Diversity, origin and tectonic significance of the Mesoarchean granitoids of Ourilândia do Norte, Carajás province (Brazil)

摘要: Abstract This study investigates the diversity, origin and tectonic significance of Ourilândia do Norte Mesoarchean granitoids, emplaced near Rio Maria-Carajas domains boundary, southeastern Amazonian Craton (Brazil). In this area, previous works has identified sanukitoids (∼2.87 Ga), (quartz) diorites BADR affinity undifferentiated leucogranites, with charnockites cross-cutting other granitoids. New geological mapping data allowed to differentiate three new groups granitoids: (i) biotite monzogranites (BMzG); (ii) epidote-biotite granodiorites (EBGd); (iii) porphyritic granitoids (pGrt). Thus, paper aims define their classification, nature, formation processes deformation aspects, discuss relations between plutonism for Ourilandia The petrographic showed that each one these can be subdivided into two facies. BMzG is differentiated equigranular (eBMzG) heterogranular (hBMzG) EBGd (hEBGd) sparsely (spTEBGd). These constitute batholiths separated by a rock strip sanukitoid affinities. Both are largely dominated rocks, less abundant lenses. pGrt individualized in (pBHGd) trondhjemites (pEBTd), which occur as smaller bodies. Structurally, central portions plutons represent lower strain domains, while borders marked large-scale shear zones, where submagmatic mylonitic fabrics ENE-WSW main direction subvertical dip, respectively. meso- microstructural indicate rocks studied syn-to late-tectonic were affected high temperature (>500 °C) low differential stress, sinistral transpression regime, indicating both related same deformational event. Geochemically, except pEBTd facies sodic affinity, grouped suites: Fe-K suite formed spTEBGd; Mg-K composed (including hEBGd pBHGd) affinity. eBMzG attributed anatexis 2.92–2.98 Ga old TTG crust. was produced intense fractionation hornblende ± clinopyroxene from Maria Granodiorite. spTEBGd, hBMzG, pBHGd show mingling evidence contrasting magmas, origins require interaction metassomatized mantle- crustal derived magmas. Geochemical modeling used identify different processes: spTEBGd enriched HFSE (Ti, Zr Y) LILE (Ba Sr) it interpreted product partial melting an mantle source, participation liquids; hBMzG generated (60%) (40%) magmas; hybridization (80%) (20%); (iv) mixture trondhjemitic (70-80%) BARD-affinity (20-30%) liquids. Therefore, at ∼2.87–2.86 significant growth reworking occurred final stages stabilization first geotectonic cycle Carajas province, all emplacement during second stage tectono-magmatic two-stage (subduction-collision) model: (2.98–2.92 Ga) - low-angle subduction slab-melt wedge metasomatism; (∼2.87–2.86 collisional environment, zones conditioned rise