Canadian Exploration Ni-Cu-PGM
The BAGB is the youngest and southernmost greenstone belt in the Archean Superior Province of the Canadian Shield. This volcano-sedimentary belt is situated just north of the Grenville Front and south of the Abitibi Greenstone Belt. The belt is divided into three parts known as the Baby, Lac des Bois, and Belleterre Groups. The northern part of the Baby Group consists of komatiitic basalts at the base, overlain by tholeiitic basalts that are in turn overlain by calc-alkali intermediate to felsic volcanic rocks and volcaniclastic sedimentary rocks. The southern part of the Baby Group and the Lac des Bois and Belleterre groups lack komatiitic rocks but include tholeiitic basalts and calc-alkalic volcanic rocks.
PGM-Ni-Cu mineralisation forms during emplacement of the intrusive phases when sulphur become immiscible in the magma forming its own liquid that concentrates within the magmatic conduit, or chonolith, or within the footwall immediate to the intrusion. PGMs have an extremely high affinity for this sulfide liquid and are efficiently scavenged and concentrated from the magma.