Gold, Gold Prospecting & Gold Identification
"A Gold mine is a hole in the ground with a liar at the top".
- attributed to Mark Twain
Little was known about gold in Wyoming in 1977. So, Dr. Daniel N. Miller, Director of the Wyoming Geological Survey at the University of Wyoming hired me to find gold, gemstones and diamonds. Over the next 3 decades, I found hundreds of gold anomalies.
I set out to map, evaluate & find more gold in the Cowboy State - and along with researching mineral deposits, I was charged with mapping mining districts and ended up mapping more than 1,000 square kilometers of complex geological terrain along with all of those mineral discoveries. At first I got stuck - I mean I really got stuck! On one excursion to the Lewiston gold district (that had been unmapped until I walked the ground), the 1975 Bronco I was driving sunk in a bog all the way to the windows. I couldn't even open a door to get out, so I had to wind down the passenger window and climb out. Then I hiked several miles to Atlantic City to get help. This became a common occurrence for me for my first decade in Wyoming until I realized I was trying to get out in the field too early in the spring. Another time, I made the mistake of driving across some moist bentonite beds and my tires grew in size as I drove long the northern flank of the Owl Creek Mountains, until the diameter of my tires would no longer fit in the wheel wells. I walked 8 miles to get help. By the time I found help, I was inches taller due to all of the bentonite stuck on my boots. Don't laugh - I know some of you did the same thing!
I discovered gold nearly everywhere I looked and was amazed at how much had been overlooked. So, how did I find so much gold? Easy! I went to known gold districts, found the strike (trend) of the gold-bearing structures whether they were veins or shear zones, and then I walked along trends of these structures and found many gold anomalies and some visible gold specimens that everyone up to that point had overlooked. Now I'm doing the same thing in Arizona. Arizona is filled with gold deposits. My recommendation would be to visit a district - such as the Oatman (San Francisco district) because veins and old mines are everywhere! Take a look at the Moss and Gold Road mines north of Oatman - these are relatively recent start-ups because someone did exactly what I do - search along trend. BUT, it the Oatman district, you have the added attraction of finding large, rich, hidden (known to prospectors as 'blind') ore shoots at depth. So, how do you find those? Good question. When I have an answer, you will be the first to know. I describe these and other deposits in my GOLD IN ARIZONA bound book and Kindle book available on Amazon with some of my other books. You won't believe how many gold deposits are just sitting out there - and I guarantee, many are commercial.
From 1977 to 2006, I published compendiums, consulted on gold deposits around the country, & mapped mining districts in Wyoming that were previously unmapped or partially mapped. I even found a whole new gold district (Rattlesnake Hills). And while I was consulting in Alaska in 1988 and 1989, seven of us found one of the 10 largest gold deposits in all of human history! Last I heard, they had about 42 million ounces drilled out, another 140 million ounces inferred, and they still had another 60% of the gold-bearing intrusive that we found at Donlin Creek to drill. No, I didn't get any of the gold, but I did get a slab of rock with my name on it - come to think of it, I'll trade my slab of rock for some of that gold!
For my first 28 years, the Geological Survey gave me the keys to a 4-wheel drive vehicle and all the freedom I needed, and I was happy, bubbly, and off and running. I can't even begin to tell you how many deposits were overlooked by previous geologists - it was as if most went to the field with blinders - and then, who knows how many I missed? I have many great tales, stories & memories about these discoveries & prospectors I met. In 2011, I wrote a book with my son, Eric (also a geologist), entitled "Gold". This book includes locations of nearly every gold deposit and occurrence I discovered and evaluated over 30 years. Many of the anomalies are worth further examination as they could lead to additional discoveries.
I sampled many gold deposits in the Lewiston district at South Pass that had little to no available information. When I mapped the district, I assayed a handful of rocks and found a few quartz vein samples assayed more than 1 ounce per ton in gold! I looked at other rocks and found visible gold. Later, I showed a vein to a gold hunter from West Virginia. I kid you not, his name was James Bond. Bond wanted to get a good sample of visible gold, so I told him to dig out some quartz from the exposed shear zone (lode) where I received 1.29 opt Au in an assay. He knocked off some quartz and found the best gold-bearing quartz samples I had seen from Wyoming - yes I was jealous! But think of the eluvium and alluvium downstream from this lode. Must be some nuggets sitting in that drainage. This is the kind of information Eric and I packed into our Gold Book.
Then there was a prospector I met in Atlantic City. His name was Shorty and owned the St. Louis mine that I wanted to get access to map. Shorty had hundreds of nuggets in ball jars in his trailer in Atlantic City, yet he was living in a single-wide, trailer in the middle of downtown Atlantic City with all 50 other people in town. He cut a hole in his trailer for a 'honey bucket'. For those who do not know what a honey bucket is - it's what we receive from Congress. Yes the gold was there - he showed me. I only wish I had a camera at the time.
