A new study may have answered a long-standing mystery, setting a rough date for the first known people in Canada’s oil and sands region. In a newly published paper, Professor Robin Woywitka of Edmonton’s MacEwan University says a combination of archeology and geology has revealed that people lived around Fort McMurray, Alta., at least 11,000 years ago and perhaps as early as 13,000 years ago. “People were in the Fort McMurray area very early on,” Woywitka said. “Fort McMurray has been a bond for millennia. It attracts people forever.” Scientists have long known that the area has a long human history. An archaeological site known as the Ancestral Quarry has yielded millions of artifacts since it was discovered there in the 1990s. But putting dates on them was difficult. Standard methods such as radiocarbon dating have been released. The region’s acidic soils destroy the organic materials on which these techniques depend. Sometimes, scientists can use sedimentary layers in the earth to date artifacts. But this area was so stable that there aren’t many places where sediments have been deposited. So Woywitka and his colleagues tried something new. They obtained satellite maps that revealed the topography of the surface precisely within a few square meters. They used this information to find locations where sedimentation was most likely to have occurred and selected five of them—one of them at the Ancestral Quarry. Sediments from these sites were dated using a technique called infrared stimulated luminescence. This technique takes advantage of the fact that sand grains collect tiny radioactive particles in their pores. These particles change 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. This 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, give or take a millennium. “It has more uncertainty than radiocarbon dating, but it’s better than nothing,” Woywitka said. The findings put these first humans at the beginning when this part of the world became habitable. The first inhabitants would have moved there within a few centuries of the catastrophic flood that drained glacial Lake Agassiz, a vast inland sea that once covered almost all of present-day Manitoba and half of present-day Ontario. The date is not too long after humans first came to North America, which most archaeologists believe happened about 16,000 years ago. They would have found a landscape far removed from the lush boreal forests and saturated wetlands that now cover much of northern Alberta. “Humans are dealing with a very different environment than what we see today — open, dry, cold,” Woywitka said. “Probably tundra or grassland.” They were probably hunting bison, Woywitka said. Other than that, little can be said. “Whether they came from the north or the south, we don’t know.” Despite the proliferation of objects, scientists cannot fit them properly into the cultural tool kits of other prehistoric people. The presence of material from other parts of the continent suggests trade networks with other regions, but little is known. One thing can be said. Woywitka points out that the flood that drained the Agassiz exposed both the good tool-making stone that drew people to the area and the oil sands, which have attracted thousands of modern residents. “People came before 13,000 to get these things,” he said. “We’re going to Fort McMurray today for resources.” We have a weekly Western Canada newsletter written by our BC and Alberta bureau chiefs, providing a comprehensive package of the news you need to know about the region and its position on the issues facing Canada. Sign up today. This content appears as provided to The Globe by the original wire service. It has not been edited by Globe staff.
