Podrobnosti záznamu

    Nearly contemporaneous evolution of the A- and S-type fractionated granites in the Krušné hory/Erzgebirge Mts., Central Europe
    Breiter, Karel
Typ dokumentu
    článek v odborném periodiku
Zdrojový dokument - seriál
    Roč. 151, 15 October
    s. 105-121
    Projekt: GAP210/10/1105, GA ČR3cav_un_auth*0263315
    Projekt: IAA300130801, GA AV ČR3cav_un_auth*0241227
    Rozsah: 17 s. : WWW
Předmětová kategorie
    A-type granite
    Bohemiam Massif
    granite classification
    Krušné hory Mts.
    S-type granite
Klíčové slovo
Abstrakt (anglicky)
   The Krušné hory/Erzgebirge Mountains is one of the best-known provinces of granite magmatism and associated metallogenesis in Europe. Variscan magmatic activity in the Krušné hory area spanned the period from 330-295 Ma. For much of this time, two types of magma were generated and emplaced in close proximity in this province. Strongly peraluminous P-rich (S-type) melts were formed alongside slightly peraluminous P-poor melts (A-type). Two suites of strongly peraluminous P, F, Li, Rb, Cs, U, Sn-rich and Zr, Th, Y, HREE-poor magmas were intruded in rapid succession over a period of about 10 Ma (about 330-320 Ma) over the entire region of the Krušné hory. Several peraluminous rhyolitic dykes near Gottesberg mark an isolated event at about 295 Ma. Slightly peraluminous F, Li, Rb, Cs, Sn, Zr, Y, HREE-rich and P-poor magmas were intruded in several events separated in space and time (325-295 Ma).
   Both magmatic episodes culminated with strongly fractionated subvolcanic granite intrusions, accompanied by explosive brecciation and followed by Sn + W mineralization of greisen type. Successive volcanic eruption of rhyolites and dacites of S-type, and rhyolites of A-type in the Altenberg-Teplice Caldera demonstrate the close temporal and spatial relationship between these two types of magma. When these two geochemically distinct types of rock are in direct contact, then the rocks of A-type are always younger. The absolute time difference between the two types can range from less than 1 Ma (the first eruption of the Teplice rhyolite versus the Schönfeld dacite in the ATC) to about 15 Ma (eruption of rhyolites at Gottesberg versus emplacement of the Eibenstock granite).
   Assumed protolith of the Variscan A-type granites in the Krušné hory area is a granulitic residue in the lower crust left after production of the Cadomian peraluminous granites, while the Variscan S-type granites originated via partial melting of fertile crustal rocks not affected by the Cadomian melting event.
    AV ČR Brno, Geologický ústav
Kód přispěvatele
    AV ČR, GLÚ
Zdrojový formát
Datum importu
    19. 3. 2014