ni-Cu-Co and Fe-Ti deposits, circa 2.2-1.9 Ga, in the Fennoscandian and eastern Baltic shields.