2015-02-262015-02-262013-06-18SILVA, Chrystophe Ronaib Peixoto da. Geologia, petrografia e geoquímica das associações TTGs e Leucogranodioritos do extremo norte do Domínio Rio Maria, Província Carajás. Orientador: Davis Carvalho de Oliveira. 2013. 76 f. Dissertação (Mestrado em Geologia e Geoquímica) - Instituto de Geociências, Universidade Federal do Pará, Belém, 2013. Disponível em: http://repositorio.ufpa.br:8080/jspui/handle/2011/6355. Acesso em:.https://repositorio.ufpa.br/handle/2011/6355The geological mapping carried out in the southeastern portion of Água Azul do Norte / PA, northern part of the Rio Maria domain, ally to the petrographic and geochemical data allowed the individualization of TTGs associations and leucogranodiorites. In this region, mapping was performed only on regional scale which allowed the extrapolation of the area of occurrence of rocks similar to Caracol Tonalite and Mogno Trondhjemite. The TTGs studied were individual in two units based on the contents of mafic minerals, concentration of magmatic epidote and degree of saussuritization of the plagioclase in: (1) Epidote-Biotite Tonalite and, (2) Biotite-Trondhjemite. In general, rocks which have a foliation defined by compositional banding which locally can be disturbed by folds and shear bands. Their geochemical characteristics are consistent with Archean TTG group of high Al2O3 and are still relatively poor in ferromagnesian elements, with HREE pattern moderaly to strongly fractionated and Eu discrete anomalies. The differences in the ratios La/Yb and Eu anomalies, allowed todiscrimination three distinct groups of rocks: The TTGs belonging to the group of high La/Yb, Sr/Y are similar to rocks Mogno Trondhjemite described in Rio Maria Domain. These rocks include the most samples of the unit Biotite Trondhjemite. In the case of TTGs with medium to low La/Yb, Sr/Y compared with the rocks of the Rio Maria area are strongly correlated with the Tonalite Caracol. These groups are composed mainly by unit Epidote- Biotite Tonalite, including also isolated samples the Biotite Trondhjemite. On the basis of geological, petrographic and geochemical data leucogranodiorites of the study area were divided into two groups: Biotite Granodiorite and Leucogranodiorite. The rocks of the Biotite Granodiorite have wide spatial occurrence in the western portion of the area. Field relationships show that these rocks are intrusive in granitoids TTGs. The available geochemical indicate that the Biotite Granodiorite have as well fractionated REE patterns, with high ratio La/Yb (33-186) and Eu anomalies quite pronounced, being strongly positive (1,11 < Eu/Eu* < 3,26). Whereas leucogranodioritos show slightly fractionated patterns, with moderate ratios La/Yb (24.7 to 34.7) and Eu anomalie absent (Eu / Eu * = 1.03). The Harker diagrams for major and trace elements do not favor a genetic link by fractional crystallization processes between the Biotite Granodiorite and TTG associations, considering present distinct evolution trends, thus indicating that the conditions of their genesis and differentiation were quite different, either by partial melting of a TTG source by the fact of the leucogranites not to present significant negative Eu anomaly, as well as for to show similar patterns of REE fractionation in relation to TTG suites, attesting that these rocks were probably not derived from precursor magmas of the TTG suites.porAcesso AbertoGeologia estratigráfica - ArqueanoGeoquímicaTonalitoCráton amazônicoÁgua Azul do Norte (PA)Província mineral de Carajás (PA)DissertaçãoCNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA::PETROLOGIACNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA::GEOQUIMICA