Going Underground

Dr. Ted Bornhorst
Dr. Ted Bornhorst, director of the A.E. Seaman Mineral Museum at Michigan Technological University.

Despite plummeting commodity prices and Michigan's declining population, mining is experiencing a resurgence in the Upper Peninsula.

Before the financial crash of 2008, the U.P. was set to explode economically with a tremendous increase in mining employment — new mining jobs at new mines — for the first time in decades. Cliffs Natural Resources announced plans to extend the life of the Empire Mine near Ishpeming six years beyond its original predicted close in 2010.

Field geologists
Field geologists (Cody Suits, Jason Evans, Joanne Scott) examine core samples in order to determine mineral content at the Kennecott Eagle Minerals Company in Marquette.

Though the company has stepped back from those plans based on a lack of global demand for steel, other natural resource firms are developing new mines. Kennecott Eagle Minerals Company, a subsidiary of Rio Tinto PLC, is set to begin mining a new mineral district in northern Marquette County rich with nickel and copper. There are also economic quantities of gold, platinum and palladium in the U.P.

Orvana Minerals Corporation is tentatively scheduled to begin construction on the Copperwood Mine in 2013.  It will be the first copper mine within the Gogebic Range of Wakefield, Mich., in more than a decade. Along the Wisconsin border, Aquila Resources' Back Forty Project is on track to mine a large zinc orebody near Stephenson. Numerous other companies, large and small, are actively exploring the U.P.

According to Dr. Ted Bornhorst, director of the A.E. Seaman Mineral Museum at Michigan Technological University and an expert in the field of economic geology, there are reasons those companies remain committed despite the news from Wall Street.

"If you go out into the market now or look on the Internet, you see that the metal prices have plummeted and yet Kennecott doesn't seem phased," Bornhorst said. "It's because the quality of that ore — the concentration of copper and nickel — is high enough where they still can make money."

Bill Williams, vice president of corporate development for Orvana Minerals Corporation, is equally optimistic about the future of mining in the U.P. Orvana is currently working on Copperwood, a large copper orebody that was originally discovered in the 1950s. Copperwood was reworked in the 1970s by Copper Range, which abandoned the orebody when it closed the White Pine mine in the 1990s.

"I've been through a couple of these (economic) cycles now," Williams said. "There is a clear timeline for making a mine. Ideally you do the planning, get the environmental work done, consider technical issues and do your engineering when the commodity price is down. We don't think (the price of copper) is going to go much lower and we believe it's eventually going to get higher."

Most of the delineation work has already been completed and the company is on a fast track. On Feb. 13, Orvana announced that historic and current core sampling efforts have shown that the stratiform copper deposit at Copperwood is "analogous to the mineralization exploited at the inactive White Pine mine."

This means that technological advances will be able to extract more copper from the deposit, once thought to be exhausted.

"The results from our new drilling and resampling of core from historical drilling confirm our belief that the results from the 1950s program are reliable," Williams said in a press release announcing the results of the sampling efforts. "We are now even more confident of the thickness and grade of the mineralization defined previously by historical drilling."



Some U.P. residents fear that increased mining will recreate environmental hazards from the past — toxic stamp sands, fly ash, "yellow boy" sludge and mercury-poisoned lakes and rivers.

The primary concern voiced by opponents to mining is the potential for acid rock drainage (ARD) from sulfide deposits. The process occurs when air, water and sulfides combine under certain conditions to create sulfuric acid.

Sulfide orebodies have been mined in Michigan for more than 100 years, but past mining practices with very limited regulation and oversight led to environmental damage in the early years of the industrial age.

"I am not opposed to mining," said Rep. Bart Stupak, D-Menominee, in response to the state Department of Environmental Quality's approval of Kennecott's mining permit. "However, these permits represent the first time the state is allowing sulfide mining. State officials must take their time and make sure sulfide mining is safe."

Geologists are quick to point out that there is no such thing as "sulfide mining." Copper, nickel or iron ore mining might occur in sulfide deposits, but nobody mines for sulfides or oxides.

The sulfide rocks which host the metals sought by miners can be different from one another. Arsenopyrite (arsenic and iron), argentite (silver), chalcopyrite (iron and copper), cinnabar (mercury), galena (lead), molybdenite (molybdenum), pentlandite (nickel), pyrite (iron), realgar (arsenic), sphalerite (zinc) and stibnite (antimony) are all present in the U.P., and the differences between types can be enormous.

"If you take a block of salt and an equal amount of loose salt and leave both outside in the elements, the salt block will slowly dissolve over time while the loose salt poured out will rapidly disperse," said Dr. Allan Johnson, professor emeritus of mining engineering at Michigan Tech. "It's the same with certain sulfides."

