A GUIDE TO FINDING GEMSTONES & GOLD

Little was known about gold in Wyoming when I began working as a geologist at the Geological Survey in 1977, thus I set out to map, evaluate & find more. I discovered gold everywhere I looked. I was amazed at how much had been overlooked. I published compendiums & mapped several mining districts that were previously unmapped or only partially mapped. I even found a previously missed ultramafic massif (mass of rocks with dark-colored ultramafic [high-magnesian] rocks) with significant palladium, nickel gold & copper mineralization. I even found a whole new gold district.

I have many great stories & memories about these discoveries & some of the prospectors I met. Hopefully, I will be able to soon finish my books on "Gold in Wyoming" and "Mountains of Gold". The first book is a summary of all of the known precious metal deposits in Wyoming & the second is a log of stories about some of the prospectors I met & includes the discoveries I made. I have stories about the hundreds of nuggets in ball jars in Shorty Haddenham's trailer at Atlantic City. This guy had plenty of gold, yet he was living in a single wide trailer in the middle of Atlantic City on public property and cut a hole in his trailer for a 'honey bucket'.  Another character found dozens of nuggets using a metal detector in old mine tailings where no one else found much gold & then there was a prospector who spent one entire winter jumping someone else's claim & panned out barrels of mica thinking he had found the Mother Lode. My research along the UP corridor also led to us finding gold anomalies everywhere including in the Laramie City dump. Many great stories also place at the Carissa mine & elsewhere in the South Pass region.  One of my favorite was a caretaker of the Carissa mine named Charlie. Charlie was a recluse. When a couple of people showed up at the old mine to steal weathered wood from the old historic mill, Charlie did not confront them, instead he decided to remove their car door and when they were finished, he offered a trade.

Photos below . A 34 oz nugget (Rock Creek, South Pass), gold from Douglas Creek, and gold from Dickie Springs (South Pass).
I was lucky enough to be able to map the South Pass greenstone belt at the southern tip of the Wind River Mountains. 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 the gold was structurally controlled in structural reefs that are rich down plunge. One deposit I mapped (Carissa) is a major deposit 1000 ft wide, 750 ft long & probably continuous a few thousand feet downdip.

This deposit was withdrawn by the legislature without any scientific review - shame on the government!. While mapping in the South Pass area, I was able to gain access to about 3 dozen historical mines and I suspect I was the first person in several of these since the late 1800s. At one mine (Tabor Grand) I even found a place where some old miner wrote the year in mud on the rib (side) of the mine tunnel.

I searched the Rattlesnake Hills near Casper because it was an obvious gold target, so in 1982, armed with the concept that the RH were part of a fractured greenstone belt intruded by Tertiary alkalic volcanic rocks, I found gold. I found gold in the RH in veins, shears, Tertiary breccias, stockworks, pyrite. I started a gold rush in the Seminoe Mountains in 1982. Historically, this area received some exploration in the 1800s but always ended up with the prospectors loosing their scalps. When I visited this very interesting greenstone belt in 1982, I found visible gold in quartz vein samples on the old mine dumps. I also recovered samples that had anomalous gold in quartz, altered greenstones, and in altered banded iron formation.

Left - Gold at the end of the rainbow at the Duncan mine, & view of part of the auriferous shear at the Carissa - a major gold deposit with potentially >US$billion in gold.

Of the samples I had assayed, they ranged from anomalous to highly anomalous. One sample of altered banded iron formation contained >1 opt. A sample of quartz vein material from the mine waste assayed 2.87 opt. The better samples were not assayed. Surrounding this anomalous area is a broad zone of propylically-altered (pistaccio to dark green) rock that is nearly 0.5 mile in diameter that probably is a large-tonnage gold deposit of some value. Nearby Deeweese Creek, an immature drainage, likely contains gold and has been overlooked by prospectors and nugget hunters alike.  Another area of interest is very large. Gravel & boulder conglomerates covering many square miles along the north flank of the Seminoe Mountains is unexplored!  Yet, myself, my assistant, as well as Charlie (RIP) & Donna Kortes sampled this alluvial deposit, we all recovered gold from every sample were took from this dry paleoplacer. In addition, we recovered several pyrope garnets & everyone tested yielded a diamond-stability signature.

Some other areas in Wyoming that I really like for gold include Mineral Hill, Purgatory Gulch, Bear Lodge and Copper Creek.  I found samples with visible gold at Mineral Hill and Purgatory Gulch.

As far as silver is concerned - nothing in Wyoming compares to Kirwin in the Absaroka Mountains. Here, AMAX collected channel samples across veins in a couple of mines that yielded >100 opt silver. Why the old miners gave up on these is anyone's guess.

Silver-rich breccia-replacement vein from the Oregon Mine, Kirwin district, northwestern, Wyoming.

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. To the east of Puzzler Hill, highly anomalous platinum-group metals were identified 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.

Platinum-group Province of southeastern, Wyoming.

HOW TO FIND GOLD, SILVER & PLATINUM

I could easily write a book on this subject (actually I'm in the middle or doing so).  There is so much to cover that I will focus on just a couple of general facts. First, there are lode & there are placer deposits. Lode deposits include veins, disseminated deposits & others found in place. Placers are deposits in which the valueble minerals are concentrated in rivers & streams.

Not all veins are as well defined as the image on the left showing the faulted Mary Ellen vein at South Pass.  But this is a classical lode. If such a deposit contains gold, you will likely find a placer deposit immediately downstream from the vein.

Gold placers typically have abundant heavy minerals including black sand (magnetite, ilmenite, hematite, zircon, spinel, garnet). Such heavy minerals may also have other valuable material including cassiterite (tin), scheelite (tungsten) ruby, sapphire, diamond & more. So look for other valuable minerals before discarding.

Placers also typically form following flash flood events, so when looking for gold in a creek, dig down! This placer from Smith Gulch at South Pass (photo below) contained gold throughout the sediment, but there was notable concentration at a contact with abundant organic material associated with coarse grain pebbles & cobbles that provided geological evidence of a past flash flood. At Smith Gulch, two such events were recognized (with good paystreaks) from near the top of the drainage to about 15 feet deep.

The photo on the left (below) is some of the gold recovered from one of these paystreaks. Think all of the gold in the world has been found?  Think again.