Contrasting Fluid Chemistries, Alteration Characteristics, and Metamorphic Timing Relationships Recorded in Hybridized Orebodies of the Missanabie-Renabie Gold District, Archean Wawa Subprovince, Ontario, Canada

摘要

Orebodies in the Missanabie-Renabie gold district (Archean Wawa subprovince, Ontario, Canada) are controversial in their genetic affiliation and have been considered both intrusion related and orogenic. The orebodies are hybrids composed of pre-orogenic, syn-orogenic, and late syn- to post-orogenic veins that spatially overlap within 2720.8 +/- 1.4 Ma biotite tonalite of the Missinaibi Lake batholith. Gold-bearing, pre-orogenic laminated quartz veins with quartz-sericite-pyrite alteration halos (the Au-1 hydrothermal event) account for the majority of gold endowment and are overprinted by (1) syn-orogenic, gold-barren quartz +/- epidote +/- chlorite +/- K-feldspar +/- hematite veins and breccias associated with hematite-bearing alteration zones (the Retrograde hydrothermal event) and (2) late syn- to post-orogenic, gold-bearing pyrite veins (the Au-2 hydrothermal event).