For instance, the sulfides of the Buck, Dober and Hiawatha mines of Iron River are not just polluting but dangerously reactive. The sulfides of Kennecott's Eagle Mine are igneous pentlandite, pyrrhotite and chalcopyrite, and don't pose the same risk.

"The iron pyrite of Iron County was the most reactive I've ever experienced," said Johnson. "A mine proposed there today with modern regulations would never be constructed. However, the sulfides you find in the Yellow Dog Plains do not react in the same way at all."

Johnson is considered by many to be a professional environmentalist. His work to remediate acid rock drainage out of the Buck, Dober and Hiawatha mines helped turn the Iron River from a habitat hazardous to biology to a DNR-designated Blue Ribbon trout stream, meeting high standards for aquatic life and water quality.

Even when ARD occurs, it isn't always harmful. Johnson notes that there is currently ARD in western Marquette County where the Michigan Department of Transportation recently widened a rock cut in a bluff full of sulfides.

"You'll find a similar reaction along the new rock cuts where MDOT widened U.S. 41," Johnson said. "Is MDOT polluting? No. It's a natural process and at those levels it's not likely to harm the environment."

Pictured Rocks National Lakeshore is "pictured" due to the erosion of iron, copper, manganese and limonite through the 42-mile-long sandstone cliff formations on Lake Superior. Despite thousands of years of erosion, the greatest lake remains pristine.

Rep. Stupak emphasized the importance of this debate when the first of potentially many new mining permits was approved by the state.

"It is critical that comprehensive independent studies be completed before additional permits are issued," Stupak said in a press release. "Once permitted, I am fearful as many as six additional sulfide mines will be allowed to operate on the shores of the Great Lakes, jeopardizing the world's largest body of fresh water."



Orvana's Bill Williams says the only reason his company is in Michigan spending money is due to the nonferrous mining legislation sponsored by Rep. Tom Casperson, R-Escanaba, and signed by Gov. Jennifer Granholm.

"That's why I could take this to my board," Williams said. "That's why we came to Michigan to invest. We felt it was very transparent. We already knew the permit process is a one-year process. If things work out well, I think there is a future for our company in Michigan."

The massive zinc orebody near Stephenson known as the Back Forty Project is just a small tip of a range extending from northeastern Wisconsin to the Mississippi watershed. There are billions of dollars of metals known and mineable just south of the Brule and Menominee rivers that comprise part of Michigan's border with Wisconsin. But as it stands right now, they will never be mined.

Following several increasingly intense confrontations, a proposal to mine millions of tons of zinc near Crandon, Wis., was first undercut when the Wisconsin Legislature passed a mining moratorium in 1998. Later, the Mole Lake Ojibwe and Forest County Potawatomi spent $16.5 million to purchase and close the operation.

"Nobody explores in Wisconsin anymore for metals because the regulatory environment is not welcoming," Bornhorst said. "The regulatory system in that state promotes no mining."

Andrew Ware "Essentially we've just focused on the top of the earth's surface over the last 200 years. There's no reason these things don't occur say, 400 meters below the surface, it's just harder to find them."

Kennecott successfully operated an open pit copper mine in Ladysmith, Wis., shortly prior to the mining moratorium. Though the copper was found in a sulfide orebody next to the Flambeau River, the Flambeau Mining Company was praised for its environmental stewardship. In July 2007, it received the Wisconsin Business Friend of the Environment Award and in 2003 the Flambeau received the U.S. Department of the Interior's Hardrock Mineral Community Outreach and Economic Security and Environmental Award. Community leaders in Ladysmith and geologists around the country cite it as an example of a bright future where mining and environmental protection partner together.



Likewise, Kennecott's Project Eagle nickel mine in Marquette County has blazed the path for others to follow. It was the discovery of this orebody in 2002 that inspired Michigan's nonferrous mining legislation. Most of the new mines now on track to open began as vague magnetic anomalies. Teams of geological explorers from Cameco, VMS, Quincy Energy and Bitterroot as well as the United States Geological Survey, the Michigan Department of Natural Resources and Michigan Tech have drilled hundreds of miles of core samples hoping to discover orebodies.

"Once you've defined a target and determined that it's worthwhile drilling, you need to file exploration plans with the MDNR, along with other soil erosion and applicable wetland permits, and essentially get the equipment out to the location and drill the core," Kennecott Eagle Minerals Exploration Manager Andrew Ware said. "Then you get the core out here to the core lodging facility and the team starts the process of measuring a large number of variables - density, point load testing, geotechnical logging, plus geological logging."

Paul Wiedman "I think everyone's proud of the coexistence we have with nature now. It's our backyard too."

Mining companies and the state of Michigan keep miles of core samples in storage for the geological record. These cores are a geological roadmap to the world beneath the Upper Peninsula. To the untrained eye, the samples are just long dowels of rock, but geologists can literally find diamonds in the rough.

