Small Nuggets at Depth

I have been working an area with a good quantity of gold that the average size would go 0.2 to 0.4 gms
The wash is goes deep and the gold spread throughout
I use a Gp3500 and 12" mono elipt nugget finder coil and have worked this area to the point of finding no more targets.
Is there a better coil combination to gain more depth on this small gold , or is the coil I'm using reached the maximum depth.

Also what depth would a 4500 be able to achieve on gold this size and the ground is quiet to mild mineralization.

Cheers Mark

G'day Mark.


The 12x7 inch grey Advantage is a very good combination on the 3500 for finding 0.1 to 0.4gm gold and above,at good depths,especially in low to medium mineralized ground. Considering the wash that your picking up small nuggets in,goes much deeper,you'll find that by using the 12" round Advantage mono or the 14x9 will go a little deeper again on similar sized nuggets,on the same machine,over the same ground conditions.
There's also a chance that slightly larger pieces of gold are lying deeper down in the same wash,just out of the 12x7s reach.If you haven't already done so, try a larger 16 or 18 inch round mono,over the same ground,as long as mineralization permits.
In quiet to low mineralization,the 4500(even on enhance)with either coil mentioned, will pick up a 0.2gm slug of gold at 3 inches plus,and a 0.4gm at 6 + inches.

Cheers kon61.

Is there water nearby? because i certainly would wash this dirt before walkin' away if you have no interest in doing that please p/m me with the location!!

Hi Mark,

As Murachu says. If its deep you are only going to go so far with a detector.
A sprightly young fellow like you might like to dig a few test holes- the deeper you go, the bigger the gold... or at least maybe more of it.
By sounds, you already have the start of some test holes!
With that size gold (and smaller) a drywasher would probably work well if water isn't handy. Different wash layers may be richer than others also- might not neccesarily be at the bottom either.
Either way, good luck.

sheech Mark! too much information lol!

Hi Mark.

I have found that different sized coils have sweet spots relating to different sized gold at different depths.

I would run an 8 inch round mono over the area and also i would also go slow with a 16-18 mono coil in case some good pieces are down deep.

Any good run of gold with some depth to the ground is worth going over with 2 or 3 different coil sizes.

A lot of people also walk away from spots where there are lots of micro nuggets. (you must use a 8 inch coil or smaller to get a signal from the little buggers when they have 2-5 inches depth to them )


cheers Tributer

Thanks for the reply s
Yes I have gone over the area with 24" monos and 16" round DDs and only two pieces found at just over a gram.
The gold here is small but have done well with the 12" elipt mono but now they have been cleaned up, was hoping to get better depth on the small pieces as there must be a lot more at greater depth, yes I have taken soil samples home to pan off and there is a good show of fine gold, but this area can't be worked with equipment so the panning is limited and it's the nuggets I'm chasing and if I can get a few inches more depth would be interesting,
My 3500 is good on this small gold to about 3 to 5 " {0.2 to 0.4 }and I don't think the 4500 would do much better, but I could be wrong and this could be the answer I have been looking for.
I might hire one to test this out, but the only problem there is getting the best settings and coil combination's and hope the extra gold found will make it worthwhile
Mark

Mark, have you tried the 16" DD in mono mode over that area?

Also, if you were going to hire a 4500, then yu'll need to hire it for a week or more with the array of settings and combo's you will face with it compared to the 3500.
What settings works well one day, can be obsolete the next day.

Hi tributer
To be honest I have a 8" commander mono but have never used it , I thought the 12" nugget finder elipt advantage coil would be better so didn't even think about giving it a try.

Hi MS, the 8" commander is on my dont leave home without list.
Suprising depth on the little bugger and the other week I got bits down to 0.028gr. I had to lick my finger to pick them up.

Hi Narrawa
Yes I did try the 16" xp on mono and it's good but a bit hard to get close to the ground ,
Madtuna , yes I will take the 8' along next time to try, It is new and came with the unit when I bought it but has been sitting in the shed for years gathering dust.
Cheers Mark

Yeppers on the 8".
The oldtimer who showed me the ropes hasn't taken his 8" mono commander off for years and he goes through a skid plate every 2 weeks or so... forget low and slow, he says "on the deck and crawl" !!

