A trace metal, stable isotope (H, O, S), and geochronological (U-Pb titanite) characterization of hybridized gold orebodies in the Missanabie-Renabie district, Wawa subprovince (Canada)

Mineralized shear zones in the Archean Missanabie-Renabie gold district (~ 1.1 Moz Au; Wawa, Ontario, Canada) locally define composite orebodies that record three hydrothermal events: (1) a pre-orogenic Au₁ event (pre-D₁ and pre-prograde-metamorphic); (2) a syn-orogenic, post-peak-metamorphic Retrograde event (syn-D₃); and (3) a late syn-to post-orogenic Au₂ event (late syn- to post-D₄). Genetic considerations indicate the orebodies are hybrids with early intrusion-related (Au₁) and later orogenic (Retrograde + Au₂) events. Pearson product-moment correlation coefficients (log₁₀) of whole-rock and LA-ICP-MS pyrite trace metal datasets distinguish Au₁ from Au₂ mineralization by Au-Ag, Au-Bi, and Au-Te correlations > 0.7 (p < 0.05) in the former, irrespective of sample medium and analytical method. An Au-Mo correlation in whole rock data (0.58–0.76; p < 0.05) further distinguishes Au₁ from Au₂ and supports an independently inferred intrusion-related origin for Au₁. Sulfur isotope data is similar for both Au₁ and Au₂ pyrite with average δ³⁴S values of − 5.5‰ ± 0.2‰ (1σ) and − 3.5‰ ± 0.3‰ (1σ) and average Δ³³S values of 0.4‰ ± 0.1‰ (1σ) and − 0.3‰ ± 0.2‰ (1σ), respectively. SIMS δ¹⁸O_quartz values for the Au₁, Retrograde, and Au₂ events largely overlap and, like δ¹⁸O_carbonate values of previous studies, tend to be lower than values typical of Archean gold deposits. The results of this study suggest that correlation coefficients in trace metal datasets are useful in discriminating and characterizing different gold events. Caution is emphasized with the use of S- and O-isotope datasets for these purposes. The presence of low δ¹⁸O values in vein quartz and carbonate is best explained by an ¹⁸O-depleted fluid formed during the Retrograde hydrothermal event. The latter is inferred at 2580 ± 21 Ma based on U-Pb geochronlogy of hydrothermal titanite, and relates to deformation and metamorphism in the nearby, amphibolite- to granulite-grade Kapuskasing metamorphic belt. Geochronological and geochemical evidence suggest that the ¹⁸O-depleted fluid may have formed via the devolatilization of biotite-bearing granitoids during deep-crustal metamorphism.