Circa 2.3-Ga magmatism of the Arrowsmith Orogeny, Uranium City region, western Churchill craton, Canada

The western margin of the Churchill craton records a complex history of Paleoproterozoic tectonism. The most prominent of these tectonic events is recorded within the 2.0 - 1.9- Ga Taltson-Thelon magmatic zone. The widespread magmatism and high-grade metamorphism of this zone, especially in Alberta and Saskatchewan, obscures an older tectonic belt, the ca. 2.4 - 2.3-Ga Arrowsmith Orogeny. In the Uranium City region of northwestern Saskatchewan, a suite of Paleoproterozoic granites represent a magmatic product of this orogen. U-Pb zircon crystallization ages were identified for the Macintosh Bay monzogranite (Ma), the Gunnar monzogranite ( Ma), the 2330 +/- 5 2321 +/- 3 Geebee Lake tonalite ( Ma), the Yahyah Lake granite ( Ma), and the Hayter Bay monzogranite 2320 +/- 44 2287 +/- 14 ( Ma). The petrological and geochemical characteristics, emplacement ages, and Nd isotopic geochemistry 2297 +/- 10 of these plutons are most consistent with a syn- to postcollisional orogenic setting, possibly coeval with a period of orogenic extension and exhumation.