A fluid inclusion and stable isotopic examination of the Boston, greenstone belt hosted, Archean lode-gold deposit, Hope Bay volcanic belt, Nunavut, Canada

Primary liquid-rich H₂O-CO₂ fluid inclusions associated with gold mineralization in the Boston Archean lode-gold deposit are of low salinity (4.4 ± 1.6 eq. wt.% NaCl, n = 91) and contain pure CO₂ (TMCO₂ = −56.8 ± 0.2°C, n = 75). Homogenization temperatures averaging 272 ± 34°C (n = 81) and pressures averaging 2.5 ± 0.5 kilobars (n = 51) are interpreted to approximate trapping conditions because of coexistence of primary CO₂ gas-rich and liquid-rich inclusions.; Carbonates from the mineralised zones vary by 1.5‰ in δ 13C (−4.6 to −3.1‰, n = 15) and 1.6‰ in δ 18O (11.2 to 12.8‰, n = 15); quartz varies by 2.1‰ in δ 18O (12.9 to 14.8‰, n = 12); and pyrite varies by 1.4‰ in δ34S (2.1 to 3.5‰, n = 8). The δ 18O_H2O, δ13CCO₂, and δ 34S_H2S values of the fluid calculated from these minerals at 272°C are intermediate between a metamorphic and magmatic source for water, sulphur and carbon.; Petrographic and geochemical data for the Boston deposit is consistent with data from Archean lode-gold deposits world wide, implying that the Boston deposit formed in a similar environment from similar gold-bearing fluids.