DEGEO - Departamento de Geologia

URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/8

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Resultados da Pesquisa

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    Stratigraphic, isotopic, and geochronological record of a superposed pro- foreland basin in the eastern São Francisco craton during west Gondwana amalgamation.
    (2020) Rossi, Ariadne Verônica Andrade; Danderfer Filho, André; Bersan, Samuel Moreira; Kelmer, Luiza Rocha; Tavares, Túlio Delôgo; Lana, Cristiano de Carvalho
    The Três Marias Formation, a siliciclastic succession that occurs at the top of the Bambuí Group, has recorded the filling of the Brasiliano foreland basin that developed on the São Francisco craton. At the eastern portion of this craton, the Três Marias Formation outcrops in Gorutuba ridge, north of Minas Gerais, which area was in- vestigated by using field work, stratigraphic analysis, and isotopic U–Pb and Lu–Hf analysis. In this area, the Três Marias Formation includes molasse deposits composed mainly of arkoses and hybrid conglomerates. The arkose sediments came into the basin through a fluvio–deltaic system located to the northeast and were reworked in a siliciclastic shelf under the influence of waves, tides and storm currents. The paleocurrents indicate a coastline around the NW and NE directions, with current flows reworking sediments parallel and transversal to the coast. The detrital zircon grains indicate a 555 ± 17 Ma maximum age of the deposition for this unit, and its main sources are related to granitoids from the pre-orogenic and pre-to syn-collisional stages of the Araçuaí orogen (ca. 630–560 Ma). The filling of the foreland basin system created in response to the Araçuaí fold–thrust belt is younger than the one existing in the occidental portion of Bambuí basin, which is related to the Brasília fold and thrust belt. Therefore, the final filling of the Bambuí basin would have been controlled by the development of these two-fold–thrust belts throughout the margins of the São Francisco craton during the assembly of West Gondwana.
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    Stratigraphic, isotopic, and geochronological record of a superposed proforeland basin in the eastern São Francisco craton during west Gondwana amalgamation.
    (2020) Rossi, Ariadne Verônica Andrade; Danderfer Filho, André; Bersan, Samuel Moreira; Kelmer, Luiza Rocha; Tavares, Túlio Delôgo; Lana, Cristiano de Carvalho
    The Três Marias Formation, a siliciclastic succession that occurs at the top of the Bambuí Group, has recorded the filling of the Brasiliano foreland basin that developed on the São Francisco craton. At the eastern portion of this craton, the Três Marias Formation outcrops in Gorutuba ridge, north of Minas Gerais, which area was investigated by using field work, stratigraphic analysis, and isotopic U–Pb and Lu–Hf analysis. In this area, the Três Marias Formation includes molasse deposits composed mainly of arkoses and hybrid conglomerates. The arkose sediments came into the basin through a fluvio–deltaic system located to the northeast and were reworked in a siliciclastic shelf under the influence of waves, tides and storm currents. The paleocurrents indicate a coastline around the NW and NE directions, with current flows reworking sediments parallel and transversal to the coast. The detrital zircon grains indicate a 555 ± 17 Ma maximum age of the deposition for this unit, and its main sources are related to granitoids from the pre-orogenic and pre-to syn-collisional stages of the Araçuaí orogen (ca. 630–560 Ma). The filling of the foreland basin system created in response to the Araçuaí fold–thrust belt is younger than the one existing in the occidental portion of Bambuí basin, which is related to the Brasília fold and thrust belt. Therefore, the final filling of the Bambuí basin would have been controlled by the development of these two-fold–thrust belts throughout the margins of the São Francisco craton during the assembly of West Gondwana.
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    The sedimentology, stratigraphy and tectonic context of the São Francisco Supergroup at the southwest boundary of the São Francisco Craton, Brazil.
    (2000) Castro, Paulo de Tarso Amorim; Dardenne, Marcel Auguste
    Neoproterozoic metasedimentary rocks of the São Francisco Supergroup occur in the Southwest part of São Francisco Craton. Three informal lithostratigraphic units composed mainly by psephites, pelites and carbonates represent the São Francisco Supergroup. The last two units formed in storm influenced muddy shelf and platform/ramp systems, respectively. The psephitic unit crops out as isolated bodies nearby the external zone of the southernmost part of Brasilia Fold and Thrust Belt. Its origin is related to fan delta systems that developed eastward, in a foreland basin, as a result of erosion of metamorphic rocks of Brasilia Fold and Thrust Belt.