Record details

Title
    10 km minimum throw along the West Bohemian shear zone : evidence for dramatic crustal thickening and high topography in the Bohemian Massif (European Variscides)
Statement of responsibility
    Gernold Zulauf, Curd Bues, Wolfgang Dörr, Zdeněk Vejnar
Author
    Bues, Curd
    Dörr, Wolfgang
    Vejnar, Zdeněk, 1923-
    Zulauf, Gernold
Language
    anglicky
Source title - serial
    International journal of Earth sciences (Geologische Rundschau)
Vol./nr.
    Vol. 91, no. 5
Pages
    p. 850-864
Year
    2002
Notes
    4 obr., 1 fot., 4 tab.
    il.
    Obsahuje bibliografické odkazy
    Zkr. název ser.: Int. J. Earth Sci. (Geol. Rdsch.)
Classfication no.
    55(1)
    551.2
Conspectus category
    55
Subject group
    bohemikum
    Český masiv
    datování Ar/Ar
    geologie regionální
    moldanubikum
    petrogeneze
    podmínky P-T
    tektonika bloková
    vrásnění variské
    zóna střižná
Geographical name
    ČR-Čechy
Keyword
    10
    Along
    Bohemian
    Crustal
    Dramatic
    European
    Evidence
    High
    Km
    Massif
    Minimum
    Shear
    Thickening
    Throw
    Topography
    Variscides
    West
    Zone
Abstract (in english)
   The West Bohemian shear zone (WBSZ) forms a steep collapse structure along which east-side-down normal movements led to the juxtaposition of the relatively cold Cadomian basement of the Tepla-Barrandian unit against high grade Moldanubian rocks. Synkinematic plutons straddle the WBSZ. The Mutěnín pluton intruded into Moldanubian crust at a depth of 23_4 km as derived by using Al-in-hornblende barometry. The Tepla-Barrandian Babylon pluton intruded at <12 km depth as indicated by phengite barometry and petrogenetic considerations. Both emplacement depths, together with mineral cooling ages, result in a minimnm vertical displacement of 10 km between 340 and 320 Ma. This large throw could be explained by overthickened crust that was weakened from below. The alkaline signature of the Mutenin diorite indicates that mantle melting was important to thermally weaken the crust at 340 Ma.
   The cold Tepla-Barrandian upper crust sank into its weak, partly molten Moldanubian substratum, resulting in elevator-style movements, not only along the WBSZ, but also along the Hoher Bogen and Central Bohemian shear zone. All these ductile normal shear zones were active simultaneously during the Lower Carboniferous and dip steeply towards the Tepla-Barrandian unit that probably formed a highly elevated plateau at this time
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    7. 4. 2008
Import date
    8. 8. 2012