Tracking the oxygen fugacity of enclave-forming granitic melts through plagioclase trace element signatures

Magma mixing and contamination are among the dominant processes in the building of the isotopic diversity of granite rocks. Felsic microgranular enclaves (FMEs) are remnants of magma mixing and they often carry xenocrysts that also record contamination and assimilation in crystallization fronts disrupted during replenishment events. In addition to isotopic changes, contamination may alter the redox state of the intruding magmas depending on the nature of the country rocks. We investigate the role played by different country-rocks on the redox trajectory of the precursor magmas of two Brazilian occurrences: the Mauá pluton, which intruded sulfide- and graphite-bearing metasediments, and the Salto rapakivi pluton, which intruded orthogneisses.