DETROIT- It's been avidly studied by geologists for centuries, but one Wayne State University researcher is proving there is still much to learn about the formation and discovery of gold.
Edmond van Hees, Ph.D., assistant professor in the Department of Geology in the College of Liberal Arts and Sciences at WSU, received a $106,503 grant from West Timmins Mining Inc. to conduct research that could give geologists a completely new understanding of how the highly sought-after metal forms, as well as provide new methods of locating gold deposits.
Van Hees, a resident of Southfield, Mich., will investigate the mechanisms of high-grade gold mineralization in the Porcupine Gold Camp of Timmins, Ontario, Canada - one of the most prolific gold mining sites in the world. Interest in the camp was generated when researchers found evidence suggesting certain gold deposits had formed at higher temperatures and 25 to 100 million years later than geologists had previously thought.
"The results are very interesting; they're changing our understanding of how this type of gold deposit forms," van Hees said. "One possible answer that we're looking into is that the gold formation took place a lot later than the metamorphism of the rest of the rocks in the area. It could be that the gold deposits are 25, 50, or even 100 million years younger than we had previously thought."
There are two different ways that gold deposits can form in bedrock. One is when the sulfur present in some high temperature, underground water systems reacts with iron in the bedrock, forming pyrite and causing the gold in solution to precipitate out of the water. The second way is when changes in temperature and/or pressure conditions cause gases such as carbon dioxide, methane and hydrogen sulfide to separate from the underground water, causing native gold to be deposited along with quartz in veins.
Using a stable isotope mass spectrometer, van Hees has developed a number of unique gold indicators that will enable him to understand the nature of gold deposits that form at higher than expected temperatures. "What we're looking for is the overall mechanism," he said. "We've found evidence for a metamorphic event at depth in the deposits right around the time they formed. This connection is something that was previously unrecognized, and we just don't know anything about it."
The information will not only allow him to investigate the nature of this type of deposit formation, but will also help in locating new gold exploration targets. Using stable isotopes measurements, for example, van Hees can differentiate between quartz that has a chance of containing gold from quartz that has no chance of containing gold.
James Tucker, Ph.D., chair of the Biological Sciences and Geology Departments at WSU, said van Hees' work has the potential to significantly change the practice of gold mining. "Dr. van Hees' new and promising method to identify and characterize gold deposits is truly exciting," he said. "While the economic impact of his work has yet to be fully realized, I expect it will be highly significant and that it will play a major role in how gold ore deposits are evaluated for years to come."
Van Hees has worked at several sites at the Porcupine Gold Camp, including its largest one, the Hollinger-McIntyre mine. Between 1910 and 1990, about $40 billion worth of gold at today's value was mined from the Hollinger-McIntyre, the largest gold mesothermal - or mid-temperature - gold deposit in the Western Hemisphere.
Van Hees came to Wayne State in 2001, but was already deep into his research on gold deposits, an interest he developed when he traveled to the city of Yellowknife in Canada's Northwest Territories near the beginning of his career.
"I was sitting in a bar, waiting for my plane, and I wound up talking to another gentleman who was working in Yellowknife - where there are gold deposits - and he showed me a piece of gold. That was the end of it, I caught gold fever."
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