Geochemistry of Mesoarchean felsic to ultramafic volcanic rocks of the Lac Guyer area, La Grande Subprovince (Canada): Evidence for plume-related magmatism in a rift setting

The spatial and temporal distribution of Mesoarchean volcanic rocks within the Lac Guyer area and their major and trace element characteristics suggest that they were emplaced into a continental rift associated with a mantle plume. The geochemical similarities between these rocks and the rift-related volcanic rocks of the younger Yasinski Group (2751-2732 Ma), and the presence of other Mesoarchean volcanic sequences with rift affinity indicate that the La Grande Subprovince was affected by two main plume-related rifting events during the Archean (ca. 2.88-2.81 and 2.75-2.71 Ga), each produced by a single or multiple magmatic plumes.