bloor construction boulder

1.5 billion year old rock unearthed during Toronto construction

Construction on major roads can be infuriating in a city as large as Toronto, to say the least — but every once in a while all that jackhammering produces a gem.

The ongoing replacement of a 142-year-old watermain along Bloor Street West between Bathurst Street and Spadina Avenue recently has unearthed an architectural relic, according to local experts, in the form of a huge ol' rock.

"Estimated to be between 1.2 and 1.5 billion years old, a 2,000-kg granite boulder has been unearthed at Major and Bloor streets during the construction of a new BIA sponsored parkette," announced the Bloor Annex Business Improvement Association on Twitter Wednesday afternoon.

"U of T expert Professor Joseph Desloges says this rock likely traveled here from Georgian Bay lodged in an iceberg between 12-15,000 years ago when Lake Iroquois dominated the landscape," the BIA continued. "As the iceberg melted the rock fell approx 150 feet to the lake bed now called the Annex."

Interestingly enough, all four of the new parkettes being installed along Bloor Street during the watermain replacement project are set to feature public benches sculpted from granite.

Material for those pieces was sourced months ago from salvaged stone at a quarry, according to the Toronto-based urban design firm DTAH. They're being sculptued by artist Robert Cram and integrating into the new DTAH-designed parkettes as art and seating.

When asked if the newy-unearthed boulder could be incorporated into one of the new parkettes, City Councillor Mike Layton told a community resident that it's up to the BIA.

"I will check with their plans," he said on Twitter. "If not, lots of space to pop it in a local park."

Lead photo by

Steven Laurie


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