A Trip Back In Time
Our Twin Otter judders upon landing on the choppy surface of one of the vast Dismal Lakes and we sit in silence, unable to talk over the noise of the engines. In this fleeting moment, our group of geologists and river guides contemplate the month ahead of us.
We’re at the start of an ambitious scientific expedition: to descend much of the Coppermine River by canoe, paddling more than 200 kilometres from Dismal Lakes to Kugluktuk, Nunavut, where the river enters the Arctic Ocean. It’s a journey that will also take us through hundreds of millions of years of Earth history, when early multi-cellular life was beginning to emerge, starting more than 1.5 billion years ago. We’re here to sample and study the rocks along the riverbanks to search for signs of early life and the possible catastrophic events that affected its evolution.
The Geological Survey of Canada organized the trip as part of its 175th anniversary. The plan had been in the works for years. Rob Rainbird, our group’s leader and a seasoned field geologist in his early-60s, had been dreaming of paddling the Coppermine River since his first survey there in the early 1990s. He and his team have spent their careers mapping the geology of remote regions of Arctic Canada using helicopters and planes on tundra tires. But they longed for a different kind of expedition—one where the pace slowed and nature drove them through time.
Rainbird spent almost every summer of his career in remote Canada and he believed the geology surrounding the Coppermine could open up a world of new discoveries. It’s the only river in the region that reliably cuts through a continuous succession of rocks that record nearly 500 million years of Earth’s history. In no other location can you pass through time like this. It also crosses the record of a huge volcanic eruption, so big that evidence of it can be seen as far south as the Great Lakes. The record in the rocks, exposed in magnificent canyons, could tell us how this eruption affected climate and life.
There is a purpose to a river. It begins its life cutting a path through the easiest terrain. On this trip, the layers of rock it crossed would tell us a story about our planet.
The trip would follow the route taken by George Douglas and August Sandburg in 1911-12 and documented in Douglas’s book, Lands Forlorn. Copper nuggets had been discovered in the Coppermine River many years before and Douglas and Sandburg went in search of the source.
When I was invited to join the trip, I immersed myself in Douglas’s account of the river. He wrote with a calm and practical style given the challenges he faced. I admired his composure in the face of unpredictable weather, wildlife and access to food.
I would soon be struck by the many similar experiences we had, despite the obvious differences in our circumstances. We had satellite phones, GPS and lightweight equipment. We were here for a month; Douglas spent the better part of a year on the water. And our aims differed. Rather than a resource reward, we sought an academic one—insights that could help us better understand life on our planet.
Our Twin Otter finds a calm inlet and the props slow and stop. We disembark and with tundra to the north, and the final flanks of boreal forest in the distance to the south, all 12 of us form a chain and unload our canoes, equipment bags and the barrels of food that will keep us going for the next month. Meanwhile, the pilot stands on the front of one of the floats with his fishing rod, pulling out lake trout after lake trout. “Something to take home to my wife for supper,” he says.
We make our way up onto a flat area of ground suitable for a campsite and the mosquito onslaught begins. They bite through my Gore-tex pants and bug jacket. There’s no protection. You can quickly tell who has spent time here before. “Just ignore them and they will ignore you,” a veteran colleague tells me. This is the first of many lessons to come.
The first part of our journey takes us east through the three Dismal Lakes to the Kendall River that runs into the Coppermine. Douglas described the lakes as getting less and less dismal the further east you go. He got through the lakes in two days.
It takes us three. We paddle head on into the wind and the waves. On the last day, paddling through the night to avoid stormy weather, we see a mother grizzly and her three cubs playing on the shore. We arrive at the Kendall River at 2 a.m., beautiful under the midnight sun.
After the choppy Dismal Lakes, the gentle water of the Kendall is a welcome reprieve. Douglas felt the same way: “It was a blessed relief to shove out on that smooth swiftly flowing river and to leave all worries behind. It was no use to worry about anything now, all we had to do was to meet circumstances cheerfully and make the best of them.”
It’s sage advice. At our first big rapids, one of our six canoes gets turned around and goes down backwards. It’s a good warm up to what we are about to contend with on the Coppermine, which comes into view soon after. Suddenly, we’re grasped by the fast-flowing current. Paddling becomes steering, with the river doing all of the work. At the other side of the river, we set up camp.
At every stop, there’s a frenzy of excitement as we survey the geology to decide whether to sample the rocks. Hand lenses (a geologist’s magnifying glass, used to examine minerals in rocks), notebooks and binoculars are pulled out of bags as we fan out to look at rocks near and far. The river cuts a cross-section through layers of ancient sedimentary rock that have been gently tilted by tectonic compression. Just as the rocks that make up the Himalayas have been pushed together and tilted up to form mountains, these rocks underwent the same movement a billion years ago. They make up the landscape of vast areas of Northern Canada and the rocks we sample are a time capsule of marine conditions more than one billion years ago. “It’s one of the most exciting places to do geology in the world,” Rainbird says.
New information from this time period gives us a clearer picture of how our planet became habitable and favourable for complex life to evolve. We can find clues about how life might exist on other planets through a better understanding of how the only known life in the universe—ours, here on Earth—originated and the environments it lived in.
