Palynology of Maastrichtian and Paleocene rocks, lower Colville River region, North Slope of Alaska
Outcrops of Maastrichtian rocks are rare on the North Slope of Alaska, and it is even more unusual to find outcrops of Maastrichtian and Paleocene age in the same vicinity. In general, Late Cretaceous and Paleogene rocks have not been well dated in published papers pertaining to northern Alaska. In this article, we describe palynomorph assemblages from 20 outcrop samples taken from nine localities along the lower Colville River and nearby areas. The latest Cretaceous palynomorph assemblages that are from marine rocks contain late Campanian or Maastrichtian dinoflagellate cysts; however, these cysts and other marine fossils are absent from the Tertiary samples, indicating that the Tertiary strata are nonmarine. Our latest Cretaceous and early Tertiary samples contain abundant spores and pollen grains and can be readily dated by reference to well-known pollen assemblages from the northern Great Plains and northwestern Canada. By dating each sampled outcrop, we can approximate the position of the Cretaceous–...