Record details

    Metamorphism and microstructures along a high-temperature metamorphic field gradient: the north-eastern boundary of the Královský hvozd unit (Bohemian Massif, Czech Republic)
Statement of responsibility
    Dirk Scheuvens
    Scheuvens, Dirk
Source title - serial
    Journal of Metamorphic Geology
    Vol. 20, no. 4
    p. 413-428
    5 obr., 2 fot., 3 tab., 3 s.bibl.
    Zkr. název ser.: J. metamorph. Geol.
Subject group
    chemismus minerálů
    metamorfóza vysokostupňová
    moldanubikum Šumavy
    vrásnění variské
    zóny metamorfní
Geographical name
    Nýrsko (Klatovy)
Abstract (in english)
   metamorphic field gradient has been inv estigated in the Moldanubian zone of the central European Variscides encompassing, from base to the top, a staurolite-kyanite zone, a muscovite-sillimanite zone, a K-feldspar-sillimanite zone, and a K-feldspar-cordierite zone, respectively. The observed reaction textures in the anatectic metapsammopelites of the higher grade zones are fully compatible with experimental data and petrogenetic grids that are based on fluid-absent melting reactions. From structural and microstructural observations it can be concluded that the boundary between the kyanite-staurolite zone and the muscovite- and K-feldspar-sillimanite zones coincides with an important switch in deformation mechanism(s).
   Besides minor syn-anatectic shearing (melt-enhanced deformation), microstructural criteria point (a) to a switch in deformation mechanism from rotation recrystallization (climb-accommodated dislocation creep) to prism
   At still higher metamorphic grades (K-feldspar-cordierite zone), where the rheological critical melt percentage is reached, rock rheology is mainly governed by the melt and other deformation mechanisms are of minor importance. In the study area, the switch in deformation mechanism(s) is responsible for large-scale strain partitioning and concentration of deformation within the higher-temperature hanging wall during top-to-the-S thrusting, thus preserving a more complete petrostructural record within the rocks of the footwall including indicators for a ?Devonian high-to medium-pressure/medium-temperature metamorphic event. Thrusting is accompanied by diapiric ascent to diatexites of the K-feldspar-cordierite zone and infolding of the footwall, suggetsing local crustal overturn in this part of the Moldanubian zone
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
Entered date
    3. 10. 2007
Import date
    8. 8. 2012