Study of fluids related to hydrothermal alteration of biotite granites from Gerês and Guarda (Portugal) [Estudo dos fluidos associados com a epissienitização de granitos biotíticos do Gerês e da Guarda (Portugal)]

• Tipo: Artigo em Revista Científica Internacional
• Data: 2010

Autores

Jaques, L (Autor) Outra; Bobos, I (Autor) FCUP; Noronha, F (Autor) FCUP

Revista

Título: Comunicações Geológicas

Vol. 97

Páginas: 81-98

ISSN: 0873-948X

Editora: LNEG - Laboratório Nacional de Energia e Geologia

Indexação

ISI Web of Knowledge

Scopus - 6 Citações

Outras Informações

ID Authenticus: P-008-E7X

Abstract (EN): In granites, particularly from Gerês and Guarda regions, occur reddish altered rocks, commonly known as "episyenites". These rocks resulted from a hydrothermal alteration process and involved alkali metasomatism, magmatic quartz dissolution and transformation of the primary minerals present in granites. The hydrothermal fluids, directly associated with the episyenitization process, were trapped in quartz microfractures - Fluid Inclusion Planes (FIP), consistent with the most important directions of altered structures. These fluids are low-salinity aqueous fluids from the H2O-NaCl system and homogenization temperatures lower than 300 °C. They have an alkaline character, possibly with a meteoric origin and circulated to a depth lower than 5 km during the final events of the Hercynian orogeny. © INETI 2010.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 18