The palynological record across the Cretaceous/Tertiary transition on

Unconsolidated, fine-grained (sandy silts), shallow marine sediments of the upper Lopez de Bertodano Formation include the Cretaceous/Tertiary boundary on Seymour Island, northeastern Antarctic Peninsula. These strata contain abundant palynomorphs and other micro- and macrofossils. The Cretaceous/Tertiary boundary is provisionally placed at a dinocyst zonal boundary that occurs within a laterally persistent glauconite-rich interval. This glauco-nite interval marks the highest, definitely in-place Maastrichtian macro- and microfos-sils. Strata above this interval are considered Danian, based on palynological evidence, in the absence of other age-diagnostic fossils. Association of Maastrichtian ammonites and microfossils with typically "Danian " dinocysts below the glauconite interval accen-tuates the transitional nature of the Cretaceous/Tertiary succession on Seymour Island. Changes in Cretaceous/Tertiary dinocyst assemblages may be related to local environ-mental change, including regression. Pollen and spore assemblages record little change and no evidence of an abrupt event for the land vegetation across the Cretaceous/Tertiary boundary. Instead, a long-term floral turnover is inferred from nonmarine species. This gradual change is consist-ent with climatic change, possibly cooling, through much of Maastrichtian and early Paleocene time