Bedrock geology of the southern Boothia mainland area (Pelly Bay-Rae Strait-Spence Bay map areas), Kitikmeot region, Nunavut

The Boothia mainland area, part of the north-central Rae Province, comprises a high-grade gneissic terrain dominated by Neoarchean metaplutonic rocks, migmatitic gneiss, Archean supracrustal rocks, and rare Paleoproterozoic supracrustal rocks. The Archean supracrustal rocks are inferred to be cor- relative with the regionally widespread Prince Albert Group. Granitic rocks and their gneissic equivalents are dominated by meta- to peraluminous, polyphase, commonly porphyritic, biotite- and hornblende-bear- ing monzogranite to granodiorite. U-Pb zircon ages indicate they are part of a 2.61 to 2.59 Ga magmatic event recognized throughout most of the Rae Province. Lesser 2.67 to 2.66 Ga plutonism represents a previously unknown age of magmatism in the Rae Province. Small outliers of Paleoproterozoic Chantrey Group metasedimentary rocks (Burwash Lake belt) occur as complex infolds in the Archean rocks, and cor- relate with other Rae Province Paleoproterozoic cover sequences, such as the Amer and Piling groups. The dominant structural fabric of the study area is a moderately to intensely developed regional trans- position foliation (S1), which is folded about map-scale, northeast-trending, Paleoproterozoic F4 folds, doubly plunging about less pervasive north-northwest-trending F5 folds. High-grade (granulite to upper amphibolite facies) metamorphism and migmatization is interpreted to have occurred during 2.6, 2.5, and 1.82 Ga metamorphic events. The north-central Rae Province has signifi cant exploration potential for diamonds. In addition, the Archean metavolcanic rocks in the area have exploration potential for base and precious metals.