A volcano erupting molten gold might seem like a case of science fiction, but sometimes
reality is stranger than fiction.
As, each year, several volcanoes around the planet actively produce gold each day, with
select individual volcanoes releasing hundreds of thousands to millions of dollars worth
of this precious metal each year.
For example, each year, the famed Mount Saint Helens within Washington state produces 7.3
kilograms of gold worth $453,000 dollars.
And this is despite the fact it is not actively erupting.
Elsewhere, Japan's Satsuma-Iojima volcano releases volcanic gasses containing numerous
molecules and fine particles of gold.
This totals 26.28 kilograms of gold each year, worth $1.63 million dollars.
Mount Erebus in Antarctica produces fine particles of gold which theoretically could be captured,
totaling 29.2 kilograms each year, being worth $1.81 million dollars.
Yet, the volcano which produces the most gold in the world is Colombia's Galeras volcano,
releasing 510 grams of gold each day, totaling $11.55 million in value each year.
In a manner of speaking, the fact that certain volcanoes release gold shouldn't be all that
surprising.
As, last year, hundreds of mining operations around the planet extracted a grand total
of 3,000 metric tons of gold, which altogether was worth $186 billion U.S. dollars.
A large chunk of this mined gold was originally concentrated via magmatic intrusions from
ancient volcanic activity, some of which then either remained at depth such as in a porphyry
deposit, or rose to the surface through groundwater, forming what is known as an epithermal deposit.
Almost all of these deposits are from rock formations which are tens of millions or hundreds
of millions of years old, with some even being more than a billion years in age.
So, by simply removing the waiting game for a volcano to become permanently extinct, it
makes sense that these very types of deposits are growing under select volcanoes.
However, since each of these aforementioned volcanoes are very much active, rising magma
occasionally melts sections of the developing ore body, causing it to be carried to the
surface and released as gas.
In my opinion, it is far too dangerous to attempt gold mining operations from any of
these 4 volcanoes, especially due to the fact that 2 of them are actively erupting.
Yet, let us for some reason hypothetically assume it was safe to do so.
A concrete dome could be used to density sort the gas, and then gold enriched gas could
be placed into a vat of chemical compounds to extract the relevant gold.
A similar methodology is used to extract the incredibly rare element rhenium at Russia's
Kudriavy volcano.
But, back to the gold.
You might have noticed that these gold spewing volcanoes have five features in common.
One, they have all produced at least 1 or more VEI 6 eruptions.
Two, they have all erupted more than 63% silica lava, with this involving trachyte, trachydacite,
dacite, or rhyolite.
Third, all four volcanoes display high degrees of hydrothermal alteration.
Fourth, each of these volcanoes have existed for more than 35,000 years.
And fifth, all of these volcanoes during eruptions emit surprisingly low amounts of sulfur dioxide.
For example, Ethiopia's Nabro volcano produced an eruption in 2011 which was only 23% the
size as the 1980 eruption of Mount Saint Helens.
And yet, both eruptions produced the same sulfur dioxide emissions, 1.5 million metric
tons.
This means that volcanoes such as El Chichon and Agung, which are known for being sulfur
dioxide rich in their eruptions are unlikely to ever produce substantial quantities of
gold.
But, why might this be the case?
The answer is volcanoes that have the potential to emit gold aren't sulfur poor per say, but
rather have their sulfur trapped in sulfide minerals before the magma reaches the surface,
instead of getting oxidized to produce sulfur dioxide.
As for why all 4 of these volcanoes have high degrees of hydrothermal alteration, this is
one sign that an ore body could be present.
Since ore bodies often take a substantial amount of time to form, it makes sense that
these volcanoes have all been active for more than 35,000 years.
And, the VEI 6 eruptions that each of these volcanoes have produced are a sign of a very
large magma chamber at depth.
Larger magma chambers have more sulfur, and more gold.
As a final note, I would like to thank my new patron Nicole Gagnon for supporting this
channel!