Crevice clay question

[backcreek]

Hi All,

Generally it is believed that gold will not penetrate clay and just sit on the top.

But my question is, what if the clay formed after some of the gold was deposited in the crevice?

I have this dilemma at the moment.

I have cleaned out a very deep crevice down to a thick layer of sticky grey clay.

The clay is about 12" deep 4" wide at the top and about 6' long and I'm wondering if it's worth my while processing the clay at the bottom of this crevice.

I have a test sample of the clay from the bottom of the crevice sitting beside the hole drying out at the moment which I'll test pan when I return. This will give me an indication of any values locked in it but I'd be keen to hear of anyones experiences with this type of situation.

Does anyone have any information on how clay is formed?

Cheers
Mick

 

[Roscoe]

Backcreek, an old fellow told me that if you get that clay roll it into balls and light a good fire over it, then crush it up into a powder and pan that off. His own words were it takes the pug out of it. I never tried it myself, but one thing i never do is let that clay get into my sluice etc. I have puddle the clay back at my home and wash the dirt out of it. I got some gold from it, but i always wonder how much i lost?....roscoe

 

[Roscoe]

I must admit i don't really understand how clay is formed myself. I just know its a pain in the butt.

 

[TenOunce Tone]

Clay is silt that has compressed over time, that is why it takes on the colour of the parent rock from which it was borne.

Wikipedia...

Clay minerals are typically formed over long periods of time by the gradual chemical weathering of rocks, usually silicate-bearing, by low concentrations of carbonic acid and other diluted solvents. These solvents, usually acidic, migrate through the weathering rock after leaching through upper weathered layers. In addition to the weathering process, some clay minerals are formed by hydrothermal activity. Clay deposits may be formed in place as residual deposits in soil, but thick deposits usually are formed as the result of a secondary sedimentary deposition process after they have been eroded and transported from their original location of formation. Clay deposits are typically associated with very low energy depositional environments such as large lakes and marine basins.
Primary clays, also known as kaolins, are located at the site of formation. Secondary clay deposits have been moved by erosion and water from their primary location

So its both physical an chemical processes at work!

Go Science!

Cheers, Tone

 

[Roscoe]

Thanks Tenounce, so how come it ends up at the bottom of the crevice. Is it that fine it moves through the upper gravels as it does on the parent rock.

 

[HeadsUp]

dig it all and process it in sections to evaluate clearly whats there and how its distributed

one area might give nothing below the clay while another WILL

i spent a day digging out the best crevice i have seen a few weeks ago for a reward of only 0.67 grams , BUT the gold was spread through different strata / layers in the crevice.

2 metres long , 50 cm deep , 20 cm wide at the top and 2 cm wide at the bottom.

there was alot of clay in it over multiple layers so i laid down the top of my highbanker until it was almost flat and put about 7 buckets of clay / gravel into it and broke it up with my fingers until it was completely washed through

i say never judge one location by another and be prepared to keep the doors of opportunity open

not a very good photo of the half dug crevice but included this to show some of the tools used

 

[trashmagnet]

hello
if you find kaolin clay with little stars (iron) in it, it's worth checking around as it is a sign of gold nearby. the historic mine in Bendigo near kangaroo flat is a good example of this
regards

 

[Roscoe]

There is some nice course bits there headsup. I find myself out a the palmer, you find gold on the top layers and the deeper you go the less you get? Maybe the chinese cleaned it out years ago. I have never found anything at the bottom, just clay with very little in it.

 

[HeadsUp]

There is some nice course bits there headsup. I find myself out a the palmer, you find gold on the top layers and the deeper you go the less you get? Maybe the chinese cleaned it out years ago. I have never found anything at the bottom, just clay with very little in it.

yes they are coarse and under a loupe magnifier they dont show much abrasion wear so they didnt come very far , in fact i have an idea where these came from but the property owner is not open to outside intrusions to explore the ground.
he owns the land so he gets to choose.

i have dug other crevices and only found gold from halfway and up , or near the top even but i will never make an assumption they are all like that

the crevice in the photos above had it spread right through in layers.

i have got my hopes up before when digging crevices that looked perfect in every way in creeks that showed fine gold from test panning , yet the crevices i dug were barren so it just means that some other bloke or had a dig and there has been no heavy rain since .

every now and then you find one that is covered in rocks , clear those away and you might find that ripper crevice hidden underneath .

