Podrobnosti záznamu

Název
    Zircon ages of high-grades gneisses in the eastern Erzgebirge (Central European Variscides) - constraints on origin of the rocks and Precambrian to Ordovician magmatic events in the Variscan foldbelt
Údaj o odpovědnosti
    M. Tichomirova, H.-J. Berger, E. A. Koch, B.V. Beljatski, J. Götze, U. Kempe, Lutz Nasdala, Urs Schaltegger
Autor
    Beljatski, B. V.
    Berger, H.-J.
    Götze, J.
    Kempe, U.
    Koch, E. A.
    Nasdala, Lutz
    Schaltegger, Urs
    Tichomirova, M.
Jazyk
    anglicky
Zdrojový dokument - seriál
    Lithos
Svazek/č.
    Vol. 56, no. 4
Strany
    p. 303-332
Rok
    2001
Poznámky
    12 obr., 3 fot., 3 tab., 3 s.bibl.
    il.
    Zkr. název ser.: Lithos
Předmětová skupina
    chemismus hornin
    datování Pb/Pb
    datování U/Pb
    droba
    granitoidy
    kambrium
    krušnohorské krystalinikum
    lužický pluton
    metamorfóza
    ordovik
    ortorula
    pararula
    prekambrium
    protolit
    vrásnění kadomské
    zirkon
Geografické jméno
    ČR-Čechy
    Krušné hory
    Rumburk (Děčín)
    SRN-Sachsen
Klíčové slovo
    Ages
    Central
    Constraints
    Eastern
    Erzgebirge
    European
    Events
    Foldbelt
    Gneisses
    High-grades
    Magmatic
    Ordovician
    Origin
    Precambrian
    Rocks
    Variscan
    Variscides
    Zircon
Abstrakt (anglicky)
   This study is an attempt to unravel the tectono-metamorphic history of high-grade metamorphic rocks in the Eastern Erzgebirge region. Metamorphism has strongly disturbed the primary petrological genetic charactesristic of the rocks. We compare geological, geochemical, and petrochemical data, and zircon populations as well as isotope and geochronological data for the major gneiss units of the Eastern Erzgebirge; (1) coarse- to medium-grained "Inner Grey Gneiss". (2) fine-grained "Outer Grey Gneiss", and (3) "Red Gneiss". The Inner and Outer grey Gneiss units (MP-MT overprinted) have very similar geochemical and mineralogical compositions, but they contain different zircon populations. The Inner Grey Gneiss is found to be primary igneous origin as documented by the presence of long-prismatic, oscillatory zoned zircons (540 Ma) and relics of granitic textures. geochemical and isotope data classify the igneous precursor as a S-type granite.
   In contrast, Outer Grey Gneiss samples are free of long-prismatic zircons and contain zircons with signs of mechanical rounding through sedimentary transport. Goechemical data indicate greywackes as main previous precursor. The most euhedral zircons are zoned and document Neoproterozoic (ca. 575 Ma) source rocks eroded to form these greywackes. U-Pb-SHRIMP measurements revealed three further ancient sourves, which zircons survived in both the Inner and Outer Grey Gneiss: Neoproterzoic (600-700 Ma), Paleoproterozoic (2100-2200 Ma), and Archaean (2700-2800 Ma)
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    5. 2. 2009
Datum importu
    8. 8. 2012