The Boa Sorte granite occurs in the southeastern region of the Pará state, northern Brazil, in the geological context of the Carajás Domain or, more precisely, in the Transition subdomain between the Rio Maria domain and the Carajás basin. It corresponds to an E-W elongated batholith, formed of biotite leucomonzogranites with subordinate granodiorites and syenogranites, with varying degrees of deformation. The textures observed in rocks with more pronounced ductile foliation suggest middle degree conditions (450°C - 600°C and 6±1 kbar) during the Boa Sorte granite deformation. To the south it makes contact with Água Limpa granodiorite, it is intrusive into TTGs and Greenstone belts, and is intruded by plutons of mafic to intermediate composition of the Diopside Norite Pium, granites of the Planalto suite and mafic dykes. Four granite groups were distinguished on the basis of their different REE patterns: (1) this is the predominant group and it is characterized by high (La/Yb)N ratios, moderate negative Eu anomalies and concave pattern of heavy REE; (2) this group show low (La/Yb)N ratios and strong negative Eu anomalies; (3) the third group is depleted in light REE elements, with (Gd/Yb)N ratios close to unity, and shows moderate negative Eu anomalies; and (4) the fourth group is characterized by low REE contents, with high to moderate (La/Yb)N ratios. The geochemical characteristics of these groups are compatible with those of weakly peraluminous calc-alkaline I-type Archean granites. These rocks have high K2O, low contents of ferromagnesian elements, moderate CaO and Na2O and moderate to high Al2O3. K2O/Na2O ratios vary between 1 and 2. Despite the large compositional overlap between these groups, on average there is an increase in the SiO2 content from the high (La/Yb)N group (1) towards the low (La/Yb)N (2) and low (Gd/Yb)N ratios (3) groups. In Harker diagrams, the first and second groups tend to line up in well-defined trends, with the third showing on average higher Na2O and lower K2O, Zr and Hf. In addition to these differences, the fourth group has on average higher contents of CaO, Ba, and Sr and lower FeOt/(FeOt+MgO) and Rb. The Boa Sorte granite was formed more probably in the Mesoarchean, at 2857±2 Ma, and resulted from partial melting processes of crustal protoliths, whose oldest ages are around 3.00 Ga. Despite some geochemical affinity with the Potassic leucogranites represented by the Xinguara and Mata Surrão plutons, this granite differs from the Leucogranodiorite-granite group of the Rio Maria Domain. On the other hand, the groups with high and low (La/Yb)N ratio show good correspondence with the Cruzadão and in some respects Bom Jesus granites of the Canaã dos Carajás area. In its turn, the low (Gd/Yb)N ratio group resembles the Serra Dourada granite, while the group with low REE contents has more affinity with the Canaã dos Carajás granite. Such evidences suggest that the region comprising the Canaã dos Carajás area and the northeastern portion of the Água Azul do Norte municipality have been affected by similar processes during the Mesoarchean evolution of the Carajás Domain. That area was subsequently affected by the Neoarchean tectonic related to the closing of the Carajás Basin.
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