High temperature hydrothermal fibrolite in «El Payo Granite», Cadalso-Casillas de Flores granitic complex (Salamanca-Caceres, Spain)

  1. Hassan Mohamud, A.
  2. Casquet Martín, César
  3. Pérez del Villar Guillén, Luis
  4. Cózar Cuello, Juan Sebastián
  5. Pellicer Bautista, María José
Revista:
Geogaceta

ISSN: 0213-683X

Año de publicación: 2002

Número: 32

Páginas: 23-26

Tipo: Artículo

Otras publicaciones en: Geogaceta

Resumen

Subsolidus replacements of fibrolite after biotite, muscovite, andalusite and feldspars have been recognized in El Payo granite near the contact with the more evolved Casillas granite. Both granites form part of the late-Variscan Cadalso-Casillas de Flores plutonic massif. Replacements follow microfractures and grain boundaries and are associated with fibrolite-quartz and less commonly fibrolite-tourmaline intergrowths. The limits of the altered zone are imprecise but the latter seems to be a thin band normal to the contact between the two granites. Base-cation leaching caused by the action of high temperature acidic hydrothermal residual fluids expelled from Casillas granite is thought to be responsible for the formation of fibrolite. Fibrolite repalcement after andalusite might probaly be indicative of metastable formation of the former within the andalusite stability field