This paper describes the petrology, geochemistry and petrogenesis of Archean granitoids. Archean granites define a continuum of compositions between several end members: (i) magmas that originated by partial melting of a range of crustal sources, from amphibolites to metasediments (‘C-type’ granitoids); and (ii) magmas that formed by partial melting of an enriched mantle source, the most common agent of enrichment being felsic (TTG) melts. Differences in the degree of metasomatism results in different primitive liquids for these ‘M-type’ granitoids.

Mixed sources, differentiation and interactions between different melts resulted in a continuous range of compositions, defined by variable proportions of each end member.

During the Archean, evolved crustal sources (sediments or felsic crust) and metasomatized mantle sources become increasingly more important, mirroring the progressive maturation of crustal segments and the stabilization of the global tectonic system.