On Wednesday of this week we presented the following paper to the Joint Mining Impact Committee of Iron and Ashland Counties and the towns of Anderson and Morse.
The presentation was met with anger on the part of some of the audience, especially from members of the Iron County Mining Impact Committee and its chair, Leslie Kolesar.
Ms Kolesar said: "With all due respect, you can't make calculations of the amount of waste rock."
and, "The people who did this survey [Item IV below] were probably looking for sulfides."
and, "Tom Evans says that there are sulfides everywhere." She also questioned the validity the scientific studies because they were not very "thick."
Another member of the audience said something to the effect of, "Why should we believe a bunch of yahoos wandering around in the Penokees and holding up a glass of water and saying, 'sulfides'?"
Please read and try to ascertain why this factual and uncontroversial paper was met with anger and aggression.
Keep in mind that the people who favor this mine have been supporting a new ferrous mining bill in Wisconsin because, "Iron mining is different than sulfide mining." and, "there are no known sulfides in the Penokee deposit."
Sulfides in the Ironwood Iron and Tyler Formations
Presented to the Joint Mining Impact Committee of Iron and Ashland Counties, Towns of Anderson and Morse
January 9, 2013
In meetings and conversations for the past two years the possibility of the presence of sulfides in the area of the proposed Penokee mine has been argued often and heatedly. These arguments have taken valuable time away from considering other important issues such as zoning, taxes, and environmental impacts. The purpose of this presentation is to, hopefully, end those arguments.
Sulfides do exist in the Ironwood Iron formation and the overlying Tyler Shale and I present 5 sources of proof.
Background of the Argument
Why does anyone care if sulfides are present? The title of Wisconsin’s current mining law, Chapter 293, section 293.50 is “Moratorium on issuance of permits for mining of sulfide ore bodies.”
This section has been labeled “The Mining Moratorium.” It is not a mining moratorium, or even, strictly speaking, by definition, a moratorium. It is actually a set of rules or qualifications which must be met before mining a sulfide ore body. This short 8 paragraph section is easily understood.
For our discussion purposes today paragraph (1) (b) is most relevant. It is the definition of sulfide ore body and reads:
(b) "Sulfide ore body" means a mineral deposit in which metals are mixed with sulfide minerals.
Last week Ann Coakley, the director of the Bureau of Waste and Materials Management, the department of the DNR which regulates mining, spoke to the Iron County Mining Impact Committee. Seeking clarification on 293.50, following the meeting I emailed the question:
“If after thorough geochemical analysis, no evidence of sulfides is indicated, would the mining moratorium, Chapter 293.50 still be a factor in permitting that mine?”
The answer I received was “If sulfides are NOT present, then the sulfide ‘moratorium’ would not apply.”
That, then is the crux of the argument. Sulfides present, the simple rules of 293.50 apply. If no sulfides are present, 293.50 does not apply.
The Presence of Sulfides at the Penokee Mine Site
First, a tiny bit of chemistry and a quick definition. There are many types of sulfide minerals (minerals containing a chemically oxidized form of Sulfur). Some of these types are slightly reactive, some very reactive. When these reactive forms are exposed to air, water and a special soil bacteria, a chemical reaction can occur to produce sulfuric acid – acid mine drainage. One of the most reactive forms is called pyrite – an iron-sulfur mineral whose common name is “fool’s gold.” Deposits containing pyrite are called pyritic. They are the easiest to identify since the crystals are gold in color and usually visible to the naked eye in “hand samples” and are thus mentioned the most frequently in field-based studies.
Other species of iron sulfides are only detectable by more sophisticated methods, and all could cause acid mine drainage.
Determining whether sulfides are present in the Penokees is actually quite simple. Just “Google” “Ironwood Formation + Pyrite” or “Tyler Formation + Pyrite.”
But the presence of sulfides in this deposit has been known for a long time. Our first reference today, goes back well before the invention of the internet.
I. Wisconsin Survey, Bulletin 71, The Geology of the Gogebic Iron Range in Wisconsin, Aldrich, 1929
This beautiful and priceless little book contains probably the most thorough assessment of the Gogebic Range ever done. I have it on loan thanks to my friend Paul Sturgul of Hurley. It is a town by town, section by section analysis of the range. The maps contained in it are exquisite and informative. We consider T44-45N~R1W which contains the majority of phase 1 of the proposed mine. This map and analysis was the result of a survey by W.O. Hotchkiss and E.F. Bean made in August of 1915.
Starting on page 206 is a detailed analysis of a cross section of the Ironwood in the Tyler Forks cut. Specimens were taken every 3 feet and analyzed. The Ironwood is about 618 ft. thick there.
On page 210, analysis of minerals at 300 feet: “rhombs of magnetite carrying some pyrite.” And 306 feet, “practically the same as 300 feet and 168 feet.” indicating pyrites at least two places in the deposit.
