Fifty-ton historic rock found in Saskatchewan, possible largest concretion on record

WATCH: What could be one of the largest geological rock findings in Sask. was recently found near Swift Current. Sierra D’Souza Butts has the story.

A unique rock formation found in southwest Saskatchewan could be one of the world’s largest concretions.

For almost 10 years, Brian and Janie Gillis have been excavating soil from their land located a few kilometres outside of Swift Current.

However, one morning workers dug out something that was not dirt.

“He just said, ‘You better come and look at the weird rock we dug out,’” Brian said.

The rock in question turned out to be a 50-ton concretion, which was formed about 80 million years ago.

“I was really excited because, to me, it looked like an egg ... but my family didn’t seem too excited,” shared Janie. “Then my husband went out for coffee with a geology friend of his, and that’s when the fire lit.”

After making phone calls and sending emails out to different curators, Janie said the geology department at the University of Saskatchewan confirmed the finding to be of significance with it being “two or three times larger” than ones found in the province’s record books.

“It comes out of really unlithified sediment and therefore it really is a cemented boulder inside unlithified or poorly lithified sediments and that’s really what a concretion is,” explained professor of geological sciences Brian Pratt.

“It really represents a geochemical precipitate in a well sphere or an oblong or even a bed sometimes.”

This is the first time Pratt has come across a concretion this large, stating findings he usually works with are at most half a metre wide — compared to this one measuring almost four metres.

Although some concretions may have fossils buried inside them, they are not all classified as fossils. Pratt pointed out a concretion is different from a fossil as it does not possess any living properties, but rather earthly elements.

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“For us in paleontology and geology, a fossil is essentially a petrified or preserved organism. A plant, an animal, a microbe, a dinosaur, a clam or a trilobite,” he said.

“… But, sometimes we say things like, ‘This is a fossil concretion,’ and when we say that, we’re really meaning that it’s old. It’s a geological phenomenon, not an archeological thing, but a geological thing."

A small pre-cracked portion of the rock was collected by Pratt and two students from the university for further examination.

“We’ll put certain acids on top and see if it’s reactive. We’ll probably have a what’s called ‘a thin section’ made, and that’s where we glue a piece down onto a glass,” he explained.

“Then we grind that down so you can see through it. Then under a special microscope, we can tell what kind of minerals we got.”

Now being sent into a lab for testing, the Gillis family is looking forward to its origin, adding they hope it can be used for educational purposes in the future and stored somewhere safe.

“I guess my biggest fear is that it’s in a spot somewhere where it will be vandalized, where someone is going to walk by with a can of spray paint and wreck it for others,” said Brian.

“It’s such a wonderful diversion, to be able to see this and know that it’s something bigger than us,” added Janie.

“It’s for us to enjoy and to take it to an educational level for kids.”