If you having trouble getting close to the ground, perhaps you could rake the area? Unless its the dreaded serrated tussock.....?


Cheers, Ferris.

I don't know how to put a pic up in this thread but put one up in the Gallery under public pic of the gold I got from the 20 L bucket of wash I took away to pan off.
The sample was taken from the area where I detected most of the small nuggets .
Wish I could peg a claim and bring equipment in but the fact is you can't in this area and now-days miners rights don't allow the small guy to do much.
The bigger small nugget in pan could have been detected but was from a one and a half foot hole dug and was well out of range of a detector.
Very frustrating.
Cheers Mark

Going by that, your looking at a rate of around 1 oz per tonne of wash ( a bit below by calculation but i assume your bucket wasnt completley full)-,

(I think mining companies operate on a cost per oz basis of around $400 to $800)

1oz per ton is hard work, but if you can manage 25 buckets a day (about half ton), there is up to half an oz in it. Not bad wages if you can get it.

If you are allowed to process by hand, the 'rotapan' style sieve device (sits on the top of a bucket with water in it) is a great help and you could fairly easily process 5 buckets an hour if they were sitting there ready to go. (still need some water- 40-60 litres would do you for a day if careful and using a catch container)

Allow a couple of hours to put the concentrates through a clean up sluice also- easiest done at home.
If you knew all this already, good luck, and if you didn't, something to ponder?

good luck.

Hi ferrious
If I can get the same result as the test panning I did , it would have to go atleast to 1/2 OZ per ton, I may take a hand operated rotary concentrator and some water with me next time I head back out there , In this area I will have to fill back in all holes and make good before I leave and hopefully if I can do some work like this without damaging the area, this may be allowed, It's fine for detecting and covering your tracks but one negative of processing wash on site is attracting unwanted attention to what is there , I was finding good fine gold years ago in another area, and after a break of a month or so ,went back and the tree which was close to my dig hole was tunneled under and the roots were cut and the tree had fallen down and was laying on it's side, Someone else either spotted me or my workings and that was the end of that.
To be honest I enjoy detecting for nuggets and this is only a hobby for me and digging is more like work but will have to do more on the finer gold in the wash now the surface nuggets have dried up.

hi
 forget the back braking stuff. hire a 4 or 45 and go over the area again.  my 4000 blows the socks off the 3000 i used to own
   

I would take a pick and shovel and take layers off the wash and stack it, taking 2 inches off at a time sweeping the 8 inch coil over the wash and the pile.

Narrawa/Madtuna
Thanks for the advice re the 8'' commander, I went back to the area and tried the coil out, picked up a very small piece at 3" and was surprised to see something so small give such a loud target response, the coil was as Narrawa said a bit noisier and it did sound off on a few hot rocks but was stable enough to use and will now be taken away each trip.
There is a definite advantage on small gold over the 12" elipt.
The area I was working has seen activity since my last trip but I did manage to pull a few nice pieces including a 4 1/2 gm specimen.
I did bring the gold pan and concentrator along but didn't give it a go as was enjoying the detecting and was doing OK there.
Anyway thanks for the tips
Cheers Mark

Have fun you lucky bugger and hope you nail a couple of big ones,regards,mark

glad the 8" worked well for you mate...now to go back to all your old areas with it.

If it's reasonably soft ground why don't you just strip off 15cm of dirt over a 2 sq m area and test it. Would not take long with a shovel.
Jigalong.

Hi Jigalong
Yes I did do a bit of shovel work but no luck that way , I didn't persist very long as have to put it back before I leave and I don't like disturbing small shrubs and grasses too much.
Madtuna , yes I will be going over my old areas again and sure it could be worthwhile with the 8" , I must admit I didn't think it would be as good as it was especially being such an old design coil.
Cheers Mark

Get hold of a 4500 and put the 8" mono Commander coil on. Leave all setting as per factory preset eccept the soil setting. Put that on enhance and I reckon you will do well. People reckon the 4500 is hard to use but of all the Minelab machines, and I have used them all, the 4500 is the easiest to use and by far the best.

