Check Those Holes (Conclusion)
Well the turkey stuffing days for 2017 are past us now, so let's move forward with some tips on checking those holes you're digging. It's a simple process as long as you have the right tools for the job.
What's the Premise?
As you're digging down toward China in that hole, you want to A) hit bedrock or B) false bedrock like a clay layer. Barring either of those two possibilities, that means you're digging into gold-bearing gravels where bedrock or false bedrock is undetermined or at great depth. Of these three scenarios the first two are the best for the simple reason that bedrock or any impermeable layer prevents those heavier pieces of placer gold from transiting ever downward. However, good gravels can be exploited in much the same manner using the same premise. That premise? Digging deeper.
(That's the spirit!)
In wet holes or those filling with water the issue can become problematic without the use of a gold detector and/or metal pinpointer. The same can be said of those holes you dig in dry placer ground where the only water you'll find is that you brought along with you in Jerry cans or plastic containers. Again test panning has its limitations in both contexts for what should be very obvious reasons. So hence the detector or pinpointer (or both).
The process is quite simple:
1) As you dig down periodically check the bottom and the sides of your hole.
2) Use a good machine with a smaller "nugget" coil that's more sensitive to smaller pieces of gold or, alternately, your pinpointer (the very same pinpointers used by coin and relic hunters).
(Use a good machine.)
3) Your detector should be set in "all metal" or "iron" mode and should be properly ground balanced to the material in and around your hole.
4) DO NOT use any sort of discrimination function on your machine that will bypass iron. By the way, most pinpointers (if not all of them) operate in an all-metal mode without any discrimination so if you choose to use only that and not a full-blown detector you're good to go.
5) The detector's sensitivity should be set as high as possible without causing problems such as erratic operating behavior, severe fluctuations, tonal garbling, etc. My recommendation? Start at the mid-level and then tune the sensitivity up or down until you get a nice steady threshold.
5) As you search with a detector note that your results will be slightly less effective as the machine's coil is held laterally along the sides of the hole. There's no escaping this fact but the efficiency differential between a coil swept horizontally and one swept vertically is not great enough to make this a life or death deal. Just note that there will be a drop off of effectiveness as the coil is swept vertically along the sides of the hole.
6) When you hear any and all targets, no matter how muted they may be, stop and dig. Place that material in your gold pan. Pan that material out to see what's what. This is true for wet and dry placers. If working dry ground you can sweep your machine or pinpointer over or through the material you just dug to find the target.
(A Garrett pinpointer.)
7) If the target you recovered is iron...good. If it's lead...also good. Both of those materials tend to be found with placer gold. Lighter materials like bits of aluminum are not so good. If the target is gold, well by golly you just made the grade!
8) Using a pinpointer is more laborious but it can be productive if used alone. If used with a good gold machine, even better. It's called a pinpointer for a reason, right?
9) Repeat this process in the hole you're digging or any new holes you dig.
Don't Give Up
In essence, this process is not oriented toward full-on mining using motorized equipment. You'd spend all your time checking holes instead of moving material. However, even in this regard it can prove helpful if applied periodically. This simple process is best employed when you're searching for coarse pieces of gold (or nuggets) where bedrock or false bedrock is visible or at shallow depth. It requires patience and persistence. So don't give up after one or two holes.
Check Their Holes!
Better yet, if you see someone else walking away from a hole they've been working at and shaking their heads in disgust, hop on over there and check it using this method. Something good may turn up for you. But do this after the other person is around the next bend. You don't want them seeing you recover a nice little nugget or pocket from the hole they just abandoned. It ain't good for public relations!
Best to one and all.
(c) Jim Rocha 2017
Questions? E-mail me at firstname.lastname@example.org