Caracterização geológica-estrutural da região aurífera de Santa Rita (Jeroaquara), norte do Greenstone Belt de Faina (GO)

• Autor(a) principal: Martins, José Eduardo da Silva [UNESP]
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/156268; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2018-02-22/000894772.pdf
• topic: Geologia estrutural; Mapeamento geologico; Prospecção mineral; Greenstone belts; Ouro - Minas e mineração; Minas e recursos minerais; Geologia estratigráfica; Faina (GO)

The Faina Greenstone Belt (FGB) is a NW-SE/SW (strike/dip), 50 km length and 6 km outward width structure, located in the Goiás Archean Block, a Granite-Greenstone terrain inserted in the Inner Brasilia Fold Belt, central Brazil. The Goiás Archean Block hosts five Greenstone Belts Terrains (Crixás, Guarinos, Pilar, Serra de Santa Rita and Faina), the first three host proved gold deposits that are currently exploited, whilst Santa Rita and Faina remain under explored. Despite being under surveyed the FGB shows many vestiges of past gold exploitation, such as various shaft works from Brazilian colonial period, such those of Cascavel Project, and more recent activities such as the disabled Sertão Mine. Orinoco Gold is currently the main player in the mineral surveying in the area; this final academic work was developed by the author during a trainee period at the exploration company. The work was a detailed (1:10.000) geological and structural mapping of a 40 km2 area in the north portion of the FGB, westwards of Santa Rita (Jeroaquara) village. The interest in this region goes by the fact that it was registered significant gold, silver, chromium and copper grades by chip sampling and whole rock analysis in this area. Also, the area is just southwards of Eliseu Target (in the same structural trend), where whole rock analysis and drilling core showed important gold occurrences. The work allowed delineating a complex stratigraphic and structural setting for this portion of the FGB. The rocks of the area are structured as four tectonic domains separated by major NW-SE/SW (strike/dipdir), NE vergence thrust faults. In the studied area these faults cause significant tectonic truncations that dictate the outcrop pattern in this part of FGB. Also macroscopic folds mapped in the area, related to various deformational phases, influences in the rocks exposition in the area. The three upper domains coincide...