[Please keep in mind that these geologists were not LOOKING FOR PYRITE and were dispassionately cataloging what was there without political or environmental concern.]
II. The Marquette Range Supergroup in the Gogebic Iron District, Michigan and Wisconsin, Schmidt, Bulletin 1460, 1980
Now into the internet age. In this study which can be found at:
pages 8, 9, 15, 21, and 22 reference the presence of pyrite in the Ironwood. Pages 24, 25, and 26 reference the presence of pyrite in the Tyler.
III. The Gogebic Iron Range – A Sample of the Northern Margin of the Penokean Fold and Thrust Belt, Cannon et. al., USGS, 2008
In this paper by the USGS’s prominent geologists Bill Cannon and Klaus Schulz, with whom I have had the privilege of touring the mine site and Copper Falls State Park, pyrite in the Ironwood is mentioned on page 9, in the Tyler on pages 14 and 35.
You can read the paper at:
IV. Geochemical Mineralogical and Structural Characterization of the Tyler Formation and Ironwood Iron Formation, Gogebic Range, Wisconsin, July 31, 2012
In this soon-to-be-released study commissioned last winter, with the cooperative effort of the geology departments at three Wisconsin universities, the most modern methods of analysis were used to determine the presence of sulfides, at an atomic level, in the Ironwood and Tyler formations.
X-ray fluoroscopy was used to determine the actual percentage of each element and x-ray diffractometry to measure the percentage of minerals, such as FeS2, in the given sample.
I do not have time to go into the details of this study but the summary has some interesting points which I paraphrase here:
First: The Tyler Formation contains significant amounts of reduced iron as sulfide (pyrite, pyrrhotite and related minerals, which could react with oxygen to generate acid mine drainage. A stably benched 200-300 m deep 7.2 kilometer long open pit mine in the Ironwood would require removal of an immense volume (on the order of 450 million m3) of waste rock from the Tyler.
Responsible monitoring and managing such a volume of waste rock and a pit of such depth over the long term would pose significant engineering challenges.
Second: The iron carbonate (siderite) present in small quantities in the Tyler Formation would not help to mitigate acid production, and the fine grain size of the rock would accelerate the
generation of acidic solutions.
Third: A 3-meter thick pyrite-bearing layer within the Ironwood Formation itself also has the potential to generate acid runoff, given the fine grain size to which the Ironwood would be crushed onsite for the magnetic separation process.
Last: The scale of a modern open pit mine in the Gogebic Range would be completely different
from historic mines in the region, which were localized, primarily underground mines that
targeted high grade ore and did not involve excavation of the Tyler Formation. In fact, a
300 m deep mine would have greater relief than any existing natural landscape feature in
the state of Wisconsin.
(For numerical results from this survey see Appendix, Table 1 and Additional Information)
V. Finally, a bit of Hearsay Evidence
I was, for a short time, secretary of the Iron County Mining Impact Committee. At an executive meeting in the office of then-chairman, Paul Sturgul, the structure of the committee was being discussed and the resolution creating it was produced. Present were the Chair, Vice Chair, secretary, a few committee members and county officials Mike Saari (County Clerk) and Dennis DeRosso (County Board Chair and County Executive).
Toward the end of the meeting some informal chit-chat was going on. Dennis told the following anecdote which I retell as my memory serves:
“When I was a young man, back in the 50’s, I worked on the crews doing the U.S. Steel cores out on the Penokee deposit. One day I took home part of one core, a piece of shiny stuff about 8 inches long. The next day the geologist made me bring it back since its absence made his core lengths not add up. I gave it back and he said, ‘It’s not worth anything anyway, just fool’s gold.’”
I didn’t say anything at the meeting but when I got home I called Dennis to ask, “do you know what fool’s gold is?”
He said, “no.”
I said, “that’s Iron Pyrite. If you’re not sure of this story you shouldn’t mention this in any mining meeting.”
“I’m sure.”, he said.
I said, “Well then you ought to tell someone about it.”
“I did,” he replied, “Bill Williams.”
Yes, there are others who were present who can confirm this.
First, none of the above information has any relevance to the actual permitting of a mine since, as Ms. Kolesar pointed out at the last Iron County Mining Impact Committee meeting, there is no chain of custody of the samples used to produce the reports. During a permitting process new cores would have to be taken. in the presence of DNR staff. Only those “secure” samples could be used in the decision process. A mine permit could not be refused based on the above data.
[Editor's note: Actually cores are never subject to DNR review. The mining company can pick and chose cores and core data to use in its application.]
However, a reasonable person could use the above information to the conclude that there are sulfides at the mine site.
The current mining law in section 293.50 specifies that if sulfides are present, the mining company must specify how it will handle this condition and must cite an existing mine with similar conditions which has operated, been closed and reclaimed with no pollution for a period of ten years.
