A small lake in southern Ontario has captured the attention of geologists around the world as it may provide clues to the world’s current geological age.
Lake Crawford, just outside Milton, Ontario, has been cited as one of the possible birthplaces of the “Golden Spike,” which marks the impact of humans on Earth and the next geological epoch that scientists call the “Anthropocene.”
Although Crawford Lake is very deep at 24 meters, its small surface area prevents the clear lake bottom soil from mixing, allowing researchers to see visible differences in samples.
“You get these undisturbed layers, much like when you chop down a tree or look at a stump and you see concentric rings,” Brock University geography professor Michael Pisalick told CTV’s Your Morning on Monday.
But unlike tree rings, which tell the age of a tree, the sediments found in Crawford Lake show history.
The waters of Lake Crawford, Milton, Ontario, Monday, July 10, 2023. (THE CANADIAN PRESS/Cole Burston)
“What we’ve found at the bottom of Lake Crawford are a number of indicators that clearly indicate that humans are affecting not only the climate system, but also the environment,” Pisaric said.
Scientists tested samples taken from the lake and found plutonium from atomic bomb tests.
“When atomic bombs exploded on the ground in the 1950s, plutonium was released into the atmosphere and spread around the world,” he said. “Lake Crawford is nowhere near these sites, but we still found plutonium.”
Researchers also found fly ash from Hamilton’s steelworks, much closer to the lake.
Scientists have also detected microplastics in the bottom of lakes, showing how waterways are connected to humans.
“Next year, and hopefully by August 2024, the International Stratigraphic Commission will now discuss whether the Anthropocene should be the new geological epic on geological timescales,” Pisalic said.
Crawford Lake is one of 12 sites being studied to find out when and where the next geological epoch began.
To hear the full interview, click the video at the top of this article.
With files from Canadian Press.