According to this article, a vast gold reserve was found last year in India. Good for India. How likely is it there is a vast undiscovered gold reserve somewhere in the US? Are there remote places that haven’t been explored yet? What about the more inaccessible regions of Alaska? What about underneath the continental shelf? My sense is that it’s not likely there’s a large amount of gold waiting to be discovered. Am I wrong?
FYI, that story about a newly discovered gold reserve in India was later found to be incorrect.
Wow. Thanks for that. Well, let’s forget about India then. The question still stands.
Though there are large amounts of gold and gems in some temples in India, such as this one.
Not an expert in this by any means but my understanding is that most gold on the surface of the planet comes from meteors. (Gold old enough to have been part of the original formation has already sunk to the center of the planet.)
If we assume that any meteor large enough to deposit an amount of gold worth talking is large enough to leave a notable crater, I would expect that we have been able to identify the likely locations to check for gold for a few decades. By this point in time, we would have already identified them all.
The above assumption, however, might be false.
It’s also possible that a sufficiently old enough collision could have been effectively erased by this point.
This website says that the US Geological Survey believes that about
18,000 tonnes of gold exists, undiscovered, in the USA. I have no idea how they came to that conclusion.
That could be talking about trace elements and powder, rather than a nice mine-able layer of gold. I’m not sure.
If they’re “undiscovered,” how would we know about them?
Asteroids. A meteor is a streak of light in the sky that only exists for a few seconds.
Meteorites. An asteroid is a solar system object that orbits the sun.
Cute, but while my post was a statement of fact correcting a misused term, yours is an incorrect snipe. A piece of an asteroid is still a piece of an asteroid even after it hits the ground, but a meteor is an atmospheric phenomenon and nothing else.
When someone fights ignorance, it helps if ignorance doesn’t fight back.
Actually, your post misused a term, which I corrected. A space object that falls to earth is a meteorite, not an asteroid. Look it up if you don’t believe me.
The irony!
The googling I did to confirm my memory was saying meteorite. The “ite” made me think they were talking about a “little meteor”, rather than something different, definitionally, from a meteor. I wanted to include larger rocks, so I removed the “ite”. Woops!
Anyhoo, NASA , to clear this all up:
I believe that NASA can be held to be authoritative on this subject.
A meteorite is a piece of an asteroid that has fallen to the Earth’s surface. It never stops being part of an asteroid. A meteor is a transient light phenomenon in the Earth’s atmosphere that takes place for a matter of a few seconds. I don’t need to look it up, I have been a meteorite collector for more than 20 years and have forgotten more about them than
you will ever know. You are not helping anybody with your Dunning-Keuger nonsense.
In geology the “ite” suffix is attached to mineral identifications. A meteorite is a rock from a meteor. A fulgurite is a rock from lightning. A trilobite is a rock with three lobes. An ammonite is a rock shaped like a ram’s horn. You will find many minerals as a word with “ite” attached to the end, including sub-types of meteorite.
Examples
Bencubbinites
Howardites
Pallasites
Acapulcoites
Nakhlites
Related to meteorites are tekties, which also have subcategories with “ite” names. Examples include:
Indochinites
Australites
Moldavites
Georgiaites.
Minerals found in meteorites include
Maskelynite
Troilite
Taenite
An early English name for meteorites is areolites. Iron meteorites were called siderites and what we now call mesosiderites were called siderolites.
Not all meteorites are asteroid in nature. Some are meteoroid. Had you looked this up as I suggested, you’d know this.
Nobody ever says “an asteroid fell to earth”, or “this is the site of an asteroid impact”. Do you ever go to the rock shop and say “show me your asteroid section?” No. It’s meteorites. Aways meteorites. Nobody ever calls it anything else. You know this.
There’s that burning white-hot irony again!
Look, you were pedantic enough to bust somebody’s chops over “meteor” not being close enough to “meteorite”. There’s some SDMB rule that states that your correction must contain an error, and that someone else must point it out. The proper protocol is that you good-naturedly have a laugh at your own expense, you don’t double down on something that could easily be resolved with 5 seconds of googling. This will surely anger the board gods and bring some form of calamity to us all, and it will be all your fault.
Moderating: enough on meteors, meteorites, and asteroids. This thread is about gold
Gold is back.
You found it not essentially in ancient craters but rather near volcanoes: the erupting flow of lava bring it at the surface, then solidifies and leaves nuggets and veins. Those can be eroded by precipitations and be dragged down the rivers, eventually accumulating in a basin.
Space rocks, both asteroids and the planetesimals that formed the Earth in the first place, have only trace amounts of gold in them. But there were trillions of them that formed the Earth. If you add up all of those trace amounts, it comes to a significant quantity. However, the Earth was melted in its earliest phase and the mantle is still fluid. Normally you’d expect a dense element like gold to fall to the core in that situation, but it has a chemical affinity for some light elements, so much of it remained in the upper levels of the planet.
After that, geologic and erosional forces cause gold to concentrate in sufficient densities. Otherwise we wouldn’t have much in the way of gold deposits, either native gold nuggets or veins of gold ore. So FrenchDunadan is correct; volcanism brings it to the surface and form veins of ore. Weathering may reduce the ore to native gold and then erosion will cause it to accumulate in certain areas. (The Klondike River in Yukon, for example.)
I appreciate learning how gold forms and accumulates at the surface, but I guess it’s difficult/impossible to say with any certainty how much is around undiscovered. I’m satisfied with the answer “we really don’t know, and there’s no easy way to find out”.
Speaking strictly out of my Ass (a little trick I call ‘Buttrillaquism’), I would say, absolutely. The world, and even the US is a pretty big place, and us human ants can only realistacly dig so deep. There are probably veins of gold so remote and impossible to reach the size of SuperTankers just waiting to be dug up. So much, in fact, that it devalues to the price of salt. Or maybe Silver. 
My guess is that it’s more along the lines of “Based on the known geological formations in the US, we estimate that roughly 18,000 tons of gold are still undiscovered in the United States”