Considering the letter of the law, that hurdle is very difficult for a mining company to clear, perhaps, in this case, impossible, because, according to EPA officials, there is no comparable example.
In the very near future a new “Ferrous” mining bill will be passed and most certainly will not include a sulfide mining moratorium if a mining company is looking for iron. Depending on your point of view that is either good because it is “fairer” to a mining company or bad because it negates the spirit of 293.50 which is that Wisconsin doesn’t want to be a guinea pig to test new technologies. At the very least eliminating 293.50 is confusing since it creates so many new issues.
By ending the argument about the presence of sulfides we can focus on those new considerations.
I am happy to answer any questions to best of my ability or to refer those interested to experts who can.
293.50 Moratorium on issuance of permits for mining of sulfide ore bodies.
(1) In this section:
(a) "Pollution" means degradation that results in any violation of any environmental law as determined by an administrative proceeding, civil action, criminal action or other legal proceeding. For the purpose of this paragraph, issuance of an order or acceptance of an agreement requiring corrective action or a stipulated fine, forfeiture or other penalty is considered a determination of a violation, regardless of whether there is a finding or admission of liability.
(b) "Sulfide ore body" means a mineral deposit in which metals are mixed with sulfide minerals.
(2) Beginning on May 7, 1998, the department may not issue a permit under s. 293.49 for the mining of a sulfide ore body until all of the following conditions are satisfied:
(a) The department determines, based on information provided by an applicant for a permit under s. 293.49 and verified by the department, that a mining operation has operated in a sulfide ore body which, together with the host rock, has a net acid generating potential in the United States or Canada for at least 10 years without the pollution of groundwater or surface water from acid drainage at the tailings site or at the mine site or from the release of heavy metals.
(b) The department determines, based on information provided by an applicant for a permit under s. 293.49 and verified by the department, that a mining operation that operated in a sulfide ore body which, together with the host rock, has a net acid generating potential in the United States or Canada has been closed for at least 10 years without the pollution of groundwater or surface water from acid drainage at the tailings site or at the mine site or from the release of heavy metals.
(a) The department may not base its determination under sub. (2) (a) or (b) on any mining operation that has been listed on the national priorities list under 42 USC 9605 (a) (8) (B) or any mining operation for which the operator is no longer in business and has no successor that may be liable for any contamination from the mining operation and for which there are no other persons that may be liable for any contamination from the mining operation.
(b) The department may not base its determination under sub. (2) (a) or (b) on a mining operation unless the department determines, based on relevant data from groundwater or surface water monitoring, that the mining operation has not caused significant environmental pollution, as defined in s. 293.01 (4), from acid drainage at the tailings site or at the mine site or from the release of heavy metals.
(3) This section applies without regard to the date of submission of the permit application.
History: 1997 a. 171.
Calculation of Amount of Battery Acid Produced by 1% Sulfur (by Weight) in One Cubic Yard of Broken Shale
Atomic Weight of Sulfur
Molecular Weight of H2SO4
Density of Broken Shale (Average)
Weight of 1 cubic yard of water
Weight of 1 cubic yard of broken shale
Percent of S by weight
Pounds of S in 1 cubic yard of broken shale
Potential pounds of H2SO4
Grams of H2SO4
Moles of H2SO4
Moles of H2SO4 in battery acid (moles/liter)
Liters of battery acid
Gallons of battery acid per 1 yard of shale at %
(Multiply 12.264 * actual percentage)
Additional Information and Calculations
Estimated Cubic Yards of Tyler Shale Removed in Phase 1 = 481,000,000 (solid)
Estimated Cubic Yards of Tyler Shale Removed in Phase 1 = 781,000,000 (broken)
Estimated Cubic Yards of Tailings Produced in Phase 1 = 248,000,000
Lowest S % found in any sample = .034, .416 gallons 5 molar acid per cubic yard or 324 million gallons from first phase waste rock.
Average S % found in all samples = .15, 1.64 gallons 5 molar acid per cubic yard or 1.28 trillion gallons from first phase waste rock.
For more calculations see:
For additional information on sulfides see:
Note: The appendix was not part of the verbal presentation.
In table 1, above we use battery acid as a common frame of reference. Acid mine drainage does not produce battery acid strength H2SO4. To be qualified as AMD the acid produced is actually 10,000 times more dilute than battery acid, that is to say, weaker by a factor of 10,000.
Many factors determine the amount and strength of acid produced; the presence of water and air, the presence of iron oxidizing bacteria, the size of the grains of pyrite in the rock, the size of the broken rock and the presence of neutralizing or buffering minerals in the rock.
If AMD does occur, it does not happen all at once in a giant flood of acid. It occurs slowly of a period of many years as the acid is released.
And, a reader just sent in this photo of the Tyler Formation along Hwy 77. Take a wild guess where the orange stuff came from.