By Jenn Watt
Published Sept. 25 2018
In groups of three hikers made their way down a slope of bedrock to the edge of a deep cylindrical hole. At the bottom sat three frogs covered in mud and leaves. Cellphones and cameras came out to capture the moment which was more about the creation of the holes than what was in them.
Perched on the edge of the rock was geologist and educator John Etches leader of the hike Finding the Harburn Wells part of this year’s Hike Haliburton offerings.
He had a long yellow rope at the ready with the unspoken implication that should one of the hikers fall in it wouldn’t be an easy task getting them back out.
The Harburn Wells are “one of the best examples of this kind of feature that you’ll see anywhere” Etches said in the parking lot as a 40 people congregated for the hike.
“It was worth the drive to Haliburton just for this” he said.
Maybe because falling into the well would result in injury or worse the Harburn Wells aren’t advertised and the path to get there includes very little signage. However during the festival Etches is able to safely take participants to see this feature which was created when Haliburton and the rest of Canada was buried under a glacier.
The theory is that the wells were created by whirlpools which took fine-grained boulders and whipped them around over the course of thousands of years burrowing down into the rock.
Etches illustrates the effect with a small rock in the bottom of his translucent water bottle. He spins it around and the rock knocks along the bottom.
“If I did this for two years what would happen to my Nalgene bottle?” he asks.
“There’d be a hole in the bottom” comes a response from the group.
In a similar fashion as the glaciers were melting a stone (or a few) would get caught up in the whirlpools slowly boring a hole in the bedrock.
Etches asked the group to imagine the entire region under two kilometres of ice. As the glacier moved it would scrape the landscape he said moving boulders along with it and exposing rock outcroppings that had been formed deep in the earth’s crust.
Etches said in the last million years it’s thought there were at least four glaciers covering Canada at different times.
Glaciers rip and scrape the landscape removing evidence from the glacier that came before.
Except he said in the case of one of the Harburn Wells.
A large well can be found on the side of a rock outcropping but rather than a contained cup shape it is in relief – broken open.
By deduction Etches said this means that during one glacial period a whirlpool was created which made this large well over thousands of years. And then a second glacier was needed to rip it open.
“That is devastatingly amazing” he said adding later: “This may be the only time you through deduction … ever see a feature from a glaciation before the last one.”