DULUTH — By any method that the Duluth Complex is rated, several experts say the nonferrous potential embedded in the geologic region makes it the largest mineral deposits ever.
The complex stretches from near Duluth northeast and north to near the Canadian border. Copper, nickel and precious metals group elements (platinum-palladium) are a major part of minerals in the complex. Two companies, PolyMet and Twin Metals, are preparing for production or getting near that goal after environmental review and permits are obtained. More companies are busy exploring other locations for deposits.
“I have no doubt this will prove to be the biggest undeveloped deposit,” said Jim Miller, a geology professor at the University of Minnesota Duluth.
Another researcher, George Hudak, minerals division director at the Natural Resources Research Institute in Duluth, agreed. “This is the largest untapped copper-nickel deposit in the world,” he said.