How Fast Does Gold Settle In Mullock?

[Stocky111]

A few months ago I dug on a nice solid signal that was coming from the bottom of a mullock heap near where it meets with the Undisturbed ground. The 1st 5 or so inches of dirt was a gravelly clay mix. Then the dirt changed to a plain gray clay. I remember thinking, ah, just hit the virgin soil beneath the mullock. Another 3 to 4 inches and the target was out. Turned out to be a nice 2.45g nugget. That got me wondering, did the nugget settle out of the mullock heap and into the original clay since the 1850's, or was it always sitting in the clay, only inches from the surface before being covered up by the heap? Is 170 years time enough for that amount of settlement to take place, or is that way too short. Any thoughts??

 

[Wally69]

Technically, about 9.81m/s/s less the frictional effects of the embedded media .... or when the soil is saturated, the viscous resistance

I would suspect it has been where it has been for well over a thousand years

:goldnugget: Nice score :goldnugget:

 

[mudgee hunter]

Being in a mullock heap..
Most likely to say it was a sticky stuck to a rock, and with a lot of rain it has washed the dirt and clay off.
And I believe it would only of separated from the host rock immediately next to it and no further.
Think Hippy missed the "mullock" heap part.
Most mullock heaps beneath the outer layer are well protected from from to wash gold to the botto of the pile.
The chances of them being suspended by a rock below out of the d deluge I believe are far greater.
Logically the upper region of the heap is from the later part of the dig. (Deeper )
But that dose always mean better, they did stop at that point for a reason.......,.

I've heard of people saying the rocks where washed etc......
I doubt it very much. Scraped at best.
Especially if it was a hard rock mullock heap.

The better the warrant to to wash such rocks at the time indicates to me logically there is a good yield.
Thus water availability becomes a large part of it...
And to hell with washing rocks.... haven't got time to be washing them because of high yield. Write it off and take the cream!
Normal human instinks to do such.

 

[mbasko]

The thing with mullock heaps is they rarely contain what's considered to be the "payable" wash layer or gold bearing rock. They knew how deep the payable wash layer was & it was usually taken away to be washed/sluiced or the gold bearing rock to be treated (crushed, stamper, quartz roasters etc.).
MH is quite right in that layers that weren't deemed payable or rock they believed had no gold wasn't worth their time to treat for little return (in most cases - in some areas mullock/tailing were reworked later to get the missed gold).
What fossickers are hoping for on mullock heaps are these missed bits of gold that may have been in the layer/s above (or below - still in the hole) what would have been considered the main paying wash layer or discarded pieces of host rock that still contains gold &/or any free gold from this rock.
Depending on what type of diggings your mullock came from could tell you whether your piece is off the mullick or an in situ piece.
If it's lead diggings then it's probably more likely the gold fell down the side of the mullock & was covered. Leads diggings are usually deeper than a detector can detect but can also be near surface or eroded so in situ is also a possibility. The average depth of the diggings could answer that?
If it's hard rock & there was some outcropping then it may have shed prior to the digging or also fell down the side of the mullock if mistakingly discarded.
I've found modern bullet cases as deep as your gold so don't doubt gold could work it's way down to 4-5" deep over more time.
Basically IMO there's no real way of telling for sure at that depth.