Above: Duluth Metals Senior Vice President of Exploration Dean Peterson, Ph.D., stands on a beach at the Kawishiwi Lake Campground, talking to the press. Left: Sulfide-bearing bedrock outcroppings such as this that have been weathered from exposure to air and water can be found in spots throughout the Duluth Complex – in and around the Boundary Waters Canoe Area Wilderness, along the Gunflint corridor and along Highway 61. “The chemistry of the nearby streams indicates that natural weathering is an ongoing process,” said Duluth Metals Senior Geologist Phil Larson, Ph.D. “The gravelly material surrounding the boulder…forms from the breakdown of coarse crystalline rocks by chemical weathering.”
Mining is sometimes referred to as an example of a boom or bust economy. Worldwide, mines come and go. But in northeastern Minnesota, fourth-generation iron miners have grandchildren who will follow in their footsteps because of the discovery of a huge deposit of gold, copper, nickel, platinum, and palladium. A lot has changed in how the mining will be done, however. According to Mining Minnesota, a coalition committed to “sustainable and environmentally responsible nonferrous (non-iron) mining development,” today’s mine is “not your grandfather’s mining operation.”
Two geologists employed by Duluth Metals, Phil Larson, Ph.D., and Dean Peterson, Ph.D., have been conducting research on land Twin Metals is hoping to mine underground near Babbitt and Ely. Twin Metals is exploring a location known as the Maturi site and has two others in mind— Spruce Road and Birch Lake—for future development.
This fall, Larson and Peterson held a tour of the company’s potential mining sites. In regard to skeptics who might expect bias in their work or their statements, Peterson said their professional ethical code is paramount. “We have to be, actually, totally honest,” he said.
Twin Metals, created in 2010, is owned by Duluth Metals and Anafagasta. The company has leased mineral rights from the federal government, the state of Minnesota, and private landowners. The company hopes to mine 1.65 billion tons of minerals underneath 32,000 acres of land. Duluth Metals was formed in 2005, and this is its first project.
Peterson recognized that Anafagasta has been criticized for its mining practices in Chile. Those problems, he said, are totally related to a lack of water to keep sulfide minerals from reaching air, where a chemical reaction takes place to create acid rock drainage. Larsen said that when sulfide-bearing rocks are exposed to both air and water, acid is created, but when the water table is as high as it is in northeastern Minnesota, air cannot reach those rocks.
According to Peterson, acid drainage became a problem from mining operations in the mountains of Colorado when rainwater percolated from the mountaintops through the rocks and into streams. He said some of this would happen with PolyMet’s proposed aboveground mining operation, but it would stop when the stockpiles were submerged under water.
In regard to the possibility of water around mined areas leaching through the bedrock deep under the ground and into streams over the course of time, Larson said, “These types of deposits actually have a tremendous acid-buffering capacity.” Rain itself is slightly acidic, he said. Some of this area’s rocks, however, are alkaline and temper the acid. In areas out west where copper mines turned the hills into honeycombs, the dominant mineral is pyrite, which is very acidic, but this area has no pyrite.
“Our goal is to get all of the sulfide minerals out of the rock because that’s where all the value is,” said Peterson.
Twin Metals anticipates mining 50-80 tons a day, and Polymet anticipates mining 32,000 tons a day, Peterson said. Twin Metals’ ore body—approximately 200 feet thick, the height of a 20-story building— has been tracked from the surface of the ground to a depth of 4,000 feet, but it goes deeper. “It’s astounding, actually,” said Peterson.
Twin Metals’ deposits have no gradient that would drive the flow of water up to the level of ground water, Larson said. The proposed Twin Metals project is in the Boundary Waters Canoe Area Wilderness and Hudson Bay watershed. If there was a lot of water where the minerals lie, however, they could not mine there. “Nobody’s figured out how to mine underground under water,” he said.
In regard to criticism from environmentalists, Peterson said that he loves the wilderness and has probably spent more time sleeping in a tent in the wilderness than most people. “We clearly know what the issues are, and as a professional geologist, it’s our job to know these issues,” he said. The science that goes into interpreting core sample is very complex and the people who do it have to understand a great deal about the earth. They respect the earth and do everything possible to ensure safety to the environment, he said. “We’re born and bred Minnesotans here.”
Long life, health, leisure time, education, health— are dependent on our ability to mine metals, Larson said. We can decide not to mine like we can decide not to farm or drink water, he said. “It’s not a yes or no thing. It’s how do we do this in the best way possible.”
Mining companies are in business to make money, Peterson said. Insurance companies and banks oversee mining projects to make sure they are not going to lose money from lawsuits over environmental degradation.
Many years can go by between investing in a mine and making money on it, Larson said. Investors are careful about where they put their money. Peterson said Duluth Metals is a publicly owned Canadian company, and the Toronto stock exchange has stringent requirements for what is traded there. The fact that the Polymet Environmental Impact Statement was scrutinized shows that the process of environmental oversight is working, he said.
When he started in the field 20 years ago, Larson said, environmental opposition was not a factor. Now they have to be able to explain to the public what is being done and how the environment will be protected. Environmental controls are built right into projects now and are in the financial plans.
A personal note
In the comment section following a July 2012 Duluth Reader article by Carla Arneson entitled PolyMet, Twin Metals, and credibility deficit, Duluth Metals Geologist Phil Larson wrote, “Hi, Carla, I saw my name pop up in an opinion column you wrote last week for the Reader. Frankly, I’m a little bit flattered by the assertion that I am at the beating heart of a vast international conspiracy to deceive and defraud the citizens of Minnesota. But more than that, I’m hurt by the insinuation that I am engaged in purposely deceptive activities in my professional life, activities intended to deceive and harm my family, friends, and neighbors.
“…It’s important to remember that mining and exploration professionals are not always able to speak freely about all aspects of what they are doing. We are required to comply with a host of disclosure regulations designed to prevent insider trading and protect the investing public. If we violate these rules, we can be fined or even go to jail. However, when it comes to our on-the-ground, day-today activities, rest assured that every aspect has undergone environmental review and is in the public record. We are more than happy to discuss with you, or anyone, our ongoing permitted activities.
“If you’d like, let’s sit down over a beverage of your choice the next time I make it up to Ely. We can talk about the things we think are important – trees, water, fresh air, children. I’ll share with you what it means to be a fifth-generation northeastern Minnesotan, and you can tell the story to me of how you came to fall in love with this beautiful land my family has called home for generations. And when we’re done talking about the important things in life, we can talk about our different visions for the future of northeastern Minnesota. I’m certain that when we’re done, we’ll find we have more in common than we think and will be on better terms as we all move forward with what must necessarily be a conversation aimed at forging a consensus about the future.”
This is the last in a fourpart series on mining in the Northland.
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