The Winnie Suite was introduced in the Saffray Lake area (Lafrance et al., 2014) to group diatexites and metatexites spatially associated with False Suite paragneiss. The Winnie Suite was extended southward in the Jeannin Lake (Charette et al., 2016) and Résolution Lake (Lafrance et al., 2020) areas. It also outcrops, but in lesser proportion, in the southern part of the Ungava Bay area (Simard et al., 2013) and in the SW portion of the Henrietta Lake area (Lafrance et al., 2015).

The Winnie Suite was divided into two informal units by Lafrance et al. (2014): 1) homogeneous porphyraceous diatexite (pPwii1), and 2) banded heterogeneous diatexite and metatexite (pPwii2).

Winnie Suite 1a (pPwii1a): Homogeneous Heterogranular Diatexite

Winnie Suite 2 (pPwii2): Diatexite and Stromatic Metatexite

 Unit pPwii2 consists of diatexite and stromatic metatexite containing 35-70% tonalitic to granitic leucosome and 30-60% migmatitic paragneiss of the False Suite (pPfas1) as elongated centimetric to decimetric rafts or preserved decimetre to decametre-wide layers. The whole forms a heterogeneous package displaying irregular, discontinuous and often chaotic migmatitic banding. Diatexite also contains numerous biotite schlierens, which in some areas are the only remnants of the melted material. Diatexite is greyish in fresh exposure and brownish to rusty in altered surface. It contains 20-30% ferromagnesian minerals, mostly brown to red biotite generally concentrated in schlierens and locally associated with hornblende (<5%). Accessory minerals are varied but less abundant than in homogeneous diatexite of unit pPwii1; there is zircon as inclusions in biotite, muscovite, garnet, opaque minerals, graphite, chlorite, apatite and kyanite. In thin sections, unit pPwii2 diatexite has the same textural characteristics as unit pPwii1. In some locations, metric layers of porphyraceous diatexite (pPwii1) were observed in the unit of diatexite and stromatic metatexite.

Winnie Suite 2a (pPwii2a): Garnet Diatexite and Stromatic Metatexite

Thickness and distribution

Migmatites of the Winnie Suite and metasedimentary rocks of the False Suite are concentrated in the central part of the Baleine Lithotectonic Domain. With an area of ~4070 km², the Winnie Suite is a dominant unit in this domain. Units pPwii2 (1794 km²) and pPwii1 (1453 km²) are the most common, while subunits pPwii2a (760 km²) and pPwii1a (63 km²) are more restricted.

Dating

The Paleoproterozoic age of ~1838 Ma obtained on diatexite samples (outcrops 2012-IL-3048 and 2015-LP-2117) represents the crystallization age of anatectic liquid. Older ages come from zircon nuclei and are mostly at ~1978 Ma and ~2836 Ma (Davis et al., 2015). According to the authors, diatexite clearly originated from a Paleoproterozoic episode of melting Proterozoic and Archean rocks. A crystallization age of anatectic liquid of ~1807 Ma (Godet et al., 2020) was also obtained in a migmatized paragneiss of the False Suite.