Detecting Large Gold Deposits At Depth

[GhostMiner]

A question for the pros here. I was watching a treasure hunting show and they were looking for a lost mine using a Whites TM 808 Treasuremaster which they claimed could detect gold or silver deposits down to 20 feet. I will preface this by saying I know about mining with excavators, trommels, & sluices but no nothing about detectors. What I am interested in is something that could detect large, concentrated gold deposits of 50 ounces or more that I think are buried in a rich faultline. The depths could be several feet or much deeper. Some of these deposits I suspect could be in the hundreds of ounces or more. Are there detectors capable of this & if you own one I would be interested in talking with you. Thanks.

[GB_Amateur]

20 meters sounds like an exaggeration, even for a large, continuous target such as an automobile.  If it's the show I watched, I think they were saying there was purportedly refined silver, possibly stacked bars.  A natural vein is a completely different ballgame.  Others here are in better position to say if a 2 box detector will work for that.  Meanwhile, here's a thread where Steve H. talks about 2 box and highlights the White's TM808.

 

[GhostMiner]

   What if you had a 1000 ounce gold deposit about 15 - 20 ft below the surface. The gold is free gold and is coarse mixed in with black sand and gravels & river rock. All in about a 20 ft X 20 ft area of raised bedrock. This is the area near Jed's dig site where we chased out the highgraders who found a good deposit. I have a couple partners working this and they are down close to 10 ft. It started out at over 2  grams per cubic yard about 6 ft down. Now at the 10 ft level it is testing out at around 4 grams per cubic yard. We are thinking it may continue to get better the deeper we go but it would be nice to see further down with modern equipment. 

[klunker]

"Gear Used; Excavators...

There, problem solved.

[Steve Herschbach]

In general forget metal detectors for deep gold deposits or accumulations. They are for individual nuggets down to a couple feet, maybe  a little more if the nugget is huge. It has to be a single conductive mass - a bunch of nuggets that are even inches apart add little to the equation.

Let's assign a nugget a detection factor of ten. Now spread out 20 of them underground, all two feet apart.

It is not 10 + 10 + 10 +10...... = 200

It is 10 + 10 + 10 +10...... = 10

In general the detection depth of your gold deposit will only be as deep as the largest nugget in the deposit.

Same issue with fine gold

klunker has it right - excavator is the answer, followed by drill. The only exception might be tracing a magnetite rich channel through comparatively magnetite lean ground with a magnetometer, where the magnetite concentrations indirectly give clues to where gold accumulations might exist.

A more detailed answer than the one GB referenced above with other options, plus videos.

 

[GhostMiner]

59 minutes ago, Steve Herschbach said:

In general forget metal detectors for deep gold deposits or accumulations. They are for individual nuggets down to a couple feet, maybe  a little more if the nugget is huge. It has to be a single conductive mass - a bunch of nuggets that are even inches apart add little to the equation.

Let's assign a nugget a detection factor of ten. Now spread out 20 of them underground, all two feet apart.

It is not 10 + 10 + 10 +10...... = 200

It is 10 + 10 + 10 +10...... = 10

In general the detection depth of your gold deposit will only be as deep as the largest nugget in the deposit.

Same issue with fine gold

klunker has it right - excavator is the answer, followed by drill. The only exception might be tracing a magnetite rich channel through comparatively magnetite lean ground with a magnetometer, where the magnetite concentrations indirectly give clues to where gold accumulations might exist.

A more detailed answer than the one GB referenced above with other options, plus videos.

 

   Thanks for the info. Yes, we always use excavators after signs of gold are worth exploring. We do bulk samples through a trommel. Usually 100 yds or more. Drilling is very expensive and I haven't found any that will come to our site because of the amount of rock. We are a tiny company & drilling is a non starter. The issues here are that we are in a remote area that requires road building on a faultline which means permits which means a lot of time. I was just hoping for a faster, cheaper solution. Guess i'll cross of the detectors. We used an excavator Gold Claimer Pioneer 30 trommel at the eastern drift mine Jed talked about early in the journal. We opened up the drift although the gravels all along that area are about the same. We processes 250 cubic yards. We averaged about a gram per cubic yard. We even found the 2 man tuttle tooth hand saw he talked about. It was broke in half. Maybe he broke it LOL. Anyway, that mine is now leased. I am looking for treasure at this stage of my life. The amount of gold Jed ended up finding. I think it's there in that faultline. 

[WesD]

You would have to have some massive beast nuggets like the Ruby Mine to push anything beyond a couple feet. Even then you have to know what your listening for, as the deeper the signal the more it tends to get drawn out and can be confused as mineralized ground noise. 

 

RUBY GOLD

[GhostMiner]

12 minutes ago, WesD said:

You would have to have some massive beast nuggets like the Ruby Mine to push anything beyond a couple feet. Even then you have to know what your listening for, as the deeper the signal the more it tends to get drawn out and can be confused as mineralized ground noise. 

 

RUBY GOLD

Thanks for the info. It sounded too easy LOL.

[Steve Herschbach]

39 minutes ago, GhostMiner said:

   Thanks for the info. Yes, we always use excavators after signs of gold are worth exploring. We do bulk samples through a trommel. Usually 100 yds or more. Drilling is very expensive and I haven't found any that will come to our site because of the amount of rock. We are a tiny company & drilling is a non starter. The issues here are that we are in a remote area that requires road building on a faultline which means permits which means a lot of time. I was just hoping for a faster, cheaper solution. Guess i'll cross of the detectors. We used an excavator Gold Claimer Pioneer 30 trommel at the eastern drift mine Jed talked about early in the journal. We opened up the drift although the gravels all along that area are about the same. We processes 250 cubic yards. We averaged about a gram per cubic yard. We even found the 2 man tuttle tooth hand saw he talked about. It was broke in half. Maybe he broke it LOL. Anyway, that mine is now leased. I am looking for treasure at this stage of my life. The amount of gold Jed ended up finding. I think it's there in that faultline. 

Drilling is expensive if hired. Can be done on the cheap by those that know how.

 

 

[GhostMiner]

6 minutes ago, Steve Herschbach said:

Drilling is expensive if hired. Can be done on the cheap by those that know how.

 

We have a few churn drill tests on our mine from the 1960's. Some of the attemps got stopped out by rock. Modern companies say it is too hard to drill where we are at because of the rock. Also, drilling requires a POO. This project is a treasure hunt and I don't want the Forest Service involved on this one. Alaska supports mining, California fight it.  We'll just keep the hole going for now & hand sampling along the faultline in other areas for now. Thanks.