Podrobnosti záznamu

Název
    Trace element composition of quartz from different types of pegmatites: A case study from the Moldanubian Zone of the Bohemian Massif (Czech Republic)
Autor
    Ackerman, Lukáš
    Breiter, Karel
    Ďurišová, Jana
    Novák, M.
    Svojtka, Martin
Jazyk
    anglicky
Typ dokumentu
    článek v odborném periodiku
Zdrojový dokument - seriál
    Mineralogical Magazine
Svazek/č.
    Roč. 78, č. 3
Strany
    s. 703-722
Rok
    2014
Poznámky
    Rozsah: 10 s.
Předmětová kategorie
    Bohemian Massif
    mineralogy
    Moldanubian Zone
    pegmatite evolution
    quartz
    trace elements
Klíčové slovo
    Bohemian
    Case
    Composition
    Czech
    Different
    Element
    Massif
    Moldanubian
    Pegmatites
    Quartz
    Republic
    Study
    Trace
    Types
    Zone
Abstrakt (anglicky)
   The evolution of the trace-element patterns of quartz during crystallization of pegmatite melt was investigated using laser ablation inductively coupled plasma mass spectrometry. The contents of Al, B, Ba, Be, Cr, Fe, Ge, Li, Mn, P, Rb, Sn, Sr and Ti were analysed in quartz from the border, intermediate and core zones of four granitic pegmatites differing in degree of fractionation and origin. The material investigated originates from the pegmatite district of the Strážek Unit, Moldanubian Zone, Bohemian Massif, Czech Republic and includes: lepidolite LCT (Li-Cs-Ta) pegmatite from Rožná; berylcolumbite LCT pegmatite from Věž ná; anatectic pegmatite from Znětínek; and intragranitic NYF (Nb-Y-F) pegmatite Vladislav from the Třebíč Pluton. The abundances of the elements analysed varied over wide intervals: <1 to 32 ppm Li, 0.5 to 6 ppm B, <1 to 10 ppm Ge, 1 to 10 ppm P, 10 to 450 ppm Al, 1 to 45 ppm Ti and <1 to 40 ppm Fe (average sample contents).
   Concentrations of Be, Rb, Sr, Sn, Ba, Cr and Mn are usually <1 ppm. Quartz from LCT pegmatites exhibits a distinct evolutionary trend with a decrease in Ti and an increase in Al, Li and Ge from the pegmatite border to the core. In comparison with the most fractionated rare-metal granites, pegmatitic quartz is relatively depleted in Al and Li, but strongly enriched in Ge. Quartz from simple anatectic and NYF pegmatites is poor in all trace elements with their evolution marked by a decrease in Ti and a small increase in Ge. There is little Al or Li and neither shows any systematic change with pegmatite evolution. Using the Ti-in-quartz thermobarometer, the outer zones of the Znětínek and Vladislav pegmatites crystallized at ∼670°C, whereas the border zone in the Rožná pegmatite yields a temperature near 610°C.
Přispěvatel
    AV ČR Brno, Geologický ústav
Kód přispěvatele
    AV ČR, GLÚ
Zdrojový formát
    U
Datum importu
    23. 10. 2014