NEGAUNEE - Professors from Michigan Tech University were in the area Thursday morning to collect a piece of ancient history.
Bill Rose, an MTU research professor specializing in volcanology, oversaw the removal of a boulder near the Marquette County Road 510 bridge that spans the Dead River. Scientists say the large rock has ties to a major meteor impact from nearly 2 billion years ago.
According to scientists, a more than six-mile-wide meteor struck the Earth at what is now Sudbury, Ontario, about 350 miles to the east of Marquette. The ensuing basin was 39 miles long and 19 miles wide.
Workers help to load an ancient boulder onto a flatbed truck Thursday near the Dead River in Negaunee Township. The rock is a relic that scientists say is connected to the second largest meteorite impact in the history of the Earth. The impact took place nearly 2 billion years ago in Sudbury, Ontario, more than 300 miles away from Marquette. (Journal photo by Matt Keiser)
Debris ended up more than 500 miles from Sudbury, and has been identified in Marquette County, L'Anse and Wakefield, among other areas.
"This records a period in ancient history that is very important, as far as the Earth is concerned," Rose said. "This was one of the last big impacts that happened on Earth and it happened at Sudbury. Even though we're miles and miles from Sudbury, there was a lot of debris that fell."
Rose said scientists had identified the unusual deposits long ago, but have only recently linked the collections to Sudbury. The material has been dubbed Sudbury impactite.
"The origin of the material has not been known until recently," he said. "We have a lot of geologic studies where rocks have been described but haven't been fully explained."
When the Marquette County Road Commission began work to construct the new bridge over the Dead River - the project was completed in 2010 - more of the impactite was exposed.
"When we were doing the Dead River bridge project, we had a lot of geologic people interested and asking about what we were going to be doing out there," Marquette County Road Commission Engineer-Manager Jim Iwanicki said. "I didn't realize the significance of what was there until Bill contacted us last week."
In addition to the impactite from near the Dead River, Rose and his crew collected iron ore boulders from Cliffs Natural Resources on Thursday.
The boulders will be returned to the Michigan Tech campus in Houghton, where they will be displayed in MTU's new Mining Boulder Garden. Rose said the boulders will be used as teaching resources.
Michigan Tech staff also will be working to design an interpretive sign, to be placed in the small park located near the Dead River bridge on CR 510 where a portion of the impactite is still exposed.
The land belongs to the road commission, but Negaunee Township is maintaining a small park - with a picnic area, a grill and parking space for a few vehicles - near the bridge.
"We've already set something up with Negaunee Township out there to showcase both the new and the old bridge," Iwanicki said. "(The sign) will bring a different type of person, looking at different types of things, out there. I think that's a win for everybody."
Kyle Whitney can be reached at 906-228-2500, ext. 250.