3 ms·

Thermodynamic model identifies how gold reaches Earth's surface

70 points by wglb 2y ago

wglb 2y ago
Referenced paper: https://pnas.org/doi/10.1073/pnas.2404731121 https://pnas.org/doi/10.1073/pnas.2404731121
ggm 2y ago
Fred Hoyle theorised (or popularised other peoples theories) that it squeezed like water from the interstitial spaces in the rock under geological time and pressure. I've got a book of his from the 60s discussing planetary formation which mentions it.
supernova87a 2y ago
Fun to imagine on geophysical length scales that each dot of gold-sulfur rich complex in the diagram could represent like several orders of magnitude more gold than has ever been mined out of the Earth to date. (No idea whether that is the right sizing, but I could totally imagine it being the case) edit: "...The estimated amount of gold ever mined is around 212,582 tonnes, according to the World Gold Council. This is roughly equivalent to a cube of gold that's about 22 meters on each side..." https://www.gold.org/goldhub/data/how-much-gold https://www.gold.org/goldhub/data/how-much-gold https://www.usgs.gov/faqs/how-much-gold-has-been-found-world https://www.usgs.gov/faqs/how-much-gold-has-been-found-world
bilsbie 2y ago
I’ve never heard a good explanation for why elements like gold appear together in veins. Why aren’t atoms of elements randomly distributed.
- mathstuf 2y ago
  What I read (in the past few months…don't have a link handy) is that gold is highly insoluble, but quartz's electrical properties can help seed crystallization of the atoms from (rock) solution (which is why it tends to appear with it).
idunnoman1222 2y ago
For the curious: Around 75% of post industrial gold mined globally comes from deposits linked to volcanic and hydrothermal activity
mathstuf 2y ago
I await for this to be incorporated into the Dwarf Fortress world seeding algorithm ;) .
ProllyInfamous 2y ago
My layperson understanding was that all of the surface gold (i.e. available to humans, not in earth's core) was delivered here via comets/asteroids. The explanation I received was that the densest atoms (e.g. gold) migrated into the core over billions of years (because: gravity; gold is twice as dense as lead).

70 points by wglb 2y ago

wglb 2y ago

Referenced paper: https://pnas.org/doi/10.1073/pnas.2404731121 https://pnas.org/doi/10.1073/pnas.2404731121

ggm 2y ago

Fred Hoyle theorised (or popularised other peoples theories) that it squeezed like water from the interstitial spaces in the rock under geological time and pressure. I've got a book of his from the 60s discussing planetary formation which mentions it.

supernova87a 2y ago

Fun to imagine on geophysical length scales that each dot of gold-sulfur rich complex in the diagram could represent like several orders of magnitude more gold than has ever been mined out of the Earth to date. (No idea whether that is the right sizing, but I could totally imagine it being the case) edit: "...The estimated amount of gold ever mined is around 212,582 tonnes, according to the World Gold Council. This is roughly equivalent to a cube of gold that's about 22 meters on each side..." https://www.gold.org/goldhub/data/how-much-gold https://www.gold.org/goldhub/data/how-much-gold https://www.usgs.gov/faqs/how-much-gold-has-been-found-world https://www.usgs.gov/faqs/how-much-gold-has-been-found-world

bilsbie 2y ago

I’ve never heard a good explanation for why elements like gold appear together in veins. Why aren’t atoms of elements randomly distributed.

mathstuf 2y ago
What I read (in the past few months…don't have a link handy) is that gold is highly insoluble, but quartz's electrical properties can help seed crystallization of the atoms from (rock) solution (which is why it tends to appear with it).

idunnoman1222 2y ago

For the curious: Around 75% of post industrial gold mined globally comes from deposits linked to volcanic and hydrothermal activity

mathstuf 2y ago

I await for this to be incorporated into the Dwarf Fortress world seeding algorithm ;) .

ProllyInfamous 2y ago

My layperson understanding was that all of the surface gold (i.e. available to humans, not in earth's core) was delivered here via comets/asteroids. The explanation I received was that the densest atoms (e.g. gold) migrated into the core over billions of years (because: gravity; gold is twice as dense as lead).