This small lake in Canada could hold markers of the next geological era. Here's what's at the bottom

A small lake in southern Ontario is catching the eye of geologists worldwide who say it could offer clues to the world's current geological era.

Crawford Lake, located just outside of Milton, Ont., is named as one of the possible birthplaces of the "Golden Spike", which marks humanity's impact on the Earth and the next geological era scientists call "Anthropocene."

• Climate Barometer newsletter: Sign up to keep your finger on the climate pulse

Crawford has a significant depth of 24 metres, but has a small surface area, so the soils at the bottom of the clear lake never mix, allowing researchers to see visible differences in samples.

"You get these undisturbed layers, very much like if you were to cut down a tree or look at a tree stump you see these concentric rings," Michael Pisaric, professor of geography at Brock University, told CTV's Your Morning on Monday.

But unlike rings on a tree that tell the age, the sediment found in Crawford Lake shows history.

The waters of Crawford Lake in Milton, Ont., on Monday, July 10, 2023. (THE CANADIAN PRESS/Cole Burston)

"What we have been able to find at the bottom of Crawford Lake is a number of different indicators that clearly show that humans are having an impact on the environment, as well as on climate systems," Pisaric said.

Scientists have even tested samples from the lake that indicated plutonium from atomic bomb testing.

"When atomic bombs were detonated above ground back in the 1950s, it released plutonium into the atmosphere and that plutonium was spread throughout the world," he said. "Crawford Lake is nowhere near any of these test sites, yet, we find plutonium."

Researchers also found fly ash from steel mills in Hamilton, much closer to the lake.

Scientists are also detecting microplastics at the bottom of the lake, indicating how connected waterways are to humans.

"The next stage over the next year and hopefully by August of 2024, the International Commission on Stratigraphy will now debate whether or not the Anthropocene should be a new geologic epic in the geologic timescale," Pisaric said.

Crawford Lake is one of 12 locations being studied in the search for where and when the next geological era began.

 

To hear the full interview click the video at the top of this article.

With files from The Canadian Press.