Record details

Title
    Izotopová geochemie a geochronologie skarnu ze Slatiny (24-33 Moravský Krumlov)
Statement of responsibility
    Vojtěch Janoušek, Jaroslava Pertoldová, Zdeněk Pertold
Other titles
    Isotopic geochemistry and geochronology of the skarn from Slatina, Moldanubian zone of the Bohemian Massif
Author
    Janoušek, Vojtěch, 1968-
    Pertold, Zdeněk
    Pertoldová, Jaroslava
Language
    česky
Source title - serial
    Zprávy o geologických výzkumech v roce 1999
Pages
    s. 53-54
Year
    2000
Notes
    1 diagr., 9 bibl.
    Anglické resumé
    il.
    Zkr. název ser.: Zpr. geol. Výzk. v Roce 1999.
Subject group
    chemismus hornin
    datování Sm/Nd
    granáty
    izotopy Sr
    moldanubikum západní Moravy
    pyroxeny
    skarn
    teplota
    tlak
Geographical name
    ČR-Morava
    Slatina (Znojmo)
Keyword
    24-33
    Geochemie
    Geochronologie
    Izotopová
    Krumlov
    Moravský
    Skarnu
    Slatiny
Abstract (in english)
   Nd isotopic dating of garnet-pyroxene skarn from Slatina (20 km N of Znojmo, Gföhl nappe of the Moldanubian unit) indicates a major metamorphic event at 415 ˝ 24 Ma (2ň; WR-grt-cpx isochron with MSWD = 0.07). This is, within an error, identical with an age calculated on the basis of the grt-WR pair only (420 ˝ 42 Ma) and resemles Sm-Nd metamorphic ages of eclogite and granulite from Winklarn, Bavaria (von QUADT - GEBAUER 1993). As the closure temperature of the Nd diffusion in garnet is high (MEZGER 1990, HENSEN - ZHOU 1995), the obtained ages are interpreted as being close to the garnet growth during the high-grade metamorphism. Significantly lower e415Nd for zircon (-8.4) compared to WR, cpx and grt (-7.3) probably indicates presence of older, inherited cores, which are indeed observable in the BSE.
   High Sr initial ratio (87Sr/86SR415 ~ 0.713), and, above all, the low ţ415Nd (-7.3) and high two-stage Nd model age (T DMNd = 1.7 Ga; LIEW - HOFMANN 1988) support a long crustal residence of the protolith and rule out its direct derivation from depleted or CHUR-like mantle in Silurian-early Devonian times
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    15. 3. 2007
Import date
    8. 8. 2012