P-Al-Th-REE obohatený zirkón a fáza blízka cheralitu v apliticko-pegmatitickom granofýre na lokalite Dubová - Horné Trávniky pro Modré (Malé Karpaty, jz. Slovensko)

Pages

81-86

Citation

ONDREJKA, Martin a UHER, Pavel. P-Al-Th-REE obohatený zirkón a fáza blízka cheralitu v apliticko-pegmatitickom granofýre na lokalite Dubová - Horné Trávniky pro Modré (Malé Karpaty, jz. Slovensko). Bulletin mineralogicko-petrologického oddělení Národního muzea v Praze. Prague: National Museum, 2009, 17(2), 81-86. ISSN 1211-0329 (print), 1804-6495 (online). Also available from: https://www.nm.cz/en/periodicals/bmpholnrhmvp/17-2/p-al-th-ree-obohateny-zirkon-a-faza-blizka-cheralitu-v-apliticko-pegmatitickom-granofyre-na-lokalite-dubova-horne-travniky-pro-modre-male-karpaty-jz-slovensko

Bulletin mineralogicko-petrologického oddělení Národního muzea v Praze | 2009/17/2

Accessory zircon and cheralite-like phase occur in Hercynian quartz - K-feldspar - albite aplitic granophyre dike cutting Devonian Ca-skarn and marbles in the Dubová, Horné Trávniky near Modra, SW Slovakia. Zircon forms euhedral to subhedral crystals. Zircon shows 1.5 to 2.7 wt. % HfO2, Zr/Hfwt. ratio attains 14 to 23. Some zircon compositions show low totals (82 - 92 wt. %), probably due to metamictization and hydration, elevated contents of P (up to 0.25 apfu, 7.6 wt. % P2O5), Al (up to 0.17 apfu, 3.8 wt. % Al2O3), Th (up to 0.12 apfu, 14 wt. % ThO2), Y+REE (up to 0.07 apfu, 4.3 wt. % (Y,REE)2O3), and also U, Fe and Ca (up to 0.1 apfu). Zircon associates with intermediate cheralite > huttonite phase, rich in Th (up to 0.63 apfu, 52 wt. % ThO2), Ca (up to 0.39 apfu, 6.9 wt. % CaO) and Y+REE (up to 0.13 apfu, 5.7 wt. % (Y,REE)2O3). The cheralite-like phase contains also elevated concentrations of Zr (up to 0.05 apfu, 2 wt. % ZrO2), Al (up to 0.17 apfu, 2.6 wt. % Al2O3), and low analytical totals (83 to 85 wt. oxide %). Textural and compositional relationships indicate a relatively rapid crystallization of the both zircon and cheralite-like phase during magmatic solidification of the host aplitic-pegmatitic granophyre which preserved their intermediate and probably metastable compositions.

086_UherOndrejka_Zirkon.pdf

081_UherOndrejka_Zirkon.pdf