Cheers, Granite

Gday MS


I still have and use on a regular basis my very first 8" minelab round mono coil that I got with the sd2100, it has done literally thousands of hours work and has paid for itself over and over again, it is the only coil I have kept out of the many I have bought over the years.

There are many places like the one you are talking about that can provide you with many small nuggets, bigger coil users would walk over such a place and never know, sometimes spots like that will yield literally hundreds of sub gram bits, adding up to many ounces, sometimes you have to get the grams in order to get the ounces, a very slow and even swing keeping the coil level and close to the ground wouldnt miss much.

I have found the 8" mono excellent on everything from the sd2100/extreme/3500 and 4500, with by far the deepest bit found with it on the 4500, I have used it for patch hunting (searching for floaters), but always like to use it close to outcrops, in creeks and dryblowings, and really rubbly hillsides where you can get it close to the ground in between the rocks.

I have not used the newer minelab commander 8" mono but would take a guess at it being about the same, maybe someone who has used both can add something here.

cheers


stayyerAU

jim /stayyer

have you ever compared the coiltek 10/5 mono against the commander 8 inch mono would there

be a great differnce between them

kanga

Gday Kanga


Yes I have tried the coiltek 10x5 mono, but it was some time back, I have never been a great fan of eliptical coils and have always found that round monos are more to my liking, also I believe that they have a depth advantage over eliptical coils where as eliptical coils have a slight advantage in sensitivity.

Being that it is a longer coil you would obviously have a wider sweep with it and the ability to poke the tip of it into nooks and crannies, if I were wanting to use a larger mono coil for the purpose of ground coverage then I would always opt for the minelab 11" commander mono over anything else.

When you are using a small mono coil for the purpose of hunting through rubble strewn ground it has to be able to give you reasonable depth as it is hard to get the coil close to the ground, I have found that the 8" minelab mono will usually detect a buried piece that is several inches in the ground while the coil is still a few inches above the ground, the 11' commander mono is also very good at this but the bigger the coil the harder it is to manouver about in the rubble.

I dont think that the difference between the two coils would be massive, but it is more likely that the advantage comes from having faith in its capability and it best suiting your particular style of detecting.

cheers


stayyerAU

pretty much word for word I'd have to agree with Stayer re: the 8" & 11" commander monos.

Something else which came to light at Tibooburra recently and has a bearing on rubble strewn ground is the thickness of the minelab skid plates verses the NF or CT skid plates.
I know skid plates are cheap, but atleast ML dont build thiers out of something akin to flimsy shirtbox plastic

Agreed. The ML skid plates are about 4 or possibly 5 times thicker thank CT and NF skid plates.

I haven't seen one come apart like the one at Tibooburra but that's what I imagine would happen after a LONG time scraping it over hard rock surfaces. As for why it "bottomed out" so soon after purchase, I don't know. But most coil owners might not realize how thin their skid plates are until they actually handle one off the coil.

Gday


As I have said my little minelab 8" mono has been well used over the years and I have not had to replace the skid plate as yet, but I dont drag my coils on the ground as I think that the noise produced by the dragging and bumping makes it hard to hear faint signals, so I am careful to get it as low as I can but its hard to avoid the odd bang on a rock or something.

The skid plates on the Nuggetfinders on the other hand are paper thin, and the real problem comes when you do not check your coils regularly for wear and tear, of course once you wear through the plate then you start to wear into the body of the coil itself, some of the coils I have noticed are prone to cracking as well, I thought that they had this sussed when the produced the new advantage coils but unfortunately I have found that they can do the same thing.

No minelab coil that I have owned has ever cracked, but I am sure that some people have had this happen with really old coils, now if I could just get minelab to produce a 14" round coil that was not as heavy as the 15" commander eliptical mono then I would be a happy camper.

The issue with the cracking of coils and the premature wearing of the skid plates is a direct result of the demand for lighter coils and the competition between nuggetfinder and coiltek, in order to produce a lighter coil there has been a trade off in the area of durability, I dont mind the wear factor of the skid plates as that is what they are designed for, to take the punishment and to protect the coil, but I am not happy that the coil body is prone to cracking.

cheers


stayyerAU