Record details

Title
    Age constraints on the Cadomian evolution of the Teplá Barrandian unit (Bohemian Massif) through electron microprobe dating of metamorphic monazite
Statement of responsibility
    Gernold Zulauf, Franz Schitter, Gudrun Riegler, Friedrich Finger, Jiří Fiala, Zdeněk Vejnar
Author
    Fiala, Jiří
    Finger, Friedrich
    Riegler, Gudrun
    Schitter, Franz
    Vejnar, Zdeněk
    Zulauf, Gernold
Language
    anglicky
Source title - serial
    Zeitschrift der Deutschen geologischen Gesellschaft
Vol./nr.
    Vol. 150, no. 4
Pages
    p. 627-639
Year
    1999
Notes
    4 obr., 2 tab., 3 s.bibl.
    Německé resumé
    Zkr. název ser.: Z. Dtsch. geol. Gesell.
Subject group
    chemismus minerálů
    datování U/Th/Pb
    domažlické krystalinikum
    kambrium
    metamorfóza
    monazit
    pararula
    subdukce
    vrásnění kadomské
Geographical name
    ČR-Čechy
    Domažlice
    Havlovice (Domažlice)
    Stráž (Domažlice)
Keyword
    Age
    Barrandian
    Bohemian
    Cadomian
    Constraints
    Dating
    Electron
    Evolution
    Massif
    Metamorphic
    Microprobe
    Monazite
    Teplá
    Through
    Unit
Abstract (in english)
   he Teplá Barrandian unit forms a major constituent of the Gondwana-derived Armorican terrane assemblage where the impact of the Cadomian orogeny can be studied in great detail and at different structural levels. Electron microprobe dating of monazites from paragneisses of the Domažlice crystalline complex, situated in the southwestern part of the Teplá Barrandian unit, helps to constrain the age of Cadomian high-grade metamorphism of this area. Monazites in three samples from different localities have been analysed and yielded weighted average Th-U-Pb model ages of 540 16,542 23 and 551 19 Ma, respectively. On the basis of the new monazite ages and pre-existing stratigraphic, structural, metamorphic and radiometric age data, a geodynamic model for the Cadomian evolution of the Teplá Barrandian unit is suggested.
   This model includes the following stages of orogenic activity: (1) southward subduction of oceanic lithosphere along the northern, Andean-type margin of the supercontinent Gondwana at 550 Ma; (2) collision of a microterrane (island arc?) with Gondwana under persisting top-to-the-N kinematics, involving slab breakoff and associated low-pressure/high temperature metamorphism at ca. 550-540 Ma; (3) crustal thinning and exhumation of high-grade metamorphic rocks, accommodated by dextral transtension and erosion of the orogenic wedge at ca. 540-510 Ma. Major crustal tilting of the Domažlice crystalline complex predates the intrusion of synkinematic Cambrian granitoids. The generally do not necessarily indicate prolonged Cadomian subduction during the Cambrian. It can be equally well explained in terms of remelting of arc-type crust in a post-collisional high-heat flow regime
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    28. 1. 2008
Import date
    8. 8. 2012