A team of University of Toronto geoscientists has made a discovery that could lead to a new understanding of ancient life on Earth and other planets: two billion-year-old water, believed to be the oldest H2O ever found, in a mine in Timmins, Ont.

"We thought, 'Wow,'" said Oliver Warr, a postdoctoral researcher and leader of the team.

"Everything about the water is brand new. We are seeing signals in all isotopes that we've identified so far that we've never seen anywhere else."

Dr. Oliver Warr, three kilometres underground in a mine in Timmins, Ont., led a team of researchers to extract two billion-year-old water. (Stable Isotope Lab, University of Toronto)

The findings stem from the researchers' earlier exploration of water in the same active copper, zinc and silver mine in 2013.

Geochemical analyses of the water at a depth of 2.4 kilometres showed it was a billion years old.

University of Toronto team members collected samples of water 2.4 kilometres underground in Timmins. (Barbara Sherwood Lollar/University of Toronto)

"Since then we've gone even deeper into the mine — three kilometres down. It's even more unique," said Warr by phone from San Francisco, where he and lead researcher Barbara Sherwood Lollar presented their discovery at the American Geophysical Union.

Calculating water's age

Warr said helium, argon, neon, krypton and xenon were found in the water. Those gases accumulate over time in the fluid trapped in rock fractures. Calculating how much of each gas has accumulated in the water helped the researchers figure out its age.

Sampling dissolved hydrogen and sulphate from water that is at least one billion years old. (G. Wunsch/University of Toronto)

"If water has been down there for up to two billion years, it can tell us something about the atmosphere at the time, or the state of the Earth, which previously we've not been able to get much insight into," Warr said.

Exotic chemical cocktail

The water is up to eight times saltier than seawater, and likely has some trace metals in it, he said.

"It won't kill you if you drank it, but it would taste absolutely disgusting,"

Although the ancient fluid isn't tasty, it may hold life.

"That could have great ramifications as to how life might exist at these kinds of depths, how it might survive," Warr said.

"It could start paving the way for understanding life on other planets as well."