Showing posts with label gold mining. Show all posts
Showing posts with label gold mining. Show all posts

Sunday, October 6, 2013

Professor Hausel's Guide to Gold

Be careful of legends! The Superstition Mountains!
Many gold
legends are nothing more than legend. Wonder
why no one ever found the
Lost Dutchman mine? Well,
maybe there's a mine out there, but why bother 
when there 
are plenty of known gold mines around the West.
You've probably heard it said before. "Gold is where you find it". Not sure what wise guy came up with that saying - but its true even though it should be obvious. But the problem is finding the location of the "where you find it".  

 I think I have a nose for finding gold deposits and its not as hard as some make it out to be. Some years ago, a group of 7 geologists (including me) was awarded the Thayer Lindsey Award for making a major gold discovery, and prior to that acknowledgement, I was presented the 2004 Distinguished Service Award for the many other gold, diamond, colored gemstone, base metal and similar discoveries. It's not that I'm that good of geologist, its just that I follow up on leads - anyone with a decent geology education could do the same.

Here are some suggestions for finding gold:

(1) Use science (unlike the CDC). Sounds pretty straight forward, but it is amazing how many promoters and scam artists swear by using unscientific methods such as dowsing, witching sticks, legends, wet dreams, feelings, legends and even fraudulent information to find gold (sort of like the democratic party). None of which will work.
The iron stained (gossan) at the Vulture gold mine, Arizona.
Learn what
 you can about veins and how to follow them
if you want to find gold
. There will be many false trails, but
some will be good. Just don't give up!
When I was at the Wyoming Geological Survey, I had one dowser who would read my ICMJ prospecting and mining journal articles and would dowse the paper and ink maps in each article, sketch a couple of pencil lines and then send me a copy of the article to tell me where the mother lode was on each paper map. This went on for a few years and I finally lost touch with him, so he was either recaptured by the authorities, or went to work for the Biden administration. I'm not sure why manipulating ink on cheap paper would allow one to find gold - but that's the kind pseudoscience that some of these guys used.

Another dowser would send me advertisements for his school of dowsing (all hand written) for a variety of courses - each class sounded like and episode of the Twilight Zone. One of his better ones (I tried to get the University of Wyoming to pay for my registration) was how to find lost dogs and other pets with a dosing rod while flying over the country in a 747. Now if you don't laugh, you should see a professional. Not sure if it was me, or my job that attracted these guys - but I must say, I did actually enjoy hearing their stories, and I'm sure I will get lots of people who would like to debate the science of dowsing, but for me, I've seen enough. Yes, I've seen people use dowsing rods and watch the stick swing up and down as they walk, but I've never seen anyone find anything more than sagebrush or dirt with dowsing rods. 
Gold nuggets from Arizona
Then there was 'Barbara' - a little old lady prospector/con artist/democrat from Atlantic City Wyoming who knew where all of the gold was! In other people's wallets. Barbara was well-known for her scams - and yes, at one time she was the chairperson of the Wyoming democratic party. 

She was only about 97-pounds soaking wet, chain smoker, serious drinker, and actually entertaining. She once sold a tourist a jar full of gold at a reduced price. He was so excited to show everyone his jar of gold at the Atlantic City Mercantile, until he discovered he had paid more than $5000 for jar full of worthless mica. Within a few days, the Atlantic City volunteer fire department responded to a fire.  Barbara's old Cadillac was ablaze.

Visible gold in rhyolite from Arizona. When you see this
much gold - you struck it rich. A rule of thumb. If you see
one tiny spec of visible gold on a rock sample, it will assay
close to 1 ounce per ton. A rock with this much gold likely
would assay 100 ounces per ton
.
On another day, Barbara latched on to a well-dressed tourist from Missouri who stepped into the Atlantic City Mercantile to ask directions. Barbara sat down with the unsuspecting visitor and did her best to sell him the Mary Ellen gold mine  south of town, until he told her he and his son Steve, actually owned the Mary Ellen mine. 

Then there was a University of Wyoming geology professor. Now this one really took the cake! The professor wrote on UW letterhead paper that 297,000,000 ounces of gold reserves existed and had been identified at Pine Mountain west of Casper, near the Rattlesnake Hills. The only problem, no gold had ever been identified at Pine Mountain even though it has been a popular site for mining scams similar to the South French Creek area in the Medicine Bow Mountains. After this professor and others were investigated by the secret service, no charges were files as no money had yet exchanged hands - so the university promoted the professor.

