2019-10-152019-10-152012-06-04CORRÊA, Lívio Wagner Chaves. Geologia e geocronologia Pb-Pb em zircão e Sm-Nd em rocha total de granitóides da região de Santana do Araguaia-PA. Orientador: Moacir José Buenano Macambira. 2012. 61 f. Dissertação (Mestrado em Geologia e Geoquímica) - Instituto de Geociências, Universidade Federal do Pará, Belém, 2012. Disponível em: http://repositorio.ufpa.br/jspui/handle/2011/11925. Acesso em:.https://repositorio.ufpa.br/handle/2011/11925Previous studies consider the region of Santana do Araguaia (PA) is a continuation of the Granite-Greenstone Terrain of Rio Maria (TGGRM) age mesoarqueana (3.0 to 2.86 Ga) is therefore interpreted as belonging to the Carajas Province Central Province or Amazon, Amazon Craton. However, recent studies have provided valuable insights, based on new geochronological data by evaporation Pb zircon, a geological context different from those presented in previous studies, suggesting a reworking of Archean rocks during Transamazonic Event. In this context, the new proposal lithostratigraphic, structural data and geochronological data allowed individualize Domain Santana do Araguaia (DSA), independent of the Carajas Province, in the case of another segment of the Amazonian Craton consists of deformed granitoids, gneisses, migmatites and sequences supracrustal with strong structuring seconds NW-SE direction, this area was included in the province or the province Transamazonas Maroni-Itacaiúnas. The area faces east and north with TGGRM in the west to the Domain Iriri Xingu basin and south with the Araguaia Belt and Parecis. Despite the more recent work performed, Domain Santana do Araguaia is still a little known sector of Pará territory, the existing geochronological data are restricted and were obtained through systematic Rb-Sr and K-Ar in the northeastern state of Mato Grosso and correlated with rocks of the DSA. But at the Para's DSA, only two units (orthogneiss Rio Campo Alegre and Rio Eighteen Tonalite) were preliminarily dated by Pb-Pb method on zircon, lacking thus confirming and expanding to other units in the region, such as Complex Santana do Araguaia greater expressiveness in the area. Also noteworthy was the lack of Sm-Nd isotopic data in this area. In this sense, the real meaning of DSA was not yet understood, because, among other facts, the information gap geochronological, to clarify the relationship between units of DSA with those of TTGRM. Considering these issues, the main objectives of the study are aimed to: a) determine the age of the protoliths of the rocks in the area, to identify lands that are Archean and Paleoproterozoic, using the Pb-Pb method (evaporation) in single crystal of zircon; b ) determine the age of the events of continental crust formation method using the Sm-Nd (whole rock); c) discuss the stratigraphic and chronological rocks to establish the evolution of the southeastern sector of the Amazonian Craton. In field studies were studied nineteen outcrops, whereas petrography and modal analyzes were performed on fourteen samples of rocks (2000 dots / thin section) that were plotted in diagrams QAP and Q-(P + A)- M 'focussed fields of monzogranites, granodiorite and tonalite and individualized in five lithotypes: Biotite monzogranite; Biotite Metagranodiorito; Hornblende-Biotite Granodiorite; Hornblende-Biotite Tonalite Metatonalito and Orthopyroxene. The last two lithotypes were first identified in the region. From a structural standpoint, the foliated biotite Metagranodiorito presents with EW direction, coincident with the regional trend of TGGRM, while the hornblende-biotite foliation have metatonalites following the NW-SE direction, with subvertical dips usually not matching the regional behavior. Microstructural analyzes identify deformation features in minerals such as wavy extinction, kink band, formation of subgrains and dynamic recrystallization. The lithotype Biotite monzogranite is isotropic and hornblende-biotite granodiorite and tonalite Orthopyroxene have only an incipient orientation of its plagioclase crystals, visible only under microscopic observation. Geochronological studies Pb-Pb zircon form performed in six samples and analyzes were made only five Sm-Nd (whole rock) using the spectrometer Finnigan Mat 262 and MC-ICP-MS Neptune, respectively, at the Laboratory of Isotope Geology (Para- iso) of the Federal University of Pará estuos The results of the different rock types are: Biotite Metagranodiorito 3066 ± 3 Ma (ML-04) and 2829 ± 13 Ma (ML-20), hornblende-biotite Metatonalito 2852 ± 2 Ma (ML- 17): Biotite monzogranite from 2678 to 2342 Ma (ML-08): Hornblende-Biotite Granodiorite 1990 ± 7 Ma (ML-16): Orthopyroxene Tonalite and 1988 ± 4 Ma (ML-13). Although Biotite monzogranite has not indicated precise age, the field data indicate a relationship in Biotite Metagranodiorito intrusive. In the case of Sm-Nd analyzes (whole rock) was selected the following samples that follow with their respective age-TDM Model: ML-04 = 3.14 Ga, ML20 = 2.91 Ga, ML-17 = 3 07 Ga; ML-16 2.68 ML-13 and Ga = Ga 2.35. The Sm-Nd isotopic data suggest that if they represent mixtures of magmas, possibly around 3.14, 3.07, 2.91, 2.68 and 2.35 Ga was extraction of magma from the mantle to the crust. Structural studies on macro and microscale feature the installation of a ductile shear zone, transcurrent character, with NW-SE direction, possibly sinistral, located in the eastern portion of the area, which mainly affected the lithotype Hornblende-Biotite Metatonalito. However, this deformation pattern is not observed in the central-southern area nor in the northern portion), where are located the areas of older rocks, which have approximately EW direction of foliation. Analyzing the ages of crystallization of the samples ML-04, ML-17 and ML-20 (3066 ± 3 Ma to 2829 ± 13 Ma) and model ages (3.14 to 2.91 Ga), the values are similar to those reported TTGRM the rocks, leading to the interpretation that the DSA is possibly a continuation of TTGRM southwest. Moreover, the results geochronological sample ML-16 and ML-13 (1990 ± 1988 ± 7 Ma and Ma 4) indicate a newest magmatism of paleoproterozoic.Acesso AbertoGeologia estratigráfica – ArqueanoGeocronologiaSantana do Araguaia (PA)DissertaçãoCNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIACNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA::GEOCRONOLOGIAGEOQUÍMICA E PETROLOGIA