Showing posts with label gold. Show all posts
Showing posts with label gold. 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, August 26, 2010

Preparation For Gold Prospecting Trips


Claim post on Federal Minerals. I get questions about claim
staking, but I'm as confused as you are. Please contact the
US Bureau of Land Management for information and hope they
provide you with the correct information - they often don't.
As a prospector, you need to learn about maps. Topographical maps provide information on geography and show locations of hills, valleys, mountains, roads, trails, creeks and towns. Geological maps show rock outcrops in relationship to the geography and likely will have locations of mines, prospect pits, trenches, tunnels, veins, faults, shear zones and folds. Geological maps also provide information on types of rocks. 

Know what areas are open to mining claims. Much Federal land is open to claiming, but some is closed to claims. To find out what is open, visit you local BLM (no, not those idiots, the other ones) office. State land cannot be claimed but often can be leased. Private land cannot be claimed unless it has Federal Minerals under the private surface. One problem with mining claims is that new claims are constantly filed, and at the end of the fiscal year, others are not renewed thus claim maps change. Unfortunately, the BLM apparently decided to eliminate claim information on their website.  

Gold nugget found in Rock Creek, South Pass.
The BLM attempts to keep information up to date on this site, but like anything the government does, it is not always correct. So use it as a general guide for mining claims and claim activity then you need to follow up with research in the county courthouse. When prospecting in the field, watch for claim posts as these provide information on claim locations, although just because there are claim posts in the field, this does not mean that the claim is active or even legal. 

Other sources that are excellent for prospecting include Google Earth. With the aerial photos and associated maps on these programs, relationships between geology, topography, mines, prospects, roads and drainages can be seen from the air prior to visiting a area of interest. 

LEWISTON GOLD DISTRICT. Schedule a trip to the Hidden Hand gold mine and vicinity in the Lewiston district of the South Pass greenstone belt in Wyoming. The legal description for the Hidden Hand mine is SE section 5, T28N, R98W and map coordinates are 42o25’30’N; 108o32’39”W. Thus, if you examine the Radium Springs quadrangle and find section 5 with the Hidden Hand mine labeled on the map, it is in the southeast quarter of that section. Or by using the map coordinates, you should be able to zero right in on the mine with Google Earth.

Inside the power house at the Vulture Gold Mine ghost town, Arizona.
Topographical maps cover the area include 2 degree sheets (scale 1:100,000) and 7.5 minute sheets. The 2 degree sheets are especially useful. These can be neatly folded and carried in a shirt pocket, glove compartment, or day pack. They represent general maps covering broad regions that are great for planning field excursions and contain information on roads and geography. For greater details, 7.5 minute quadrangles (scale 1:24,000) are invaluable. Topographical maps are available at some sporting goods stores, outfitter stores, the WGS, US Geological Survey (USGS), University of Wyoming Geology Library and local colleges and libraries. The WGS and USGS will also have geological reports and geological maps, many which can be ordered on-line or over the phone.

 The coordinates of the Hidden Hand mine places it within the Radium Springs quadrangle near the top of the map. The map to the north is the Atlantic City map which may also be useful. Geological maps provide important geological relationships associated with the mine, such as rock types, nearby structures such as faults, shear zones, folds. Find a copy of the geological map of the Radium Springs quadrangle (Hausel, 1988e). Other geological maps in this area that will be of use Atlantic City (Hausel, 1989), Miners Delight (Hausel, 1992e) and South Pass City (Hausel, 2007). Now find a copy of Report of Investigations 44 (Hausel, 1991a). This report will be useful as it is a detailed discussion of the geology and gold at South Pass. Another report that will be useful when learning geology and rock types of the area is Reprint 49 (Hausel and Love, 1992). This report was put together for the Wyoming Geological Association and describes important rock outcrops and will lead you on a personal field trip through South Pass. Now, see if you can find Wyoming Geological Survey Bulletins 68, 70, 71, and 72.

A 7.5 ounce nugget found in tributary of Rock Creek, WY
The Hidden Hand mine is located about 8 miles east, southeast of Atlantic City along the Lewiston road (also referred to as the Oregon trail road) south of both the Lewiston ghost town site and Strawberry Creek. The mine is on a patented claim. Patented claims are claims filed under the 1872 mining law that had enough value the government allowed the claimants to purchase the property at a fair market price. This was done in the 19th century to try to stimulate interest in mining and development of the West (something the government today no longer does - now they just discourage development and protect bugs, flowers and dirt). Today, it is impossible to patent claims. Although I never had access problems to this mine because it sits in the middle of BLM ground surrounded by vast, empty, wasteland, it could easily be blocked off. There is a very disturbing trend that non-mining people buy patented mining claims and then close it off because they feel they have something of value when they have little to nothing other than coyote pasture. This is what has happened to many of the diamond deposits in the State Line and Iron Mountain districts. If it isn't the democrats stealing our future, it's the government stealing our land. Have you seen what the legislature did to the Carissa mine? This once potentially productive gold mine (it likely has more than a million ounces of gold in the ground) is now Wyoming's version of Disneyland.

When this district was mapped (Hausel, 1986c) I stayed in a tent near Lewiston for much of one summer and did not see another person all summer. But that was 25 years ago. Maps that cover this area include the Radium Springs 7.5 minute (1:24,000 scale) topographic and geological maps. 

