Podrobnosti záznamu

Název
    Variation of deformation mechanisms within the progressive-retrogressive mylonitization cycle of limestones: Brunovistulian sedimentary cover (the Variscan orogeny of the Southeastern Bohemian Massif)
Údaj o odpovědnosti
    Petr Špaček, Jiří Kalvoda, Eva Franců, Rostislav Melichar
Autor
    Franců, Eva
    Kalvoda, Jiří
    Melichar, Rostislav
    Špaček, Petr
Jazyk
    anglicky
Typ dokumentu
    článek v periodiku
Zdrojový dokument - seriál
    Geologica Carpathica
Svazek/č.
    Roč. 52, č. 5
Strany
    12
    s. 263-275
Rok
    2001
Poznámky
    6 obr., 1 fot., 3 tab.
    il.
    Zkr. název ser.: Geol. carpath.
Předmětová skupina
    brunovistulikum
    deformace
    devon
    geotermometrie
    hranice zrn
    kalcit
    metamorfóza nízkostupňová
    moravskoslezské prevariské paleozoikum
    mylonit
    mylonitizace
    nukleace
    rekrystalizace
    vápenec
    vrásnění variské
Výraz tezauru
    Brunovistulicum
    limestones
    microstructures
Geografické jméno
    Chudčice (Brno-venkov)
    Čebín (Brno-venkov)
    ČR-Morava
    Kadov (Znojmo)
    Lažánky (Brno-venkov)
    Lažany (Blansko)
    Skalice (Znojmo)
    Šebetov (Blansko)
    Újezd (Blansko)
    Vohančice (Brno-venkov)
Klíčové slovo
    Bohemian
    Brunovistulian
    Cover
    Cycle
    Deformation
    Limestones
    Massif
    Mechanisms
    Mylonitization
    Orogeny
    Progressive-retrogressive
    Sedimentary
    Southeastern
    Variation
    Variscan
    Within
Abstrakt (anglicky)
   This study deals with the calcite mylonites of the brunovistulian cover developed in the frontal thrust area of the Moravian nappe units. The inhomogeneous structure of sedimentary protoliths allowed the analysis of the contrasting behaviour of calcite in matrix and porphyroclasts and the interpretation of microfabric evolution during deformation under low temperature conditions. Several stages of microfabric characterizing progressive as well as retrogressive deformation are distinguished. Generally, the progressive phase of mylonitiztion is characterized by grain growth in the matrix and the grain size reduction of the porphyroclasts deformed brittlely and the strain was strongly localized into the ductile matrix. With continuing evolution the onset of the dynamic recrystallization of porphyroclastic occurred, which obviously preceded a significant grain growth in the matrix.
   With rising temperature during deformation, grain growth predominated after grain size homogenization was finished. The lack of effective dynamic recovery along the stages of the progressive low temperature phase of deformation is discussed. Core-and-mantle structures which are characteristic of the initial stages of progressive deformation carry microfabric features which documented the dominance of grain boundary bulging and/or nucleation recrystallization. Formation of subgrains within the porphyroclasts is only a rarely observed feature which probably could not lead to significant grain size reduction

   This study deals with the calcite mylonites of the Brunovistulian sedimentary cover developed in frontal thrust area of Moravian nappe units. The inhomogeneous structure of sedimentary protoliths allowed the analysis of the contrasting behavior of calcite in matrix and porphyroclasts and the interpretation of microfabric evolution during deformation under low temperature conditions. Several stages of microfabric evolution characterizing progressive as well as retrogressive deformation are distinguished. Generally, the progressive phase of mylonitization is characterized by grain growth in the matrix and the grain size reduction of the porphyroclasts leading to a stress-induced equilibration of grain size. During the initial deformational stages the calcitic porphyroclasts deformed brittlely and the strain was strongly localized into the ductile matrix.
Přispěvatel
    Česká geologická služba
    MU Brno, Přírodovědecká fakulta
Kód přispěvatele
    ČGS (UNM)
    MU, PřF
Zdrojový formát
    R
    U
Datum vložení
    13. 7. 2007
Datum importu
    8. 8. 2012