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. [...]