The Wanapitei Complex consists of a variably metamorphosed gabbronorite lying immediately adjacent to the Grenville Front Boundary Fault. U–Pb zircon geochronology indicates a crystallization age of for a noritic component, with both Grenville-aged (ca. 1000 Ma) metamorphism and minor older inheritance indicated. Geochemical evidence is consistent with plagioclase–pyroxene fractionation, but indicates additional open-system behaviour. data indicate contamination of a depleted mantle by light rare earth element-enriched material during the Penokean. This was followed during emplacement by extensive contamination of the then isotopically near-chondritic magma with variable amounts of evolved Archean crustal material, on the order of 40% in extreme cases, generating εNd(1.75) values between 0 and −7.5.