Aragão Granite - Nhandú intrusive Suite - An oxidized, A2-type granite, from 1967 to 1964 Ma from the Alta Floresta Gold Province - Amazonian Craton

Abstract

The Aragão Granite, located at the Alta Floresta Gold Province (AFGP), consists of a granitic stock of around 80 km2 with medium to thick granulation, porphyritic texture and monzogranitic to sienogranitic modal composition. Geochemical data indicate to an A2-type affinity, similar to granitic magmas of evolved active continental margins. The U-Pb SHRIMP in zircon crystallization ages of 1964 ± 11 Ma and 1967 ± 2 Ma allow its inclusion into the Nhandú Intrusive Suite and its correlation with the Creporizão Intrusive Suite of the Tapajós Mineral Province (TMP), in the Pará State. Associated with Aragon granite, a porphyrithic megaenclave medium to thick, with porphyritic texture and granodioritic to monzogranitic modal composition, occurs. The enclave presents a geochemical pattern similar to shoshonitic granitic magmas, and their crystallization age U-Pb SHRIMP in zircon (1995 ± 5 Ma) indicates relation with granitoids of the Cuiú-Cuiú Complex. The Aragão Granite occurs hosted in a foliated granites where the U-Pb SHRIMP crystallization age is 2009 ± 4 Ma. These results suggest that the host rocks of Aragao Granite are part of the Cuiú-Cuiú Complex. The stratigraphical correlation determined in this work indicates that the eastern portion of AFGP represents the extension of Tapajós-Parima Province, south of Cachimbo Graben, north of Mato Grosso State.