SHRIMP U-Pb dating of tuff-derived and detrital zircons from Cadomian marginal basin fragments (Neoproterozoic) in the northeastern Saxothuringian Zone (Germany)

Zircons from two Neoproterozoic tuff layers from the northeastern Saxothuri ngian Zone were studied by SHRIMP ion microprobe analysis. The tuff layers are from the Rothstein Formation (Doberlug Syncline) and the Lusatian Main Group (Lusatian Anticline) with both units representing fragments of Cadomi an marginal basins. Concordant Pb-206/U-238 ages (95 % confidence) of 566 /- 10 Ma (Rothstein Formation) and 574 +/- 8 Ma (Lusatian Main Group) for t he tuff-derived zircons reveal an Upper Vendian age not only for the volcan ic activity in the continental are source of the tuffs and associated terri genous sediments, but also for the contemporaneous depositional processes i n the marginal basins. Dating of detrital zircons from a Neoproterozoic gra ywacke (Rothstein Formation) suggest the occurrence of earlier Cadomian mag matism and a Paleoproterozoic crustal component in the source area.