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Trabalho de Conclusão de Curso
Petrografia e geoquímica do Complexo Uraricoera, embasamento da porção central do Escudo das Guianas, noroeste do Estado de Roraima
The objective of this project was the petrographic and geochemical characterization of the rocks of the Uraricoera Complex, an orthoderived basement of the northwest portion of the state of Roraima, leading to its subdivision into 5 main lithofacies: (1) biotite-hornblende metagranites and gneiss...
Autor principal: | Macêdo, Bruna Yumi Iimori |
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Grau: | Trabalho de Conclusão de Curso |
Idioma: | por |
Publicado em: |
Brasil
2023
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Assuntos: | |
Acesso em linha: |
http://riu.ufam.edu.br/handle/prefix/6875 |
Resumo: |
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The objective of this project was the petrographic and geochemical characterization of the rocks
of the Uraricoera Complex, an orthoderived basement of the northwest portion of the state of
Roraima, leading to its subdivision into 5 main lithofacies: (1) biotite-hornblende metagranites
and gneisses; (2) biotite metagranites and gneisses; (3) biotite meta quartz syenites; (4)
granulites; and (5) metadiorites and amphibolites. In general terms, these rocks have chemistry
similar to type-I granitic associations, subalkaline, metaluminous to weakly peraluminous, with
calcium-alkaline affinity, probably related to a volcanic arc environment. From the existing
microstructures, it was possible to infer a high-grade metamorphism with a peak in granulite
facies, in addition to two retrometamorphisms, one in amphibolite to greenschist facies, and
another in greenschist to prehnite-pumpellyite facies. |