NWT RESEARCH DATABASE

Regions: Sahtu Settlement Area

Tags: physical sciences, geology, fossils, paleontology

Objective(s): To better understand how the K-T extinction affected polar regions, and whether the extinction was more severe in the High Arctic.

Project Description: To better understand how the K-T extinction affected Polar Regions, and whether the extinction was more severe in the High Arctic, the researchers will search for dinosaur and mammal fossils in the Brackett Basin. Previous work by the Geological Survey of Canada has found Cretaceous and Palaeocene rocks of the Summit Creek Formation along the Mackenzie, and to the south, in the Tertiary Hills. The area has never been explored for vertebrate fossils, but dinosaur bone has been found in the area (Art Sweet, pers. comm. 2010). Our goal is primarily to collect small fossils such as teeth, small bones, and scales. The project will look for vertebrate fossils in three locations in the Brackett Basin. These are (1) the Tertiary Hills, (2) the bank of the Mackenzie River, near Police Island, and (3) the confluence of the Brackett and Great Bear rivers. Fossils will be located by walking out eroded outcrop and looking for bones weathering from the rock. If productive localities are located, then the investigators will proceed first by surface collecting fossils that have washed out of the sediments. Second, the researcher will excavate fossiliferous sediments using hand tools and wash the sediment through fine screens to extract bones, teeth, and scales. Excavations will be small and shallow (involving no more than a few cubic meters of sediment). The location of each site will be recorded using a GPS and documented with photographs, and a small stake will be driven in to permit the location of these sites in the future. Dr. Thomas Hadlari will study the stratigraphy of the localities to determine the relative ages of the beds, and collect samples from volcanic ash beds for radiometric dating, to provide absolute dates for the sediments. Environmental impact will be minimal (the areas are already undergoing active erosion). Once collected, fossils will be transported to the Royal Tyrrell Museum for sorting, preparation, and study. The researchers plan on presenting the results of the study to the community upon return to Norman Wells. The fieldwork for this study will be conducted from July 28, 2010 to August 12, 2010.