Journal of

GEOsciences

  (Formerly Journal of the Czech Geological Society)

Original paper

Martin Števko, Pavel Uher, Jiří Sejkora, Malíková Radana, Radek Škoda, Tomáš Vaculovič

Phosphate minerals from the hydrothermal quartz veins in specialized S-type granites, Gemerská Poloma (Western Carpathians, Slovakia)

Journal of Geosciences, volume 60 (2015), issue 4, 237 - 249

DOI: http://dx.doi.org/10.3190/jgeosci.202



An interesting association of phosphate minerals (fluorapatite, triplite, arrojadite-group minerals and viitaniemiite) was studied from intra-granitic hydrothermal quartz veins with minor amounts of albite, orthoclase, muscovite, fluorite, rhodochrosite, arsenopyrite, pyrite, bismuthinite and kobellite. The veins occur in highly evolved, Permian topaz-zinnwaldite leucogranite at the Elisabeth adit near Gemerská Poloma, Gemeric Unit, Western Carpathians (eastern Slovakia). Fluorapatite is enriched in Mn (~4 wt. % MnO, 0.3 apfu Mn) and frequently replaced by triplite, representing the first known triplite occurrence in Western Carpathians. This mineral forms irregular aggregates (≤ 7 cm across), Mn/(Mn + Fe) atomic ratio of which attains 0.68 to 0.78 and F/(F + OH) = 0.89-0.92. “Fluorarrojadite-(BaNa)” to its Mn-dominant analogue “fluordickinsonite-(BaNa)” (both minerals still not approved by IMA-CNMNC) occurs as aggregates up to 2 cm across, showing Sr-rich (~1.7 wt. % SrO, ~0.36 apfu Sr) and Sr-poor (≤0.6 wt. % SrO, ≤0.13 apfu Sr) compositions with W site F/(F + OH) = 0.74-0.80 and M site Mn/(Mn + Fe) = 0.39-0.52. Rare viitaniemiite is Mn-rich (10 to 11 wt. % MnO, 0.34-0.38 apfu Mn). The phosphate mineralization in quartz represents a high-temperature hydrothermal assemblage. The F-rich Mn, Fe, Ca-bearing phosphates, fluorite, and muscovite precipitated most likely in presence of alkali- and fluorine-bearing post-magmatic fluids which altered primary magmatic minerals (especially Li-rich micas and alkali feldspars) and liberated some elements (Fe, Mn, Al, Ba, Sr, Na, K) from the adjacent granite.

Journal of Geosciences, Published by © Czech Geological Society, with support from the Czech Geological Survey.
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ISSN: 1803-1943 (online), 1802-6222 (print)
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SNIP (Scopus, 2015): 0.700

IF (ISI, 2015): 1.326

Policy: Open Access

ISSN: 1802-6222

E-ISSN: 1803-1943