Crevicing Still Remains One of Your Best Gold Recovery Methods (Part 3)
("Bigger" may be better for commercial mining operations, but "smaller" can work for the rest of us.)
Large-scale or commercial placer miners would probably throw their heads back and laugh in disdain at this series of posts. After all, for them it's all about about moving dirt...lots of dirt. So the concept of a lone individual or a pair of "pards" rooting around in bedrock cracks and crannies for gold is laughable.
However, for us little guys and gals on the small-scale end of the mining spectrum crevicing or gold sniping makes perfect sense. Especially since we're working with hand tools and a pocketful of loose change instead of pricey construction equipment and monthly checks from the Discovery or History Channels.
3. The Bedrock Factor
As I mentioned in the first post of this series, shallow or exposed stream or wash bedrock is a mandatory prerequisite for crevicing. Without available bedrock to explore and work, crevicing will do you about as much good as sinking your life savings into an ice cream truck franchise in Antarctica. It ain't gonna work.
I've spoken about the differences between real and false bedrocks in the past but it's probably a good thing to hit that point again here. Real bedrock is the underlying rock structure or "country rock" of any given gold locale. Real bedrock forms an impenetrable layer that gold cannot move past or through, despite its weight and density. The more angular and highly fractured the bedrock, the better a gold "catcher" it'll be.
Here's the Kicker
Sure, false bedrocks such as clay layers can prevent all that heavy gold from moving downward in a running stream or dry wash too. I've seen that happen numerous times in my 33 years of small-scale mining and prospecting, and I've recovered some decent placer gold off false bedrocks along the way.
Here's the kicker though...so listen closely. Unlike real bedrock, false bedrock will rarely (if ever) contain fissures or narrow cracks or crevices where gold can accumulate in the way it does when real bedrock is involved. By way of example, I can't recall one instance in my convoluted mining career where I was working false bedrocks and actually did any crevicing.
(There are cracks and crevices galore in this angular bedrock...this type of real bedrock is always preferable over smooth, water-worn bedrock.)
Typically, you'll be right back to the "moving more dirt" routine (the correct way to work false bedrock layers, by the way) using your sluice box, dredge, dry washer, highbanker, or that super-duper, do-it-yourself set up you jury rigged just for moving dirt on occasions like these.
That said, remember this VERY IMPORTANT point straight from the old war horse's mouth (I know you're thinking "ass" aren't you?!)
"Both real and false bedrocks will stop gold's downward movement, but only real bedrock has the ability to concentrate that gold in cracks and crevices."
Or to put it in terms even a Washington, D.C. politician could understand, "You can't crevice clay."
Curve Balls and Change Ups
I know as sure as I'm sitting here pecking out these words that a few of out there are shaking your heads and saying, "Well hell's bells J.R., I've hit some good pockets and pay streaks on clay layers." Yep, undoubtedly you have. But listen to yourself for a moment..."pockets and paystreaks." Placer gold pockets and paystreaks can be found in bench and stream gravels too. That said, my question to you is this: "How many crevices did you find in the process of working those clay layers?"
We all know that Ma Nature likes to throw us curve balls on occasion, so there are exceptions to every rule. I don't know about you, but it when it comes to crevicing for gold I'll opt for focusing on the general rules of order and deal with the exceptions on the rare occasions when Ma Nature winds up and tries to strike me out with a change-up pitch.
Good luck and keep smiling.
If you liked this post, you may want to read: "Keep it Simple"
(c) Jim Rocha (J.R.) 2012
Questions? E-mail me at firstname.lastname@example.org