Gold definitions - "Alluvial", "Eluvial", "Colluvial" etc.

Reg Wilson

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Actually gold that is in a state of travel from reef to its point of rest is called colluvial.
 
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Actually gold that is in a state of travel from reef to its point of rest is called colluvial.
Yes - whereas near its origin is eluvial

Alluvial: Detrital material which is transported by a river and usually deposited along the river's pathway, either in the riverbed itself or on its floodplain.

Colluvial: Weathered material transported by gravity action such as on scree slopes.

Eluvial: Weathered material still at or near its point of formation.
 

WalnLiz

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Yes - whereas near its origin is eluvial

Alluvial: Detrital material which is transported by a river and usually deposited along the river's pathway, either in the riverbed itself or on its floodplain.

Colluvial: Weathered material transported by gravity action such as on scree slopes.

Eluvial: Weathered material still at or near its point of formation.
Great to see "some" people picking at straws....Virtually all gold is derived from "Primary" gold and is then given a secondary name depending on where it ends up. Alluvial gold is given this term when it has been deposited and moved by water in streams and does not mean it originated within the watercourse.
Eluvial gold is disintegration of rock and gold at the site where it originates...not there through water movement alone but also other forces such as gravity. It's essentially primary gold which generally hasn't travelled far from its original source. I won' talk about Colluvial gold as it is not what is talked about in the thread.
If Goldierocks wishes to do a thread on Colluvial gold to enlighten us please do so. Cheers Wal.
Mod Edit: Posts split to new thread Wal where the definitions can now be discussed without cluttering up your thread.
 
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WalnLiz

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Actually gold that is in a state of travel from reef to its point of rest is called colluvial.
Please look up Colluvial Reg as it depends on how far the gold travels from its primary source. If it only travels a short distance from this source it is more often than not referred to as Eluvial and that is what we are chasing. Terminology depends on which books you are reading. The point of the thread is hunting for gold and not a lesson in terminology.. if you would like to do a thread on terminology please do so as I would love to read it.
Mod Edit: Posts split to new thread Wal where the definitions can now be discussed without cluttering up your thread.
 
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Diginit

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Please look up Colluvial Reg as it depends on how far the gold travels from its primary source. If it only travels a short distance from this source it is more often than not referred to as Eluvial and that is what we are chasing. Terminology depends on which books you are reading. The point of the thread is hunting for gold and not a lesson in terminology.. if you would like to do a thread on terminology please do so as I would love to read it.
Thanks for clarification as the statement of "from reef to its point of rest" had me confused. If I find it an pick it up then I guess you could say it was having a rest when I found it, but most likely was still travelling on it's journey to wherever? Just my take on it as a layman. o_O But I do know that I wish a lot more of it would have a rest on my pathway 😂🤣
 

mbasko

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Yes - whereas near its origin is eluvial

Alluvial: Detrital material which is transported by a river and usually deposited along the river's pathway, either in the riverbed itself or on its floodplain.

Colluvial: Weathered material transported by gravity action such as on scree slopes.

Eluvial: Weathered material still at or near its point of formation.
Always good practice to include the source when cut/pasting information unless you are the author of copyrighted material.
Under Placer Deposits:
 

WalnLiz

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Always good practice to include the source when cut/pasting information unless you are the author of copyrighted material.
Under Placer Deposits:
Thanks mbasko...great idea to separate the thread and get input on the different terminology so that the original thread can remain on topic. The thread was not meant to be a cut and paste session in the first place.
 

Hawkear

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Is it possible then that alluvial, eluvial and colluvial gold can all be found in the one spot as terms such as those refer to the mechanism of transport and deposit not just how far gold is from its source.
Another thought is if you have a small quartz speci just broken off a reef and laying nearby on the surface is it eluvial? Then the next day it rolls down the slope into a flatter area is it colluvial? Could it be considered either one or the other or both like schrodingers cat.
Maybe we are splitting rabbits, or hares, actually I meant hairs.
The best of us will have a geologically informed instinct for how gold travels once it is released from a reef and the how can become the where.
A definition involving the mechanism of transport and deposit is best for that.
 
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Nice to have someone teach me about gold deposits. What would I know?
Reg,
An experienced prospector and miner has voiced an opinion to me that gold can travel up to 35 kilometers or more.
I suppose anything is possible, how can that happen?
Teach us please.
 

Hawkear

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The burden of explanation or proof should be on the person who gives an opinion not someone else.
I see Dav79 has given another method of gold transportation which could be responsible for moving it considerable distances.
I am happy to accept any opinion provided it can be supported by facts. What would be needed is proof that gold found at a location is identical to gold from a source 35 Ks away.
 

Reg Wilson

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EVIE/BEE, A few years back James Beatty and I discovered an unworked area where we proved up gold over several thousand acres. There were only a couple of 'spec' holes in this whole area and no workings. The old timers obviously liked the look of some of this ground but could not prove it up. Before the secret got out we recovered quite a large amount of gold. No big nuggets turned up, the biggest being a little under five ounces.
The whole area was Permian and all the gold was very worn, some looking like worn soap. Some research revealed that a large boulder of granite was found in this location where there was no pluton or contact zone. This anomaly was particularly interesting due to the fact that the nearest granite of this type was located in northern Tasmania.
The nearest proven gold deposit was over twenty Ks away, so it is anyone's guess as to how far this gold may have travelled. (perhaps in glaciers)

PS This was in Victoria.
 
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The burden of explanation or proof should be on the person who gives an opinion not someone else.
I see Dav79 has given another method of gold transportation which could be responsible for moving it considerable distances.
I am happy to accept any opinion provided it can be supported by facts. What would be needed is proof that gold found at a location is identical to gold from a source 35 Ks away.
The person who gave me that opinion said that the gold moved via floodwater. I never wholly believed that.
 
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