Syntectonic plutonism in north-central Wopmay Orogen (early Proterozoic), Hepburn Lake map area, District of Mackenzie

Abstract

Syn- to post-tectonic plutons in the area are clustered to form the composite Hepburn and Wentzel batholiths. Although granite is most abundant, the overall compositional range is from granite to pyroxenite. In general, the plutons become more basic and less deformed with time. The peak of metamorphism is related to the earliest granites, younger plutons being discordant with respect to the metamorphic isograds. Wentzel Batholith is the roof of a plutonic complex exposed in the core of a major anticlinorium. Hepburn Batholith comprises the floor and feeders to a pancakeshaped plutonic complex preserved in the keel of a synclinorium. The batholiths were emplaced during closure of these folds and after craton-vergent thrusting. Their setting is comparable to that of Cenozoic continental collision zones.