Initially delineated as a quartzite klippe (Taylor, 1979), the Hutte Sauvage Group was defined as a formal lithostratigraphic unit by van der Leeden (1994) in the Hutte Sauvage Lake area from which it is named. This unit was elevated to group rank due to metamorphic recrystallization (lower amphibolite facies) and deformation that were not sufficient to destroy sedimentary structures of >2 mm, or to substantially alter the form of conglomerate fragments. A basin and sedimentation environment analysis could therefore be conducted as part of an in-depth study (Girard, 1992).

Jackson and Taylor (1972) considered the rocks now assigned to the Hutte Sauvage Group to be part of the Aphebian supracrustal cover associated with the Lake Harbour Group, defined on Baffin Island in the Northwest Territories. Van der Leeden (1994) mentions that this correlation seems premature given the distance between the two units. Subsequent mapping and checks conducted as part of the Southeastern Churchill Province synthesis(Lafrance et al., 2018) indicate that rocks of the Hutte Sauvage Group are quite distinct from those of the Lake Harbour Group.

The Hutte Sauvage Group is a metamorphosed assemblage of sandy rocks that has been divided into four informal subunits by van der Leeden (1994): 1) meta-arkose; 2) conglomeratic meta-arkose; 3) quartzitic meta-arenite; and 4) quartzitic metawacke. However, the author did not draw the contacts between units due to the gradual transition from one subunit to another and the mapping scale.

Van der Leeden (1994) was unable to establish the stratigraphic sequence of the Hutte Sauvage Group. The well-marked lithological dissymmetry suggests the presence of more than one sequence and lateral facies changes from east to west. The western portion of the unit consists mainly of meta-arenites and metaconglomerates with a marked presence of hematite. These rocks exhibit horizontal stratification, planar oblique and scallop stratification, laminations, channels, lag deposits and reversed crossbeds.

Meta-arkose (subunit D2a of van der Leeden, 1994) is white, pale pink, light yellowish green or grey, locally altered beige. The grain varies from medium to very fine sand. Conglomeratic varieties exist, however, apart from the presence of pebbles and blocks, grain recrystallization and deformation make it difficult to identify detrital grains. Orthose is more abundant than microcline. The yellowish-green colour of some meta-arkoses appears to be caused by a small amount of muscovite-sericite and epidote. Meta-arkose is locally spotted dark red due to the presence of hematite flakes up to 15 mm long and <0.1 mm thick. Some red quartz is hematite plated. Specularite (≤2%) is disseminated or concentrated in millimetric laminae. Conglomeratic meta-arkose beds contain some fragments of quartz (up to 5 cm in diameter) and white granitoid 3 mm to 30 cm by 1 to 15 cm. Some beds contain rare grey metasiltite pebbles.

The bedding thickness of meta-arkoses ranges from <1 mm to 35 cm. Laminations are composed of specularite aggregates. Beds are often uneven, continuous and of regular composition; others are channel-shaped, discontinuous and non-uniform. Oblique stratification is common, mainly in scallops, locally planar or tabular. Centimetre to decimetre-thick crossbeds are also observed. Reversed crossbeds, sorted beds, and erosion channels 1 to 2 m deep are described by van der Leeden (1994). Meta-arkose also contains 5-10% calcareous metasandstone. These rocks are white to light beige with a dark brown patina. The matrix is a medium to very coarse arkosic sand. The calcite cement easily alters, leaving pebbles in positive relief. These pebbles are mainly unidimensional, rounded to elongated fragments of white granitoids, quartz and, more locally, fine metavolanics or fine green metasedimentary rocks. The lateral and gradual transition from calcareous metasandstones to sandy marbles was observed locally. Marbles are pinkish white or pale beige, fine grained, massive to low-foliated and 10 to 30 cm thick.

The conglomeratic meta-arkose subunit (D2b, van der Leeden, 1994) also includes polymictic arkosic metaconglomerate and some interstratified meta-arkose. The matrix varies from meta-arkose to feldspathic metagrauwacke in which biotite is more abundant. Clasts do not have unimodal grain size, ranging from millimetres to centimetres (maximum 32 cm). Metaconglomerates are not typical of those formed of beach gravel. Pebbles are subangular to subrounded; in several places, their form has been modified by tectonic stresses. The variety of pebbles observed includes: 1) biotite or hematite-spotted white granitoid; 2) medium to coarse-grained pale pink or white granite; 3) pink aplite; 4) foliated biotite quartzofeldspathic gneiss; 5) mylonitic augen quartzofeldspathic gneiss; 6) smoky or milky quartz; 7) grey schist; 8) grey siltite or dacite; 9) schistose porphyritic andesite; 10) amphibolite; and 11) fine-grained green ultramafic rock. Metaconglomerate is locally deformed in fault zones.

The quartzitic meta-arenite subunit (D2c, van der Leeden, 1994) also includes metasubarkose. Rocks are white or greenish white, their composition is more mature than the meta-arkose subunit and calcareous beds are absent. They still contain hematite in small spots and specularite in disseminated grains and laminae. Meta-arenite contains small (some large) rounded monomineralic pebbles of quartz, very fine quartz aggregates, orthose or microcline aggregates. Large quartz fragments are mostly light or milky white, rarely smoky, yellowish (citrine) or purple (amethyst). Because meta-arenite grains are often flattened in schistosity, bedding and crossbeds are more difficult to detect.

Finally, the quartzitic metawacke (D2d, van der Leeden, 1994) or quartz-muscovite schist subunit contains local specularite laminae and red muscovite ± hematite spots. Some of these rocks contain trace piemontite. There are fewer clasts, represented by small pebbles flattened in schistosity. They are mostly composed of quartz and quartz or microcline aggregates. Since deformation is more intense in this subunit, bedding is difficult to detect.