| Texto completo | |
| Autor(es): |
Ruberti, Excelso
;
Enrich, Gaston E. R.
;
Gomes, Celso B.
;
Comin-Chiaramonti, Piero
Número total de Autores: 4
|
| Tipo de documento: | Artigo Científico |
| Fonte: | CANADIAN MINERALOGIST; v. 46, p. 14-pg., 2008-08-01. |
| Resumo | |
The Barra do Itapirapua ( BIT) carbonatites in southern Brazil belong to the final stages of the Early Cretaceous alkaline rock - carbonatite magmatism of the Ponta Grossa Arch Province. The BIT complex is a dyke and vein stockwork in which four main carbonatitic phases are recognized, mainly magnesiocarbonatites and ferrocarbonatites. These carbonatites are generally overprinted by pervasive hydrothermal events. The C-O stable isotopic data indicate re-equilibration under hydrothermal conditions at temperatures between 375 and 80 degrees C. Significant amounts of REE fluorocarbonate minerals, relatively Sr- and Th-rich, were deposited. Syntaxy between synchysite-(Ce) and parisite-(Ce) is very common owing to the similarity in structures, with alternating (001) layers of (CeF), (CO3) and (Ca). However, bastnasite-(Ce) occurs as individual crystals, overgrown by the synchysite and parisite polycrystals. Textural and chemical reactions between the REE fluorocarbonates provide insights into the mobility of rare-earth elements during fluid-rock interaction. The BIT complex is considered to be of potential economic interest for production of the rare-earth concentrates. (AU) | |
| Processo FAPESP: | 01/10714-3 - A evolução do magmatismo alcalino na Plataforma Sul-Americana: implicações petrogenéticas e geodinâmicas |
| Beneficiário: | Celso de Barros Gomes |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 06/01459-3 - Quimica de minerais acessorios, parageneses, condicoes de cristalizacao e evolucao magmatica em intrusoes sieniticas alcalinas meso-cenozoicas da plataforma brasileira. |
| Beneficiário: | Gaston Eduardo Enrich Rojas |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |