Wednesday, October 9, 2013

Gold Deposits Near Cheyenne, Wyoming

Yes, its a silly looking hat. But in Wyoming, even the GemHunter needs to be warm. 
When I began working for the Wyoming Geological Survey, we were a relatively productive government agency in charge of unraveling the geology associated with mineral deposits as well as  in charge of finding new mineral deposits. But, we were one of the smallest agencies in the State: a very sad commentary for a state that makes its living off mining and oil and gas resources. In addition, our salaries were just one step above that of a custodian.

Not only was most of the legislature uninterested in the State's mineral resources, but I found many at the University of Wyoming were also anti-mining. This is a very strange concept particularly since the University of Wyoming and many of the professors owed their jobs and existence to the mining and oil and gas industries. But even educated professors are under the assumption that money grows on trees.

During the first couple of years I worked at the Survey, I was asked to assist in building a Childrens' Museum in downtown Laramie - it was going to have a geology theme. I donated rocks and assisted in building a mine tunnel for the kids to walk through and on the outside of this exhibit, one board member requested we put on a simple pie diagram to show kids and parents how important mining and oil and gas was to the state. It was a pie diagram showing ad valoreum taxes to the state. Whoa - was this a bad idea.
hydrothermal alteration mineral assemblages found in the Silver Crown district, Wyoming.
One of the board members, a flaming liberal from the university, demanded that the pie diagram be modified to show mining, oil and gas were not important - she demanded we make up statistics to fit her agenda! "Mining can't be important she exclaimed - it's bad for the environment and attracts dirty people". I mentioned they were dirty because they have to work for a living (unlike her) and mention mining was also referenced in the Holy Bible, and no where did it indicate mining was a bad profession - remember the Golden Fleece? This was a sheep skin used in a sluice to extract gold. As I suspected, she was not into the Bible. Most extreme liberals have never heard of the Bible or any facts.

Visible gold is seen in rock sample adjacent to brassy pyrite in
this sample from the Copper King
That was one of the first times I saw science taking it in the shorts for politics - and this was 30 years ago. I finally quit working at the Children's Museum when the rest of the board sided with the liberal and modified the pie diagram to show mining and oil and gas contributed little to the state. I didn't want to be associated with lies - but over the years, I found this was characteristic of people with political agendas from the state geologist, to the governor, to the president.

When I left the Wyoming Geological Survey, they actually had a Chinese and Russian communist on the staff and a director who thought the US Constitution was made only to control others, and had nothing to do with him. Now why did some of my friends give up their lives in Vietnam?

How did I get onto that subject? Ah, I know, I was thinking about the time I worked on the Copper King property while at the WGS. Over the years, I developed a fascination with different mining districts, and one of my favorites was the Silver Crown district. At one time I had planned to do a detailed study of the hydrothermal alteration patterns at the Copper King mine and acquired drill core from the US Bureau of Mines. I was hoping to find money to pay for thin sections and microprobe analyses, when the director decided the core (several $million worth of core) was collecting dust and without warning, he transported all of the core on a weekend to the city dump.
Stockworks at the Copper King
In spite of this and other set-backs, I was able to spend time on the ground at the Silver Crown district and at the Copper King mine and was able to map the accessible underground mines in the district (Hausel and Jones, 1982) and over the years, I spent time researching the mineralization and alteration at the Copper King mine and nearby properties (Hausel, 1997). It became clear to me that the Copper King was a deeply eroded core of a Proterozoic age gold-copper porphyry system and over the years when I had exploration geologists and company CEOs visiting my office on the UW Campus while they were searching for ideas for gold mines, I told many that this was one of my top picks for a commercial gold deposit. Some of these people listen, and it was picked up time and time again. But like most commercial gold deposits, development awaits the right alignment of the stars.

Most people are under the impression when a commercial gold (or other metal or gemstone) deposit is found, it is "Eureka" and then the mining begins. Unfortunately, that never happens except in the movies. "Mines are made, they are not found" was stated at some talk I attended at the Northwest Mining Convention many years ago. It takes the right circumstances, people, investments, government support, etc, etc, etc. Take a look at the Pebble deposit in Alaska. A prophyry deposit so large that it dwarfs the Bingham Canyon deposit in Utah. Can you imagine finding a $100 billion deposit and no one can figure out how to make a mine out of it?  I can. We found a $60+ billion gold deposit at Donlin Creek Alaska in 1988, and no one can figure out how to make a mine out of it yet. I found a gold district in Wyoming in 1981-1982 at the Rattlesnake Hills that likely has $5 to 10 billion in gold, and again, no one can make a mine out of it.

Pervasive propylitic altered quartz monzonite
The Copper King mine near Cheyenne, was drilled by the US Bureau of Mines (one of the few productive government agencies that met its demise under Clinton and Gore because it didn't fulfill their political agenda of making things greener - so thousands of government employees were terminated, valuable research ended, all because a few politicians wanted to promote global warming whether fact or fiction) and several different exploration companies. Today, it is reported the property has a gold equivalent resource of 2 million ounces in gold and copper. Hey, now someone should be able to put that kind of property in production especially since it is sitting adjacent to I-80 and just down the road from Cheyenne. Access is good.

And it is apparent that the deposit is bigger - based on exploration and drilling - it is open in every direction (except up, maybe). That's right, drilling has yet to find the limits of the ore deposit. However, the ore appears to end to the east - or does it?  I recently mapped a fault and found that the footwall on the east side had down dropped - how far down is anyone's guess at the moment, but it needs to be drilled to find out if the mineralization continues in that direction. I would be very surprised if it does.

Then there is the problem of having similar anomalies in the area. Terry Klein of the USGS pointed out that there were similar hydrothermal anomalies nearby, and I worked on another I found that appears to be very large, but could not map the anomaly due to private land access problems. 

Remember I mentioned that the deposit doesn't appear to continue up in the sky. When I misled you as considerable erosion has occurred in this area since the Proterozoic. So, large amounts of gold are likely sitting in conglomerates and streams - including some that drain into Cheyenne. Can you imagine that - placer gold in downtown Cheyenne.

References Cited

Hausel, W.D., and Jones, S., 1982, Geological reconnaissance report of metallic deposits for in situ and heap leaching extraction research possibilities: Geological Survey of Wyoming Open File Report 82-4, 51 p.

Hausel, W.D., 1997, The geology of Wyoming's copper, lead, zinc, molybdenum, and associated metal deposits: Geological Survey of Wyoming Bulletin 70, 224 p.