One of my colleagues, Corentin Loron, a PhD student from the University of Liège in Belgium, is hunting for fossil-rich layers in the rocks. He holds up a hard, dark rock called chert and explains that it contains microfossils—tiny single and multi-cellular organisms invisible to the naked eye—some of which may be species totally 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, over lunch.
Meals are another reminder of how different our expedition is from Douglas’s. He writes: “While at lunch we saw a flock of young geese gravely swimming down the river in a long line; they looked at our canoe awhile, then decided to turn back. We overtook them later on and murdered four of them with a little .22 pistol. But our needs were imperative, and those young geese gave us some of the most delicious stews I ever tasted.”
Lunch for us usually consists of items that keep well like sausage, cheese, apples, and trail mix. Occasionally, when time allows, there will be a nice pasta salad.
“This is the way to do geology,” Rainbird says as we paddle through a quiet and calm section of river, able to lie back and relax. We aren’t beholden to helicopter maintenance and weather schedules. We travel at a pace that allows for contemplation. Rainbird and his cohort can chew over the data, and observe and recognize patterns. The river takes us everywhere we need to go. We aren’t missing anything.
Halfway down the Coppermine River, the landscape drastically changes. The river becomes less forgiving and we are forced to traverse rapids in canoes now filled with rock samples. There’s Muskox Rapids, where a herd of muskoxen graze nearby; Sandstone Rapids, enclosed by layered cliffs of red sandstone; and Escape Rapids, where the exit is through a narrow gorge.
A canoe group follows us through the latter. They’re a hodge-podge of paddlers from all over Canada on a guided river trip. The rapids swallow one of their boats. We mount a rescue mission, with three groups recovering a canoe stuck upside down on a rock. Thankfully, the paddlers had already swum free.
Once everyone is safe and drying by a fire, we camp together on the edge of the cliffs overlooking the rapids. This canoe group is fascinated by the purpose of our journey and they pepper Rainbird with questions. He enthusiastically explains what exactly they have spent the last week paddling through. They tell us their trip is now more complete with an understanding of these rocks and suggest their guides employ some geologists in the future.
Geologists always have certain questions on their minds when examining layers of sedimentary rocks. What kind of environment were the sediments deposited in? When and how were they laid down? And under what climatic conditions? Was this layer of rock once a riverbed, the ocean floor or a glacier? Structures and minerals in the rocks reveal clues to how they were deposited. You can even tell the direction an ancient river flowed, just by looking at structures formed by the currents and imprinted in the rock.
The sandstones at Sandstone Rapids were deposited by another river more than a billion years ago. Further down the Coppermine, above the layer of sandstones, we reach lighter-coloured sandstones and dark mudstones that were deposited in a shallow marine environment. These rocks suggest the sea level must have risen, inundating the region with water. The mudstones contain small black flakes of organic-rich material, hinting that microfossils might be preserved.
The fossils we are looking for are broadly named Acritarchs, derived from the Greek words acritose, meaning confusing, and arch, meaning old. We really are looking at some old and confusing rocks. (Who says geologists don’t have a sense of humour?)
In the field, all we can do is take samples. We won’t see the fossils until we can use powerful microscopes back at a lab to examine them.
Our last night on the river is spent at Kugluk, or Bloody Falls—a spectacular set of rapids not suitable for canoes. Pools teem with Arctic char making their way upriver to spawn. We have been travelling for 26 days and have a long portage carrying barrels that were once full of food and are now full of rocks. We spend the night chatting with Kugluktuk residents out fishing. They show off their catch and laugh when we tell them we haven’t caught a char in a month on the river.
The next day, we pull out a tarp and sail our linked canoes down the last section of river, buffeted by favourable southerly winds. Entering Kugluktuk, the hamlet of 1,500 people at the mouth of the Coppermine River on the Arctic Ocean’s coast, we are warmly greeted by smiling children who have many questions about our time on this legendary river. We only have a day to clean and pack up our gear, but the people of Kugluktuk invite us into their homes for coffee whenever we walk past. (Rainbird returned to Kugluktuk later in the year to present an account of our trip to the community.)
I check my email after a glorious month without internet. Not much has happened. It’s as if time stood still. When Douglas returned home, the news was grim. “The loss of the Titanic was the news which made the greatest impression on us,” he writes.
The rocks we collected are pulled apart and analysed in labs all over the world. The results exceed even Rainbird’s expectations: we found exquisite microfossils that yield new evidence for diversification of early life on Earth, approximately 1.1 billion years ago. “The findings suggest that early species specialization was related to predation and that this change occurred at a much earlier time in Earth’s history than previously documented,” Rainbird says. “What this means is that things were a bit further along the evolutionary trail at that time than we originally thought—a time when it looked like very little was happening.”
Picture our early Earth, with massive volcanoes erupting and the land and sea seemingly devoid of life. We knew organisms existed at this time, but the complexity of the microorganisms we discovered, and the fact that they preyed on each other, are new.
The results from our trip change the way we look at an earlier time on our planet. The experience had already done that for me.