 

[backcreek]

dig it all and process it in sections to evaluate clearly whats there and how its distributed

one area might give nothing below the clay while another WILL

i spent a day digging out the best crevice i have seen a few weeks ago for a reward of only 0.67 grams , BUT the gold was spread through different strata / layers in the crevice.

2 metres long , 50 cm deep , 20 cm wide at the top and 2 cm wide at the bottom.

there was alot of clay in it over multiple layers so i laid down the top of my highbanker until it was almost flat and put about 7 buckets of clay / gravel into it and broke it up with my fingers until it was completely washed through

i say never judge one location by another and be prepared to keep the doors of opportunity open

https://www.prospectingaustralia.com/forum/img/member-images/414/1383304888_st.jpg

not a very good photo of the half dug crevice but included this to show some of the tools used
https://www.prospectingaustralia.co...es/414/1383305878_2013-10-21_18-48-29_954.jpg

Good advice there HU and my thoughts entirely about the highbanker. I always intended to process the clay in this crevice but I'm doing well with the material above the clay so one day when it takes my fancy I'll return and process it. In the meantime I might bring some samples home and puddle it in a bucket with an electric drill and mixer and see what it produces.

 

[WalnLiz]

We don't bother much with clay based crevices Mick and find in most areas the gold sits on top of the clay. The time it takes to puddle a bucket of clay for a small amount of gold is best spent digging adjoining crevices.

Take the bucket of clay and the bucket of adjoining crevice wash.... and the latter will always produce more gold with much less work and mess. I find that it's always a volume game that wins out in the long run,

Cheers Wal.

 

[backcreek]

Thanks Wal,
That's what I was thinking as well.
It can't hurt to bring a sample home and give it a go when I have nothing to do, (Ha Ha as if that it ever going to happen!)

In the meantime I'll keep processing the top layer.

Let me ask you this Wal, have you ever detected gold in clay?

 

[HeadsUp]

We don't bother much with clay based crevices Mick and find in most areas the gold sits on top of the clay. The time it takes to puddle a bucket of clay for a small amount of gold is best spent digging adjoining crevices.

Take the bucket of clay and the bucket of adjoining crevice wash.... and the latter will always produce more gold with much less work and mess. I find that it's always a volume game that wins out in the long run,

Cheers Wal.

cant argue with the time / volume thing

Its only in the last couple of months i have started to improve my " scan , test , assess " approach

Time in the field is precious , and the best outcome is improved by our ability to assess each location and quickly discard some , while choosing to put time into those that will be productive.

if we are in a location that yielded only 3 specs from 4 hours work , then we spent 3.5 hours too long there.

 

[Roscoe]

I think the problem with puddling clay is the gold (fine) just floats out with the sediment? I think that's what this old fellow was trying to tell me with cooking the clay first, then crushing it. From what he said it does not return back to clay, thus the fine gold wont float away. Has any one tried this technique? Next time i go out crevicing i will bring the clay back home with me and give it a try and see what happens. could we being losing a lot of fine gold by puddling?

 

[Guest]

I put clay in a large plastic tub (50L)
Add a bottle of hydrogen peroxide, Half tube of tooth past and a good squirt of washing liquid mix it up with a paint mixer on my cordless drill Mix mix mix! Scrap the top 3rd of muddy sludge out of the container and pan the rest. Then repeat.
You will loose some tinys but you can atleast run it though your rotapan or sluice
Without blocking it up
I got this recipe off google a while ago that a bloke posted in I guess he had it worked out but I only use it in clay that pays

 

[Roscoe]

Well, i have to say zuke that is an interesting recipe there mate. Hey, if it works then stick to it. I have know idea what effect the peroxide has on the clay mate.

 

[Guest]

Doesn't work real well without the toothpaste

 

[WalnLiz]

Thanks Wal,
That's what I was thinking as well.
It can't hurt to bring a sample home and give it a go when I have nothing to do, (Ha Ha as if that it ever going to happen!)

In the meantime I'll keep processing the top layer.

Let me ask you this Wal, have you ever detected gold in clay?

Certainly have Mick, even in the Tuena region, but it has always sat on top of the clay. Have got small nuggets in clay crevices and proceeded on many occasions to bottom out the crevices with no avail. (except for a few small flakes). :|
.

Cheers Wal.

 

[Roscoe]

Walnliz, I have watched a heap of your youtube videos wal. Liz is the queen of rock crevicing. I really enjoyed watching them thanks. Wal, what do you mean by clay crevices? thanks roscoe

 

[xray1982]

Someone told me the other day clay has positive and negative charges and if you change them to one or the other it breaks up quickly. Has anyone heard of this?