Podrobnosti záznamu

Název
    Composition of Nb, Ta, Ti, Sn-bearing oxide minerals from the Homolka phosphorus-rich granite, Czech Republic
Údaj o odpovědnosti
    Pavel Uher
Další názvy
    Proceedings of the International Conference "Genetic Significance of Phosphorus in Fractionated Granites" (IGCP Project No.373) (Variant.)
Autor
    Uher, Pavel
Jazyk
    anglicky
Zdrojový dokument - seriál
    Acta Universitatis Carolinae, Geologica
Svazek/č.
    Vol. 42, no. 1
Strany
    p. 169-172
Rok
    1998
Poznámky
    2 diagr., 1 fot., 1 tab., 10 bibl.
    Zkr. název ser.: Acta Univ. Carol., Geol.
Předmětová skupina
    chemismus hornin
    cín
    fosfor
    granit
    moldanubický pluton
    niob
    oxidy
    tantal
    titan
Geografické jméno
    ČR-Čechy
    Homolka
Klíčové slovo
    Composition
    Czech
    Granite
    Homolka
    Minerals
    Nb
    Oxide
    Phosphorus-rich
    Republic
    Sn-bearing
Abstrakt (anglicky)
   The Homolka magmatic centre represents a highly evolved P-rich granite of Upper Carboniferous age. Since it is enriched in Nb, Ta and Sn, the granite contains disseminated rare-element minerals. In course of the electron microprobe study were identified ferrocolumbite to ferrotantalite, ixiolite (or disordered Ti-rich ferrocolumbite), niobian-tantalian rutile, pseudobrookite and cassiterite. Ferrocolumbite-ferrotantalite shows atom. Mn/(Mn+Fe) = 0.14-0.30, Ta(Ta+Nb) = 0.12-0.53 and elevated WO3 = 0.5-4.9 wt.%. Ixiolite (or disordered ferrocolumbite) is also W-rich ( 6.7 wt.% WO3) but depleted in Mn and Ta: Mn(Mn+Fe) = 0.01-0.11 and Ta/(Ta+Nb) = 0.19-0.24. Oscillatory zoned rutile is strongly enriched in Nb and Ta (13-17 wt.% Nb2O5 and 10-18 wt.% Ta2O5), and contains also 3 wt.% SnO2. Pseudobrookite is poor in W, Nb, Ta and Sn, but locally markedly Zn-rich ( 8.7 wt.% ZnO). Cassiterite is nearly pure, depleted in Nb and Ta.
   Described minerals crystallized under magmatic, low- O2 conditions, only ixiolite was exsolved at subsolidus stage and pseudobrookite originated probably by post-magmatic oxidation of ilmenite in a higher O2 environment
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    18. 2. 2008
Datum importu
    8. 8. 2012