The Archean units of Vila Tancredo region, North of São Fálix do Xingu (PA), reveal granitoids and microgabros little or intensely deformed, separated into seven groups based on their mineralogical, textural, or compositional aspects. These are: pyroxene microgabbro I; pyroxene microgabbro ii; biotite trondhjemite protomylonite; biotite granodiorite protomylonite, amphibole-biotite granodiorite mylonite, biotite monzogranite protomylonite, and biotite monzogranite mylonite. These seven groups have distinct geochemical behaviors, being recorded in the granitoid rocks that exhibit predominantly medium to high K calc-alkaline composition, with subordinate shoshonitic affinity, and magmatic arc tectonic affinity. The mafic rocks are transitional between calc-alkaline and tholeiitic. the granitoids are dominantly peraluminous, whereas the mafic rocks are metaluminous. Negative values of ɛNd suggest contribution from archean crust in the petrogenesis of these rocks.
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