Friday, March 02, 2007

Diamonds: Minnesota's buried treasure? Read the stories

More mining news from Lori Andreson, our correspondent: Diamonds! Fabulous wealth in Minnesota? Read on:

Mar 2, 2007 8:17 am US/Central

Study: There May Be Diamonds Under Minnesota
(AP) Minneapolis A newly released study finds there are geological and chemical hints there may be diamonds in quantities large enough to mine under Minnesota.

The study by the University of Minnesota and an Australian mining company found features across Minnesota similar to those in Canada which led to diamond strikes.

The key features of the study were kept private for two years as part of a rare deal the university signed in 2004 with the mining company WMC Corporation.

Harvey Thorleifson is head of the Minnesota Geological Survey and a world-renowned diamond geologist. He's scheduled to present the findings next week in Toronto.

Thorleifson says the big surprise was the discovery of indicators that point to pipes of kimberlite, the underground rock formations where diamonds are often found.

Thorleifson calls the findings significant, but says they are far from a guarantee of diamond mines in Minnesota's future.

(© 2007 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. )

Minnesota's geology reveals road signs to diamond riches
Don't start digging yet, but a study suggests a treasure trove lies beneath the state
Pioneer Press
They rarely yell "Eureka!" in the diamond exploration game. But surprising details from a just-released survey of Minnesota has the state's top geologist saying: "Maybe."

An exhaustive study by University of Minnesota researchers and an Australian mining company discovered geological markers across Minnesota similar to those in Canada that have led to huge diamond strikes over the past 10 years.

Held in secret for two years as part of a rare deal the U signed in 2004, the newly published findings reveal patterns researchers didn't expect — mineral arrows that may point to pipes of kimberlite, the underground rock formations where diamonds are most commonly found.

"We did find something and it's like the first hints" that led to diamond-field discoveries in Canada, said Harvey Thorleifson, head of the Minnesota Geological Survey and a world-renowned diamond geologist.

It's no "X marks the spot" discovery. It will take several years to trace back the mineral markers to see if they lead to kimberlite and, perhaps, diamonds.

Thorleifson called the findings significant but compared them to a hunting dog picking up the scent of a fox: Sometimes the fox is never found.

He plans to unveil the findings next week at an international prospector's convention in Toronto.

A diamond strike might seem unlikely in Minnesota. Scattered exploration in the central part of the state 20 years ago failed to find a mother lode. But geologists have long seen Minnesota's glaciated terrain as potentially fertile diamond territory, and chemical and computer testing of soils to find diamond markers has improved dramatically.

Hired in 2003 to lead the Minnesota Geological Survey, Thorleifson helped develop many of the indicator-minerals tests as a scientist in the Geological Survey of Canada. That work helped establish Canada's booming diamond industry, which didn't exist 10 years ago.

Thorleifson's reputation and the potential to discover a billion-dollar industry were compelling enough that the U in 2004 agreed to let the mining company, WMC Corp., withhold publication of the study's most sensitive findings for two years.

Diamonds form in rock that is about 2.5 billion to 3 billion years old. They rise to the surface in explosive eruptions and can be found in the carrot-shaped formations of kimberlite, named for Kimberly, South Africa, where it was first discovered in the late 1800s.

Diamonds have been found around North America, including Wisconsin, but mining was nearly nonexistent. That's changed over the past 20 years as geologists began examining the sandy sediments of land scraped by glaciers.

Because kimberlite is soft, some of it can catch in the glacier and leave a trail traceable to its source.

Geologists sample soils, looking for kimberlite indicator minerals, such as garnets. After a few hits, they follow the trail in the direction the glacial ice came from; if the number of markers increases, they may lead to kimberlite — and, maybe, to diamonds.

That's how it has played out in Canada, now one of the world's fastest-growing diamond producers.

Garnets with just the right chemical makeup were the survey's "complete surprise" in Minnesota, Thorleifson said. Found in a couple of spots, including near the Twin Cities, the garnets held levels of magnesium and chromium that flag them as particularly good markers to lead the way to kimberlite.

