Correlating middle Cretaceous palynological records from the Canadian High Arctic based on a section from the Sverdrup Basin and samples from the Eclipse Trough

Quantitative palynological analyses undertaken on the middle Cretaceous Hassel Formation of the Sverdrup Basin and reputedly equivalent rocks from the Eclipse Trough, about 850km east, provide convincing evidence that they are coeval and of Late Albian-Cenomanian age. We base this conclusion on statistical definition of two palynomorph populations that occur in both spot samples from the Eclipse Trough and in samples from a measured section at Hoodoo Dome, Ellef Ringnes Island in the central Sverdrup Basin, which demonstrate a broad correlation to previously reported palynofloras from North America. By applying ordination techniques, we demonstrate that the range of variability of palynomorph composition of samples from the reputed Hassel Formation in the Eclipse Trough are within the range of variability defined for samples from the Hassel Formation, Hoodoo Dome. Comparable proportions of dicotyledonous angiosperm pollen characterize samples from both localities, but diversity and relative abundance are lower in both of the Canadian Arctic deposits than in more southern Middle and Late Albian-Cenomanian-aged rocks of North America. To explain this, we propose that restricted angiosperm diversity and continued dominance of gymnosperms and ferns into the Cenomanian in the Canadian Arctic reflect relatively cool continental climate conditions or barriers to migration, such as the Western Interior Seaway.