Gold is where you find it.
I’ve always pondered this deep thought along with others, like; you don’t know what you don’t know and; it’s always in the last place you look that you’ll find what you’re looking for. I haven’t been able to argue with this logic, but because I’m a geologist and have worked in gold exploration from Canada to the tip of South America, I’ll take the liberty of opining on gold.
Working at 15,000 feet in the middle of the Andes Mountains, I’d take a break and on occasion wonder about important questions in my life such as; Why is gold so rare? Why does man value gold? Where did the gold in the crown in my tooth come from? Then reality would set in and I’d think about where gold occurs and how to find it.
Astrophysicists tell us that gold shouldn’t occur on earth, that it came from meteorites that brought it from other parts of the universe. That after millions of years, the meteorites that crashed into our planet were incorporated into the makeup of the earth and gold has been remobilized into deposits where we find it today. This is still not helping me find a gold deposit so I can put beans on the table.
In geology class I learned that there are two main groups of gold deposits; hard-rock and placer. The placer deposit is the one most familiar to the general public. Gold weathers out of the host rock and is concentrated in the gravels of streams and rivers. It’s the type of deposit that weekend miners love. They join mining clubs and go out with metal detectors and gold pans hoping to find a few nuggets so they can show their friends.
The hard-rock deposit types, where gold is still in the rock, are more complicated. They have been extensively studied by renowned scientists, explored for by multimillion-dollar companies and are still not completely understood. What we do know is that they are mostly related to hydrothermal activity (hot water usually near hot-molten rocks that have now cooled). They’ve been categorized into deposit types with fancy names such as; volcanic-hosted-low-sulfidation-epithermal, and quartz-vein-orogenic-mesothermal. These are great names but how do they help the weekend miner find gold?
First of all, not all types of hard-rock gold deposits form placers. The richest gold mining area in Arizona, Oatman, didn’t have much of a placer. Yes, there’s some placer gold in the streams below Oatman, but being the largest deposit in Arizona, you’d think there would be a huge placer under Bullhead City. No such luck.
The gold found in this type of deposit, volcanic-hosted-low-sulfidation-epithermal, occurs as very fine grains. When the rock weathers, the gold is too small and doesn’t form placers. On the other hand, look at the placers found in the Mother Lode country of California. There’s a lot of placer gold and it occurs in fairly large nuggets, the largest weighing 103 pounds. This type of deposit is a quartz-vein-orogenic-mesothermal type and it does form placers.
The placers near Meadview, Arizona, are the strange type that are not fully understood. There doesn’t appear to be a source for the gold but you can find nuggets up to several ounces. The gold is most commonly found in the washes that have reddish colored dirt at the caliche layer- referred to as false bedrock. If you are in dirt that is gray or white, your chances of finding gold are pretty low. My partner and I worked a gold-saver placer-machine for a summer and found some good gold but couldn’t sell the project to a mining company. Since we’re against manual labor, especially at our age, we decided to cut our losses and try to figure out where the gold came from. We have ideas but they must wait until we have renewed energy to go prospecting. For now, our thoughts on where the gold in Meadview came from and where there may be more will join the other important questions and logic in our lives- gold is where you find it.
The moral of this discussion is, if you want to find placer gold, look in areas that have the type of deposits that form placers and don’t waste your time looking below the wrong types. Identify the specific type of ground that has the gold- red colored dirt, curve in a stream, etc., and focus your efforts on the best ground. On the other hand, if you’re looking for a hard-rock deposit of the epithermal type, look for areas with small placers that have fine grained gold and follow them up-stream to the source.
Should you find a hot spot with large nuggets, give me a call so I can join you but don’t tell anyone else - don’t want to cause a stampede of weekend gold miners.