Now if you examine Google Earth, you should see distinct foliation (closely spaced lines) in the Miners Delight Formation metagreywacke that trend to the northeast. The rocks in this area are folded, faulted and turned on end. Also noticeable is the alignment of the Burr Mine with the Hidden Hand mine and this trend parallels regional foliation. A nearly east-west to northeasterly trending line of vegetation is visible southwest of the Hidden Hand that represents a cross-cutting shear zone that intersects the primary shear at the Hidden Hand. There are several prospect pits and a number of backhoe trench scars (some remain open, others are reclaimed) cut perpendicular to the primary shear zone.

A portion of the Radium Springs Geological Map near the Hidden Hand mine by the author showing shear zones and mines in this part of the South Pass greenstone belt. Greenstone belts are famous for gold in veins and shear zones.

A few things to note on the map: (1) the mine is located at the intersection of a group of shear zones (wiggly lines). At least 5 shear zones (faults) are apparent in the field and on aerial photos. Because of this, the mine shaft sits in highly brecciated and incompetent rock. (2) The mines (black and white squares) and prospect pits (x’s) line up on the map and on aerial photos as these essentially follow the shear structures that are buried under a few inches of dirt. (3) The Hidden Hand shear zones are offset along faults (dark, solid bold lines) to the south (where they appear to terminate) and to the north at Strawberry Creek. (4) A few hundred feet of the shear structures continue under much younger rock and dirt labeled as Tu along the bank of Strawberry Creek. Thus there is likely some gold sitting under Tu. (5) Strawberry Creek and Burr Gulch likely accepted much of the eroded gold eroded during the past, thus downstream from these shear zones (to the east) would be a very good place to prospect for placer gold.
 
The shaft was sunk on a 10- to 30-foot-wide, N40oE-trending, 62oNW-dipping shear in chloritized, hematitic metagreywacke (the normally black rocks actually have a slight reddish to greenish hue due to rock alteration) The shaft was 110-feet deep and the shear was explored by at least 640 feet of drifts prior to 1926. Ore from the 30-foot level was reported to run as high as 75 opt Au (ounces per ton in gold). In 1916, about 1000 tons of ore with an average grade of 4 opt Au were reportedly stockpiled. Some specimen-grade material assayed 3,100 opt Au (since there are only 32,000 ounces in a ton, this indicates that this specimen contained 9.6% gold). I must point out that such high assays must be questioned and are suspect.

Samples of altered metagreywacke that I collected from the dump contained only trace gold (Hausel, 1989). This discrepancy suggests one of a two possibilities: (1) the reported assays were exaggerated or (2) that the property developed a reputation for producing excellent gold specimens that the mine dump was thoroughly picked over by collectors over the years. Little information about this district and mine has been published and the mine workings are inaccessible, thus it is difficult to provide much in the way of conclusions. In addition, the explored structure at the Hidden Hand mine exhibits considerable brittle deformation – something that is more typical of Laramide faulting (post gold mineralization) in this region.

When looking at the Hidden Hand or other prospects, mines and districts, try to learn as much as possible. Soon you will become an expert prospector. If a prospect has a vein, try following the vein on the surface: look for minerals that are described in the area. Try to visualize the vein in three-dimensions. What does the vein look like at depth, how far does it go into the earth: five feet, 500 feet or 5,000 feet? Does it pinch and swell at depth? Does it pinch to 1 inch, is it faulted at depth, does it swell to a giant vein? Of course you can’t be certain, but sometimes there are things around you that give you clues as to what might happen at depth. One minable gold vein in Yellowknife, Canada that I looked at several years ago was only 1 foot wide on the surface, but at 100 feet deep, it is 8 feet wide and rich in gold! What angle does the vein project downward into the earth? 

Outcrop of the distinctly dipping Vulture vein.
Now it’s time to call on the wisdom of Albert Einstein because we need to take a trip back into geological time. If we could step into a time machine and go back about 50 million years, what would the vein and surrounding topography look like? How far in the air would the vein (and surrounding country rock) have projected before erosion leveled the terrain to its current level: 20 feet, 200 feet or 2000 feet? Where did all of the gold in the eroded quartz vein go? If the level of erosion was 2000 feet, there could be considerable gold in the nearby creeks, gulches and draws. Is the vein folded? Folds in quartz are often great places to look for gold enrichment known as ore shoots. 
Limonite-stained gossan found in glory hole near the Vulture vein 
in Arizona.
As an example, look some photos of the Vulture gold mine in Arizona. The vein provides an excellent example of a dipping vein. The photo was taken along its strike (or trend) such that from the point the picture was taken, the vein continues perpendicular to the surface of the photo. Off in the distance is a wooden structure which represents part of the old headframe where a decline shaft was sunk along the vein. The dip of the vein or angle that it projects from the surface into the ground follows the flat surface along the left edge of the vein: here it dips about 40 degrees. But not only is the vein of possible interest. When you walk around this mine area, several things of interest pop up. To the right of the photo is a glory hole of altered rock that is gossaniferous and stained by tawny yellow to brown limonite that likely has some gold. This sits below the quartz vein. Sitting adjacent to this pit and on top of the rock unit is some eluvial and alluvial material that past gold miners thought might be of interest as they dug an adit into the material. In Arizona, there are lots of eluvial gold deposits that eroded from adjacent gold deposits (many are hidden today).  Also, by walking around the area, other things of interest include rehealed breccias (the angular rock fragments have been cemented together with silica rich material). These probably contain gold and in some of the rich porphyry copper districts in Arizona, similar breccia pipes are good indicators of mineralization at depth. And the possibility of older rocks in the Vulture area containing structurally controlled gold may be worth checking because the old vulture mill sits on old, folded schist and gneiss.