Vein copper deposits include various vein-type deposits in which copper is the dominant metal. The deposits are structurally controlled and occur in faults, fault systems, and vein-breccia zones; replacement zones in associated country rocks are also present. They are typically small, but are highly varied in both size and grade. Although vein copper deposits occur in association with many different host rocks and in diverse geological settings, two main subtypes are recognized, which are based on the associated intrusive rocks; the deposits do not necessarily occur in these rocks in all cases, but they are likely genetically related to them. The first subtype consists of vein copper deposits associated with mafic intrusive rocks; these have been referred to as ‘Churchill type’ after the Churchill Copper (Magnum) deposit in British Columbia (Kirkham, 1973). Other examples of this subtype include the Davis- Keays and Bull River deposits in British Columbia; Bruce Mines, Crownbridge, Ethel Copper, and some veins in the Cobalt district, Ontario; Icon-Sullivan, Quebec; and deposits in the East Arm of Great Slave Lake (e.g., Susu Lake) and Coppermine River (e.g., Copper Lamb) areas, Northwest Territories (Fig. 17-1).