Once something catches the team's attention, the core takes another journey. 

"If there's something of interest in terms of mineralization, we'll actually take that core and cut it in half; half of that core goes up to the prep-lab in Thunder Bay and then a split is sent off to Vancouver, where they conduct geochemical analysis to determine how much metal is actually in that piece of rock," Ware said.

The whole process starts with a general survey of a region of interest, such as the Western Upper Peninsula. A magnetic survey will identify geophysical anomalies. Gravity surveys will begin to paint a picture indicating where different types of rock can be found. What started out as a large mass of gabbro with low nickel content might end up being a smaller mass with significantly elevated amounts of nickel and copper.

This was the case for the Eagle deposit. After drilling the discovery hole in 2002, Kennecott was able to conduct an order of magnitude study by 2004, broadly analyzing the economic potential of the mine.

"Then you move forward to a pre-feasibility study, and you climb down to about 10 percent error, then to the feasibility study where you are expected to get everything at 5 percent," Ware explains. "Now we're into the mine planning phase where you really sharpen your pencil and make sure everything's right on."

Rio Tinto has taken residence in Cleveland Cliffs' old building, next door to the Cliffs Shaft Mining Museum in Ishpeming. Geologists and mining engineers can pore over a 3-D model of the Eagle orebody, while the dry room where horse teams drove supplies in for miners generations ago sits across the parking lot.

While 19th century miners had to have a good eye underground for safety's sake, technology has made things a bit safer, for both mine workers and the environment. Computer modeling, combined with breakthroughs in research and remediation efforts, have refined the industry over the last 20 years.

"We operate in different areas of the world; some are extremely sensitive areas of the world; and actually, mining underground there's less of a footprint," KEMC Mine Manager Paul Wiedmann said. "The last mine I came from, Green's Creek, was operating out of the (Admiralty Island) National Monument (in Alaska). That was a very small footprint mine and it was a great example of environmental stewardship. I think everyone's proud of the coexistence we have with nature now. It's our backyard, too."

Despite some opposition from the Keweenaw Bay Indian Community, some residents of Powell Township and activist groups, the local governments in Marquette County have passed motions supporting the Eagle project nearly unanimously. The vast majority of anti-mining public sentiment appears to represent a very vocal minority, especially in the scientific community. Many communities are eager to see a mining resurgence, as Ovana's Bill Williams has found in his meetings with the community of Wakefield, where his company is proposing a new copper mine.

"You're always going to get opposition, so it's nice to find an orebody in a mining-friendly jurisdiction," Williams said.

Most of the easily accessed orebodies around the world have been found and mined or determined to be un-mineable. According to Kennecott's Andrew Ware, the future of mining depends on finding targets farther beneath the surface.

"With the rare exception of finds like the Back Forty orebody in Stephenson, just about gone are the days were you can go out in the field and discover something on the surface," Ware said. "Most of those have already been discovered and mined out.

"Essentially we've just focused on the top of the earth's surface over the last 200 years," Ware added. "There's no reason these things don't occur say, 400 meters below the surface, it's just harder to find them."  



Though the mines were a huge source of economic growth for Michigan, their rise came at the cost of the environment. Even 19th century writers described the destructive properties of stamp sand, the coarse byproduct created when native rock is crushed by stamp mills. E.B. Hinson, a New York admirer of Michigan's copper industry, wrote in 1891 that the sheer volume of stamp sand washed into Portage Lake threatened navigation, which led to federal intervention and prompted a shift to disposing stamp sand and slag in Houghton County's Torch Lake.[1] In addition to problems posed by accumulation, stamp sand often contains traces of heavy metals like lead and mercury, some of which can cause environmental and health problems.

Today, Torch Lake is a Superfund Site and a Great Lakes Area of Concern. The EPA estimates that 20 percent of its original volume was displaced by copper industry waste totaling 200 million tons.[2] However, in 1988 the EPA began an in-depth investigation of the site in order to determine whether the barren slag surrounding the lake could be reclaimed. Following ten years of preliminary research, remediation work at the lake began with the introduction of six inches of fertile topsoil held in place by fast-growing vegetation.[3] After 800 acres of stamp sand and slag were remediated by autumn 2005, the construction at the site was declared complete.[4] Since then, the EPA has further endeavored to remove contaminated sediment and provide asbestos abatement at the site, and two areas are being developed for residential use.

[1] Hinson, E. B.. "Native Copper of Michigan." Journal of the American Geographical Society of New York 23 (1891): 324-338.

[2] www.epa.gov/glnpo/aoc/trchlke.html

[3] www.epa.gov/region5superfund/npl/michigan/MID980901946.htm

[4] cfpub.epa.gov/supercpad/cursites/csitinfo.cfm?id=0503034