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We report new and refined legacy data on 1.77 to 1.74 Ga gabbros, basalts, and granites (Kivalliq Igneous Suite) in the Tebesjuak Lake map area (NTS 65-O). Uranium-lead (baddeleyite) ages for a coarse alkali gabbro at Mallery Lake (1769 ± 6 Ma) and for a subalkaline gabbro at the southwest-ern end of the McRae Lake dyke (1753.6 ± 1.2 Ma) were determined. Uranium-lead (zircon) ages of 1752.6 ± 4.1 Ma and 1746.7 ± 4.3 Ma were obtained for the Pamiutuq granite intrusion and a quartz-feldspar porphyry dyke, respectively. Gravimetric/magnetic modelling of the Mallery complex is con-sistent with a gabbroic ring dyke about 8 km in diameter and 1 km tall surrounding a granite core, with an underlying mafic sill or intrusive complex. Petrographic and geochemical data support a petrogenetic link between the Mallery gabbro, a coarse anorthosite body (Fish intrusion), and basaltic lavas in the map area, all of alkali basalt composition. These data indicate the presence of bimodal volcanism near the base of the Pitz Formation, and establish the oldest age of Kivalliq anorogenic igneous activity at ca. 1.77 Ga.