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Process the overburden or not?
chrischch  
Posted : Monday, 6 August 2012 4:10:50 PM(UTC)
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So when sluicing, its often the goal to get down to bedrock. What i want to know is, do you process all the overburden or just the last bit near the bedrock? Obviously if theres not muchgold in it, then theres no point lugging all that overburden to the sluice. What do you guys do in this situation?
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1864hatter  
Posted : Monday, 6 August 2012 5:58:39 PM(UTC)
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I usually throw it away and tpick the gold up off the bedrock. Unless ist got lots of clay in it that is
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Lammerlaw  
Posted : Monday, 6 August 2012 7:18:54 PM(UTC)
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I guess I am after the cream and not the curds and whey so any overburden goes west without any further ado. If there is any doubt then I might fire the overburden into the current of the river and then have a look at the bedrock at the end of the day to see if there is anything worth while there but I cannot ever recall any decent finds over the years which would have made processing the overburden lucrative.
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1864hatter  
Posted : Monday, 6 August 2012 7:26:59 PM(UTC)
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Up the wakamarina I have found nuggets up to 2.5 grams sitting in sorta hardpack clay stuff at a few spots thats why I mentioned the clay.
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Lammerlaw  
Posted : Monday, 6 August 2012 8:03:43 PM(UTC)
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Originally Posted by: 1864hatter Go to Quoted Post
Up the wakamarina I have found nuggets up to 2.5 grams sitting in sorta hardpack clay stuff at a few spots thats why I mentioned the clay.
In general aree with Graham


Hi Matt - yes there are exceptions and with a bit of experience, trial and error and a bit of local knowledge the exceptions become known - in some places the 'overburden' will be auriferous as in areas where the gold was found as layers within the overburden. Indeed in some areas there were layers of gold bearing wash folowed by a layer of barren material and then more gold bearing wash and so on.

On properties like mine it is simply goodbye overburden here comes the gold so no worries about 'reading' the lie of the land. When the bottom is reached the gold can be in or on one of several layer - it can be in the river wash gravels or/and it can be on top of a layer of fine gray silty clay or clayish silt, it can be below the silt layer on top of the bedrock and it can be within the cracks and crevices of the bedrock. The overburden being peat and then clay can be dispensed with safely without any further consideration.
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mineforgold.co.nz  
Posted : Monday, 6 August 2012 8:20:12 PM(UTC)
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In some rivers you will find that the top might contain a layer of flood gold, and from there it is a long way down to hard rock and there might not be much gold in between. So given that you are talking about sluicing not other methods of gold extraction then you might well be better off just working the flood gold layer.
It really all depends on the situation.
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chrischch  
Posted : Monday, 6 August 2012 8:31:23 PM(UTC)
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Originally Posted by: mineforgold.co.nz Go to Quoted Post
In some rivers you will find that the top might contain a layer of flood gold, and from there it is a long way down to hard rock and there might not be much gold in between. So given that you are talking about sluicing not other methods of gold extraction then you might well be better off just working the flood gold layer.
It really all depends on the situation.


I was thinking that but thought I may have missed something. Its a looooong way to bedrock at some of the spots Ive been to. I wasnt sure how fast the gold would sink to the bottom. I imagine a good flood would churn things up and jiggle the gold down.
Guess it could always be test panned at diff levels but i'm so slow with the pan, it would take me all day just to do that! Trying to maximise my colour for the limited time i get at spots during weekend trips is my goal now I have the basics.
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