Levantamento estrutural da porção norte do Greenstone Belt do rio Itapicuru e dos Alvos Encantado e C1W, Bahia

• Autor(a) principal: Massaro, Camila [UNESP]
• Data de Publicação: 2012
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/119880
• topic: Geologia estrutural; Metamorfismo (Geologia); Ouro - Minas e mineração; Minas e recursos minerais; Itapicuru, Rio (BA)

The study area is located in the geological context of the northern portion of the Rio Itapicuru Greenstone Belt (GBRI), located northeast of the São Francisco Craton, Bahia State. The GBRI is known for its great economic potential for gold mineralization, looking south at Fazenda Brasileiro Mine and North Mine Maria Preta, is situated in the study área. The structural pattern of the northern portion of the Greenstone, theme of this work, is of great importance to understand the mineralization present. To characterize the structural model three geologic sections (scale 1:25000) were made with NW-SE and EW directions and detailing two mineralized targets, Encantado, located northwest of the area, near the city of Nordestina, and C1W, located near Itapicuru River, west of the Maria Preta mine. Thus, field work and petrographic analysis were conducted, that allow to indicate the existence of two structural domains characterized by the existence of a main foliation, low angle dipping main foliation and another with high dip angle, both with NW, moreover, folds occur in the area Dn-1 and post-Dn folds. Dn-1 folds are observed less frequently but they occur mainly forming an oblique foliation and the Sn is present in porphyroblasts observed in petrographic analysis, whereas in relation to the folds post Dn, there are more than one type of folding in area, which differ by the orientation of their axis, a post Dn NS and EW Dn another post. Moreover, two areas of metamorphic green schist (biotite zone) and medium amphibolite, which are directly related to the structural domains found