Record details

Title
    Granitoid magmatism of the NW Bohemian massif revealed : Gravity data, composition, age relations and phase concept
Statement of responsibility
    W. Siebel, R. Trzebski, G. Stettner, L. Hecht, U. Casten, A. Höhndorf, P. Müller
Other titles
    The German deep drilling project, KTB (Variant.)
Author
    Casten, U.
    Hecht, Lutz
    Höhndorf, A.
    Müller, P.
    Siebel, Wolfgang
    Stettner, G.
    Trzebski, R.
Language
    anglicky
Source title - serial
    Geologische Rundschau
Vol./nr.
    Vol. 86, no. Suppl.
Pages
    p. 45-63
Year
    1997
Notes
    11 obr., 5 tab., 3 s.bibl.
    Zkr. název ser.: Geol. Rdsch.
Subject group
    biotit
    chemismus hornin
    datování K/Ar
    datování Rb/Sr
    granitoidy
    intruze
    metamorfika
    moldanubický pluton
    petrogeneze
    pole gravitační
    prvky stopové
    smrčinský pluton
Geographical name
    Bor (Tachov)
    ČR-Čechy
    Rozvadov (Tachov)
    SRN-Bayern
Keyword
    Age
    Bohemian
    Composition
    Concept
    Data
    Granitoid
    Gravity
    Magmatism
    Massif
    NW
    Phase
    Relations
    Revealed
Abstract (in english)
   The Late Variscan granitoids of the NW Bohemian Massif (northeast Bavaria, west Bohemian) constitute four partly contiguous granitoid complexes: Fichtelgebirge, northern Oberpfalz, Waidhaus-Rozvadov and Bor, incorporating more than 20 intrusive units. Based on gravity data, the granites can be modeled as steeply inclined slab- and wedge-like bodies with thickness between 2 and 8 km. A rough estimate of the total volume of the granites is approximately 18 000 km3. Within the four areas named above, composition ranges from less evolved dioritic rocks, known as the redwitzite suite, to highly evolved granites. Their isotopic ages, initial Sr ratios and Nd(T) values are discussed and their origin interpreted. The age and isotope data discussed herein suggest episodic rather than continuous magmatic activity.
   From a combination of field and analytical data, a three-stage cycle of granitoid intrusion is proposed: (a) a first phase (cca 350-325 Ma) of two contrasting magma types coexisting in a close spatial context, the redwitzites (phase Ia) and the older granites (phase Ib), (b) a second phase with emplacement ages of 315-310 Ma comprising all younger granites of the northern Oberpfalz and the Waidhaus-Rozvadov complex and (c) a third phase with emplacement ages of 305-295 Ma restricted to the Fichtelgebirge
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    3. 7. 2008
Import date
    8. 8. 2012