Mackenzie River Expedition

The main thrust of my current research is examining the end-Cretaceous mass extinction. 65 million years ago, a massive asteroid crashed into the Yucatan Peninsula, leaving a crater more than 100 miles wide. Vast quantities of molten and vaporized rock were blasted into the high atmosphere, resulting in a period of cold and darkness. A host of other apocalyptic events probably coincided- sulfate droplets may have continued to block out sunlight even after the dust had settled; debris re-entering the atmosphere may have cooked much of the life on land; shockwaves and tsunamis would have killed anything in the immediate vicinity of the impact. The result was the most severe extinction in the past quarter-billion years, which wiped out upwards of 70% of all species on earth.

One of the few good terrestrial fossil records of this time period is in the Great Plains of western North America. Very little is known about how it happened in other parts of the world. With that in mind, I started scouring the literature for sites that preserved this critical interval. One of the few unexplored areas I found was located in the Arctic of Canada, just under the Arctic Circle. This site, in the Northwest Territories, along the Mackenzie River, has rocks deposited just before, and just after, the extinction.