The Upper Jurassic–Lower Cretaceous in the Isfjorden area (central Spitsbergen), consisting mostly of dark shales, with local carbonate-seep deposits, have been analysed for marine palynomorphs and palynofacies. Two dinoflagellate cyst assemblage zones have been defined in the Slottsmøya Member (Agardhfjellet Formation). The palynostratigraphic zones are established with reference to ?13Corg curves, and are correlated with Early Volgian to Late Ryazanian foraminiferal zones and ammonite zones from the same area. A Leiosphaeridia bloom at 45.62 m in the Janusfjellet profile is correlated with a comparable bloom recovered from several locations on the western Barents shelf. Palynofacies analysis is used to interpret relative sea-level changes and is also used to constrain the sequence stratigraphy of the studied sections at Janusfjellet and Knorringfjellet.
Dinoflagellate cyst biostratigraphy, palynofacies, depositional environment and sequence stratigraphy of the Agardhfjellet Formation (Upper Jurassic-Lower Cretaceous) in central Spitsbergen (Arctic Norway)