Record details

Title
    Review of Nd isotopic data and xenocrystic and detrital zircon ages from the pre-Variscan basement in the eastern Bohemian Massif: speculations on palinspastic reconstructions
Statement of responsibility
    Ernst Hegner, Alfred Kröner
Other titles
    Orogenic Processes: Quantification and Modelling in the Variscan Belt (Variant.)
Author
    Hegner, Ernst
    Kröner, Alfred
Language
    anglicky
Source title - serial
    Geological society special publication
Vol./nr.
    Vol. 179
Pages
    p. 113-129
Year
    2000
Notes
    7 obr., 1 tab., 4 s.bibl.
    Zkr. název ser.: Geol. Soc. spec. Publ. (London).
Subject group
    datování Sm/Nd
    datování U/Pb
    Gondwana
    metagranit
    metasedimenty
    metavulkanity
    moravskoslezská oblast
    paleogeografie
    paleozoikum
    prekambrium
    vrásnění prekambrická
    vrásnění variské
    západosudetská oblast
    zirkon
Geographical name
    Afrika západní
    Amerika jižní
    Česká republika
    Polsko - jihozápad
Keyword
    Ages
    Basement
    Bohemian
    Data
    Detrital
    Eastern
    Isotopic
    Massif
    Nd
    Palinspastic
    Pre-Variscan
    Reconstructions
    Review
    Speculations
    Xenocrystic
    Zircon
Abstract (in english)
   Nd crustal residence ages combined with xenocrystic and detrial zircon ages of Neoproterozoic and early Palaeozoic granitoid gneisses and metasediments from the NE Bohemian Massif (West Sudetes and Erzgebirge) suggest an origin from a basement with significant Grenvillian and Svecofennian-Birimian-Amazonian age components. Largge contributions from Archaean crust appear to be missing. Nd modes ages of 1.4-1.7 Ga as well as Meso- to Palaeoproterozoic zircon xenocrysts ages for the Lugian Domain (Jizerské, Krkonoše, and Orlica-Snieznik Mountains) are interpreted as evidence a predominantly Palaeoproterozoic basement that underwent rejuvenation during Meso- and Neoproterozoic-Ordovician magmatic events. Our interpretation of the Nd model ages may be relevant for the western part of the Variscan Belt, where a similar range of Nd model ages characterizes large crustal segments.
   Samples from the Silesian Domain (Desná Dome, Staré Město Belt, Velké Vrbno Unit) of the Brunia Microcontinent, in thrust contact with the Lugian Domain, yielded Nd crustal residence ages of 1.1-1.3 Ga, which coincide with the oldest ages of xenocrystic zircons. Brunia is interpreted as apredominantly juvenile Grenvillian-age crustal segment, possibly constituting a former arc batholith outboard from the more ensialic setting of the Lugian Domain. Nd crustal residence ages for our 77 whole-rock samples, including 41 new data, as well as 185 yenocrystic and detrial zircon ages from the northern and northeastern Bohemian Massif aggree with those of Neoproterozoic rocks from northern South America and support an origin from a northwest Gondwana palaeogeographical location
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    30. 4. 2007
Import date
    8. 8. 2012