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.