Greenstone-hosted quartz-carbonate vein deposits (orogenic, mesothermal, lode gold, shear-zone-related quartz-carbonate or gold-inly deposits) / Кварц-карбонатные жилы в зеленокаменных породах (орогенные, мезотермальные, золоторудные жилы ...)

Simplified definition Quartz and carbonate veins with valuable amounts of gold and silver, in faults and shear zones located within deformed terrains of ancient to recent orogenic  reenstone belts. Scientific definition Greenstone-hosted quartz-carbonate vein deposits (GQC) are a sub-type of lode gold deposits (Poulsen et al., 2000) (Fig. 1). They are also known as mesothermal, orogenic (mesozonal and hypozonal - the near surface orogenic epizonal Au-Sb-Hg deposits (Groves et al., 1998) are not included in this synthesis), lode gold, shear-zone-related quartz-carbonate or gold-only deposits (Roberts, 1987; Colvine, 1989; Kerrich and Wyman, 1990; Robert, 1990; Kerrich and Feng, 1992; Hodgson, 1993, Kerrich and Cassidy, 1994; Robert, 1995; Groves et al., 1998; Hagemann and Cassidy, 2000; Kerrich et al., 2000; Goldfarb et al., 2001; Groves et al., 2003; Goldfarb et al., in press; and references therein). They correspond to structurally controlled complex epigenetic deposits hosted in deformed metamorphosed terranes. They consist of simple to complex networks of goldbearing, laminated quartz-carbonate fault-fill veins in moderately to steeply dipping, compressional brittle-ductile shear zones and faults with locally associated shallow-dipping extensional veins and hydrothermal breccias. They are hosted by greenschist to locally amphibolite facies metamorphic rocks of dominantly mafic composition and formed at intermediate depth in the crust (5-10km). They are typically associated with iron-carbonate alteration. The mineralization is syn- to late-deformation and typically post-peak greenschist facies or syn-peak amphibolite facies metamorphism. They are genetically associated with a low salinity, CO2-H2O-rich hydrothermal fluid thought to also contain CH4, N2, K and S. Gold is largely confined to the quartz-carbon ate vein network but may also be present in significant amounts within iron-rich sulphidized wallrock selvages or silicified and arsenopyrite-rich replacement zones. They are distributed along major compressional to transtensional crustal-scale fault zones in deformed greenstone terranes of all ages, but are more abundant and significant, in terms of total gold content, in Archean terranes. However a significant number of world-class deposits are also found in Proterozoic and Paleozoic terranes. International examples of this sub-type of gold-deposits include Mother Lode-Grass Valley (U.S.A.), Mt. Charlotte, Norseman and Victory (Australia) (Fig. 2). The best Canadian examples are SigmaLamaque (Quebec); Dome and Kerr Addison (Ontario); Giant and Con (Northwest Territories); San Antonio (Manitoba); and Hammer Down (Newfoundland). <...>