One way to learn about gold is to read some good gold prospecting books. Then find a gold district near your town you can visit (don't buy and jars of gold) and get out on some mine dumps and start examining the area around the old mines. Look for any lineaments such as narrow quartz veins running towards the old mine dump you are standing on and walk along this vein. If there area lots of prospects on the vein, this start looking at the vein and learn all you can. See if you can follow the vein for a few hundred feet, a few thousand feet. 

The color of natural gold is impressive. These gold flakes from the Dickie Springs paleoplacer
gold deposit in Wyoming, have very high specific gravity. As you swirl water in your pan, these flakes
 will be difficult to move (unlike mica). Mica will seem to stay in place as you swirl water in your
pan, but when you look close, mica tumbles in the water because of low specific gravity.

You might also look for linear depressions. These could be related to faults or shear zones. See if there is much in the way of prospects on these depressions. If there are, it is likely an old mineralized shear zone.

(2) Learn what gold looks like. This is important. Visit museums, look at photographs in books and on the Internet. Usually, the only thing that is mistaken for gold is pyrite and mica and sometimes chalcopyrite. Most people mistaken mica for gold - like Barbara's friend at the Atlantic City mercantile. Years ago, I wrote an article for the ICMJ about a prospector in Centennial Wyoming who had been jumping someone else's mining claim on the Middle Fork of the Little Laramie River all winter long. His name may have been 'John', but he used different aliases when talking to me. Anyway, he mined all winter using snow shoes to get to the claim and recover all of the gold he could, hopping not to be discovered. He told me he accumulated a few barrels filled with gold in his single wide trailer at Centennial. Finally, he brought in a couple of Ball jars filled with the material to verify his riches. You could see the disappointment when I told him he had some high-quality planting soil, but no gold.

Visible gold in quartz and hematite, Carissa Mine,
South Pass, Wyoming
(3) Visit old mining districts. Read about the old mining districts you visit and keep in mind a couple of things - legends are just that - they are legends often concocted by an old prospector in a bar in the past after having one too many drinks. So why waste your time on some one's past drunk when there are still plenty of gold deposits to be found. It is extremely rare (actually rarer than getting the truth from a politician) for any gold mine to be mined out. Gold miners always leave a lot of gold in the mines and in the veins that they mined along. At one time not so long ago, gold prices were only about $18/ounce, then about $20/ounce and then $35/ounce. Just the other day (1/17/22), they were $1,824/ounce

When gold prices are low, miners only mine high grade material, typically material that assays better than 0.2 opt Au. Today, some companies mine gold ore at an averages of only 0.01 to 0.02 opt (ounces per ton) and better. So, the past miners left all of the low-grade gold ore and often missed a lot of high-grade gold ore. Think about it, how many times have companies gone back into old mines or old districts and began mining in an old mine. New mining districts are rarely found, so stick to the mining districts until you have a lot of good experience.

It is worthwhile to visit old gold mines that made a profit prior to the War Production Board closing all gold mines in the US in 1942. Many of these mines never reopened after the second world war for many reasons, but these were commercial mines at a low gold price. At today's gold price, which is about 50 times greater than when these mines closed, these should be viable.  Also, search the old US Bureau of Mines publications on mining districts. The Bureau of Mines was an excellent and pragmatic group of geologists, engineers and chemists who were mostly fired from their jobs after producing extremely valuable material on mines, exploration, mining, recovery, etc. simply because of the Clinton Administration who objected to their scientific data - i.e., it wasn't green. Politics like this destroys people's lives and does little to help anyone (other than multi-millionaires like Clinton and Gore).

Giant King gold mine, CA. Note the iron stained (gossan) in the blue serpentinite. Some serpentinites have gold, some platinum and palladium, some will have nickel, and in California, some may have gemstones of benitoite or sapphire.


Thursday, June 28, 2012

Gold Processing & Extraction While Bear Hunting


Visible gold in goethite and quartz,
Mary Ellen Mine. (Steve Gyorvary specimen).
If you decide to mine lode gold, you can keep it simple and dig for specimen-grade gold samples from veins and breccias. Although such samples with visible gold are rare and more valuable than the price of gold, if you have the right vein or ore shoot, they are worth pursuing. When ever you see gossans or tawny to brown limonite and goethite in quartz - look for visible gold! Gossans are something prospectors need to learn to recognize. 

