Skip to comments.Meteorite impact debris found in Minn. (from Sudbury impact in Canada, 1.85B Years ago)
Posted on 07/16/2007 9:41:55 AM PDT by NormsRevenge
GRAND MARAIS, Minn. - A forest fire has led to a chance discovery of debris from the impact of a meteorite 1.85 billion years ago, more than 450 miles away at Sudbury, Ontario.
Geologists had scheduled a field trip in May along the Gunflint Trail in northeastern Minnesota, but most areas they wanted to explore were closed because of a wildfire that charred more than 118 square miles.
Geologist Mark Jirsa of the Minnesota Geological Survey went up the trail to scout new locations and, in a spot he had never visited before, stumbled across debris now linked to the Sudbury impact.
That impact created a crater more than 150 miles across, scattering rock and dust over nearly a million square miles.
"It's fairly dark rock," Jirsa said. "They look like concrete, but in this concrete you would throw pieces of rock of all sizes and shapes and in all possible orientations."
Previously, material thrown out by the impact had been found as far from Sudbury as Hibbing, about 125 miles farther to the southwest from Grand Marais. However, the tiny fragments at Hibbing were found in core samples from 800 to 1,000 feet below the surface, while the rock layer containing larger chunks at the Gunflint site lies exposed.
"I think the excitement for the people of Minnesota is that we are one place in the world where you can see evidence of an ancient meteorite impact," said University of Minnesota geology professor emeritus Paul Weiblen, who is studying the debris. "This is the second-oldest and second-largest impact crater in the world."
Can’t be. The earth is only 9,000 years old. /sarcasm
Thought it was 6,000 but made to look several billion...
Minnesota - #2 in meteor fragments over 1 billion years old. Congrats.
Looks to be in pretty good shape for nearly two billion years old. Even figuring 1.5 billion, It should have seen 1500 ice ages, no?
A billion here, a billion there — pretty soon you’re talking about a long time.
My first thought is that it must have been remnants of Mondale’s presidential run... 8^)
Disclaimer: I am not a geologist, a cosmologist or a climatologist, but I am very familiar with the Sudbury Crater as a result of morons commenting on the "toxic" nickel used in hybrid car batteries...
First of all, the age of 1.85 billion years for the impact introduces ridiculously complex factors into the find.
At least three glaciations took place affecting the entire area since then. Finding evidence of the impact there is meaningless. How far did the glaciers move the stuff? Was it in a terminal morraine?
Shouldn't the fragments be long buried?
Could these be evidence of secondary impacts (calving) not subject to glaciation?
Who's on first?
Note: this topic is from 2007. Nobody tells me nothin'. Thanks NormsRevenge.
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Yeah, now the impact was 1,850,000,004 years ago. Makes a ton of difference. :)
The little fellow is happy to have avoided ending up in a Prius battery.