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Question about an old hardrock mining operation

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Hello all !

Recently I ran across a mine in which there were several drifts cut into the mountain above each other (assuming I have my terminology correct).  Outside of each of the horizontal shafts were two piles of ore (with quartz and visible gold in some of it).  One pile always seemed to have been classified or crushed to less than an inch while the other pile (usually much larger-approx 15' high) was 3-4 inches in size.  It was in the larger pile that I typically saw the small gold.  

This was obviously an old operation and there were many hundereds of old rusted out cans outside of the mine at the bottom of the mountain.

I was wondering if anyone could describe (in general)  the typical operation the old timers would run to extract their gold which typically results in two piles nearby each horizontal shaft?  These piles are hundreds of feet up on the hillside.  In this case it seems like they have left a lot of gold.  I am sure I could crush and pan a lot of ore but I am primarily interested in detecting these piles for the slightly larger stuff that may have missed their well trained eyes.  But to properly metal detect such piles, I would like to get an idea of the basic steps these miners were taking with these piles.  I appreciate any input.   

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Andyy,

Some pics and GPS cords would help with explaining the process used by the miners.:brows:

In all seriousness the piles may have been classified by size for transport by mule if no roads are around? Saw similar to what you described in the Panamint Mountains near Death Valley. The mines were only accessible by mule and had similar high grade piles near the entrance.

DP

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I can't say as to why, on my claim, I have a few test holes started where they went into the red quartz going up a hill, at least a dozen holes, but none of them were dug more than three to five feet and they stopped.  A few people who've been through my claim say they think there was a rock crushing operation, but I don't really see a huge operation, maybe a small one.  Any samples I've taken from this area of the claim have gotten no gold, so whatever they were after probably wasn't gold, but some other not so valuable metal today.  Oddest thing is these hard rock test holes are absent from the area of the claim that has gold.

I do think it'd be worth crushing the ore with visible gold to get an idea of how much free mill gold would come out of it.  Personally, I would not be able to resist that myself.  From there, if the ore piles are rich enough, I'd consider taking a rock crusher to site.  Probably have to be more than a few tons of ore to make it worth your while and also need to be a permitted op. There was a post on one of the boards / Forums about someone who had crushed a couple of tons of ore and ran it through his drywasher to get a few grams of gold. If not worth your time, could be a claim worth staking for the future.

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Thanks, DP and Chris.   Just to be clear, it wasn't visible gold in every piece.  It was a couple here ... a couple there.  It was still a lot of work to find it and you had to have very good eyes to even know it was there.  So the old timers did seem to get the majority. 

My bet was that the smaller piles had the high grade ore that they were crushing and hauling away on mules.  Maybe that was the material picked out of the big piles.  That was at least what I was imagining.  But I also don't think they could have seen the inside of those larger pieces.  Eventually, I will get back into that area with my GM1000 and a rake to see if they left any good pieces behind.  :D  Tried it originally with my ZED.  But with so much trash, that was impossible.  ZED is only good on tailing piles with very little trash.  

If I get back out there and find something, I will let you guys know what I learn.

Andyy

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Fantastic find. Sounds like you have quite a journey before you. Smaller sounds like the best has been worked to some extent and you don't go through all that trouble for nothing as in in days of   old it had to be 1oz a ton to run and profit-John

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I have a vein that runs 2 ounces to the ton but you won't hear anything with a detector...

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Sounds cool Andy!
Keep us updated. Ive got a little crusher you can use if you want to crush some up and pan it out.

Tom H.

 

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A picture or two would help a lot. What did the stuff in the smaller pile look like? Was it possibly crushed from the bigger pile?

I'd definitely crush and pan some samples though. If you're seeing visible color... get busy. :miner:

 

Edited by ArcticDave
added stuff
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Cowkiller crushed a few of the rocks and found one had a golden surprise.  You may be able to make out the fine gold in the second pic.  But it is hard to see.

 

IMG952018012295175021.jpgIMG952018012095182550.jpg

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Sounds like a great discovery Andy. My suggestion is to keep this location to yourself until you fully understand the potential. Veins come and go. They pinch out, swell, and have pockets. My better half and I chased down a vein a 5-6 years ago that the old timers gave up on. We found a lot of gold before the vein pinched out and faulted. Just chiseled it out and crushed it later. I attached a photo of me (my hand) handing her another nice piece.

As to how your area was worked, that's hard to say without knowing more details about the location. And I won't be asking you. I've seen all kinds of mine workings and reworkings over the years. With old digs miners often built an arrastra nearby to crush and process the ore. In many cases, the old timers mined by sight, they would just hand cobble the ore and throw out any piece that did not have visible gold. I've found more than a dozen muilti-ounce specimens in old talings and have lost count of the number of smaller species detecting and by sight. 

Two piles could be many reasons. Research has proved, more than once, that after the initial miners left, others came in and kept mining the lode and processing the tailings. Some old timers would bring in a small stamp mill and crush on site. When they were done, they'd leave and take the mill with them to the next spot or to sell. It was fairly common for the old times to separate the various grades of ore if there were multiple producing digs in one area. Sometimes the miners separated the ore grades from just one single dig, high and low grade. Methods could vary on number of factors.

One method we've used over the years is to take a rake and attach neodymium magnets to it. Rake the piles starting at the bottom. This will save you a lot of time digging trash with a detector. You may consider drywashing the tailings too.

34.jpg 33.jpg

Edited by Rod
typo fix and addition
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45 minutes ago, Andyy said:

Cowkiller crushed a few of the rocks and found one had a golden surprise.  You may be able to make out the fine gold in the second pic.  But it is hard to see.

