Bedrock and Gold: The mysteries . . .

Lanny in AB

Gold Member
Apr 2, 2003
5,670
6,413
Alberta
Detector(s) used
Various Minelabs(5000, 2100, X-Terra 705, Equinox 800, Gold Monster), Falcon MD20, Tesoro Sand Shark, Gold Bug Pro, Makro Gold Racer.
Primary Interest:
Prospecting
Do you love to chase the gold? Please join me--lots of gold hunting tips, stories of finds (successful and not), and prospecting poetry.

Nugget in the bedrock tip:

I had a visit with a mining buddy this past weekend, and he told me of an epic battle to get a nugget out of the bedrock, and of what he learned from the experience. I thought some of you might like to learn from his mistake.

While out detecting one day, he came across a large sheet of bare bedrock. The bedrock was exposed because the area had been blasted off with a water cannon (a monitor), by the old-timers! It was not fractured bedrock, in fact it was totally smooth.

He was not optimistic at all of the prospects of a nugget. But, for some reason (we've all been there) he decided to swing his detector over that bedrock. After a long time, just as he was about to give up on his crazy hunch, he got a signal, right out of that smooth bedrock.

There was no crevice, no sign of a crevice, nada! So, he had to go all the way back to camp to get a small sledge and a chisel. The signal in the rock intrigued him, but he still wasn't overly optimistic. For those of you that have chased signals in a similar situation, sometimes there's a patch of hot mineralization in the bedrock that sounds off, but this spot, according to him, was sharp and clear right in the middle of the signal, not just a general increase of the threshold like you get when you pass over a hot spot in the bedrock.

Anyway, he made it back to the spot and started to chisel his way into the bedrock. If any of you have tried this, it's an awful job, and you usually wind up with cut knuckles--at the least! Regardless, he kept fighting his way down, busting out chunks of bedrock. He kept checking the hole, and the signal remained very strong.

This only puzzled him all the more as he could clearly see that it was solid bedrock with no sign of any crevice. He finally quit at the end of the day, at a depth of about a foot, but still, nothing in the hole.

An experienced nugget shooting friend dropped by the next morning to see him, and asked him how the hunt was going. My buddy related his tale of the mysterious hole in the bedrock, and told the friend to go over and check it out, and see if he could solve the riddle.

Later in the day, the other nugget hunter returned. In his hand was a fine, fat, sassy nugget. It weighed in at about an ounce and a quarter! After my friend returned his eyeballs to their sockets and zapped his heart to start it again, he asked where the nugget had come from.

Imagine his surprise when he heard it came from the mystery hole!! He asked how deep the other guy had gone into the bedrock to get it. "Well, no deeper" was his reply.

So, here's the rest of the story as to what happened. When the successful nugget hunter got to the bedrock, he scanned the surface got the same strong signal as my buddy. He widened out the hole and scanned again. Still a solid tone. He widened the hole some more so he could get his coil in, and here's the key and the lesson in this story, he got a strong signal off the side of the hole, about six inches down, but set back another inch into the side of the bedrock!!

My unlucky friend, the true discoverer of the gorgeous nugget's resting place had gone deep past the signal while digging his hole!!

Now, of course, a good pinpointer would easily solve this problem. The problem was, my buddy didn't have one, so why would he widen the hole, right? Well, the other guy was the one with more experience, and that's why he did. It was a lot more work, but what a payoff!

So, my buddy's butt is still black and blue from where he kicked himself for the next week or so for having lost such an incredible prize.

Some nugget hunting lessons are harder than others to learn. . . .

All the best,

Lanny


P.S. When in gold country--check the bedrock, regardless of whether it looks likely or not! Mother Nature likes to play games sometimes.

 

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Upvote 7
I moved this response to my home thread. It was a reply about air tests for targets basically, or even if they matter at all, with some other information thrown in about sizes of coils and what their respective design strengths are, etc.

