Podrobnosti záznamu

    Clasts of Variscan high-grade rocks within Upper Visean conglomerates - a missing link in the late Variscan evolution of Central Europe: constraints from U-Pb chronology
    Gerdes, Axel
    Kotková, Jana
    Novák, Milan
    Parrish, R.R.
Typ dokumentu
    článek v periodiku
Zdrojový dokument - seriál
    Journal of metamorphic Geology
    Roč. 25, č. 8
Výraz tezauru
    clast Upper Visean conglomerates U/Pb geochronology
Klíčové slovo
Abstrakt (anglicky)
   In this paper, U-Pb zircon, monazite and rutile data for crystalline rocks deposited as clasts in the Upper Visean conglomerates at the eastern margin of the Bohemian Massif are reported. U-Pb data of spherical zircon from three different granulite clasts yielded a mean age of 339.0 +- 0.7 Ma, while oval and spherical grains of another granulite pebble define a slightly younger date of 337.1 +- 1.1 Ma. These ages are interpreted as dating granulite facies metamorphism. Thermochronology and the derived pressure-temperature (P-T) path of the granulite pebbles reflect two-stage exhumation of the granulites. Near-to-isothermal decompression from at least 44 km to mid-crustal depths of around 22 km was followed by a near-isobaric cooling stage based on reaction textures and geothermobarometry. Minimum average exhumation rate corresponds to 2.8-4.3 mm/year. The extensive medium-pressure/ high-temperature overprint on granulite assemblages is dated by U-Pb in monazite at c. 333 Ma.
    MU Brno, Přírodovědecká fakulta
Kód přispěvatele
    MU, PřF
Zdrojový formát
Datum importu
    8. 8. 2012