If you decide to mine your lode using open pit or underground methods - you will need deep pockets to pay for mining as well as permitting. In this case, it may be easier to start looking for a company that has the expertise and deep pockets.

Detrital gold is by for the best type of gold to search for as a prospector as it has already been mined by Mother Nature, and now it is up to you to figure out how to concentrate it. To extract placer (detrital) gold from a creek using a gold pan (not recommended as it will wear out your back), sluice, trommel, dredge or some other concentrating equipment, you will likely need permits from the State or Feds. The government is totally out of touch when it comes to permitting, as in most cases they will try to permit you to death. Some states may even require a permit to operate a gold pan on public property even though this would be as absurd as requiring a permit to operate a fork in a restaurant; however, Democrats were actually talking about this when I left Wyoming. One of the easiest ways to find out rules and regulations for prospecting in your state is to join a local prospecting club. Many gold prospecting clubs are associated with the Gold Prospectors Association of America: and there are independent groups such as the Wyoming Prospectors Association. 

GRIN AND BEAR IT! And don't forget to support the NRA, unless you are willing to prospect grizzly country without a gun. Just imagine, panning in Wyoming, Montana, Alaska or even Washington DC and you look up just in time to see a grizzly licking its chops while staring at you 50 feet away. Sure, you can use that brand of bear repellant spray your university professor recommended even though he/she/it has never seen a grizzly except on TV. 

In the woods, a bear can easily sneak up to you, particular when it sees you are listed in the specials on the menu. Remember, it can charge as fast as 35 mph! But, you have that handy, dandy spice, errr, repellant in your pocket or back pack. How fast can you get that vial out of your back pack? "Oh, there it ...." "CHOMP".  

If you are lucky, you may have a little more than a second to get that thing out of your pocket, get the cap off, point and squirt, but I'll bet you end up served on the dinner special. That 700 to 1,500 pound grizzly can cover a short 50-foot distance in .... can you believe 1 second! Don't believe me, you can do the math yourself. And if you are lucky enough to point and shoot your little spice vial. I imagine that  bear mass, with all of its kinetic energy, is not going to stop easily - "splat and chomp!" 

So, the next time your hike and bike Berkeley professor tells you to use repellent, remember he/she/it is thinking about human sacrifice to keep the bears well fed. But if you have a gun, particularly a very large gun (12 gauge), 44 or 45 cal., you may stand a chance. But, why not a 357 magnum? Well, because one of our geologists in Alaska shot a typical, everyday, meat-loving black bear in-between the eyes at point blank range as it was trying to eat another geologist. All it did was give the bear a nasty headache. It knocked the bear down, but then it got up, and ran off until the next day, when it decided to come back looking for another geology snack.

GOLD PANNING POLLUTION. When I was in Wyoming, there was a faculty member in the  Geology Department who thought gold panners were polluting Douglas Creek in the Medicine Bow Mountains. Obviously, she never tried to operate a gold pan herself, otherwise she would not have made such a ridiculous statement.  Gold panning is a real, serious, pain in the neck (as well as the back and especially, the lower back). 
Gold Panning in the Medicine Bow Mountains, Centennial
Ridge district.
No one found gold at what was known as the
Mother Lode, but some found nice specimens of pyrite
(fool's gold)
 and some found almandine and pyrope garnet!
Pyrope garnet is a tracer 
mineral for finding diamonds!
So, somewhere upstream
there is an eroding diamond pipe
leaking pyrope garnet (and maybe diamonds) into
 the creek.

Years ago, I met two prospectors from Lander Wyoming who were working Smith Gulch at South Pass while I was mapping the greenstone belt and old mining districts, and they were recovering about 20 ounces of gold per week. At 1600/ounce, that's only about $32,000 per week. Not bad for two guys.

Often we get use to seeing gold pans filled with gold - this does not really happen in real life; so when we see gold filled pans, remember, the gold was found with some other equipment and placed in the pan for a photo opt.

Panning is an easy - it just takes a little confidence and a couple of pans full of sand and mud, and soon you will be an expert. Gold has a very high specific gravity (15 to 19.3), which means you are going to have to make an serious effort to wash gold out of your pan. So put a little effort into your panning. If you are ending up with a tablespoon or two of what is known as black sand (mostly magnetite with a few minerals such as ilmenite, zircon, etc), with specific gravities around 4 to 5, you are doing good. But be assured, you probably did not wash out much gold as it is 3 to 4 times heavier by volume, than those black sands. 

