An Archean volcanic-related gold-sulfide-quartz vein orebody; the Geant Dormant Mine, Abitibi Subprovince, Quebec, Canada

In this deposit Au-bearing lenses are hosted by a volcano-sedimentary succession and an intrusive felsic complex. All the rock units and the lenses are cut by hornblende-rich mafic dykes. The bulk ductile deformation is weak, heterogeneous, and dominated by a subvertical elongation. It is characterized by a planar fabric containing a mineral lineation that affects all rock types. Mineralization occurs in four cogenetic styles that are rich in base-metal sulphides: 1) narrow quartz veins, economically most important; 2) stratabound ore within sedimentary horizons; 3) synvolcanic faults; and 4) pre-existing joints. The geometry of the orebody displays increasing complexity towards the S (the palaeosurface). A pre-deformational volcanic origin for the mineralization is indicated which contrasts with typical shear-related models of Arhcaean Au mineralization and opens up the potential for locating comparable Au-quartz vein deposits in strain-free parts of Archaean greenstone belts, which have generally been considered as infertile Au areas.