The post-variscan cover units of the different Greywackezone nappes were so far interpreted as juxtaposed sediment sources with similar ages. In order to examine this assumption, samples of the Silbersberg, the Veitscher and the Präbichl Metasandstones as well as of the Semmering Quartzite were taken and used for detrital U/Pb zircon analysis. The detrital zircon analysis was done with a LA MC ICP MS.The analysis demonstrated that the sediment sources were quite different, and therefore did not originate of the same sediment basins. The direct basement of the individual basins was exposed to erosion after the Variscan orogeny. Still, the detritus of the sediment basins originates only partly of the associated basement. If the age spectra of the detrital zircons are compared with the published ages of the basement terrains of the Alpine and Carpathian Realm, the following sources can be suggested:The age distribution of the Silbersberg Metasandstone zircons lacks of Ordovician aged zircons and depicts middle Devonian population, which is most likely comparable to ages from the Kaintaleck Complex.The likeliest delivery area of the Semmering Quartzite, which possesses an obvious accumulation of Ordovician und Permian zircons, are the units south of the current Tauern Window.The Veitscher Metasandstone and the connected dominant Upper Cambrian to Ordovician ages, but also the Lower Carboniferous aged zircons, are quite similar to the age spectra of the Tatric and Veporic units of the Carpathian.A dominant Lower Carboniferous age group can be seen in the age spectra of the Präbichl Fm, as well as an Ordovician aged zircon population. The source area consists therefore probably of resedimented Paleozoic layers and Lower Carboniferous magmatites.The zircon populations of all the samples reflect the break up stages of Gondwana until the formation of Pangea.