Podrobnosti záznamu

Název
    Exhumation of high-grade rocks in the Saxo-Thuringian Belt: geological constraints and geodynamic concepts
Údaj o odpovědnosti
    Wolfgang Franke, E. Stein
Další názvy
    Orogenic Processes: Quantification and Modelling in the Variscan Belt (Variant.)
Autor
    Franke, Wolfgang
    Stein, E.
Jazyk
    anglicky
Zdrojový dokument - seriál
    Geological society special publication
Svazek/č.
    Vol. 179
Strany
    p. 337-354
Rok
    2000
Poznámky
    10 obr., 4 s.bibl.
    Zkr. název ser.: Geol. Soc. spec. Publ. (London).
Předmětová skupina
    alochton
    bohemikum
    denudace
    dóm
    mariánskolázeňský bazický komplex
    metamorfika
    metamorfóza vysokotlaká
    ochlazování
    paleozoikum
    profil seizmický
    saxothuringikum
    vrásnění variské
    zóna subdukční
Geografické jméno
    ČR-Čechy
    SRN
Klíčové slovo
    Belt
    Concepts
    Constraints
    Exhumation
    Geodynamic
    Geological
    High-grade
    Rocks
    Saxo-Thuringian
Abstrakt (anglicky)
   he Saxo-Thuringian Belt on the northern flank of the European Variscides resulted from SE-ward subduction of a Cambro-Ordovician rift basin under the Teplá-Barrandian (Bohemian) margin. It contains ultra-high-pressure (UHP) metamorphic rocks. which are now exposed in different tectonic settings, and were exhumed in different modes, under different thermal regimes. Eclogites of the upper allochthon (tectonic klippen of Münchberg, Wildenfels and Frankenberg) originated from early Devonian (c. 400 Ma) subduction. Cooling ages in the klippen, combined with clast spectra and ages of detrital minerals in the foreland flysch record exhumation in Famennian time. The high-pressure (HP) rocks rose in a narrow corridor along the suture zone, were retrogressed under amphibolite facies conditions, and rapidly recycled into the foreland flysch. Rocks of the lower allochthon are exposed in dome structures emerging from under the relative autochthon. The HP Saxonian Granulites were formed at c.
   20 kbar/1050 °C, and the Erzgebirge contains diamond-bearing quartzo-feldspathic rocks, associated with eclogites Peak temperatures of the lower allochthon were attained at c. 340 Ma. Immediately afterwards, these rocks were emplaced under the floor of the relative autochthon, which, at this time, was a foreland basin receiving clastic sediments from the orogen adjacent to the SE. Emplacement of the lower allochthon is most clearly documented in the Saxonian Granulite Dome, in which HP granulites are juxtaposed against low-pressure-high-temperature (LP-HT) rocks of the hanging wall. The interface is a zone of HT shear, which cuts out 60 km of crustal thickness. In more internal parts of the belt (Erzgebirge), the newly emplaced lower allochton was subsequnetly reworked by thrusting and polyphase refolding.
   Emplacement of the hot, low-viscosity lower allochthon was probably driven by buoyancy and the hydraulic gradient between the crustal root to the SE and the lower crust of the foreland
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    3. 5. 2007
Datum importu
    8. 8. 2012