Record details

    Tourmalinites in the metamorphic complex of the Svratka Unit (Bohemian Massif): a study of compositional growth of tourmaline and genetic relations
    Buriánek, David
    Čopjaková, Renata
    Houzar, Stanislav
    Škoda, Radek
Publication type
    článek v periodiku
Source title - serial
    Journal of Geosciences
    Roč. 54, č. 2
Thesaurus term
    B- F-rich fluids
    Czech Republic
    mica schist
    Svratka Unit
Abstract (in english)
   Tourmalinites from the Svratka Unit form stratiform layers hosted in mica schists. The chemical composition of tourmaline from tourmalinites varies from Al-rich schorl to dravite. The tourmaline usually exhibits three compositional domains, which are, from centre to the rim: a chemically inhomogeneous brecciated core (zone I), a volumetrically minor internal rim zone II, and a dominant outermost zone III. The compositional variability of tourmaline in all the zones is controlled by the (X YAl WOH) (XNa Y Mg WF)-1 and YFeYMg-1 substitutions. The tourmaline of the zone I corresponds to highly vacanced X-site, Al-rich schorl with lower F (up to 0.43 apfu), which is interpreted as an older, low-temperature hydrothermal tourmaline. Tourmaline of the zone II corresponds to dravite rich in F (reaching up to 0.66 apfu) crystallizing during the prograde metamorphism. Lastly, the Al-rich schorl-dravite of the zone III, grew most likely during retrograde metamorphism.
    MU Brno, Přírodovědecká fakulta
Contributor code
    MU, PřF
Source format
Import date
    8. 8. 2012