Caracterização geológica do Grupo Canastra na região da Represa de Estreito, MG

• Autor(a) principal: Hartung, Rafael Francisco [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/11449/155467; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-06-05/000884241.pdf
• topic: Rochas metamorficas; Mapeamento geologico; Paleocorrentes; Minas Gerais

Since 1959, in the geological literature, studies have been recorded on metapelitic and metapsamytic rocks of the Canastra Group. In the region of the Estreito's Dam, in the southwest of the State of Minas Gerais, this lithostratigraphic unit emerges below the Passos Nappe, in a structural window, representing the nucleus of a brachyantiform structure of kilometer size. It has an oval shape, with a major NW-SE axis, that until the present work had only been systematically mapped in its southeastern portion. The present work presents the results of the geological mapping, in a scale of 1: 50,000, of this structural window as a whole and the integration with the data obtained by mapping carried out in the southeast portion of the same, contributing, in this way, to increase the geological knowledge of the Group Canastra in this region. Three units in the Canastra Group were individualized (Micaceous Quartzite Unit, Metarenite Unit, Metassilite Unit). Of the nine known units of Nappe de Passos, only three occur in the studied area (Unit A, Unit B, Unit C). In addition to these units, Phanerozoic rocks are identified, represented by the Aquidauana and Serra Geral Formations, that belong to the Paraná Basin. In the Metarenite Unit, that has a low metamorphic degree and is poorly deformed, the contours of the sedimentary grains are partially preserved, as well as primary structures such as wave-marks and cross-stratifications. Thirty-one measurements of paleocurrent were performed, indicating three main directions: N35º, N135º, N185º. This dispersion pattern strengthens the current interpretation that the rocks of the Canastra Group represent marine environment. The metamorphism that reached the area was the regional orogenic of the barrovian type, reaching, up to ... (Complete abstract electronic access below)