EDMONTON – New research may have answered a long-standing mystery by putting a rough date on the first known humans in Canada’s oil sands region.
EDMONTON – New research may have answered a long-standing mystery by putting a rough date on the first known humans in Canada’s oil sands region.
In a recently published paper, Professor Robin Woywitka of Edmonton’s MacEwan University says a combination of archeology and geology has revealed that people were living around Fort McMurray, Alta., at least 11,000 years ago and perhaps 13,000 years ago .
“People were in the Fort McMurray area very early,” Woywitka said.
“Fort McMurray has been a nexus for millennia. It has drawn people forever.”
Scientists have long known that the region has a long human history. An archaeological site known as the Ancestors’ Quarry has yielded millions of artifacts since it was discovered there in the 1990s.
But putting dates on them has been difficult.
Standard methods such as radiocarbon dating are out. The acidic soils of the area destroy the organic materials on which these techniques depend.
Sometimes scientists can use sedimentary layers in the earth to date artifacts. But this area has been so stable that there are not many places where sediments have been deposited.
So Woywitka and his colleagues tried something new.
They took satellite maps that revealed the topography of the surface to a precision of a few square meters. They used this information to find places where sedimentation was most likely to have occurred and selected five of them, one of them at the Ancestors Quarry.
The sediments at these sites were dated using a technique called infrared-stimulated luminescence.
This technique takes advantage of the fact that grains of sand collect small radioactive particles in their pores. These particles deteriorate at a known rate when exposed to light. So the longer they are buried, the more particles there will be.
Infrared light causes these particles to release energy. It can then be measured to reveal when the host sand grains were buried, along with the stone tools buried next to them.
In this case, the answer was 12,000 years, a millennium.
“It has more uncertainty than radiocarbon dating, but it’s better than nothing,” Woywitka said.
The findings placed these first people right at the beginning of when that part of the world became habitable. The first inhabitants would have moved there a few centuries after the catastrophic flood that drained glacial Lake Agassiz, a vast inland sea that once covered almost all of what is now Manitoba and half of present-day Ontario .
The date is not long after humans first arrived in North America, which most archaeologists believe was about 16,000 years ago.
They would have found a landscape far removed from the lush boreal forests and abundant wetlands that now cover much of northern Alberta.
“People have a very different environment than we see today: open, dry, cold,” Woywitka said. “Probably tundra-y or grassland.”
They probably hunted bison, Woywitka said. Beyond that, little can be said.
“Whether they came from the north or the south, we don’t know.”
Despite the proliferation of artifacts, scientists cannot fit them neatly into the cultural tools of other prehistoric people. The presence of materials from other parts of the continent suggests trade networks with other areas, but little is known about them.
One thing can be said.
Woywitka notes that the flood that drained Agassiz exposed both the fine tool-making stone that drew people to the area and the oil sands, which have attracted thousands of residents today.
“People came 13,000 ago to get these things,” he said. “We’re going to Fort McMurray today to look for resources.”
This report by The Canadian Press was first published on July 31, 2022.
— Follow Bob Weber on Twitter at @row1960
Bob Weber, The Canadian Press