It was early morning on the Coppermine River in Nunavut, Canada. A gentle mist rose from the surface of the glassy water, the sun’s first pink rays sparkling in the moving current. In the distance, the gurgling sound of faster flowing water was punctuated by birds waking in the trees, dragonflies chasing the buzz of mosquitoes and black flies, and the soft sound of a paddle as it pushed through the water.
This past July eight geologists, four river guides, six canoes, eighteen paddles and a lot of gear (watertight barrels filled with food and tents) went on an inspiring scientific expedition — descending over 200 km of the remote Coppermine River by canoe from Dismal Lakes to Kugluktuk where the river enters the Arctic Ocean.
Rocks sculpted by the Coppermine River took us on a journey through 500 hundred million years of Earth history, starting over 1.5 billion years ago when the earliest multicellular life was beginning to emerge on Earth. Studying and sampling the rocks along the riverbanks, and hiking into the wilderness using drones to map the area, we were able to expand the history of early life on Earth.
We followed the route of George Douglas and August Sandberg (documented in the book Lands Forlorn), who explored this region in 1911-12 in search of the source of copper — nuggets of which could be found in the riverbed. They travelled up and down the Coppermine River by canoe, dressed in animal skins and sourcing food from the land along the way. We followed their paddle strokes with our modern canoes, barrels of food and Gore-Tex clothing, examining the same rocks, this time in search of the story of life.
This is the edge of the polar tundra environment of Arctic Canada, the final flanks of the boreal forest. Adrian, our Inuit wildlife monitor (there to make sure we don’t have any unwanted encounters with grizzly bears), points out the blueberry bushes and caribou tracks. Unfortunately, it’s late July and the blueberries aren’t out for a few weeks but the mosquitoes sure are.
We are about 80km southwest of the Inuit settlement of Kugluktuk, that lies on the Arctic coast and will be the end point to our 200-km lake and river journey. The vegetation is declining as we move north, though the wildlife isn’t. We are rewarded with sightings of bald eagles, grizzly bears, wolves, muskox and even golden eagles as we move north. It’s the rocks we are here for though, and in this part of Canada it’s a hike across the boggy tundra to reach the rocky outcrops.
From the top of a nearby mountain, escarpment after escarpment can be seen exposing cliffs of ancient sedimentary rock that have been tilted by tectonic movement and can now be seen making up the landscape of vast areas of northern Canada. Each layer a time capsule of marine conditions over a billion years ago.
We are on the lookout for some of the world’s oldest fossils, microscopic fossils of early eukaryotes (an organism whose cells have a nucleus containing DNA and other organelles enclosed within membranes). Corentin Loron, one of the geologists on the trip, is hunting for fossil species that are new to science: “What’s exciting is finding out how and when life diversified, what the world looked liked a billion years ago, what was living back then,” he says.
This is the first part of our journey looking at a time when life on Earth began to increase in size and complexity. We paddled east through the three Dismal Lakes (beautiful but dismal weather would be a better description) to the Kendall River, which then joins the Coppermine River.
Douglas and Sandberg got through the lakes in two days. It took us nearly double that time, but we blame the weather for that. We even sailed down one of the lakes when the wind was behind us — with a makeshift sail made from a tarp, spare paddles and duct tape — but it still took us longer!
Each night we arrive at a new camp, and the first priority is getting a shelter up. In our modern world of cities, we take for granted a roof over our heads. In the wilderness you know only too well the importance of shelter; it can be the difference between life and death. Up here the weather changes in a heartbeat, from hot sun to freezing wind and rain.
The second priority, of course, is food! We brought in our food with us, everything from cereal and fruit to meat and vegetables – as long as it will keep for a month (most of the food we are eating by the end is dried). As we eat through the food, usually the canoes would get lighter. But we are geologists and we replace food with rocks, filling our barrels with samples that will go home to labs around the world.
Along the Kendall River the landscape drastically changes — layers of dark volcanic rocks, lava flows from a huge volcanic event, overtake layers of the life-bearing sedimentary rocks we studied at Dismal Lakes.
This is known as the Mackenzie volcanic event and the scale of it is huge. Similar to the Columbia River flood basalts, evidence from the ancient eruptions here can be found over 2,000 km away in southern Canada. Early studies found about 150 lava flows with a total thickness of 3 km — and we sampled nearly all of them.
Eruptions of this scale have a massive impact on the Earth’s climate and life systems, causing huge extinction events like the one that wiped out the dinosaurs. We sampled these rocks to find out what this event did to life at the time and how long these eruptions lasted.
Once the samples are back in the lab and analysed we will get a sense of how the planet reacted to such a major outpouring of magma. Volcanic eruptions release huge amount of carbon dioxide and other gases into the atmosphere, drastically changing the planet’s climate and affecting life. We could certainly see the huge impact it had on the stunning landscape around us, with layers and layers of dark black rock dominating the skyline.
As the water kindly moves us further down the Coppermine River we come across the rocks that overlie the lava flows and discover whether life made it through such a huge volcanic event, completing our story of this strange time period over a billion years ago.
The 12-member expedition was led by Geological Survey of Canada scientist, Dr Rob Rainbird with a team of Canadian and international scientists. National Geographic and BBC photographer, writer, and geologist Dr Vivien Cumming documented the expedition north of the Arctic Circle.
Vivien Cumming will be posting a series of blogs on National Geographic Voices starting here: https://voices.nationalgeographic.org/2017/08/24/exploring-earths-wildest-places-to-journey-back-in-time/
You can read more about the expedition here: http://science.gc.ca/eic/site/063.nsf/eng/h_97409.html