Three phases of the Anialik River igneous complex (ARIC) give U–Pb zircon ages in the range −2705–2683 Ma, and three units from the adjacent northwestern Anialik River greenstone belt (ARGB) give ca. 2678 Ma ages. Titanite from unsheared ARIC rocks crystallized during localized metamorphism and deuteric alteration between 2693 and 2683 Ma. Hydrothermal titanite in wall rocks to gold-mineralized shear zones crystallized during early shear zone development (2670 ± 1 Ma) and was subsequently locally altered to rutile, with gold occurring within the rutile-bearing assemblage. Unaltered second-generation hydrothermal titanite, overgrowing the rutile assemblage, crystallized during later brittle–ductile movement (2656 ± 2 Ma) and provides a minimum age for gold mineralization. Relatively high 207Pb/204Pb ratios of Pb in gold-associated galena suggest that it was partly derived from significantly older crustal material, possibly underlying the igneous complex and greenstone belt. This interpretation is consistent with other evidence for the existence of > 3.0 Ga crustal rocks to the west of the study area. A late crosscutting granite gives an age of [Formula: see text] and is therefore part of the Pan-Slave tectono-thermal event. These results, and other data for the Slave Province, indicate temporal variations in the development and deformation of predeformational greenstone belts. The new ages show that regional deformation and metamorphism in the northwestern Slave Province followed shortly after major magmatism, and that gold mineralization might have occurred during the late Archean accretion of the greenstone belt and igneous complex to an older crustal domain to the west.

Late Archean crustal accretion in the northwestern Slave Province is suggested to have involved approximately west-northwest -east-southeast directed horizontal compression that produced three episodes of deformation recognizable in the northwestern Anialik River igneous complex (ARIC) and Anialik River greenstone belt (ARGB). Observations show that the ARIC was probably emplaced as a series of synvolcanic sills prior to the earliest deformational event. Regional shortening produced a pervasive foliation, downdip lineations and folding in the ARGB, and an early, subsequently folded, foliation in the northwestern ARIC. Postfold ductile and brittle-ductile deformation produced regionaland outcrop-scale shear zones including the Sheeted Zone, which defines the ARIC-ARGB contact. Younger rocks of the northwestern ARGB appear to have been tectonically juxtaposed along the Sheeted Zone against the older rocks of the northwestern ARIC. Greater brittle response, enhanced permeability, and cyclical increases in fluid pressure led to the development and concentration of an anastamosing network of gold-quartz vein bearing shear zones in the ARIC. Steep to subvertical shear-related linear fabrics show that regional-scale and mineralized shear zones have a large component of vertical shear with predominantly east-side-up movement. The age relationships, proximity, and similarity of deformational structures in the Kangguyak gneiss belt, containing a craton-scale ductile deformation zone, and shear zones within the Arcadia Bay area, suggest contemporaneous development and regional late Archean structural relationships similar to those of shear zone hosted gold-quartz vein mineralization seen in the Abitibi Subprovince (Canada) and Yilgarn Craton (Australia).