Petrogenesis and tectonic of the Urucum granitic suite, Rio Doce Valley (Minas Gerais – Brazil): an example of syn to late collisional peraluminous magmatism associated with high-angle transcurrent shear zone ; Petrogênese e tectônica da suíte granítica Urucum, Vale do Rio Doce (Minas Gerais – Brasil): um exemplo de magmatismo sin- a tardi-colisional associado a zonas de cisalhamento direcionais de alto ângulo

International audience ; The Urucum suite (582 ± 2 Ma, zircon U-Pb age), situated in the Mid-Rio Doce Valley, eastern part of Minas Gerais State, is characterized by elongated, NW-SE and N-S trending granitic massifs associated with the Conselho Peña-Resplendor high-angle shear zone. It corresponds to a syn to late collisional magmatism that presents dominant solid-state foliation. Four facies are distinguished within the Urucum suite: (i) a porphyritic (Urucum); (ii) a medium- to coarse nequigranular (Palmital); (iii) a tourmaline-bearing, and (iv) a pegmatitic facies. These facies are peraluminous, with alumina saturation index varying from 0.98 to 1.38. SiO 2 contents vary from 70.7 to 73.7 wt%, with K 2 O values ranging from 3.5 to 5.7 wt%, Na 2 O from 1.9 to 4.4 wt%, MgO from 0.6 to 1.2 wt%, and CaO from 0.3 to 0.9%. Harker-type diagrams show rather continuous trends from the less-evolved Urucum facies to the more evolved tourmaline-bearing and pegmatitic facies. The behavior of several major oxides and trace elements (Fe 2 O 3 , MgO, MnO, CaO, TiO 2 , Al 2 O 3 , K 2 O, Rb and Ba) reflects the role played by fractionation of ferromagnesian minerals, feldspars and accessory minerals. Initial Sr87/Sr86 ratios vary from 0.711 to 0.716, with εNd (580 Ma) values between -7.4 to -8.2, and Sm-Nd TDM model ages ranging from 2290 to 1840 Ma. ; : A suíte Urucum (U/Pb em zircão: 582 ± 2 Ma), situada na região do Vale do Médio Rio Doce, leste de Minas Gerais, caracteriza-se por plutons graníticos alongados (NW-SE e N-S) sin a tardi-colisionais associados à Zona de Cisalhamento de Alto Ângulo de Conselho Peña-Resplendor. São rochas foliadas, com predomínio da foliação no estado sólido em relação à foliação magmática. Foram caracterizadas quatro fácies: (i) porfirítica (Urucum), (ii) inequigranular média a grossa, (iii) com turmalina, e (iv) pegmatítica. Essas fácies são peraluminosas, com índice de saturação em alumina entre 0,98 e 1,38. Os teores em SiO 2 variam entre 70,7 e 73,7%, com valores de K 2 O entre 3,5 e ...