LAUSR

Abstract Neoarchean hybrid granitoids from the Vila Uniao suite are located in the central portion of the Canaa dos Carajas domain, Carajas Province (Amazonian craton, Brazil), and suggest that magma mixing events played an important role in their origin. According to complete evidence, including field observations, petrography, geochemical modeling, zircon SHRIMP and LA-MC-ICP-MS U-Pb ages, and Nd-Hf isotope data, we propose a geodynamic model based on initial mafic underplating promoted by lower crustal delamination, which generated mantle-derived mafic melts that were injected into the lower/middle crust (composed of Mesoarchean felsic granulite) and caused partial melting, producing leucogranitic melts. The interaction between these contrasting felsic and mafic magmas occurred by both mixing and mingling processes. The hybrid magma ascent and emplacement occurred in a N–S pure shear-dominated transpressional tectonic regime, with an E–W sinistral sense of tectonic movement, in which the hybrid melt was channeled into pre-existing shear zones trending E–W (Itacaiunas shear zone). This tectonic regime (transpressional) proceeded coevally with the hybrid magma cooling, producing 2.75–2.73 Ga Neoarchean deformed A-type granitoids with a syntectonic nature in the Vila Uniao suite, in addition to the Pium diopside-norite, which represents the mafic endmember generated by underplating.