HOUGHTON - Formed more than a billion years ago by rivers flowing through a giant prehistoric valley, Jacobsville sandstone has played an important role both in scientists' attempts to understand the Earth of more than a billion years ago and in the more recent history of the Copper Country.
The Carnegie Museum will host a reception and presentation at 6:30 p.m. tonight for its exhibit "Written in Stone: Exploring the Natural History of the Jacobsville Sandstone."
At 7 p.m., William Rose, professor emeritus of geological engineering and sciences at Michigan Technological University, will give a presentation entitled "Reading the Jacobsville Sandstone: What Does It Tell Us About Earth History?"
Garrett Neese/Daily Mining Gazette
The Carnegie Museum will host a reception tonight for a new exhibit, “Written in Stone: Exploring the Natural History of the Jacobsville Sandstone.”
Rose also put together the exhibit, which includes displays of sandstone and a demonstration of the water processes that formed it, among other items.
"Bill Rose is a wealth of knowledge," said museum director Elise Nelson. "He loves rocks. He's very enthusiastic."
Borings taken near Munising reveal the Jacobsville sandstone formation dates back an estimated 1 billion to 1.8 billion years.
Rivers eroded mountains south and east of the Keweenaw, depositing the soils along the bed; the mix of iron with the earth's rising oxygen levels created the signature red color of the sandstone.
The geological processes creating the sandstone have remained constant, allowing scientists to reconstruct how they were created. Nelson pointed to sandstone specimens bearing the marks of ripples and mud cracks.
"That part of it is to show that you can get clues as to how it was formed," she said.
Another part shows sandstone from a core drilling 6,000 feet deep laid out along a timeline showing when the rock was formed and the conditions at that time.
Within the next couple of weeks, the museum will also receive some panels from an exhibit on local sandstone architecture that was on display this summer at the Keweenaw Heritage Center in Calumet.
If not for a gloomy weather forecast, Nelson would have scheduled Friday's presentation to be hosted outside, where the museum is displaying its latest item: a large sandstone boulder.
"It's a new piece to the museum's collection to complement the exhibit," Nelson said. "It'll stay. It's not going away."
Nelson said the exhibit has shed a new light for her on sandstone and its contribution to the area's geology.
"I'd always noticed the sandstone, but I'd never appreciated it," she said. "And this is something that distinguishes us from a lot of other small towns."