Ordovician graptolite biostratigraphy of the Rugen wells, NE Germany

Ordovician strata are identified in the Early Palaeozoic succession of the Rugen wells based on macro- and microfaunas. The Lower Ordovician is dated by the trifidum acritarch flora of late Tremadoc age, whereas the Middle an d Upper Ordovician is dated by graptolite faunas. The Holmograptus lentus, Pterograptus elegans, Pseudamplexograptus distichus, Hustedograptus teretiu sculus and Nemagraptus gracilis Zones of Middle to Upper Ordovician age are identified. Tectonic stacking is clearly evident from the Rugen 3h well, i n which Upper Ordovician (Caradoc, Nemagraptus gracilis Zone) is overlain b y Middle Ordovician (Darriwilian). The lithological and biostratigraphical succession of Rugen is easily compared with the Brabant Massif and the Ebbe Anticline of the Palaeozoic terrane East Avalonia, but differs strongly fr om that of Saxo-Thuringia and Perunica.