Journal of

GEOsciences

  (Formerly Journal of the Czech Geological Society)

Original Paper

Edvín Pivec, Miroslav Štemprok, Jiří K. Novák, Miloš Lang

Tourmaline as a late-magmatic or postmagmatic mineral in granites of the Czech part of the Krušné hory - Erzgebirge batholith

Journal of the Czech Geological Society, volume 43 (1998), issue 1-2, 17 - 23

Tourmaline is an accessory mineral of the Late Palaeozoic granites of the Krušné hory - Erzgebirge batholith (290-330 Ma). Its occurrence is distinctly regionally dependent; it is common in the Western pluton of the batholith and extremely rare in granites of the Eastern pluton. Very low content of Mg and Fe in granites cause the rare occurrence of tourmaline in the pluton in spite of a high content of boron in granite melt, eg in Blatná granite body. The magmas themselves were incapable of conserving much boron as displayed by the occurrences of tourmalinized phyllites and tourmalinites at contact of this body. All the tourmalines examined correspond to schorl-dravite series with a low content of uvite component, especially in metasedimentary rocks. A higher concentration of fluorine in tourmaline is in greisenized granites, whereas the lowest contents were found in tourmalines occurring in wolframite - quartz veins at Rotava. Thus, the chemistry of tourmalines indicates the conditions of their crsytallization.