It's possible they may point the way to a kimberlite plume between the Twin Cities and Duluth or western Wisconsin, he added.

Canada began producing diamonds in 1998 when the EKATI diamond mine opened in the Northwest Territories. Two other mines have opened nearby since 2003.

With this multibillion-dollar business, officials say, Canada is now the third largest producer of rough diamonds by value after Botswana and Russia. At least two more Canadian mines plan to open in coming years.

Initial results here are exciting because they mirror those found in the early days of diamond exploration in northwestern Canada. Thorleifson and others, though, say there's a long road ahead.

"The report looks thorough and is a good first step in assessing the potential for diamond deposits and other mineral deposits in Minnesota," said Brooke Clements, vice president for exploration at Ashton Mining of Canada in Vancouver.

Clements, who explored central Minnesota in the mid-1980s with another firm, cautioned that the samples in this newest report had no more than one grain of each of the mineral species that might lead to kimberlite.

"While there are examples of instances where kimberlite pipes were discovered after an initial sample had only one indicator grain, more work is required to assess the significance of these results," he said.

The next steps involve follow-up soil surveys that likely will include northwestern Wisconsin to see if the markers will lead to kimberlite formations, Thorleifson said. That process will take several years of work and consultation with other geologists.

"There is a source out there somewhere," said Thorleifson. "Sometimes it's kimberlite but there are no diamonds … or you might have a kimberlite with beautiful diamonds that might be too deeply buried. Sometimes you can't find it."

Paul Tosto covers higher education and can be reached at or 651-228-2119.


Download a copy of the NRRI Diamond Brochure.pdf

Contact Steve Hauck

Minnesota has:

an Archean-aged Superior Craton root that underlies two-thirds of Minnesota, and diamondiferous kimberlites that have been found elsewhere within the Superior Craton in Ontario and Michigan.
major crustal structures that cross-cut Minnesota’s cratonic root, e.g., Vermilion Fault Zone, Great Lakes Tectonic Zone, Quetico Fault, etc., which are excellent kimberlite exploration areas.
Kenora-Kabetogama and Keweenawan dike swarms that intersect these and other structures and could have provided pathways for kimberlite emplacement, e.g., similar to the kimberlites found in the Kyle Lake and Attawapiskat kimberlite clusters in northern Ontario.
an Archean terrane with calc-alkaline lamprophyres that is time-equivalent with the Michipicoten greenstone belt in Ontario that has diamondiferous calc-alkaline lamprophyres associated with diamondiferous heterolithic breccias.

Minnesota also has:

been a mining state for >110 years.
reasonable mining taxation and economic incentives, as well as an established permitting process.
excellent regional and local bedrock and glacial mapping.
an excellent aeromagnetic and gravity database covering the entire State.
drill core and associated records for >5,100 drill holes.
an online database of mineral exploration records.
regional and statewide glaciofl uvial soil and stream sediment surveys.
Download a copy of the NRRI Diamond Brochure.pdf

Precambrian Research Center Summary

Minerals Industry

The demand for field geologists comes largely from the resurgent mineral exploration industry, locally and globally. "We can’t find any qualified people" has come to be a commonly heard refrain from the minerals industry as they seek to find field-trained geologists to hire for a renewed boom in minerals exploration. Fueling this increase in exploration is the global recovery from a 15-20 year depression in metal prices that is itself triggered by economic recovery in the West and the rapid industrialization in China. The level of metal consumption in China is forecast to grow by more than 80% over the next decade, and when including India and all of the rest of Southeast Asia, a total of 3 billion people are going through an industrial revolution. Although the minerals industry has always been cyclical, this next boom period looks to sustain itself for the foreseeable future. Moreover, new technologies, such as fuel cells and specialty steel, are causing increase interest in previously low demand metals like platinum, palladium, and titanium.

