Researchers Discover New Impact Crater in the Arctic
- Research Communications
University of Saskatchewan
August 07, 2012
Researchers discover new impact crater in the Arctic
Researchers from the University of Saskatchewan and the Geological Survey of
Canada (GSC) have discovered a massive meteor impact from millions of years
ago in Canada's western Arctic.
Located on the northwestern part of Victoria Island, the impact crater, or
astrobleme, is about 25 km wide and is Canada's 30th known meteorite impact
"It's another piece of the cosmic Earth puzzle," explained U of S geology
professor Brian Pratt, who made the discovery with GSC colleague Keith
Dewing. "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."
The researchers discovered the crater two summers ago while exploring the
area by helicopter for the Natural Resources Canada (NRCan) Geo-Mapping for
Energy and Minerals program, and it took two years to properly assemble the
geological maps and submit their article for publication. Pratt and Dewing
named the new discovery the Prince Albert impact crater after the peninsula
where it is situated.
And while there is no way to pinpoint the exact timing of the impact,
evidence suggests the crater is younger than about 350 million years but
older than about 130 million years. One of the questions asked of Pratt is
how could something this large lay undiscovered for so long.
"Several geologists visited that area in the '60s and '70s," said Pratt. "It
was those old industry reports of steeply tilted strata, unusual in the
western Arctic, that had us intrigued. Unless you recognized the telltale
clues, you wouldn't know what you were looking at. You might see a bunch of
broken rocks and wonder how they got there, but we found abundant shatter
cones. These are radiating crack surfaces up to a metre in size that are
formed from the enormous amount of energy created when a meteorite slams
into the Earth's crust. Our map showed that the feature is circular which is
characteristic of impact craters. It's an exciting discovery."
There are at least 160 known meteorite impact features on Earth. Because of
the extent of ocean coverage, the effects of weathering and erosion, and the
dynamic nature of plate tectonics, Pratt said geologists believe many more
meteorites must have hit the Earth but there is now no trace of them.
For maps and additional photos, visit the U of S Flickr gallery