Structural and metamorphic control on the Borden gold deposit, Chapleau, Ontario

Abstract

The Borden gold property is a multi-million-ounce deposit that is located 10 km east of Chapleau and 160 km southwest of Timmins. It occurs within the Wawa Subprovince of the Archean Superior Province. What is atypical about the Borden gold deposit is its location near the southern margin of the Kapuskasing Structural Zone (KSZ), a structurally controlled region of granulite and upper amphibolite facies metamorphic rock. The deposit occurs within the Borden Lake Belt, an eaststriking lithological assemblage, consisting of metasedimentary, felsic and mafic gneisses. Gold mineralization is hosted by garnet-biotite gneiss (±sillimanite), amphibolite (±garnet) and deformed quartz veins. Lithons of granulite facies rock are surrounded by foliated amphibolite facies gneisses and schists. Structure and microstructure indicate polymetamorphism with retrograde amphibolite facies metamorphism after granulite facies metamorphism. [...]