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Perisphinctes Ravine - a key Jurassic-Cretaceous boundary succession in Kuhn Ø, NE Greenland
Simon Kelly, Bill Braham, John Gregory, Peter Doyle, Dominic Strogen, Andrew Whitham

Building: Muséum d'Histoire Naturelle de Genève
Room: Lobby /Hall/
Date: 2018-12-05 12:12 PM – 12:15 PM
Last modified: 2018-12-01

Abstract


An important biostratigraphical reference section across the Jurassic-Cretaceous boundary is documented from Perisphinctes Ravine, eastern Kuhn Ø, Northeast Greenland. A continuous section extends for some 220m from the Bernbjerg Formation (Early Volgian-Ryazanian) up into the Mid Cretaceous Sandy Shales (Valanginian-Hauterivian). The mudstone-dominated succession contains 21 concretionary beds in the Late Kimmeridgian to Ryazanian interval, which contain well-preserved macrofauna, It was also sampled for micropalaeontology and palynology. Integrated biostratigraphic data are here displayed in table form.

The latest Kimmeridgian is characterised by the bivalve Buchia tenuistriata. The earliest Volgian is characterised by the appearance of ammonites, Pectinatites groenlandicus with the last B. tenuistriata and first B. mosquensis. The latest Early Volgian is marked by the last Pectinatites. The earlier part of the Mid Volgian is marked by the successive Dorsoplanites gracilis, Epipallasiceras apertum and Crendonites anguinus zones, the latter containing the last B. mosquensis. The latest part of the Mid Volgian is characterised by B. russiensis with Laugeites greenlandicus at the top. The earliest Late Volgian is marked by the appearance of Epilaugeites vogulicus with B. terebratuloides, and followed by Prochetaites tenuicostatus with B. fisheriana and B. unschensis. The latest Ryazanian/earliest Valanginian is characterised by B. inflata with Tollia sp. The early Valanginian is characterised by Buchia keyserlingi with polyptychitid ammonites. The later Valanginian to earliest Hauterivian is marked by B. sublaevis. The later part of the Early Hauterivian is marked by B. sublaevis with B. crassicollis. In the Kimmeridgian to Late Ryazanian interval foraminiferal zones from F3 to F8 were recognised of the Svalbard succession. In addition Radiolarian events were identified in the Late Kimmeridgian, earliest Mid Volgian and Late Volgian. The microfossil successions are correlated with the palynological zonations for northwest Europe and the North Sea.