Record details

    Marbles with carbonatite-like geochemical signature from variegated units of the Bohemian Massif, Czech Republic, and their geological significance
Statement of responsibility
    Stanislav Houzar, Milan Novák
Other titles
    Mramory geochemicky podobné karbonatitům z pestrých jednotek Českého masivu a jejich geologický význam
    Houzar, Stanislav
    Novák, Milan, 1952-
Source title - serial
    Journal of the Czech Geological Society
    Vol. 47, no. 3-4
    p. 103-109
    2 obr., 2 fot., 1 tab., 30 bibl.
    České resumé
    Zkr. název ser.: J. Czech geol. Soc.
Subject group
    analýza petrografická
    chemismus hornin
    facie amfibolitová
    moldanubikum Šumavy
    moldanubikum západní Moravy
Geographical name
    Česká republika
    Český Krumlov
    Korolupy (Znojmo)
    Muckov (Český Krumlov)
    Olešnice (Blansko)
    Vranov nad Dyjí (Znojmo)
    Vratěnín (Znojmo)
Abstract (in english)
   Marbles with carbonatite-like geochetnical signature (MCC) were recently found at several localities of ordinary calcite marbles (OMC) in the Český Krumlov (Muckov), Vratenin (Korolupy), Olešnice (Olešnice-Lamberk) and Vranov (Vranov) Units, respectively. The rock complexes hosting the MCC are built of dominant metapelites with locally common intercalations of quartzites, calcite and dolomite marbles, minor metabasites, graphite-rich rocks and locally scapolite- and tourmaline-bearing rocks (metaevaporites?). The mineral assemblages of the OMC and MCC are very similar and include Cal+Dol+Phl, Cal+Dol+Tr, Cal+Qtz+Phl+Na,Al-enriched amphibole (tremolite, fluortremolite, edenite, pargasite, magnesiohornblend), Cal+Dol+Tr+Di. Relatively abundant diopside in the Moldanubian marbles indicates a higher grade of metamorphism relative to the Moravicum. The MCC have variable contents of Si and Al from almost pure marbles to silicate-rich rocks with up to 31.7 wt. per cent SiO2 and 4.49 wt.
   per cent A12O3, high SiO2/Al2O3 = 21.35-6.18 is typical. The associated OMC and MCC do not exhibit any apparent differences in the major elements, disregarding slightly lower SiO2/Al2O3 ratio, slightly increased Na and K contents in the MCC, nevertheless, they are enriched in Nb < = 393, Mo < = 28, REE total < =124, Zr < = 4212 and Sr < =1063 (all in ppm). The carbonatite-likc geochemical signature may be caused by admixture of detritus from relatively primitive volcanic rocks or participation of the evaporitic fluids mobilized from host rocks. Presence of the MCC in lithologically similar metamorphosed volcanosedimentary sequences, currently classified into distinct geological units (Moldanubicum, Moravicum), indicates that they may represent an identical unit in the Bohemian Massif
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
Entered date
    25. 3. 2008
Import date
    8. 8. 2012