Aerial view of steeply tilted sedimentary rock strata, indicating meteorite impact. Researchers found this massive crater, about 25 km wide, on Victoria Island in the Canadian Arctic. They say it was caused by a meteorite millions of years ago. (photo: Brian Pratt)

Researchers at the University of Saskatchewan have discovered a massive crater in the Canadian Arctic caused by a meteorite millions of years ago.

The depression is about 25 km wide, located on the northwestern part of Victoria Island, which sits north of Nunavut and the Northwest Territories, along part of the Northwest Passage.

U of S geologist Brian Pratt and Keith Dewing, of the Geological Survey of Canada, have been working to map the crater ever since they discovered it two years ago while exploring the area by helicopter.

They saw "shatter cones" - large, radiating cracks formed by the impact of a meteorite slamming into the Earth.

"Unless you recognized the telltale clues, you wouldn't know what you were looking at," Pratt said in a statement. "You might see a bunch of broken rocks and wonder how they got there."

The researchers also noted the crater is characteristically circular.

And while there is no way to pinpoint exactly when the meteorite hit, Pratt and Dewing said evidence suggests it was about 130 million to 350 million years ago.

"It's another piece of the cosmic Earth puzzle," Pratt said. "Impact craters like this give us clues into how the Earth's crust is recycled and the speed of erosion, and may be implicated in episodes of widespread extinction of animals in the geological past."