Record details

    Single zircon ages and whole-rock Nd isotopic systematics of early Palaeozoic granitoid gneisses from the Czech and Polish Sudetes (Jizerské hory, Krkonoše and Orlice-Sněžník Complex)
Statement of responsibility
    Alfred Kröner, Petra Jaeckel, E. Hegner, Mojmír Opletal
    Hegner, E.
    Jaeckel, Petra
    Kröner, Alfred
    Opletal, Mojmír
Source title - serial
    International journal of Earth sciences (Geologische Rundschau)
    Vol. 90, no. 2
    p. 304-324
    10 obr., 2 fot., 4 tab., 3 s.bibl.
    Zkr. název ser.: Int. J. Earth Sci. (Geol. Rdsch.)
Subject group
    datování Sm/Nd
    datování U/Pb
    vrásnění grenvillské
    vrásnění kadomské
    vrásnění kaledonské
    západosudetská oblast
Geographical name
    Deštné v Orlických horách (Rychnov nad Kněžnou)
    Frýdlant (Liberec)
    Jablonné nad Orlicí (Ústí nad Orlicí)
    Polsko - jihozápad
    Špindlerův Mlýn (Trutnov)
    Vrchlabí (Trutnov)
    Zdobnice (Rychnov nad Kněžnou)
Abstract (in english)
   Granitoid orthogneisses make up the predominant rock type in the West Sudetes from Jizerské hory in the NW to the Orlické hory and Sněžník Mountains in the SE. These generally strongly foliated gneisses are calc-alkaline in composition and display trace element characteristics suggesting generation in a volcanic arc seeting. Single zircon ages reflecting the time of emplacement of the gneiss protoliths define a relatively narrow Cambro-Ordovician range between 502 and 515 Ma. This is similar to previously reported zircon ages from the Czech and Polish West Sudetes and documents an important and regionally extensive post-Cadomian magmatic event that we relate to continental arc magmatism on the margin of Avalonia that developed during closure of the Tornquist Ocean. An age of 492 Ma for a microgranite dyke curring deformed and metamorphosed orthogneisses in the Orlické hory shows the main deformation to be early Paleozoic.
   Zircon xenocryst minimum ages range between 546 and 2070 Ma and show maxima in the Cadomian/Pan-African (550-850) and Grenvillian (1000-1300 Ma) time brackets. The Grenvillian event is also evident from Nd mean crustal residence ages that vary between 1.34 and 1.87 Ga. From these data we suggest that the pre-Variscan granitoid gneisses of the Czech West Sudetes were largely generated by melting of a predominantky Grenville-age basement that was part of the northern margin of Gondwana and may have been related to Grenville-age basement now identified in northern South America
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
Entered date
    7. 4. 2008
Import date
    8. 8. 2012