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Icelandic Rocks Suggest Meteorites Brought Gold To Earth
sciencehabit writes "Gold, platinum, and other precioius metals were sucked into Earth's molten iron core soon after our planet formed. So where did all of the material for our fancy jewelry come from? According to high-precision measurements of two isotopes, or atomic variants, of tungsten in 4-billion-old rocks from Greenland published online today in Nature [the abstract adds a bit more; the full version is paywalled, though], precious-metal-bearing meteorites struck Earth around this time, coating the planet in a veneer containing gold, platinum, and other elements long after their native counterparts had disappeared into the planet's core."
Just a nitpick, but they use the word "veneer" several times in the abstract. It makes it sound like a thin solid sheet of precious metal. That's not what they're trying to imply. They're trying to emphasize the "thinness" of it, but not really getting the "scattered" part.
Probably "dusting" has some specific connotation to geologists. Maybe "scattering" would suit the situation.
Iceland is very green.
Greenland is full of ice.
And never the twain shall meet, or be mixed up.
http://en.wikipedia.org/wiki/Iceland
http://en.wikipedia.org/wiki/Greenland
I've read the abstract but it's not clear that they're talking about enormous quantities of added gold/platinum/whatever. One interesting thing about gold, silver, copper, platinum, and some of the other precious metals is that they're soluble in hot water, so what you form is these huge underground plumes of rising hot water, over local hot magma areas, and the plumes are filled with dissolved metals. When the water rises enough it cools and the metals precipitate out -- primarily in cracks through which the water moves, forming veins that contain very high concentrations of precious metals. These plumes can be many, many miles high, and can pull up/concentrate metals from significant depths, so it's not clear to me that early gravity sorting of heavy metals downwards would result in no heavy metals at the surface. (An interesting side-note is that since each metal has a different solubility in water, as the water rises and cools, different metals precipitate out at different points, so if you find silver you're likely to find at least some gold nearby, but most likely not at exactly the same spot.) Note that I'm not a geologist, just an amateur gold hunter, but this is the explanation I've been given by my geologist friends.
Nostalgia's not what it used to be.
"Gold, platinum, and other precioius metals were sucked into Earth's molten iron core soon after our planet formed."
Forget lottery tickets I'm buying a shovel!
For me the songs of Pláhnetan, Bellatrix, Trúbrot etc suggest many things, but I've never considered them as offering any insight into the metalurgical make up of the earths crust. Maybe it's a specific niche of Icelandic Rock?
While I'm sure that some precious metals have arrived from space after the earth's accretion, I think it's rather a stretch to think that the concentration in places like South Dakota or Alaska/Yukon are the result of impact events.
It's true that these elements settled into lower strata, but it must also be remembered that many volcanic events are fueled by plumes of material that emanate from the core itself (the Yellowstone Caldera is believed to be such). That certain metals were concentrated in the lower strata during Earth's early formation does not mean that 100% of them stayed there.
I support the Slashcott and will not be reading or commenting from 2/10/14 to 2/17/14. Beta is steaming pile of dog shit
'Meteorites' brought everything to Earth.
Iceland != Greenland.
In fact, it wouldn't make a speck of sense if it was Iceland being studied, because Iceland is a geologically very young volcanic island with rocks no more than ~40 million years old, whereas the rocks being studied in this paper are 4 billion years or so and among the oldest on Earth. The whole point of the paper is to show that tungsten isotopes have changed over Earth history, and that the change happened quite early. They do compare the old Greenland tungsten isotopic measurements to more recent igneous rocks such as the ones from Iceland, but you could have as easily mentioned Hawaii, the Azores, the Canary Islands, and several other "recent" locations used for the comparison. Iceland isn't special in that respect.
The premise of this paper is that the difference can be explained if the early Earth (>4 billion or so) chemically differentiated initially and most of the siderophile elements (things like tungsten, gold, platinum, etc.) sank to the core during that process, leaving the surface rocks more depleted. That's the time the Greenland samples may represent. Then at a younger time, speculated to be near the ~3.8 billion year late heavy bombardment, a bunch more meteoritic stuff was dumped on the top (more siderophile-enriched), mixed into the upper part of the mantle, and igneous rocks have been generated mainly from that upper mantle source ever since (including the more modern samples they are comparing to, and also the ~2 billion-year-old samples they also show). There are other scenarios, but it is plausible and ties in with other evidence about the late heavy bombardment (such as Nd isotopic data from Sm/Nd and Hf/W dating). They model the effects of some alternative models and show those models can't easily be used to explain what is seen. It's a pretty testable hypothesis as people continue to do tungsten isotope studies on rocks of a variety of ages before and after the late heavy bombardment. This is a pretty bold paper.
Icelandic rocks should quit 'suggesting' things and start providing evidence and facts! :) Who taught rocks to talk anyway? I know there isn't much to do there...
