Podrobnosti záznamu

Název
    Chronological constraints on the pre-Variscan evolution of the northeastern margin of the Bohemian Massif, Czech Republic
Údaj o odpovědnosti
    Alfred Kröner, Pavla Štípská, P. Jaeckel
Další názvy
    Orogenic Processes: Quantification and Modelling in the Variscan Belt (Variant.)
Autor
    Jaeckel, P.
    Kröner, Alfred
    Schulmann, Karel
    Štípská, Pavla
Jazyk
    anglicky
Zdrojový dokument - seriál
    Geological society special publication
Svazek/č.
    Vol. 179
Strany
    p. 175-197
Rok
    2000
Poznámky
    9 obr., 3 s.bibl.
    Zkr. název ser.: Geol. Soc. spec. Publ. (London).
Předmětová skupina
    datování U/Pb
    kambrium
    magmatismus
    metamorfika
    ordovik
    orlicko-sněžnické krystalinikum
    silesikum
    staroměstské krystalinikum
    vápenato-alkalický typ
    zirkon
    zóna riftová
Geografické jméno
    ČR-Morava
    Hanušovice (Šumperk)
    Horní Lipová (Jeseník)
    Kouty nad Desnou (Šumperk)
    Králíky (Ústí nad Orlicí)
    Ludvíkov (Bruntál)
    Skorošice (Jeseník)
Klíčové slovo
    Bohemian
    Chronological
    Constraints
    Czech
    Evolution
    Margin
    Massif
    Northeastern
    Pre-Variscan
    Republic
Abstrakt (anglicky)
   New single zircon ages enable us to provide an evolutionary scenarion for the Neoproterozoic to Cambro-Ordovician tectonic history of part of the easternmost Sudetes along the northeastern margin of the Bohemian Massif. The easternmost crustal segment (Brunia) yields Neoproterozoic ages from both autochthonous and allochthonous Variscan units; these ages document a Cadomian (Pan-African) history that may be linked with the northern margin of Gondwana. A Cambro-Ordovician magmatic-thermal event in Brunia is represented by granitic to pegmatitic dykes intruding Neoproterozoic crust and by localized partial anatexis. Farther west a narrow zone of Cambro-Ordovician rifting is identified (Staré Město belt), marked by gabbroic magmatism, bimodal volcanism and medium-pressure granulite facies metamorphism.
   The westernmost crustal domain (Orlica-Snieznik dome) is represented by Neoproterozoic crust intruded by Cambro-Ordovician plutons consisting of calk-alkaline granitoid rocks and affected by widespread Cambro-Ordovician anatexis. The geodynamic setting of the Neoproterozoic and Cambro-Ordovician domains is similar to that of the Western Sudetes, where both Cambro-Ordovician rifting and calc-alkaline magmatism were identified. We discuss the rifting mechanics in terms of sequential crustal thinning along the northern margin of Gondwana. The calc-alkaline magmatism, in conjuction with crustal rifting, is related to a back-arc geometry in front of retreating south-dipping subduction zone during progressive closure of the Tornquist Ocean southeast of Avalonia
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    3. 5. 2007
Datum importu
    8. 8. 2012