2019-09-022019-09-022012-04RAMOS, Jéssica Negrão. Caraterização de feições sedimentares nos jaspilitos da formação Carajás. Orientador: Joel Buenano Macambira. 2012. 91 f. Trabalho de Curso (Bacharelado em Geologia) - Faculdade de Geologia, Instituto de Geociências, Universidade Federal do Pará, Belém, 2012. Disponível em: http://bdm.ufpa.br/jspui/handle/prefix/1875. Acesso em:.http://bdm.ufpa.br/jspui/handle/prefix/1875Ferriferous Carajás District is located in the southeastern Pará state being represented by the Carajás ridge (main area) and East ridge (smaller areas). In these ridges occur jaspilites of the Carajás Formation, which comprise more than 90% of this formation. In this work was realized a study of sedimentary primary structures (meso and microscopic) preserved in the jaspilites, aiming to characterize their depositional environment and establish parameters for defining the pile. Sedimentary structures typical of jaspilite such as banding and lamination represent the bedding of the rock and show that during the precipitation of a centimeter layer would have pulses with the deposition of extremely thin sheet sand lenses, at the bands of opaque would be lenses and lamination of silica minerals and at the bands of silica lenses and lamination of opaque minerals. These features are interpreted as primary depositional. The study of sedimentary features has never been used for correlation of different deposits, such as those occurring in the North ridge, therefore the study of these features, in this work, will suggest whether it is possible the correlation between these deposits, maybe allowing, extensions to other ore bodies in the region. The Carajás Formation is here regarded as Superior type BIF and are not metamorphosed. Sedimentary structures were divided into A) primary: 1) banding, 2) plane-parallel laminations, 3) structures of scour and fill 4) levels of intraclast sand; B) secondary: 1) inter-penetrative contacts, 2) features of thinning, 3) features of rupture of bands, 4) pod structures, 5) spherulite sand and 6) increasing particle size of the chert. The analysis of the features found along the jaspilite showed that in the Lower Portion (70m) opaque bands are thicker, while in Higher Portion (150m) the silica are thicker, reflecting a gradual depletion of iron in sea water from the beginning to the end of the deposition. In addition, levels of intraclasts and the sedimentary structures of scour and fill occur only in the Higher Portion, showing the action of laminar currents, while in the Lower Portion, the absence of these structures shows that the environmental conditions were comparatively more stable and constant. Therefore, the primary sedimentary structures in detail, maybe criteria to differentiate the lower portion of the upper portion and be used to establish the pile of the jaspilite deformed areas and make correlations with other deposits of the Carajás Formation BIFs.Acesso AbertoSedimentos (Geologia) – Carajás, Serra dos (PA)Jaspilitos. Feições sedimentares primáriasDistrito Ferrífero de CarajásFormação CarajásCNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIATrabalho de Curso - Graduação - Monografia