Distance That Alluvial Gold Travels

[Poida]

Hi all

I have been finding some gold while panning a particular section of a creek. I noticed that some of the pieces are very jaggered and rough whilst some are smooth and well worn.

Is it likely the jaggered pieces have shed from the source immediately close by and the smooth pieces from far away? How far in metres or kilometres does gold typically travel in a creek or river to loose roughness and be become smooth?

 

[AngerManagement]

Not to be a smarty but if there was a clear cut formula there would be a lot of happy chaps...

So many variables - The rate of flow and how much banging about and on what it was banging is all subjective... And even when one backtracks, it does not always mean there is a big pot waiting for you..

 

[Mackka]

I would like to know that formula AM and I would ask you to join me.
Mackka

 

[savage bitter]

can travel many km if not hundreds that is were you need to start looking at maps and try to follow it back can be a lot of work and a lot of digging and samples to test

 

[Wishfull]

Odd really. Going by the density of gold and if it has travelled k's away from the original source and still at almost gound level in depth. Bed rock beneath maybe.
Then again people find it in salt lakes. One of lifes little mysteries ?

 

[cairnspom]

Also you have to be aware that some of the gold will travel downstream on its own and be water worn, while some may travel downstream in host rock and weather in situ and be 'jagged'

 

[Guest]

Also you have to be aware that some of the gold will travel downstream on its own and be water worn, while some may travel downstream in host rock and weather in situ and be 'jagged'

What he said is what I would say also.
Panning and loaming is the way to go to find the source of where the gold has been shedding.

 

[user 4386]

It is often a constant in a particular area. Same topography, same rainfall, same gold grain size in the source rocks results in similar transport distances. However such areas are fairly confined in extent. Around Ballarat, abundant coarse gold only travels a few km in the main (although the gold leads are longer, they are often replenished from other gold sources along their length, so go for tens of km) - sometimes only 500 m from source in the main city goldfield area. However the fine gold at Beechworth travelled at least as far as Eldorado (26 km) over granite that had no gold (so it was not replenished along the way and was still economic at Eldorado, partly because of associated tin derived from the granite). There are really two ways in which alluvial gold is deposited (1) close to source, by being largely left behind as lighter rock washes away, and (2) distant from source where a drop in stream velocity causes it to fall out from suspension in the water. The first is classical Ballarat, the latter classical Eldorado (stream velocity dropped as the stream moved out of the granite to where it was dammed by the metamorphic aureole in sedimentary rocks adjacent to the granite (think of it as a hard rock bar formed by "cooking" of the sandstones etc by the granite). The first is great for small miners, the latter more suitable for large tonnage but low grade sluicing and dredging (e.g. Cocks Eldorado dredge is still preserved on its pond at Eldorado).

 

[metaldetective]

Not to be a smarty but if there was a clear cut formula there would be a lot of happy chaps...

So many variables - The rate of flow and how much banging about and on what it was banging is all subjective... And even when one backtracks, it does not always mean there is a big pot waiting for you..

You can always gauge the distance by the gold yr finding, course closer, well worn - further a field. You can also find non alluvial gold in creeks ?? Meaning in stringers, contacts, faults that cross a river or creek. So if your chasing a possible source, you need to follow the gold indicators, area Geology, Topography.

 

[Nightjar]

Found this piece and another 10/11grams in a creek, only a few metres apart. Extensive searching along the banks either side revealed a couple of tidlers. About 20 metres down stream an exposed quartz/ironstone reef banked up with sand, crossed the creek. I returned with dryblower and shovel. Hours of digging away the sand up against the reef then I used the dry blower. Digging/brushing and dryblowing and returning to the camp to pan the dryblower material.
1 1/2 ozs of fine gold ended up in my jar.
To this day have never found the source, probably requires earth moving equipment to take a metre or so off surroundings.

 

[Nightjar]

 

[Moneybox]

The size of the gold will have some influence on how movable it is with the soil erosion.



I think the type of terrain makes a big difference. In hilly country with steep hills and gullies the soil movement is probably limited to the type of soil and water flow.



Some areas are almost solid rock so nothing seems to move far but other areas are easily eroded so the gold goes along for the ride being deposited in spots where the water slows or is restricted.



Some items don't seem to move at all



Wide open country can be altogether different. The gold deposited here might have been done many moons ago as the hills eroded. Perhaps water flow or glacial action helped distribute it but it tends to be spread wider with less distinct boundaries to the deposits.



There were areas with rich deposits of large nuggets in this flat country but the fine gold seemed to spread far and wide. For that we try to process huge volumes of dirt, sometimes for very little, other times there's more but there's no easy way to track down where it came from or where it is now.




Even in these wide expanses of open country the gold can be beautifully water worn but of course there's no water.

 

[Moneybox]

View attachment 16502

That's a beautiful nugget Nightjar. I've always wanted to make a piece of jewellery from something we've found by Mrs M won't wear it.

 

[Mackka]

Yes beautiful. I knew a bloke in Canberra whom would come into the shop once a month for supplies and he had a similar nugget on a thick gold chain and in the middle he had put the diamond from his Mothers Engagement ring. Only knew him by his nickname, Nugget, and he was Polish with no teeth and as brown as a berry. Lovely bloke but one month he never came back .

 

[grubstake]

The size of the gold will have some influence on how movable it is with the soil erosion.

View attachment 16505

Wow, those rich specimens are a fantastic sight!