Hydrothermal quartz veins occur west of the Juá Hill (Gouveia-MG). They form a typical "rosario"- shape structure, which is controlled by the stratigraphy and tectonic setting of the area. The veins are usually zoned and have been observed emplaced in quartzites of the São João da Chapada Formation (Espinhaço Supergroup). The latter covers mica-schists of the Rio Paraúna Supergroup and is overlain by a sill of metabasic rock. Main attitude of the quartz veins (around N05ºE/73ºNW e N18ºE/74ºSE) indicate possible conduction direction and emplacement. Genetically these veins are related to the formation of shear zones during the Brasiliano Cycle.
quartz; mineral deposits; structural geology
