Prospects at work

[user 4386]

How bazaar, I was just thinking about you ey.
Dunno, will buy a dolly pot tomorrow if the shops open.
When I look at this on geovic, this pit is a big fat area of a lead.
'If' there is some colour left, where is best to sample?
Should I wait until I dig a few meters back off the cap and sample what's under it to make sure it's virgin?
Will the colour be high in the gravels under the cap, or at the bottom of the gravels sitting on the decomposed slates?

Sitting on bedrock and up to tens of cm into bedrock along fractures.

 

[20x]

Old timers timbers..

 

[20x]

On the hammer..

 

[20x]

Juicy..

 

[Franco]

Well you sure do have the tools to get the job done.
Nothing like big boys toys.

 

[user 4386]

Are you finding that very iron-cemented gravel is towards the top of the gravel? And what is the overall average gravel thickness?

 

[20x]

Are you finding that very iron-cemented gravel is towards the top of the gravel? And what is the overall average gravel thickness?

It all seems to be random but the dark iron staining is top to bottom, it's a good 2m Thick.
Only got a couple of hours in today (rain), need more time to get a good look..

 

[user 4386]

It all seems to be random but the dark iron staining is top to bottom, it's a good 2m Thick.
Only got a couple of hours in today (rain), need more time to get a good look..

Usually very difficult to separate the gold from heavily iron-cemented material. The old-timers called it "cement" and would often have to put it through a quartz-crushing battery to break it up before separating the gold. Often that made it uneconomic so they just left it unworked except where very rich in gold.

The reason for my questions is that the iron cementing process occurred once the gravel was uplifted and exposed to the atmosphere, the iron cementation occurring from the top downwards, so often more heavily cemented near the top. I find it often breaks into solid blocks at top, but although also iron-rich, crumbles into fragments more readily lower down. So there might be a case for separating lower wash from upper wash if you find that, as the lower wash may be easier to treat. In the 1980s/1990s some material of this type was successfully treated (eg south of Avoca where it produced hundreds of kg of gold).

And don't ignore the top few tens of cm of underlying bedrock - it often contained a third of the gold that was recovered, half as much as in the overlying gravel.

 

[20x]

Usually very difficult to separate the gold from heavily iron-cemented material. The old-timers called it "cement" and would often have to put it through a quartz-crushing battery to break it up before separating the gold. Often that made it uneconomic so they just left it unworked except where very rich in gold.

The reason for my questions is that the iron cementing process occurred once the gravel was uplifted and exposed to the atmosphere, the iron cementation occurring from the top downwards, so often more heavily cemented near the top. I find it often breaks into solid blocks at top, but although also iron-rich, crumbles into fragments more readily lower down. So there might be a case for separating lower wash from upper wash if you find that, as the lower wash may be easier to treat. In the 1980s/1990s some material of this type was successfully treated (eg south of Avoca where it produced hundreds of kg of gold).

And don't ignore the top few tens of cm of underlying bedrock - it often contained a third of the gold that was recovered, half as much as in the overlying gravel.

Ok, this is a sample I brought home, majority of the upper looks like this, fine grained and angular..

 

[20x]

This is the bottom of our pump sump hole, cemented gravels are larger and rounded, arrow pointing to the slate bottom..

 

[20x]

Included in the cemented gravels there is the odd blob of pipe clay..

 

[user 4386]

I've seen a lot of that from Haddon south through Smythesdale and Scarsdale, and north of Linton towards Snake Valley. The pipe clay looks like a fragment of very weathered bedrock that used to be a bedrock cobble in the gravel before the gravel was weathered. That upper stuff looks as hard as hell (not sure how you wash that without it going through a ball mill first), the lower gravel looks a bit easier to break up.. Have you tried washing stuff from the uppermost part of bedrock?

 

[20x]

I've seen a lot of that from Haddon south through Smythesdale and Scarsdale, and north of Linton towards Snake Valley. The pipe clay looks like a fragment of very weathered bedrock that used to be a bedrock cobble in the gravel before the gravel was weathered. That upper stuff looks as hard as hell (not sure how you wash that without it going through a ball mill first), the lower gravel looks a bit easier to break up.. Have you tried washing stuff from the uppermost part of bedrock?

Only a fist size piece I crushed in the dolly, zero colour.
I googled paleo channel, the larger water worn section would be best, and even more if I chase that slate gutter down to it's bottom.
The problem is..
The larger water worn gravels are approx 1m Below design/finish surface of the project.
I might have to go 'oops' on the hammer.

 

[20x]

Goldierocks..
The good thing is my project manager is very interested in finding a bit of colour, but as usual I'm the guinea pig, appreciate anything you say

 

[user 4386]

Only a fist size piece I crushed in the dolly, zero colour.
I googled paleo channel, the larger water worn section would be best, and even more if I chase that slate gutter down to it's bottom.
The problem is..
The larger water worn gravels are approx 1m Below design/finish surface of the project.
I might have to go 'oops' on the hammer.

I don't think dollying the bedrock stuff will help - what you are after is gold (and perhaps fine gravel with gold) that has washed from above into cracks in bedrock. More a case of washing it in a pan.

 

[20x]

We have first evidence , from the pipe clay blob..

 

[20x]

Goldierocks..
I've never seen anything like this and I'm guessing not many others have either coz of its depth. I see a majar historical significance.
Surely there is an EL over it, how is this allowed to happen?
It's fete is sealed and will all be covered with everyone's wheel bin rubbish!

 

[user 4386]

I am not sure what you are saying is unique - as I mentioned this sort of rock extends for tens of km in both the Haddon-Scarsdale and Linton-Snake Valley region. However I was just mentioning these things on the Ballarat 50K map sheet, they are repeated all over the central goldfields and have been extensively mined. Bealiba, Castlemaine, Ararat, Stawell, Beaufort, St Arnaud, Rokewood, Pitfield to name just a few.

It has obviously been worked, anything left will be minor (patches remain, I mentioned Sedimentary Holdings former mine south of Avoca). I would not think the EL holder would be interested. Large areas of this are covered by new estates, e.g. around Haddon. Beaufort cemetery is built on these rocks, and the old open pits have been extensively used for land fill all over the place.

How much gold have you seen there? My experience is that leads of this age mostly contain fine gold, and nuggets are sparse. They pre-date the important gold leads with their major nuggets.

They are far less abundant farther east (eg Maldon, Daylesford etc). It relates to them having been preserved by uplift in the west.

 

[20x]

I could share an ilistrattion of paleo leads and troughs, but whatever I see, your just,an assumption based on other work.
Who are you!!!!!!

 

[user 4386]

I could share an ilistrattion of paleo leads and troughs, but whatever I see, your just,an assumption based on other work.
Who are you!!!!!!

?????
Just a consultant who advises major mining companies on working palaeovalley gold.