Resumo

AVILA, Julio C.; RUBINSTEIN, Nora; MORELLO, Orquídea  e  FOGLIATA, Ana. Age and characterization of a lithium mica associated with a greisen system in the Rosario Mine, Sierra de Fiambalá, Catamarca. Rev. Asoc. Geol. Argent. [online]. 2008, vol.63, n.1, pp.43-48. ISSN 0004-4822.

This work deals with a mineralogical study and the age of a lithium mica obtained from the selvage of wolframite quartz veins from La Rosario mine, which crops out close to Ayacucho Granite, Sierra de Fiambalá, Sierras Pampeanas Occidentales of Catamarca province. This mineral species was identified through different analytical techniques that include X-ray diffraction, chemical analyses and infrared spectrometry analyses. The results of the studies indicate that its structure corresponds to zinnwaldite and its chemical composition allows locating it inside the biotite-siderophyllite-zinnwaldite-lepidolite series. The isotopic ages obtained for the Ayacucho granite (340 ± 8 Ma) and this hydrothermal mica (339 ± 8 Ma) confirm a Carboniferous age for this intrusive and the genetic link with hydrothermal mineralization.

Palavras-chave : Zinnwaldite; Carboniferous Greisen; Ayacucho granite; Sierras Pampeanas; Catamarca.

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