CRETACEOUS DINOFLAGELLATE CYSTS FROM THE SMOKING HILLS AREA, NORTHWEST TERRITORIES, CANADIAN ARCTIC

The Smoking Hills area, located on the east side of Cape Bathurst and adjacent to Franklin Bay, hosts Cretaceous sedimentary strata largely exposed on the banks of the Horton River that cuts through the Anderson plains. In the summer of 2018, the Geological Survey of Canada (GSC) lead its first fieldwork in the area since the initial GSC surveys were conducted in the late 1960s, collecting high stratigraphic resolution samples for multi-disciplinary stratigraphic investigations, paleoenvironmental reconstructions and insights on the tectonostratigraphic evolution of the Arctic. This study focusses on the highly diverse and abundant dinoflagellate cysts from the Lower Cretaceous Langton Bay (Berriasian-Valanginian(?) to early Middle Albian) and Horton River formations (Middle Albian), and the Upper Cretaceous Smoking Hills (Santonian to Campanian) and Mason River formations (Campanian to Maastrichtian).

Specific objectives are (1) to update the taxonomy of Cretaceous dinoflagellate cyst species reported in the western Canadian Arctic to allow for regional correlations across similarly aged strata, (2) to establish age equivalence of Cretaceous strata from the Smoking Hills area and the Sverdrup Basin (Isachsen, Christopher and Kanguk formations), which currently constitutes the reference framework for Canadian Arctic stratigraphy, and (3) to attempt paleoenvironmental reconstructions to resolve oceanographic changes associated with the influence of Western Interior Seaway (Smoking Hills area) compared to the late post-rift stage of the Sverdrup Basin. Preliminary results indicate excellent palynomorph preservation, low thermal maturity of samples and high species diversity.