Preliminary paleopalynology of the Kanguk Formation (Upper Cretaceous), Remus Creek, Canadian Arctic Archipelago: II. Terrestrial Palynomorphs

Resumen

A total of 78 terrestrial palynomorph taxa were identified from 39 samples collected at about one metre intervals from the Kanguk Formation (Upper Cretaceous) on Remus Creek, Ellesmere Island, Canadian Arctic Archipelago. The terrestrial palynomorphs constitute 49 % of total palynomorphs and are found in a marine facies where dinocysts and acritarchs are abundant. However, in the upper part of the section the terrestrial taxa dominate over marine palynomorphs indicating regressive conditions. Miospores and gymnosperm and angiosperm pollen grains, throughout the section, are small and thin-walled with varying degrees of preservation. Taxodiaceae-Cupressaceae pollen are the most abundant with common ocurrences of smooth trilete miospores and the accessory presence of small tricolpate pollen. The majority of the terrestrial taxa of the Kanguk Formation can be assigned to a Late Cretaceous boreal realm. Their character, distribution and variations in relative percentages through the section imply initial transgressive conditions followed by regressive conditions in the upper half of the section. The Kanguk terrestrial palynomorph assemblage suggests that the nearby continental areas were vegetated. The Taxodiaceae-Cupressaceae complex associated with terrestrial paralic environments was probably the dominant regional vegetation and, despite the high latitud, most likely, an open boreal forest compossed of gymnosperms was present in the area. A small, but significant, fraction of the total of the terrestrial assemblages is considered to be reworked from Albian-Cenomanian sediments probably from the underlying Hassel Formation. Thus, reworked taxa document the existence of an unconformity between these formations.