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| FRAGA,LUCIO M.S.; NEVES,SORAYA C.; UHLEIN,ALEXANDRE; SIAL,ALCIDES N.; PIMENTEL,MARCIO M.; HORN,ADOLF H.. |
| Neoproterozoic carbonate rocks comprise different stratigraphic units in the southern part of the Espinhaço Ridge, Minas Gerais, Brazil. C, O- and Sr-isotope analyses were carried out along four selected stratigraphic sections across these formations. These are: (i) the Rio Pardo Grande Formation in the upper portion of the Espinhaço Supergroup, sampled in section 3; (ii) Macaúbas Group laminated limestones (Tijucuçu Farm) and dolostone layers (Domingas Formation) have been respectively sampled along the so-called sections 1 and 2, and (iii) the lower stratigraphic units of the Bambuí Group, sampled in section 4. Laminated limestone samples from the Macaúbas Group have δ13C values as high as 10.9‰ decreasing up section to -1.1‰ and 87Sr/86Sr values vary... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sr isotopes; C isotopes; Carbonates; Macaúbas Group; Bambuí Group; Marinoan glaciation. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000200633 |
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| CAXITO,FABRÍCIO A.; UHLEIN,ALEXANDRE; MORALES,LUIZ F.G.; EGYDIO-SILVA,MARCOS; SANGLARD,JULIO C.D.; DIAS,TATIANA G.; MENDES,MONICA C.O.. |
| The Rio Preto fold belt borders the northwestern São Francisco craton and shows an exquisite kilometric doubly-vergent asymmetric fan structure, of polyphasic structural evolution attributed exclusively to the Brasiliano Orogeny (∼600-540 Ma). The fold belt can be subdivided into three structural compartments: The Northern and Southern compartments showing a general NE-SW trend, separated by the Central Compartment which shows a roughly E-W trend. The change of dip of S2, a tight crenulation foliation which is the main structure of the fold belt, between the three compartments, characterizes the fan structure. The Central Compartment is characterized by sub-vertical mylonitic quartzites, which materialize a system of low-T strike slip shear zones... |
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Palavras-chave: Brasiliano Orogeny; Doubly-vergent fan; Rio Preto fold belt; São Francisco craton; Structural analysis. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000301101 |
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