Podrobnosti záznamu

Název
    Multiple magmatic pulses of the Eastern Volcano-Plutonic Complex, Krušné hory/Erzgebirge batholith, and their phosphorus contents
Údaj o odpovědnosti
    Miroslav Štemprok, František V. Holub, Jiří K. Novák
Autor
    Holub, František V.
    Novák, Jiří K.
    Štemprok, Miroslav
Jazyk
    anglicky
Zdrojový dokument - seriál
    Bulletin of geosciences
Svazek/č.
    Vol. 78, no. 3
Strany
    p. 277-296
Rok
    2003
Poznámky
    11 obr., 1 fot., 8 tab., 3 s. bibl.
    il.
    Zkr. název ser.: Bull. Geosci.
Předmětová skupina
    chemismus hornin
    dajka
    fluor
    fosfor
    granitoidy
    greizenizace
    ignimbrit
    kaldera
    karbon
    komplex vulkanoplutonický
    krušnohorský pluton
    lithium
    magmatismus
    mikrogranit
    peň
    proces polyfázový
    profil vrtný
    původ korový
    ryolit
Geografické jméno
    Cínovec (Teplice)
    ČR-Čechy
    Fláje (Most)
    Krupka (Teplice)
    Moldava (Teplice)
    Nakléřov (Ústí nad Labem)
    SRN-Sachsen
    Telnice (Ústí nad Labem)
    Teplice
Klíčové slovo
    Batholith
    Complex
    Contents
    Eastern
    Hory/Erzgebirge
    Krušné
    Magmatic
    Multiple
    Phosphorus
    Pulses
    Volcano-Plutonic
Abstrakt (anglicky)
   ranites of the eastern part of the Krušné hory/Erzgebirge (Czech Republic/Germany) outcrop in separate minor stocks formed by Late Palaeozoic CaO-rich biotite monzogranites of the Older Intrusive Complex (QIC) and syenogranites or alkali feldspar granites of the Younger Intrusive Complex (YIC). These, along with abundant rhyolites and granite porphyry dykes, constitute the Eastern Volcano-Plutonic Complex (EVPC). Using new analyses as well as older unpublished and literature data, we evidenced that these rocks display a wide spectrum of phosphorus contents ranging from very low (well below 0.1 wt per cent P2O5) to intermediate contents (from 0.1 to 0.4 wt per cent P2O5). No equivalent of the high-phosphorus fractionated granites with P205 0.4 wt per cent known from the western Krušné hory/Erzgebirge is present in the EVPC. We have demonstrated that the QIC granite bodies comprise a number of petrographic varieties and some of them represent individual magmatic pulses.
   Relatively elevated phosphorus contents in the evolved members of the Fláje granite massif may reflect their origin as individual magma batches from heterogeneous crustal sources. We observed the marginal Preisselberg granite enriched in P among the predominant P-poor YIC granites; this granite probably originated also as a separate magma batch. On the contrary, the rhyolitic ignimbrites, granite porphyries and YIC granites were derived from a younger, huge and long-standing magmatic system which presumably was formed and maintained as a consequence of significant thermal input from mantle-derived mafic magmas. These mafic magmas homogenized granitic partial melts from lower crustal sources and produced large volumes of highly evolved magma portions via fractional crystallization. The granite magmas with I-type or transitional I/S-type characteristics evolved towards the low-P2O5 compositions.
   This process was disturbed by episodic hybridization of the granite magmas with the mantle-derived melts or products of their fractionation at depth. The YIC granites probably represent residual, late-stage melts rich in volatiles, with strongly increased incompatible element abundances due to prolonged crystal fractionation. Their composition was strongly affected by interaction with an aqueous fluid phase that changed the phosphorus distribution in only a minor way. Late magmatic and post-magmatic processes obscured the primary chemical characteristics namely in the Li-rich granites. This fact could be the reason for the absence of any correlation between the generally low P2O5 and highly variable alumina-saturation indices. The phosphorus contents thus reflect various aspects of rather complex genetic histories of Late Variscan igneous rocks in the EVPC, particularly within the lower and middle crust.
   In contrast with the role of phosphorus, the contents of lithium and fluorine are more dependent on subsolidus alterations of granites induced by hydrothermal fluids in late
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    27. 9. 2007
Datum importu
    8. 8. 2012