Wabush Lake, Labrador, is situated a few miles from where the unmetamorphosed younger Precambrian strata of the northwest-trending Laborador geosyncline are truncated by the southwest-trending structures of the Grenville orogenic province. Field mapping and lithologic comparisons show that the metasedimentary rocks exposed within this portion of the Grenville province can be correlated with the unmetamorphosed strata of the Labrador geosyncline.
The distinctive stratigraphic units of the Wabush Lake area are quartzite, marble, muscovite and kyanite schists, and iron formation of carbonate, silicate, and oxide facies. The principal ores of the iron formation are martite-magnetite quartz rock and specular hematite quartz rock. Facies of regional metamorphism range from epidote amphibolite near the postulated “Grenville front” to granulite and migmatite farther south.
Superimposed folding throughout the area can be explained as the impression of Grenville province deformation upon earlier structures of the Labrador geosyncline.