Ok, so here's the thing with air tests and gold. First of all, a one gram nugget does not have a lot of surface area. Compare the surface area of a dime or a penny to your nugget, and you'll get the idea. Moreover, I've had all kinds of nugget retrieval experience where as soon as the nugget was dislodged from its original resting place, the signal strength dropped off. And, if I've moved the piece of gold more that just a bit, it's far harder to find it again than when it was surrounded by its original minerals and dirt.

To clarify something else, a big coil is not designed to be as sensitive in the air or in the ground as a smaller coil: you use the coil as designed for its strengths and purpose--big coils for depth and size, smaller coils for smaller and shallower gold. And with your DD coil, it will find tiny gold close to the surface or gold lying on the surface. I was shocked at how small a piece the 705 with the elliptical DD (10X5) could find.

Never underestimate whatever is going on in the ground that enhances the nugget signal, and never get discouraged from the results of air tests: a test of gold resting in intact ground is nothing like an air test, and vice versa. You really need to file that information deep in your brain so you know the purposes for air or ground testing, and it will save you a lot of confusion in the future.

On a related note, read that manual nightly until you've absorbed every bit of advice on how to use your machine in all metal mode to detect gold. Read and reread to learn the way to meet your need. See if you can find any youtube videos or free ebooks on using the machine. Check out tips on the manufacturers home site. Read what Steve Herschbach has to say about the value of air tests vs. a true ground test for gold in undisturbed ground. It's revealing and necessary.

Learn your machine and it will find you the gold. With me, I was so busy learning my pulse machines that I wrote of my VLF! That was just wrong-headed thinking. I had to have surgery on my shoulder, and while it was healing, I could not use my heavy pulse machines. So, I was forced to learn the 705, and it did not disappoint at all. The simple fact was that I hadn't done the research and put in the time to learn the strengths or methodology of the all metal mode for detecting gold, nor the special optional features of the machine while in all metal mode. For me, necessity was the mother of motivation to drive me to swing something lighter. Now, I love that little machine when I want to swing a detector all day and don't want to feel worn out.

So, learn it and you'll earn it, the gold that is.

All the best,

Lanny
 

That is an issue, and it does help with falsing if you can stop that wire from moving. It has to be a design flaw. I've used gorilla tape to stop mine from moving but the epoxy route sounds like a better idea. When you get it to run quiet, it works very well for small spaces. I keep fiddling with mine, so I think I'll try the epoxy to see what happens. Thanks for the tip.

All the best,

Lanny

(As posted in Cdn forum) "I've had the Falcon MD-20 for about 3 months and can say it is a great unit! It will find the smallest of gold - as well as a very useful tool for detecting black sand deposits. I have had some longevity issues however. After using the unit for a month or so the RCA male connection going into the unit appeared to have a short. The unit would go off by itself and became very frustrating. The end solution was chopping off the original connector - and soldering on a new RCA plug to connect the wand to the main case. I am sure Falcon will repair this issue for you - but it should be designed a little better. When these units are being packed - and used in the field all day, they should be able to stand up too a little more abuse. It almost seemed as if the internal soldering had become compromised."
 

Seascene, thanks for the information.

All the best,

Lanny
 

Seascene, thanks for the information.

All the best,

Lanny

Most welcome... hopefully helpful. Also, found this in my notes about re-calibrating the MD 20. Hopefully, someone on the forum will confirm or edit the following re-calibrate instructions:

"You can easily re-calibrate the unit by using the following instructions:
Make sure you only adjust R2.

1 Open up the box and locate R2 on the circuit board. It is
probably a blue square directly behind the ground balance knob. Scrape the wax seal off the top of R2 and using a small straight blade
screw driver turn R2 counter clock wise until it stops.
2. Turn the unit on and turn both knobs counter clock wise. Place
the copper ring just over the red line on the probe. You should hear
no sound at this time.
3. Turn R2 clockwise until the unit sounds. Slide the copper ring
back to the black line. The unit should stop sounding. Slide the
copper ring back toward the red line. The unit should sound just as
the copper ring covers the red line.

The MD20 should be ready for use.
You will not invalidate your warranty by turning R2."
 

