Resumo
O arcabouço geológico de Roraima é dividido em quatro domínios litoestruturais: a) Urariqüera (WNW-ESE a E-W), terreno vulcano-plutônico-sedimentar em 1,98-1,78 Ga; b) Guiana Central (NE-SW), cinturão de alto grau em 1,94-1,93 Ga e Associação AMG (1,5 Ga); c) Parima (NW-SE a E-W), terreno granito-greenstone em 1,97-1,94 Ga e d) Anauá - Jatapu (NW-SE, NE-SW e N-S), terreno granito-gnáissico em 2,03-1,81 Ga.
Abstract
Four major domains are present in Roraima State: 1) the Urariqüera Domain with WNW-ESE and E-W trends and dominantly calc-alkaline granite and volcanics and sedimentary cover rocks; 2) the Central Guyana Domain trending NE-SW and containing high-grade metamorphic rocks and a typical AMG association; 3) the Parima Domain with NW-SE structural lineaments and post-Trans-Amazonian granite–greenstone terrains; and 4) the Anauá-Jatapu Domain with NW-SE and NE-SW trends and widespread calc-alkaline and alkaline granite.
Key words: Amazonian Craton, Guiana Shield, Stratigraphy, Structural geology, Roraima Brazil
Dernière mise à jour le 01.07.2015