IOWA CITY — Beneath the hills and valleys, cliffs and woodlands that bejewel the landscape around Duluth, Minn., scientists have discovered a figurative gold mine in the form of actual mineral mining potential — and Iowa researchers believe something at least as valuable could be hiding in this state’s northeast corner.
The prospect has University of Iowa-based geologists consumed with answering the question of whether an underground formation spanning 10 Iowa counties is similar to the geologic complex beneath the Duluth area — which analysts say contains minerals worth up to $1 trillion.
If the UI-based Iowa Geological Survey finds the Northeast Iowa Formation is roughly the same age as its Minnesotan counterpart, researchers believe the Hawkeye state could be harboring economically valuable deposits of copper, nickel, platinum and other minerals.
“The more data we collect, the better picture we can paint,” said Ryan Clark, a geologist with the Iowa Geological Survey. “If it’s promising, then a mineral company could come in and do its own testing.”
Researchers are basing their optimism on analyses by the U.S. Geological Survey, which has been assessing the country’s mineral resources in response to rising global demand for the materials used in industrial, medical and technology products.
The government’s interest in the billion-year-old Midcontinent Rift System — a formation stretching from Kansas to Michigan — led it to Iowa, where airborne assessments produced evidence of economically valuable geology.
Specifically, USGS findings signaled underlying geology in the form of a horse shoe-shaped complex in Decorah and similar rings in the area of Elkader, Manchester and Vinton.
“There are a lot of minerals up there,” Clark said. “From what I’ve been told by the USGS, if one or a few of these anomalies do end up being similar to the Duluth Complex, what we have is larger.
“It could be a significant find, if in fact it turns out,” he said. “But we are still a long way from proving that.”
‘Needle in a haystack’
Right now, only one window into the region’s mystery mineral prospects exists — a core drilled near Elkader by a mineral company in the 1960s. UI researchers are pulling rocks from that core and testing the age of minerals found within.
“We have used modern techniques to try to find a needle in a haystack,” Clark said, noting colleagues “have been going through with fine-toothed combs for anything we can find that could possible yield an age.”
The Iowa Geological Survey could seek funding to drill a second core for further research in the hilly region. The USGS had a plan to do just that before its budget was cut last year.
“We are sitting and waiting to see if the funding is restored or not,” Clark said.
If it is, Iowa could pursue financing for underground monitoring. If it’s not, the state could take the helm in creating a new core, or a mineral company could come in and pay to drill.
“But their purpose might be different from ours,” Clark said. “Our job is to get a better understanding of what the whole formation is.”
Should Iowa geologists achieve adequate access to the untapped trove, Clark said, “I really believe we would get the information of what this rock formation is, and prove that it’s similar to the Duluth Complex.”
Public vs. private
One known difference between the Duluth and Northeast Iowa complexes is ownership of the land under them.
Much of the Duluth Complex is on public property, managed by the state’s Department of Natural Resources.
That includes “School Trust Lands,” which is property the federal government granted Minnesota at statehood for schools, according to Minnesota’s DNR. The state today boasts 2.5 million acres of School Trust Lands, along with another 1 million acres of severed mineral rights, which occurs when the state sells the land but retains the rights to subsurface materials.
For revenue generated from the School Trust Lands, Minnesota established a permanent school fund for the benefit of K-12 public schools, according to Peter Clevenstine, assistant director of minerals in Minnesota’s Division of Lands and Minerals.
Leasing land to mining companies has produced hundreds of millions in revenue for the K-12 and public university trusts, according to Clevenstine.
Although the mineral-rich public property has been known about for decades, Minnesota only now is pursuing its mining potential.
“We have three deposits of nonferrous metals that are not producing,” he said. “If they do start producing, we could put another $2 billion into the permanent school trusts for K-12 education.”
Mining operations must complete environmental reviews and jump through permitting hoops before that can happen. But one company is close to meeting its requirements — recently landing a permit from the state and waiting on its last from the federal government, according to Clevenstine.
“We have the opportunity now in the next 30 years from three operations to have $2 billion added to that trust,” he said.
Iowa’s situation is different. Most of its underground potential sits under privately-owned land, according to Clark. That means any company — or state or government entity, for that matter — must negotiate with individual landowners over access and royalties.
“The lack of public land has been an issue,” Clark said.
He’s found a defunct limestone quarry that owns land in the target area and is willing to provide access for research.
“That is the closest thing I’ve found to being able to drill this next research hole,” Clark said. “If it does go to the exploration phase, where a company can come in, they would have to enter into an agreement with whoever owns the land.”
That commercializing side is where the economic potential for Iowa lies. Arriving mineral companies would create jobs and generate revenue through taxes, fees and the like.
But Clark and Clevenstine stressed this work requires care in protecting the land while also exploring the potential benefits.
“It’s our job to balance and protect those natural resources and also provide economic opportunities for the wide use of these resources,” Clevenstine said.
So long as Iowa maintains that bilateral view, Sen. Dan Zumbach, R-Ryan, said he’s OK with further research and even exploration into the hidden potential of the region he represents.
“I think it’s important that no matter how you use your resources, you need to be thoughtful,” he said. “It’s always exciting to see new potential for job opportunities, and you need to look at those things. But you always want to be respectful to the environmental as well.”