I will bite. Why would anyone have to perform the R2 adjustment? I would expect (and maybe wrong) to think the R2 is a macro switch was intentionally wax sealed by the manufacturer, so it would not be moved. ie. they set it once and the only necessary adjustments are micro tuning with the copper ring. At the end of the R2 recalibration, has anybody had the dial optimized to a new spot?
 

I will bite. Why would anyone have to perform the R2 adjustment? I would expect (and maybe wrong) to think the R2 is a macro switch was intentionally wax sealed by the manufacturer, so it would not be moved. ie. they set it once and the only necessary adjustments are micro tuning with the copper ring. At the end of the R2 recalibration, has anybody had the dial optimized to a new spot?

Good point and maybe will be answered here. The re-calibration procedure originated from Falcon tech by over the phone instruction to a poster on a Cdn prospecting forum who passed it on to the forum. As such, my concern in the above posting is that the instructions heard were correct.
 

I moved this here to my main thread. It's some thoughts I had running through my snow-bound brain today:

Gold fever in winter gets bad
'Cause minin’ just ain’t to be had.
No pannin’ to do
Gets me feelin’ blue.
This fever's sure drivin’ me mad!

So how does a miner stay sane
When fever is cookin’ his brain?
Is shoppin’ the way
To get through the day?
Will toys kill this gold-fevered pain?

My shed and my basement are filled.
Will buyin’ more stuff get me killed?
My wife’s said, "Enough!"
But she ain’t so tough . . .
As long as she don’t see we’re billed.

I know of a prospectin’ store
With coils and detectors and more.
So, I’m off to buy,
And then I will try
To sneak it inside the back door.

All the best,

Lanny
 

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Some thoughts on detecting:

I had the chance to detect an abandoned placer pit this past summer. There was a lot of exposed bedrock, and everything sure looked good, but the gold just wouldn't come out to play as I worked my way down-slope.

I worked right up to the standing water in the bottom of the excavation, and all of my work only turned the magnet on the end of my telescoping wand into a porcupine on steroids from finding all the little bits of track and blade left by the excavators and dozers.

The pit sloped down at about a thirty degree angle as that's how the bedrock sloped away from the mountain. Originally there was a heavy covering of glacial clay, gray stuff mostly, with a top covering of yellow wide-channel-run with some heavily oxidized pockets of cobbles. But what that top channel held is a story for another day.

So, I was down in the bottom of the excavation, and I took a breather. It was a warm afternoon, not hot, but pleasant. There were just a few tiny white clouds, little puffs really, located way up in the cobalt sky that sailed high above the tallest peaks. The song birds played a pastoral, wondrous symphony. The sound of the rushing river floated down to me, a never ending sound of the liquid current of life. The pines and firs generated a comfortable background for the brighter, fresher greens of the Tamaracks. How was I so lucky to be in such a beautiful place.

After my little break, and after a cool drink of water, I looked back upslope in the excavation and noticed a slight rise in the bedrock, a mini-ridge if you like, about a third of the way from the top edge. I'd collected so much metal there on the way down that rather disgusted, I'd moved on quickly just to get away from the mess. But now that I looked back at it, it got me thinking. "If I was a piece of gold, that would sure slow me down, if not outright stop me." So, back upslope I went.

I had the Minelab 5000 with the little 5 inch sniper coil, a great match for the bedrock I was working. There were hot and cold zones that fluctuated quite rapidly in the bedrock, and the chunks of magnetite were prolific in their pea-sized plenty. That little coil ignored everything except metal, and soon I was building a fresh beard on the super-magnet.

After I'd cleared the ridge of the loud, obvious targets, it was time to slow down, to start scrubbing the ground and to investigate every little break in the threshold. There was a spot that still had some clay trapped in a little pocket and the threshold broke. I scraped off about an inch of the clay and scanned the spot again. This time the threshold break was a weak, repeatable tone, one there when I scanned from a 90 degree crossover as well. I couldn't imagine it would be iron or steel as the capping of clay seemed virgin.