Another prospector found more than a hundred nuggets using a metal detector in dredge mine tailings where no one else bothered to look. Then there was a prospector who spent an entire winter jumping claims & panned out barrels of mica thinking he had found the Mother Lode. He had barrels potting soil, but no gold, so karma got him. My research along the Union Pacific Railroad corridor also led to gold anomalies. We even found gold anomalies in the Laramie City dump.
There was a caretaker of the Carissa mine at South Pass City, named Tony. Tony was a recluse. When a couple of people showed up at the old mine to steal weathered wood from the old historic mill, Tony did not confront them, instead he decided to remove their car door. When they finished, he offered to trade doors.
I mapped the South Pass greenstone belt at the southern tip of the Wind River Mountains (greenstone belts almost always contain gold, iron, nickel and other valuable deposits). This area included several historic gold districts: Lewiston, South Pass, Atlantic City, Miners Delight & others. I identified several hundred gold anomalies in the area & found that the gold was structurally controlled in folded reefs that likely have rich ore shoots that continue down plunge for thousands of feet. At the Carissa mine, gold occurs in a 1000-foot wide shear zone, that is at least 950-feet long & probably continuous to a few thousand feet downdip. In other words, it appears to be a major gold deposit. But, in the wisdom of politicians, the legislature purchased the mine and withdrew it from mining, without scientific review! Shame on you guys!
While mapping South Pass, I was able to gain access to about 3 dozen historical mines and was the first person in several since the late 1800s. At one (Tabor Grand), I came across markings in a mine rib, where some old miner inscribed the date in the mud.
I searched the Rattlesnake Hills near Casper because it was an obvious gold target. In 1982, armed with the concept that the Rattlesnake Hills were part of a fractured greenstone belt intruded by Tertiary alkalic volcanic rocks, I found gold! I found gold in veins, shears, Tertiary breccias, stock works and pyrite. I started a gold rush in the Seminoe Mountains in that same year. Historically, the Seminoes were prospected in the 1800s but many prospectors lost their scalps. When I visited the greenstone belt in 1982, I recovered rocks with anomalous gold in quartz, altered greenstones, and in altered banded iron formation.
One sample of altered banded iron formation from the Seminoe Mountains had >1.0 opt. The sample of quartz from mine waste assayed 2.87 opt. Better samples were not assayed. Surrounding the anomalous area was a broad zone of propylically-altered (pistaccio to dark green) rock mapped by Terry Klein of the USGS that is nearly 0.5 mile in diameter that could contain a large-tonnage gold deposit of value.
Deeweese Creek, an immature drainage, likely contains gold. It drains this area. Then there is gravel & boulder conglomerates covering many square miles along the north flank of the Seminoe Mountains! Yet, Charlie (RIP) & Donna Kortes sampled this alluvial deposit with me, and we recovered gold in every sample we took from this dry paleoplacer. I also found several pyrope garnets that were tested and all yielded diamond-stability geochemical signatures!
Other areas in Wyoming with gold potential include Mineral Hill, Purgatory Gulch, Bear Lodge, Silver Crown and Copper Creek. I found samples with visible gold at Mineral Hill, Purgatory Gulch and at the Copper King in the Silver Crown district.
As far as silver is concerned - nothing in Wyoming compares to Kirwin in the Absaroka Mountains. Here, AMAX collected channel samples across veins in mines that yielded >100 opt silver. Why the old miners gave up on these veins is anyone's guess.
Platinum-group metals are found at a number of localities in southeastern Wyoming. I located a vein and shear zone at Puzzler Hill north of Encampment with highly anomalous palladium, platinum, silver, gold and copper. East of Puzzler Hill, highly anomalous platinum-group metals were discovered in Lake Owen and Mullen Creek complexes. At one location, the New Rambler Mine, actually operated on a copper-enriched palladium deposit in the early 1900s.
Lode deposits include veins and disseminated deposits where the rocks are found in place. Placers are detrital deposits that have valuable minerals concentrated in rivers & streams. Gold placers typically have abundant heavy minerals including black sand (magnetite, ilmenite, hematite, zircon, spinel, garnet). Such black sand may also contain other valuable material including cassiterite (tin), scheelite (tungsten) ruby, sapphire, diamond & more. So look for all valuable minerals in your gold pan.
Placers are enriched after flash floods. So when looking for gold, dig down! The Hudspeth-Presgrove placer in Smith Gulch at South Pass, contained gold throughout the sediment, but there were notable enrichments at contacts with abundant organic material associated with coarse grain pebbles & cobbles suggesting that past flash floods were responsible for the gold enrichment. A second pay streak was found on bedrock. Similar pay streaks were recognized in nearby Rock Creek.
So, how do you identify gold? Easy, look for a high price tag. Just kidding. Gold is malleable (remember watching those cowboy movies where the old prospector bites the nugget to check if it was gold), and it is very, very heavy (about 19 times heavier than an equivalent volume of water). Need more information about GOLD, just click Here.