The Béryl Sud Pluton was defined by Moukhsil and Doucet (1999) in the Village Lakes area (sheet 33B03) to describe a late-tectonic intrusion cutting the Eastmain Group south of Béryl Lake. Mapping work of Bandyayera and Caron-Côté (2019) shows that this intrusion extends further south, in the NW part of sheet 32O14 and the NE corner of sheet 32O15.

Moukhsil and Doucet (1999) subdivided the Béryl Sud Pluton into two separate units: nAbes1 and nAbes2. 

Unit nAbes1 makes up 98% of the Beryl Sud Pluton. It consists of homogeneous medium-grained, locally coarse-grained, foliated tonalite and contains centimetric to decimetric pegmatitic pockets. The rock is light grey in altered surface and medium to dark grey in fresh exposure. In the Village Lakes area (sheet 33B03), unit Abes1 contains 5% locally migmatized biotite-andalusite paragneiss enclaves. To the NE of the Glas Lake area (sheet 32O14), the Béryl Sud Pluton tonalite contains metric to decametric enclaves of amphibolitized diorite (5-20%) and tonalitic gneiss (1-5%). In places, enclaves are partially assimilated, giving the rock a heterogeneous and heterogranular appearance with diffuse contact restites. In proximity to the enclaves, the tonalite grain size is coarser than in the rest of the rock. Foliated tonalite is characterized by 2-10% biotite, 1-5% hornblende and 1% magnetite.