Perisphinctes Ravine – a key Jurassic-Cretaceous boundary succession in Kuhn Ø, NE Greenland

A major biostratigraphical reference section across the Jurassic-Cretaceous boundary is documented from Perisphinctes Ravine, eastern Kuhn Ø. A continuous section extends for some 220m from the Bernbjerg Formation (Early Volgian-Ryazanian) up into the Mid Cretaceous Sandy Shales (Valanginian-?Hauterivian). Well preserved macrofaunas, particularly ammonites, bivalves and belemnites, as well as microfossils and palynological material are present. Biostratigraphic and palaeoenvironmental data are displayed in an integrated table using Stratabugs. This section contains important correlations between the different biozonation schemes applicable in eastern Greenland. In the lower part of the section, dark Volgian-Ryazanian mudstones contain pectinatitid, dorsoplanitid and chetaitid ammonites together with buchiid bivalves. Calcareous mudstones of Late Ryazanian – Valanginian age are rich in buchiids and belemnites with a few ammonites. Later Valanginian-?Hauterivian red-beds and dark mudstones are characterised by belemnite faunas. This section provides correlations with other Boreal and Sub-Boreal regions, such as Arctic Canada, NW Europe, Svalbard, Russian Platform and Siberia.