The Wentworth Pluton is a granitic intrusion located in the eastern Cobequid Highlands, Nova Scotia. It is the largest in the suite of gabbro and A-type granite intrusions in the region, emplaced into an active shear zone in the late Palaeozoic. The pluton is believed tomay be formed through a complex interaction between two granitic melts (sodic and calcic) and a gabbroic melt. Granites are described as syenogranites and monzogranites ranging from metaluminous to peralkaline, with both pre-, syn-, and post-gabbroic varieties present. Amphiboles include primary arfvedsonite and secondary riebeckite in sodic granites, and primary edenite and secondary actinolite in calcic granites. A number of rare REE-Y-Nb phases are found within these rocks across all stages including allanite-(Ce) and chevkinite-(Ce) in the early magmatic stages; hingganite-(Y) in the late magmatic stages; samarskite-(Y), fersmite, aesynchynite-(Y); and probable hydroxybastnäsite-(Ce) and thorite in post magmatic/hydrothermal stages. Geochemical data for accessory minerals can be found in Papoutsa & Pe-Piper (2013) and for amphiboles and whole rock data in Papoutsa & Pe-Piper (2014).