In the Bohier Island geological map, Beauchamp et al. (2018) mapped part of the Digne Pluton, but associated it with the Misasque Complex. The Digne Pluton was introduced in 2020 following geological mapping of the Cadieux Lake project (Beauchamp, 2020). This intrusion individualizes a very homogeneous tonalitic to granodioritic mass from its adjacent unit, the Misasque Complex, which is a heterogeneous assemblage of tonalitic to granitic gneiss, dioritic gneiss, tonalite, granodiorite and granite.

The main foliation is weakly to moderately developed and is marked by the alignment of chloritized biotite and muscovite in clusters and by the elongation of quartz. Stretch lineation, when present, is marked by the alignment of small biotite aggregates and by stretching of quartz. As they approach the Digne Shear Zone, Digne Pluton rocks are more deformed. They become L>>S tectonites altered to chlorite or muscovite or calcite. Locally, rocks of the Digne Pluton are highly altered. They are similar to muscovite schist cut by a quartz vein network. Muscovitization of the rock is reminiscent of greisen-type alteration associated with hydrothermal circulation linked to the emplacement of peraluminous plutons (outcrops 18-PG-4044, 18-PG-4045 and 18-PG-4046).

The Digne Pluton contains numerous enclaves of amphibolite, amphibolitized gabbro, diorite, quartz diorite and pyroxenite, some of which have been identified as lithological units on geological maps of the Cadieux Lake (Beauchamp, 2020) and Bohier Island (Beauchamp et al., 2018) areas. These enclaves are, in the majority of cases, heavily deformed. They correspond to L/S tectonites. The mineral lineation is recrystallized and marked by stretching of hornblende. Enclaves are medium to coarse grained and granoblastic. They contain hornblende, plagioclase and varying amounts of clinopyroxene, magnetite and biotite. The Digne Pluton is cut by undifferentiated granitic (aplitic to pegmatitic) intrusions, some of which are associated with the Wahemen Suite.

Geochemical analyses of samples collected during summer 2018 mapping (Beauchamp, 2020) indicate that the Digne Pluton is composed of tonalitic and granodioritic rocks (Debon and Lefort, 1983). These rocks are mostly magnesian, peraluminous and type I granitoids (Maniar and Picolli, 1989). Samples, of calcic to calc-alkaline affinity (Frost et al., 2001), plot in the volcanic arc granite field. The rare earth diagram normalized to CI chondrite (Palme and O’Neill, 2004) shows light rare earth enrichment over heavy rare earths. Finally, the spider diagram normalized to the primitive mantle (McDonough and Sun, 1995) shows negative anomalies in Nb, P, Sm and Ti, and positive anomalies in Ta, La, Ce, Nd, Zr and Hf.