I scraped as much clay and small stones out of the pocket with my pick as I could, then scanned again. This time the signal was solid, but still very soft. As I was now at bedrock, with no more covering clay, my brain was telling me it was likely a small target, whatever it was. I chipped at the bedrock and worried the magnet in the pocket, but no clinging iron or steel this time. Scanning again produced the same soft tone.

I took out a chisel I always pack along when working bedrock and gently chipped away at the edges of protruding bedrock. The signal was marginally stronger this time, but still soft. So, I went to work on the pocket with the chisel and popped out a bunch of broken bedrock from the bottom. There was nothing in the hole but a clear signal in the pile. Sifting and dropping bits of the pile onto the coil, I soon heard the target hit. As I moved the material around on the coil with my finger, I heard the target slide. A bit more maneuvering produced the nugget. It was a round little beauty, about the size of a BB-gun BB, thus the soft sound I'd heard in the bedrock.

I wish I could say I liberated more nuggets that day, but that was all there was, and the only reason I found it was because it got hung up by that slight change in the slope of the bedrock. Another lesson learned that payed off in a big way later that same season, but that's a tale for another day.

All the best,

Lanny
 

I will bite. Why would anyone have to perform the R2 adjustment? I would expect (and maybe wrong) to think the R2 is a macro switch was intentionally wax sealed by the manufacturer, so it would not be moved. ie. they set it once and the only necessary adjustments are micro tuning with the copper ring. At the end of the R2 recalibration, has anybody had the dial optimized to a new spot?

The re-calibration sequence is correct.
And: "Recalibration may be required because of component value changes caused by age or temperature extremes"

... from Falcon
... hopefully will help settle down the wee beastie for some. Just tested mine after re-cal and works fine again....
 

The re-calibration sequence is correct.
And: "Recalibration may be required because of component value changes caused by age or temperature extremes"

... from Falcon
... hopefully will help settle down the wee beastie for some. Just tested mine after re-cal and works fine again....

That's great! I've seen those instructions before, but I can't remember if they came on a card with the machine or if I found them online. Regardless, I'm glad your machine is running smoothly again.

All the best,

Lanny
 

This little video is amazing! It's not a true fit for my thread, but as I love to scuba, and as I love to recover gold by diving while dredging, I just have to post it! I'd be making all kinds of noise underwater as well if I'd found something like that!! Plus, watching a video like this really does help soothe my gold fever winter blues.



Plus, here's another fever bustin' video that reminds me of what it's like to be minin':


And, if this one doesn't cure the winter blues fever, nothin' will:





All the best,

Lanny
 

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This gold is amazing:


The two that follow are just fun!



This last one can only be described as incredible. I mean, I've found sun-bakers before, but this thing is in a league of its own for a sun-baker!


All the best, and I hope I've helped somewhat with your (and my) winter blues gold fever,

Lanny
 

The Montana video? Wow. You showed me what was happening in my Area 1 mine and filled in several pieces of my puzzle. Only thing missing (for me) is the location of a very long hand built sluice.
 

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What the heck, here's some more:





All the best, and I'm feeling much more gold recharged now,

Lanny
 

Thanks for dropping in Jeff! Always nice to hear from you, and I certainly hope that this is the year when you'll tie into some beautiful gold.

Now that I've posted some golden eye-candy, I'll have to get around to writing another story or two before too long.

All the best,

Lanny
 

Is there any visible bedrock? It's hard to tell from your picture, but as the hillside by the channel seems to have remained quite similar, there must be something making the river right-angle like that.

Can you use a dredge to sample along the hillside to see where of if there's any bedrock to be hit? If not, a good sampling program along the side will tell you what Mother Nature's been dropping along there over the years.

As for your inside bend, that looks quite promising if there's good gold in the area as nature can't construct a much better low-pressure system in the water flow than the one in your pictures! The first jut (starting from the left, if the stream is flowing left to right) will drop some gold in a suction eddy during high flow, and the big bend that follows will create a super-suction eddy where heavies will have to drop out during high flows, with fines dropping during regular flow.

