Meso- and Neoarchean evolution of the Island Lake greenstone belt and the northwestern Superior Province: Evidence from lithogeochemistry, Nd isotope data, and U-Pb zircon geochronology

Geological, geochemical and geochronological data indicate that the tectonic evolution in the Island Lake greenstone belt and in the northwestern Superior Province took place in three main stages. The first two stages involved the generation of Meso- and Neoarchean volcanic assemblages and contemporaneous plutonic rocks, which is interpreted to be due to southward dipping subduction under the North Caribou terrane. This plate tectonic model is in contrast with well-documented northward dipping subduction south of the North Caribou terrane. The third stage involved movement along late transpressional shear zones at ca. 2.70 Ga. At the end of this geodynamic process the Hudson Bay terrane was terminally docked to the North Caribou terrane along the North Kenyon Fault.