High Grade Deposit Formation

[diggit]

Well I'll be Flocced!

Interesting article in Australian mining magazine...

Credit to Professor Anthony Williams-Jones of the Department of Earth and Planetary Sciences and PhD student Duncan McLeish

https://www.australianmining.com.au/news/research-reveals-formation-of-ultra-high-grade-gold/

'As the concentration of gold in hot water is very low, very large volumes of fluid need to flow through the cracks in the Earths crust to deposit mineable concentrations of gold, the team explained.

This process would require millions of years to fill a single centimetre-wide crack with gold, whereas these cracks typically seal in days, months or years.

Using a powerful electron microscope to observe particles in thin slices of rock, we discovered that bonanza gold deposits form from a fluid much like milk.

The researchers said gold colloids found in the hot water of the Earths crust act like milk in the way they flocculate to form a jelly when their charge breaks down.

Once flocculated, the jelly-like gold becomes trapped between cracks in the rocks to form the ultra high-grade, highly valuable deposits which mining companies hope to discover.

An understanding of this phenomenon had never been realised before, until Williams-Jones and McLeish made the discovery.

We produced the first evidence for gold-colloid formation and flocculation in nature, and the first images of small veins of gold-colloid particles and their flocculated aggregates at the nano-scale, they said.

 

[Deepseeker]

Great article. :Y:

The Fosterville mine has the highest grade in the world with 42.4 grams per tonne at the time of the report. That is an amazing yield!

 

[user 4386]

Well I'll be Flocced!

Interesting article in Australian mining magazine...

Credit to Professor Anthony Williams-Jones of the Department of Earth and Planetary Sciences and PhD student Duncan McLeish

https://www.australianmining.com.au/news/research-reveals-formation-of-ultra-high-grade-gold/

'As the concentration of gold in hot water is very low, very large volumes of fluid need to flow through the cracks in the Earths crust to deposit mineable concentrations of gold, the team explained.

This process would require millions of years to fill a single centimetre-wide crack with gold, whereas these cracks typically seal in days, months or years.

Using a powerful electron microscope to observe particles in thin slices of rock, we discovered that bonanza gold deposits form from a fluid much like milk.

The researchers said gold colloids found in the hot water of the Earths crust act like milk in the way they flocculate to form a jelly when their charge breaks down.

Once flocculated, the jelly-like gold becomes trapped between cracks in the rocks to form the ultra high-grade, highly valuable deposits which mining companies hope to discover.

An understanding of this phenomenon had never been realised before, until Williams-Jones and McLeish made the discovery.

We produced the first evidence for gold-colloid formation and flocculation in nature, and the first images of small veins of gold-colloid particles and their flocculated aggregates at the nano-scale, they said.

Well...this seems to be a sensationalized version of what was found. However entire gold deposits can form in thousands of years. The reason being that while the gold content of a fluid may be low, it can always deposit most of that gold as it passes the same point in a vein, so gold can build up fairly rapidly. i.e. it is not being deposited out evenly along the area of a vein in constant amount. If you go to Champagne Pool hot spring system in N ew Zealand, gold is being deposited around the rim of one of the pools in real time - but that is not exactly what the researcher is talking about (the reference is specifically to very large amounts of gold deposited in a short time). Gold also gets deposited in the pipes of the Broadlands NZ hydrothermal power station. The researchers discovery seems credible and intersting for extre,ely high grade parts of some veins (however even at Fosterville, most gold does not form in masses like that, but as micron-sized grains.

Fosterville was the highest grade in the world for the first quarter of the year a couple of years ago - drill core I have lifted there has been quite heavy over tens of cm length simply because of its gold content. However some Victorian mines averaged double that grade, and one large mine averaged that grade over its entire decades of production.

And beware of articles released to mining journals without any reference to the information being in a peer-reviewed scientific journal (although it may just be a case of time - scientific journals are notoriously slow to publish compared to space-fillers in a mininh mag).