Revised stratigraphy of Kap Rigsdagen beds, Wandel Sea Basin, North Greenland

The Wandel Sea Basin in eastern North Greenland comprises Upper Palaeozoic –Paleogene sediments. Most stratigraphic units are well dated but new palynological analyses of the 85–100 m thick succession at Kap Rigsdagen, North Greenland have revealed two stratigraphically significant dinoflagellate cyst assemblages which change the earlier age assignment of the succession. The lower assemblage suggests a late Barremian age for the sediments. These sediments and the underlying, coarse-grained sediments (barren of dinoflagellate cysts) show similarities to the upper Ladegårdsåen Formation in Peary Land, also of late Barremian age. Consequently, this part of the Kap Rigsdagen succession is herein referred to the Ladegårdsåen Formation. The upper part of the Kap Rigsdagen succession yielded a diverse dinoflagellate cyst assemblage dominated by reworked Lower and Upper Cretaceous species but includes Lower to Middle Eocene taxa. Alterbidinium? aff. bicellulum is the only abundant Eocene species in these strata. This part of the succession is referred to the Thyra Ø Formation based on lithology and paralic depositional environment of Early to Middle Eocene age. Similar rich reworked Cretaceous dinoflagellate cyst assemblages in Paleogene deposits have previously been reported from North and East Greenland. In all cases, this magnitude of reworking responds to regional uplift events in connection with the North Atlantic break-up and sea-floor spreading.