Podrobnosti záznamu

Název
    Ultrapotassic plutonic rocks of the durbachite series in the Bohemian Massif : petrology, geochemistry and petrogenetic interpretation
Údaj o odpovědnosti
    František V. Holub
Další názvy
    Ultradraselné plutonity durbachitové série v Českém masivu: petrologie, geochemie a petrogenetická interpretace
Autor
    Holub, František V.
Jazyk
    anglicky
Zdrojový dokument - seriál
    Sborník geologických věd. Ložisková geologie, mineralogie
Svazek/č.
    Vol. 31
Strany
    p. 5-25
Rok
    1997
Poznámky
    2 obr., 3 fot., 6 dg., 4 tab., 4 s.bibl.
    České resumé
    Zkr. název ser.: Sbor. geol. Věd, ložisk. Geol. Mineral.
Předmětová skupina
    chemismus hornin
    granitoidy
    hybridizace
    minerály horninotvorné
    moldanubikum
    petrogeneze
    prvky stopové
    složení draselné
    středočeský pluton
Geografické jméno
    ČR
Klíčové slovo
    Bohemian
    Durbachite
    Geochemistry
    Interpretation
    Massif
    Petrogenetic
    Petrology
    Plutonic
    Rocks
    Series
    Ultrapotassic
Abstrakt (anglicky)
   Ultrapotassic plutonic rocks of Hercynian age are widespread in the southern (Moldanubian) part of the Bohemian Massif. The most prominent group of them is represented by the durbachite series comprising porphyric amphibole-biotite melasyenite (durbachite), quartz melasyenite and melagranite, usually referred to as the Čertovo břemeno type. Mafic microgranular enclaves of ultrapotassic composition occur frequently in all members of the series. All these rocks are highly magnesian and rich in Cr (Ni) as well as in many hydromagmatophile elements (namely Rb, Cs, U, Th). Their chemical composition corresponds to relatively Si-rich minettes and related melasyenite to melagranite porphyries which are common in Central and South Bohemia. The mafic members of the durbachite series probably represent primitive, mantle-derived ultrapotassic magma which was only slightly modified by fractionation and (or) hybridization.
   The ultrapotassic magma probably originated within highly anomalous domains of the lithospheric mantle which have been modified by a strong depletion and subsequent, perhaps subduction-related, enrichment in some hydromagmatophile elements. Geochemical characteristics of the more acid members of the durbachite series, namely the high Mg and Cr, linear trends in simple variation diagrams and only slight decrease of Mg/(Mg+Fe) values with increasing silica, are compatible with an origin by mixing of the ultrapotassic mafic magma with (leuco) granitic melts, perhaps derived from the continental crust
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    21. 3. 2008
Datum importu
    8. 8. 2012