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Navegando FCT - Faculdade de Ciências e Tecnologia por Assunto "Anicuns-Itaberai metavulcanosedimentary sequence"

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    Relatório final do mapeamento geológico 1:50.000 da região de Anicuns (GO) - área 02
    (Universidade Federal de Goiás, 2021-11-25) Silva, André Luiz Gonçalves e; Assis, Túlio Moreira de; Nogueira Neto, José de Araújo; Nogueira Neto, José de Araújo; Nascimento, Estela Leal Chagas do; Souza, Valmir da Silva
    The 1:50.000 scale geological survey of the Anicuns region (GO) consisted in mapping an area of 128 km2, inserted in the domain of the inner zone of the Brasília Belt. In terms of mapped units, the area is constituted by metabasic-ultrabasic and metasedimentary psamo-pelitic rocks of Anicuns-Itaberaí Metavulcanosedimentary Sequence overlapped on ortho- and paraderived gneiss rocks of Anápolis-Itauçu Complex. This entire set is intruded by syn-tectonic granitic rocks of Lage Granite and Córrego Santa Rosa Metadiorite. Basic dykes related to 125º azimuth and alluvial sediments complete the local stratigraphy. In structural terms, the area contains five deformational phases related to the Brasiliano Event (the first indicated by intrafolial folds): the second formed nappes with an eastward vergence (Sn and Sn+1 foliations), the third formed interference patterns due to the change in regional stress (Sn+2 foliation) and the fourth and fifth formed transcurrent faults and sinister shear zones (Sn+3 foliation). The metamorphism of the rocks of Anicuns Itaberaí Metavulcanosedimentary Sequence varies from greenschist facies to amphibolite facies. In the Anápolis-Itauçu Complex, the metamorphism reaches amphibolite facies conditions higher than the amphibolite/granulite facies transition. The tectonic compartmentation of mapping area is marked by lateral placement of rocks of different crustal levels, but which were submitted to the same phases of regional deformation, related to compressional processes with an eastward trend. The contacts between the mapped units were defined based on the tectono-stratigraphic relationships observed in the field, complementing them with information extracted from the photointerpretation and geophysical maps.