PROTEROZOIC COLLISIONAL TECTONISM IN THE TRANS-HUDSON OROGEN, SASKATCHEWAN

Isotopic and structural data from the juvenile Reindeer zone of the Trans-Hudson orogen, northern Saskatchewan, indicate a pre-1.85 Ga thermotectonic event, possibly reflecting arc-continent collision, followed by a more extensive, nappe-forming, ca. 1.83-1.80 Ga thermotectonism during terminal continent-continent collision. Preliminary data from the adjacent, ensialic Cree Lake zone suggest high-grade reworking of Archean crust by the pre-1.85 Ga event. In the Rae province to the west, high-grade metamorphism and reworking of Archean crust occurred about 2.0 Ga and may be related to the formation of the coeval Taltson magmatic zone. © 1990 Geological Society of America.