Podrobnosti záznamu

Název
    Middle/Late Cambrian intracontinental rifting in the central West Sudetes, NE Bohemian Massif (Czech Republic): geochemistry and petrogenesis of the bimodal metavolcanic rocks
Autor
    Dostal, J.
    Patočka, František
    Pin, CH.
Jazyk
    anglicky
Typ dokumentu
    článek v odborném periodiku
Zdrojový dokument - seriál
    Geological Journal
Svazek/č.
    Roč. 36, č. 1
Strany
    s. 1-17
Rok
    2001
Poznámky
    Projekt: GA205/93/0341, GA ČR
    Projekt: IAA3111102, GA AV ČR
    Rozsah: 17 s.
    Výzkumný záměr: CEZ:AV0Z3013912
Předmětová kategorie
    bimodal metavolcanics
    Early Palaeozoic
    northern Gondwana
Klíčové slovo
    Bimodal
    Bohemian
    Cambrian
    Central
    Czech
    Geochemistry
    Intracontinental
    Massif
    Metavolcanic
    Middle/Late
    NE
    Petrogenesis
    Republic
    Rifting
    Rocks
    Sudetes
    West
Abstrakt (anglicky)
   The Early Palaeozoic East Krkonoše Complex situated in the central West Sudetes, NE Bohemian Massif, is a volcano-sedimentary suite containing abundant mafic and felsic volcanics metamorphosed to greenschist facies.The trace element distribution patterns and Nd isotope signatures (ENd500 = +3.1 to +6.6) of the metabasalts indicate that they may be related to a rising mantle diapir associated with intracontinental rifting. At the early stage, limited melting of an upwelling asthenosphere produced alkali basalts and enriched tholeiites which compositionally resembled oceanic island basalts.
   A later stage of rifting larger degrees of melting at shallower depths generated tholeiitic basalts with E-MORB to N-MORB characteristics.The values of (87Sr/86Sr)i = 0.706 and ENd500 = -5,1 of the metarhyolites as well as the lack of rocks with intermediate composition suggest that the felsic rocks were formed by partial melting of continental crust triggered by mantle melts.The geochemistry of the bimodal metavolcanics and their association with abundant terrigenous metasediments suggest that the felsic-mafic volcanic suite was generated during an early stage of intracontinental rifting. This process, widespread in Western and Central Europe during the Early Palaeozoic, is an evidence of large-scale fragmentation of the northern margin of the Gondwana supercontinent.
Přispěvatel
    AV ČR Brno, Geologický ústav
Kód přispěvatele
    AV ČR, GLÚ
Zdrojový formát
    U
Datum importu
    8. 8. 2012