Campo DC | Valor | Idioma |
dc.contributor.author | Sabaté, Pierre | - |
dc.contributor.author | Marinho, Moacyr M. | - |
dc.contributor.author | Vidal, Philippe | - |
dc.contributor.author | Vachette, Michelle Caen | - |
dc.creator | Sabaté, Pierre | - |
dc.creator | Marinho, Moacyr M. | - |
dc.creator | Vidal, Philippe | - |
dc.creator | Vachette, Michelle Caen | - |
dc.date.accessioned | 2012-01-10T23:31:07Z | - |
dc.date.available | 2012-01-10T23:31:07Z | - |
dc.date.issued | 1990 | - |
dc.identifier.issn | 0009-2541 | - |
dc.identifier.uri | http://www.repositorio.ufba.br/ri/handle/ri/5103 | - |
dc.description | p. 325-338 | pt_BR |
dc.description.abstract | A 500-km north-south alignment of granitic intrusions cross-cuts the central part of the Silo Francisco craton. These late- to post-tectonic granitic bodies are emplaced between two Archean blocks (Jequié and Gaviio blocks) and cross-cut the Contendas Mirante volcano-sedimentary sequence and the metasedimentary rocks of the Serra de Jacobina. They are
two-mica or muscovite-garnet-bearing peraluminous granites. Rb-Sr systematics show that these granites were emplaced during the Transamazonian orogeny ( ~ 1.9 Ga). The high
initial STSr/86Sr ratios (0.706-0.748) and the very low £'Nd(t) ( -- 13 to -5) indicate a crustal origin. The possible sources
are: ( 1 ) the Jequi6 block; (2) the Contendas Mirante sequence; and (3) the Gaviio block, including some early Archean
domes [trondhjemitie-tonalitic-granodioritic (TTG), Boa Vista type ] which were tectonically emplaced within the volcano-
sedimentary sequence. The currently available Rb--Sr and Sm-Nd data are not consistent with reworking of the 3.5-Ga TTG. The combination
of field and isotopic constraints preclude the Jequi~ block and the Contendas Mirante sequence and favour instead the Gaviio block medium-grade terrains as the source for the peraluminous granitic line. The available data suggest that a continent-continent collision occurred during the Transamazonian orogeny, which followed subduetion/obduction marked by volcanism (are-tholeiitic, calc-alkaline and shoshonitic) and related plutonism. | pt_BR |
dc.language.iso | en | pt_BR |
dc.title | The 2-Ga peraluminous magmatism of the Jacobina- Contendas Mirante belts (Bahia, Brazil) Geologic and isotopic constraints on the sources | pt_BR |
dc.title.alternative | Chemical Geology | pt_BR |
dc.type | Artigo de Periódico | pt_BR |
dc.identifier.number | v. 83 | pt_BR |
Aparece nas coleções: | Artigo Publicado em Periódico (IGEO)
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