Stamp mill at Goldfields, Arizona
While panning for diamonds in California, we recovered a gemstone known as benitoite near Poker Flat and chromian diopside from serpentinite in northern California (Hausel, 1996). In Wyoming, we panned many gem-quality garnets, some diamonds, and numerous sapphires and rubies and found dozens of localities where gold had not been reported before (including the Laramie City landfill!) (Hausel and others, 1994). In samples panned in the Laramie Mountains near Vedauwoo, we found fluorite (easy to recognize in black sands - it is purple in this area and crushes easily) and many samples with chromian diopside and pyrope garnet near Eagle Rock. This suggests there are undiscovered diamond pipes! 

While searching for evidence of diamond pipes, we found distinct, small, structurally-controlled vegetation anomalies including one at (41o17'39.96"N; 105o22'46.95"W) along the edge of Eagle Rock. This same area has several beaver ponds to the northwest, any of which could be hiding diamond pipes.

Not too far from Eagle Rock, we identified other possible diamond pipes that remain a mystery. These included the Bowling Pin Anomaly (41o11'15.39"N; 105o19'34.67"W), a circular depression with carbonate in soils that had a couple of bowling pins in the depression. The entire area has many such anomalies including the HJ17 depression (41o12'01.92"N; 105o19'10.46"W). Further south (actually just south of the interstate) we identified 42 highly suspicious cryptovolcanic structure of which anyone of them could be a kimberlite (diamond) pipe. All of these anomalies remain untested due to various access problems.

Arrastra gold concentrator. This was a very primitive grinder with large rocks
attached to a pivot at the center. A mule would walk around in circles pulling
a lever that would continue to drag the boulders over a trough where gold-
bearing quartz would be placed to be crushed.
Other minerals of interest found while panning include a lot of white material that was impossible to pan out. It was too heavy! So I stuck it under a black light and with short-wave ultraviolet light, it exhibited strong, blue fluorescence - it was scheelite (a tungsten ore)! This was recovered from samples (along with gem-quality iolite) near the old strong mine along the 9th street road in the Laramie Mountains.

And what else did we find? At one location in extreme northwestern Colorado, 4 diamonds, 17 rubies and 24 pyrope garnets were panned. Wow, what a find! Actually, this was the site of the historical 1872 diamond hoax fraud which occurred near what is now called Diamond Peak. This diamond scam was amazing as it was an outcrop that was salted in 1871 and 1872 and the crooks scammed US Senators (first time in history that scam artists scammed scam artists). 

A primitive roller mill displayed at the Douglas Museum, Jerome, Arizona.
Eric Hausel stands adjacent to the mill.

References Cited

Hausel, W.D., 1991, Economic geology of the South Pass granite-greenstone belt, Wind River Mountains, western Wyoming: Geological Survey of Wyoming Report of Investigations 44, 129 p.

Hausel, W.D., 1996, Pacific Coast diamonds-an unconventional source terrane in Coyner, A.R., and Fahey, P.L., eds., Geology and ore deposits of the American Cordillera, Geological Society of Nevada Symposium Proceedings, Reno/Sparks, Nevada, p. 925-934.
Hausel, W.D., and Stahl, S., 1995, The great diamond hoax of 1872: Wyoming Geological Association Resources of Southwestern Wyoming Guidebook, p. 13-27.
Hausel, W.D., Marlatt, G.G., Nielsen, E.L., and Gregory, R.W., 1994, Study of metals and precious stones in southern Wyoming: Geological Survey of Wyoming Open File Report 94-2, 61 p.


Gold from Douglas Creek Wyoming. Photo shows gold recovered with the black sands removed (the penny is just used for scale). To remove black sands, simply wait until your panned concentrates are dry. Get a large and strong magnet, cover it with a paper towel and slowly sweep over the concentrates - whamo - nearly all of the black sands will be removed. What you have left is a little gold, garnets, mica and if you look close, you may even find diamond indicator minerals such as pyrope garnet, chromian diopside, picroilmenite, chromite and/or diamond. Diamond has a specific gravity of 3.5 and will often end up in the black sand concentrates. Much of the lighter colored material will be removed during panning: most of which will be quartz with a little feldspar. Quartz has a specific gravity of only 2.7.

Mining on Douglas Creek using a long tom and a
dredge on a rotating platform with shovel.