Podrobnosti záznamu

Název
    Nature of protolith and metamorphic development of Moldanubian HP granulites - a geochemist's point of view
Autor
    Franěk, Jan
    Janoušek, Vojtěch
    Vrána, Stanislav
Jazyk
    anglicky
Typ dokumentu
    článek ve sborníku
Zdrojový dokument - monografie
    Mineralogická a petrologická konferencia MinPet, 23.-24.5 2013. Zborník recenzovaných abstraktov a príspevkov
Strany
    2
Poznámky
    Akce: 2013/05/23 ; Bratislava
Výraz tezauru
    HP granulites,eclogite-facies metamorphism,geochemistry,Moldanubian Zone, Bohemian Massif
Klíčové slovo
    Development
    Geochemist's
    Granulites
    HP
    Metamorphic
    Moldanubian
    Nature
    Point
    Protolith
    View
Abstrakt (anglicky)
   Petrogenesis of voluminous, widespread and compositionally fairly uniform Moldanubian HP (ternary Fsp-Grt-Ky) granulites in the orogenic root of the Variscan orogen remains controversial. Previous studies of the best exposed and most variable Blanský les Granulite Massif (BLGM) have shown that the prevalent felsic types originated by ~340 Ma HP-HT metamorphism of mid-Ordovician-Silurian (Kröner et al. 2000) acid metaigneous rocks. Such refractory protoliths suffered only limited geochemical modification (loss of U, Th, and Cs to a small-scale HP melt: Janoušek et al. 2004; Lexa et al. 2011). We suggest that the Saxothuringian felsic crust rich in heat-producing elements was emplaced close to the thickened Moho depth via continental subduction/relamination. After thermal incubation, rheological weakening accompanied by a low-degree dehydration melting would trigger gravitational instability and ascent of the orogenic lower crust. The partially molten contaminated mantle produced chara
   cteristic potassic magmas with crust-like Sr-Nd isotopic signatures, intimately related with HP granulites in space and time (Janoušek & Holub 2007; Schulmann et al. 2009; Franěk et al. 2011b; Lexa et al. 2011; Maierová et al. 2012).
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (RIV)
Zdrojový formát
    R
Datum importu
    15. 10. 2014