This unit was named by Lamothe (1994) to describe a sedimentary bed at the top of the Povungnituk Group. It was previously a member of the Beauparlant Subgroup, which is now reduced to the rank of formation (Moorhead, 1989, 1996a, b).

The Nuviliq Formation is an allochthonous assemblage of sandstone, siltstone, limestone, dolomitic limestone and volcaniclastics forming the upper part of the Povungnituk Group, in the Southern Domain. Siltstone represents the unit’s most abundant lithology. Phyllite and slate beds are interstratified between siltstone beds. Several mafic to ultramafic sills of the Lac Esker Suite intrude into sedimentary rocks. The central portion of the Nuvilic Formation has an abundance of decimetric beds of fine-grained or lapilli tuff, likely of epiclastic nature (Moorhead, 1996a). Near the contact with the Chukotat Group, there is a concentration of disseminated to massive pyrrhotite and pyrite mineralization in fine-grained sedimentary beds. Massive sulphide layers, locally brecciated, likely synchronous to sedimentation, contain anomalous values in zinc, copper, nickel and light rare earths (Giovenazzo et al., 1991). Concentrations of light rare earths are presumably due to the detrital input associated with the erosion of the Cécilia Formation’s alkaline volcanic edifice (Giovenazzo et al., 1991).

Little information is available.