Minnesota Issues

On top of this increased global need for trained field geologists, a more local need exists for the next generation of industry-based Precambrian geologists in Minnesota. The single most important need exists within companies mining taconite along the Mesabi Iron Range, which together contribute nearly $1.3 billion to the state’s economy every year in the form of purchases, wages and benefits, and taxes and royalties. It is imperative that these established mining facilities have access to the next generation geologists for their staffs (the vast majority of their current geologists are UMD graduates). As well, UMD graduate student research projects on a variety of topics within the Biwabik Iron Formation could play an important role in sustaining existing mines and planned expansions into the future. In addition, a second need is looming as Minnesota is poised to develop a wholly new mining district focused on Cu-Ni-PGE deposits of the basal Duluth Complex. PolyMet Mining Corporation is in the final stages of permitting to mine the NorthMet deposit (formerly known as the Dunka Road deposit) located near Hoyt Lakes. Other related deposits have also seen increased activity in recent years, Teck-Cominco’s Babbitt deposit, Franconia Mineral’s Birch Lake deposit, and Wallbridge Mining’s Maturi Extension deposit. The potential exists that if PolyMet is successful in permitting and developing a base and precious metal mine, these other deposits are sure to follow. This will generate an incredible local demand for field-trained geologist with B.S. and M.S. degrees. Besides the CU-NI-PGE deposits of the Duluth Complex, other companies are spending money in the state in their search for gold, nickel, titanium, and diamonds.
Precambrian Research Center
Valuable minerals lie beneath our feet, but if we don't know where to dig, they will stay locked underground. NRRI economic geologists have done extensive mapping of Minnesota's bedrock terrain for minerals exploration. Now, however, they are looking to the future and hoping to train the next generation of skilled field geologists.
Our beginning of time starts in the Precambrian era, including the formation of the earth itself, and stretches ahead some four billion years to the Cambrian era.
Bedrock that formed during Precambrian time holds valuable minerals, and Minnesota is rich with this mineral-laden rock, but it's a challenge for geologists to map it. The young earth was quite volatile and volcanic back then, causing melting, shifting, uplifting and eroding of the bedrock. It left behind a complex mix of rock and minerals. More often than not these ancient rocks aren't even included in field projects for U.S. geology students.
Globalization of the world's economy and a spectacular rise in the standard of living of millions of people means we need to be smart with how we use our earth's resources. The minerals industry is entering an anticipated era of expansion, but that growth is slowed by a need for trained field geologists, especially in the Precambrian terrains that hold much of the world's ore deposits. More than ever, geoscientists skilled in modern mapping and map-making are in high demand.
NRRI economic geologist Dean Peterson has teamed up with Jim Miller of the Minnesota Geological Survey to form the Precambrian Research Center at NRRI and UMD's Department of Geological Sciences. This center will provide training and support to upper-level college students, as well as professional geologists, in modern methods of geologic mapping of glaciated Precambrian terrains. It has received strong support from UMD's College of Science and Engineering and is a collaboration between the NRRI, UMD's Department of Geological Sciences and the Minnesota Geological Survey.
"This is a new way we geologists can help NRRI meet its mission of supporting natural resource-based industries," said Peterson. "Iron ore is in high demand world-wide and is expected to continue to rise. We just need more specially trained geologists to map the geology, interpret geological processes and predict where potential ore deposits may be found."
This summer, the Precambrian Research Center at NRRI will launch a 6 credit, 6 week Precambrian field camp for both undergraduate and graduate students from throughout North America, which will include a week of mapping and primitive camping in the Boundary Waters Canoe Area. The Center will provide research assistantships and grants to qualified students, as well as continuing education and field experiences in advanced mapping courses for professional geologists. Digital geologic mapping and upper level courses on field mapping will also be offered.
The Center will rely on expert advice and direction from a preeminent board of advisors with members from minerals exploration and mining industries, the U.S. Geological Survey, State and Provincial Surveys, and U.S. and Canadian colleges and universities.
"Geologic mapping is quickly becoming a lost art," said Miller. "We simply have not been mentoring students in this experience-intensive activity. This Center will hopefully help reverse that trend by creating well-trained mappers who can pick up where we leave off in unraveling the mysteries of the Precambrian."