Campo DC | Valor | Idioma |
dc.contributor.author | Sighinolfi, G.Paolo | - |
dc.contributor.author | Sakai, Tereza | - |
dc.creator | Sighinolfi, G.Paolo | - |
dc.creator | Sakai, Tereza | - |
dc.date.accessioned | 2013-04-20T15:05:10Z | - |
dc.date.available | 2013-04-20T15:05:10Z | - |
dc.date.issued | 1974 | - |
dc.identifier.issn | 0009-2541 | - |
dc.identifier.uri | http://www.repositorio.ufba.br/ri/handle/ri/9941 | - |
dc.description | Texto completo. Acesso restrito. p. 23–30 | pt_BR |
dc.description.abstract | The U and Th distribution in K-rich acid metavolcanics affected by postmagmatic processes
has been studied. Th (20 ppm) and U (2.41 ppm) average abundances are well within
the normal ranges for granitic rocks, but the Th/U values are appreciably higher than
most of the values reported. Since the rhyolitic magma is supposed to have been formed
by partial melting of pre-existing rocks, the high Th/U ratios may be due: (1) to an extreme
magmatic fractionation towards a K-rich trend in the magma chamber or during
magma displacement; and (2) to high Th/U ratios in the original material, probably ancient
crystalline basemental rocks depleted in U with respect to Th during previous cycles. The
possible influence of postmagmatic processes on U and Th distribution is discussed, and
evidence of U mobilization and redistribution within the formation is set forth. | pt_BR |
dc.language.iso | en | pt_BR |
dc.publisher | Chemical Geology | pt_BR |
dc.source | http://dx.doi.org/10.1016/0009-2541(74)90094-1 | pt_BR |
dc.title | Uranium and thorium in potash-rich rhyolites from western Bahia (Brazil) | pt_BR |
dc.title.alternative | Chemical Geology | pt_BR |
dc.type | Artigo de Periódico | pt_BR |
dc.description.localpub | Salvador | pt_BR |
dc.identifier.number | v. 14, n. 1–2 | pt_BR |
Aparece nas coleções: | Artigo Publicado em Periódico (IGEO)
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