Siliceous microfossils and agglutinated foraminifera from the Upper Cretaceous Smoking Hills and Mason River formations in the Smoking Hills area, Northwest Territories

Abstract

Five microfossil groups are herein described from the Upper Cretaceous Smoking Hills and Mason River formations in the Horton River area (Northwest Territories). Microfossil assemblages from the Smoking Hills Formation are dominated by radiolarians and foraminifera whereas the Mason River Formation mainly contains diatoms, silicoflagellates, and sponge spicules. These microfossil groups have been reported before in these units and age-equivalent strata from the Canadian Arctic except for radiolarians. The radiolarian assemblage described in this study represents one of the most diverse and abundant assemblages reported in Campanian-Maastrichtian rocks in North America and can be used to reconstruct the climatic, paleoceanographic, and paleobiogeographic conditions that took place at the end of the Cretaceous Period. This Open File documents the stratigraphic occurrence of the microfossil types.