Palynology of cretaceous and tertiary strata, Northeast Baffin island, Northwest Territories, Canada: Implications for the history of rifting in Baffin bay

Palynomorphs from outliers of the Quqaluit and Cape Searle formations in half-grabens off northeast Baffin Island are examined in order to elucidate the history of rifting and sedimentation. Two distinctive assemblages, herein called the Gemmatriletes clavatus - Cicatricosisporites potomacensis Zone (GC Zone) and the Trivestibulopollenites betuloides-Pesavis parva Zone (TP Zone) are recognized. The lower part of the GC Zone in the lower part of the Quqaluit Formation consists of a low diversity assemblage of long ranging schizaealean spores and gymnosperm pollen; a late Neocomian and Aptian age is suggested from this assemblage. In addition to the name bearing species, the upper part of the GC Zone in the upper Quqaluit Formation contains a diverse spore and pollen assemblage, including Camarozonotriletes ambigens, Cicatricosisporites crassiterminatus, Appendicisporites matesovae, Foveogleicheniidites confossus, Tappanispora sp. cf. Tigrisporites verrucatus, Foveotricolpites sphaeroides, Tricolpites sagax, Retitricolpites sp. and Rousea sp. cf. R. georgensis; this assemblage indicates a late Albian and Cenomanian age. The TP Zone in the Cape Searle Formation has well preserved specimens of Trivestibulopollenites betuloides, Pesavis parva, Quercoidites microhenrica, Tricolpites hians, Rhoipites crassus, Tricolporopollenites cingulum, Carpinipites ancipites, Paraalnipollenites alterniporus, Triatriopollenites granilabratus and Polyvestibulopollenites verus; this assemblage indicates an early and middle Paleocene age. Palynomorph biostratigraphy supports geophysical inferences that the history of rifting and sedimentation in Baffin Bay began by the Early Cretaceous when North America and Europe separated. However, predominantly non-marine sedimentation in what is now Davis Strait suggests a distinctive Cretaceous history for Baffin Bay. Reactivation of faults in the Paleocene corresponds with changes in plate motions as Davis Strait opened and Greenland and North America rotated apart.