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| Format: | Artículo científico |
| Sprache: | en |
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Academia Brasileira de Ciências
2004
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| Online-Zugang: | https://www.redalyc.org/articulo.oa?id=32776412 |
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Inhaltsangabe:
- The southern Araçuaí belt and the Dom Silvério Group: geologic architecture and tectonic significance. (Parte b) Guilherme G. Peres Hanna Jordt-Evangelista Fernando F. Alkmim Multidisciplinaria (Ciencias Naturales y Exactas) Araçuaí Araçuaí belt Brasiliano event West Congo orogen Dom Silvério Group The Araçuaí belt corresponds to the external portion of the western half of the Araçuaí-West Congo Neoproterozoicorogen. TheAraçuaí belt fringes the São Francisco craton to east and is separated from the crystallinecore of the orogen by the Abre Campo geophysical discontinuity. The southern Araçuaí belt involves fourmajor lithologic units: the Archean and Paleoproterozoic gneisses of the Mantiqueira Complex, the PedraDourada Charnockite, the Paleoproterozoic Borrachudos Granitoid, and the metavolcanosedimentary rocksof the Dom Silvério Group. The Dom Silvério Group occurs in a NNE-SSW striking belt and consistsof a thick package of metapelitic rocks with intercalations of quartzites, amphibolites, meta-ultramafics,banded iron formations, gondites and marbles. All units of the southern Araçuaí belt underwent four synmetamorphicphases of deformation in the course of the Brasiliano event. The first phase, synchronous to aregional amphibolite facies metamorphism, was associated to a general tectonic transport towards north alongthe left-lateral Dom Silvério shear zone and its low angle segment. The second and third phases representprogressive stages of a west directed shortening, which led to the development of local thrusts and pervasivefolds in several scales. The fourth phase is extensional and reflects the collapse of the orogen. 2004 artículo científico 0001-3765 https://www.redalyc.org/articulo.oa?id=32776412 en http://www.redalyc.org/revista.oa?id=327 Anais da Academia Brasileira de Ciências application/pdf Academia Brasileira de Ciências Anais da Academia Brasileira de Ciências (Brasil) Num.4 Vol.76