 

IMG952018012295175021.jpgIMG952018012095182550.jpg

I can see it fine. You need to investigate those piles further Andy. Like Rod said...keep it on the down low until you've done all you want.

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The top picture is from a couple small rocks with no visible gold. I didn't weigh it but it was way better than I thought it would be. Andy that spot is going to pay good. Get the buckets and the monster I will bring gb2!

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What was the question again ? :idunno: :4chsmu1:

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Thanks Dave and Rod.

In all honesty, it was Cowkiller's young eyes that found gold in nearly the first piece he picked up.  From there things got exciting.  It'll be fun to explore it more.  Of course that was the one time I decided to leave my Gold Monster home... :barnie:

Rod - interesting perspective on possibilities of others working it or why they may have separated it.  I'll probably never know.  And as for the rake and magnet idea, yes, this is a good trick i have used in the past.  It'll be a must for this spot.  That is a nice specimen you have shown. Maybe we'll get a little lucky, too.  

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4 minutes ago, adam said:

What was the question again ? :idunno: :4chsmu1:

LOL.

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My experience from the two ore shoots I have been working was that the probabilty of a crusher not being available led to the high grade ore tossed in the dump. If it was a pocket mine, they took the spoils and left the next grade of rocks needing to be crushed to the side. In my instance, they followed the vein, 45° incline shafts, until the work became too difficult, then caved both shafts. Neither went more than 18 feet down. Also, the grade gold here is not favorable to PI detection, GB 2. This specimen, over an ounce of gold in it, barely sounds off with a 5000 or Garrent ATX swung over it. Gold looks like coral, arboresecent.

586.0 sm.jpg

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On 2/5/2018 at 5:08 PM, Rod said:

I've found more than a dozen muilti-ounce specimens in old talings 

Any pictures ? Would be awesome to see a "multi-ounce" specimen !!   :yesss:

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Nice finds Andy

I suggest the first thing you do is check the status of the land, claims, private,withdraws, federal,state etc. and get a claim or lease agreement if possible. These old piles can range from a few grains to several Oz's of gold per ton.
 AzNuggetBob

 

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On 2/10/2018 at 9:32 AM, adam said:

Any pictures ? Would be awesome to see a "multi-ounce" specimen !!   :yesss:

Your question illustrates the point I was making above perfectly. The detector is the right tool to locate unseen/not visible gold in tailings. The good stuff is not always visible by sight. How fun is looking at a chunk of rock with no visible gold? :rolleyes: I’ll share a few stories and photos below.

The first photo was taken in 2003. I sure don’t miss that old brick battery on the GP Extreme :old: In fact, if you remember the spot where I got you over your first nugget with a detector :black_knight_standing: the spot this stuff came from is just a few degrees north east from there as the crow flies north, somewhere in the next 50 miles. The old pan and pick heads were a real bonus. Some friends and I were exploring an old mine site and noticed some serious hand stacking in the creek below the mine, the rocks of the hand stacks were just peeking out of the pine needles. We decided to take a closer look. We soon found that the entire gully, which was several hundred feet in length, was hand stacked from bottom to top. There was a lot of trash in the gully and it did not take long to determine that we were the first folks in there with detectors. In fact we simply were not properly prepared to work the wash given the amount of trash. We needed a rake with neodymium magnets and did not bring one. The gully, the hand cobbles around the mine, and tailings both produced some great gold over the course of several subsequent trips. The specimens banged hard on the detectors (I had my trusty old White’s GMT along also). Few had visible gold but later proved to be loaded (ounces) when tested and crushed (more on that later). I spoke with one of my friends who accompanied me hunting this area a few months ago and while he's not detecting much these days, we shared some great memories around this spot :thumbsupanim He still has one of his large specimens that weighed in with just over three ounces of gold in it.

pines1.jpg

The second and third photos below show just how mineralized this mine was in parts of the vein system. The specimen in photo contained, galena, pyrite, and significant gold. 
pines2.jpg

pines3.jpg

The photos below show a few samples of the best high grade I’ve ever found along with some nuggets found a ways downstream of the dig site. When I handed chunks of this stuff to my friends Las and Dennis they were blown away. These two pieces were part of a much larger piece that again, banged hard on the detector but had no visible gold. I just wish that the original finders missed more, but I'm grateful for what they left behind :yesss:

saz1.jpg

saz2.jpg

As far as testing the specimens to determine how much gold is in them you have a few choices. You can crush them, pan out the gold, dry the gold and weigh it, or perform a Specific Gravity test. I’m not going to write up how to perform this type of test as there are more than a handful of instructions posted online already. Google is your friend (not really). Hope this helps and inspires folks :head:

Edited by Rod
grammatical/typo
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Andy, to me that ore has potential for a leach pit.

I know an old timer from this forum, still around but not actively posting anymore, that partnered up and had a small time leaching operation.  I don't have too many details, but he was able to recover ounces of gold, but best I can tell he only ran it a couple of times.  The operation was done at his partner's property, and the partnership fell apart.

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I tried to pm you Andyy . It didn't like me.  Try to contact me if ya can. 

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On 2/11/2018 at 7:53 AM, Rod said:

Your question illustrates the point I was making above perfectly.

So true,So True  ...I completely misunderstood when you said  " I've found more than a dozen muilti-ounce specimens"  I did not realize you meant  multi ounce host rocks with some gold in them....  You illustrated my misconception perfectly though. Thank you 

 

 

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19 hours ago, adam said:

So true,So True  ...I completely misunderstood when you said  " I've found more than a dozen muilti-ounce specimens"  I did not realize you meant  multi ounce host rocks with some gold in them....  You illustrated my misconception perfectly though. Thank you 

 

 

Thanks for making me laugh, I almost spit my coffee out :ROFL:

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