So, hopefully your bend will produce some nice fine gold on a regular basis, with the coarser stuff dropping during higher flows. There's a shot at hitting a very nice pay streak if it hasn't been worked that much, but I know nothing of the gold recovery history for your claim. Additionally, you may have some coarse gold slam into that right-angle of the side-wall and spin out gold as it loses velocity there as well.

It should prove to be a very interesting sampling session for you. Moreover, be sure to let us know how it works out in the 2016 season.

All the best,

Lanny

Took advantage of the beautiful weather here and hiked into the claim and it was worth every second of the hike in. Yes Lanny there is exposed bedrock.( this explains the hard right angle ) The point is all bedrock and extends a long way into the river (should be a good drop zone) The hill side also has exposed bedrock and possible more when the snow is gone. The high water mark shows and where it meets the upper bench it looks like it is exposing and eroding each year. We did some pan sampling and got some fine river flood gold flakes. The real surprise was the amount of black sand. When near the end of panning down to the very last fines at the very least half the pan was black sand. Looks like many years of good detecting here..........

River 2.JPG......River 3.JPG......River 6.JPG
 

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Took advantage of the beautiful weather here and hiked into the claim and it was worth every second of the hike in. Yes Lanny there is exposed bedrock.( this explains the hard right angle ) The point is all bedrock and extends a long way into the river (should be a good drop zone) The hill side also has exposed bedrock and possible more when the snow is gone. The high water mark shows and where it meets the upper bench it looks like it is exposing and eroding each year. We did some pan sampling and got some fine river flood gold flakes. The real surprise was the amount of black sand. When near the end of panning down to the very last fines at the very least half the pan was black sand. Looks like many years of good detecting here..........
/QUOTE]

Well, it's nice to know you've got bedrock, and it's great to know you found color, plus I wish you well with your detecting. I admire your tenacity to get out to inspect your claim on a snowy day. But, I've gone out chasing the gold in the snow myself, so I understand the drive to do so, especially this time of year.

All the best,

Lanny
 

Took advantage of the beautiful weather here and hiked into the claim and it was worth every second of the hike in. Yes Lanny there is exposed bedrock.( this explains the hard right angle ) The point is all bedrock and extends a long way into the river (should be a good drop zone) The hill side also has exposed bedrock and possible more when the snow is gone. The high water mark shows and where it meets the upper bench it looks like it is exposing and eroding each year. We did some pan sampling and got some fine river flood gold flakes. The real surprise was the amount of black sand. When near the end of panning down to the very last fines at the very least half the pan was black sand. Looks like many years of good detecting here..........

View attachment 1266875......View attachment 1266879......View attachment 1266880

Hi Cariboo5... what a lovely, scenic claim site you have there. I hope that you have a great summer finding gold... regardless how much or what tools are employed... it's all good. Thankyou for sharing those marvelous photos and making a wintertime effort to visit the claim to do so. Please keep us posted about your sampling activities, and of course any interesting rocks that produce a "beep" on your detector. Be safe out there Dave, and good luck. :)

Jim.
 

Hi Cariboo5... what a lovely, scenic claim site you have there. I hope that you have a great summer finding gold... regardless how much or what tools are employed... it's all good. Thankyou for sharing those marvelous photos and making a wintertime effort to visit the claim to do so. Please keep us posted about your sampling activities, and of course any interesting rocks that produce a "beep" on your detector. Be safe out there Dave, and good luck. :)

Jim.

Thanks Jim, I'm sure looking forward to this spring & summer here. With the diversity and size of this claim we plan to employ different methods such as: sampling in a grid pattern from the bar up to the hillside, metal detecting, sniping and working the bedrock, setting up the high banker as a wash plant and hauling hand dug pay dirt to it and gravity suction dredging.

The area does have magnetite so there is a chance of a "hot" beep. Would be nice to come across the lodestone variety which would be a first for me. If lady luck gives us a hot rock I will let you know.

Thanks again Jim & have a good one......

The attached picture is the top of the claim which gives us more ground to cover.


River.JPG
 

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