Podrobnosti záznamu

Název
    Distribution of Th, U and K and petrophysical properties of granites in the Czech part of the Smrčiny (Fichtelgebirge) pluton
Údaj o odpovědnosti
    Marta Chlupáčová, Miroslav Štemprok, Ivan Gnojek
Autor
    Chlupáčová, Marta
    Gnojek, Ivan
    Štemprok, Miroslav
Jazyk
    anglicky
Zdrojový dokument - seriál
    Věstník Českého geologického ústavu (Bulletin of the Czech Geological Survey)
Svazek/č.
    Vol. 73, no. 4
Strany
    p. 287-299
Rok
    1998
Poznámky
    3 obr., 6 diagr., 19 bibl.
    České resumé
    Zkr. název ser.: Věst. Čes. geol. Úst. (Bull. Czech geol. Surv.)
Předmětová skupina
    draslík
    granit
    granit dvojslídný
    magnetická susceptibilita
    porozita
    profil geochemický
    saxothuringikum
    smrčinský pluton
    thorium
    uran
Geografické jméno
    ČR-Čechy
    Smrčiny
Klíčové slovo
    Czech
    Distribution
    Fichtelgebirge
    Granites
    Petrophysical
    Pluton
    Properties
    Smrčiny
    Th
Abstrakt (anglicky)
   The set of 57 granite samples from the Smrčiny (Fichtelgebirge) pluton was analysed by gamma-ray spectrometry for Th, U and K. In addition magnegnetic susceptibility, densities and porosity were measured. The granite samples are represented by G1 and G1S (G1Sm) granite types according to Richter and Etettner (1979) of the Older Intrusive Complex (OIC). The results of laboratory measurements of radioactive elements were compared with airborne regional gamma-ray spectrometry. Compared with the average granite the G1 type is weakly enriched in Th and U. G1S type also enriched in U but depleted in Th whereas the G1S type is strongly impoverished in Th. Magnetic susceptibilities are low (only up to 160x 10-6 SI) indicating that the granites may belong to olmenite series. The mean values of magnetic susceptibility decrease from the G1 to G1S m. The grain densities are between 2.62 to 2.70 g.cm-3 whereby the G1 granites are slightly denser than G1S and G1S m granites.
   The porosity averages about 4.8 vol. % in biotite granite (G1) and 3.9% in two-mica granite (G1S). Muscovite granite (G1Sm) is the most porous with an average of 5.2 vol.%. Thorium is in a positive correlation with Ba, Cr, Sr, Zr and in a negative correlation with F, Ca, Li, Rb and Sn. Uranium does not show correlations with these elements, except of the weak one with Li. Uranium also exhibit no correlation with F, Ga, Li, Rb, and Sn. Uranium does not show correaltions with these trace elements, except of the weak one with Li. Uranium also exhibits no correlation with thorium. Airborne gamma-ray spectrometry revealed that the pattern of U-distribution is not related to the granite types. Uranium is regionally increased in the southern part of the Czech portion of the Smrčiny pluton. A lack of significant correlations between some trace elements and between petrophysical properties and trace elements in the G1Sm granite type wasnoted.
   This is explained by the effect of postmagmatic processes on these rocks in subsolidus stage of granite development
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    18. 2. 2008
Datum importu
    8. 8. 2012