ARCHEAN TECTONIC AND METALLOGENIC EVOLUTION OF THE SUPERIOR PROVINCE OF THE CANADIAN SHIELD

The Superior Province of the Canadian Shield has mainly experienced an Archean tectonic history, comprising several cycles of volcanism, plutonism and tectonism. Although the rocks of the Superior Province span more than 500 million years of Archean time, most mineral deposits formed in an interval of 100 million years or less, corresponding to a period of accretion of oceanic and pre-existing continental fragments in the late Archean at approximately 2.7 Ga. In accord with recent tectonic syntheses which argue for the accretionary origin of the Superior Province, the metallogenic history of the Superior Province can also be interpreted in the same context provided secular anomalies in the early history of the earth are acknowledged for relatively unique deposit types such as komatiitic nickel deposits and voluminous iron formations. Volcanogenic massive sulphide, lode gold and granitoid-associated deposits, as well as Ni-Cu, PGE, Cr and Ti deposits associated with mafic/ultramafic intrusions, are readily interpreted in terms of the construction and accretion of late Archean island arcs.