My degree is in geology; while I have no problem with the idea that some of the deposits came from asteroids and the like, there are far too many other ways that many of these deposits can be formed here on earth. I know that for precious metals like gold and silver, hydro-thermal deposits are quite common sources of these ores (with a large number of these being found in or around granite sources.)
'Icelandic Rock' was ABBA's greatest rival in the late 70's. They did indeed bring much gold to earth.
The party's over
Gold, silver and platinum are scattered all over the earth waiting to be found, and each new find drives down the price of that commodity. Bitcoins, on the other hand, exist only in the Earth's molten interior and in a fixed quantity and are therefore more valuable than the "so-called" precious metals (not to mention the euro and the dollar).
http://en.wikipedia.org/wiki/Gold_in_California
Scientists believe that over a span of at least 400 million years, gold that had been widely dispersed in the Earth’s crust became more concentrated by geologic actions into the gold-bearing regions of California. Only gold that is concentrated can be economically recovered. Some 400 million years ago, California lay at the bottom of a large sea; underwater volcanoes deposited lava and minerals (including gold) onto the sea floor; sometimes enough that islands were created.[1] Between 400 million and 200 million years ago, geologic movement forced the sea floor and these volcanic islands and deposits eastwards, colliding with the North American continent, which was moving westwards.[2]
Beginning about 200 million years ago, tectonic pressure forced the sea floor beneath the American continental mass.[3] As it sank, or subducted, beneath today's California, the sea floor heated and melted into very large molten masses (magma). Being lighter and hotter than the ancient continental crust above it, this magma forced its way upward, cooling as it rose[4] to become the granite rock found throughout the Sierra Nevada and other mountains in California today — such as the sheer rock walls and domes of Yosemite Valley.[5] As the hot magma cooled, solidified, and came in contact with water, minerals with similar melting temperatures tended to concentrate themselves together.[5] As it solidified, gold became concentrated within the magma, and during this cooling process, veins of gold formed within fields of quartz[4] because of the similar melting temperatures of both.[6]
It sounds like any time geologists can't figure something out, the answer is "meteors". From life, to water, to now gold and silver, the refrain is "meteors". Kinda starting to sound a bit repetitive over the past decade, or is it just me? I am obviously not a geologist.
https://www.accountkiller.com/removal-requested
How did that Icelandic rock (mentioned in title) get to Greenland (summary)? Is the submitter perhaps afflicted with geographasia americana, whose symptoms include thinking that distinct countries/provinces are the same thing?
Forget Earth--go to the Moon or Mars for getting the goodies closer to or at the core. Sure, both still have molten gooey centers but we can get a lot closer to the center than here on Earth. After all, if one says meteorites brought metals to Earth the same deal applies to the Moon especially since it used to be part of Earth. (No doubt stirring the pot when that happened...)
Heck, digging deep enough to get heat and power from the core would make it much less likely for a stray meteorite to wipe out your living area. Decompression would also be unlikely given all the doors from there to the surface. Only problem would be gravity and possible moon quakes as water and air would be unlikely to escape.
FTS:
... precious-metal-bearing meteorites struck Earth around this time, coating the planet in a veneer containing gold, platinum, and other elements long after their native counterparts had disappeared into the planet's core."
Correct me if I'm wrong (I'm sure you will), but isn't the present theory of the origin of the Earth that it was formed by meteoritic bombardment? Where would these so-called "native counterparts" have come from except from said meteors? This summary suggests all the glittery stuff came from the stragglers of the same event.
Isn't the Earth considered to be about 4 billion years old? In other words, WTF is the summary suggesting (besides a monumental lack of reading comprehension)?!?
What are "4-billion-old rocks" [sic].
[I won't bother to mention the Greenland/Iceland confusion as others are carrying that torch well already.]
A collective faceplant rang out like a thunderclap as all the under-employed geeks wondered how people like that get and retain employment.
"Tongue tied and twisted, just an Earth bound misfit
Vikings carried it there.
Or it could have been a swallow
(Erik the Viking was written by the same people that wrote Monty Python)
Well then, if a significant amount of gold came from meteorite bombardment. Then doesn't it hold that our local asteroid fields should have vast amounts of the stuff? Shouldn't a spectral scan of the sky hint at all this?
Let's go get some.
I've seen this so many times recently -- "Ha ha, Greenland is made of ice, and Iceland is made of green grass!" That's such an oversimplification. Iceland has the largest glacier in Europe; just ignoring all of Iceland's other glaciers, that one (Vatnajökull) alone takes up 8% of the country, and is very visible when you approach the country from the south and east (where most settlers would be coming from). And as for the "grass" part that sometimes gets thrown in when describing Iceland, it's not that grassy of a place place at all. Oh, sure, there are ample grassy areas, but there's even more moss, lichen, and plenty of higher plants like blueberries, crowberries, bilberries, etc (and nowadays, lupine). And most of the interior is a barren moonscape. Come winter, the whole island gets snow, although it doesn't stick that well in the southwest (last winter they only had 14 days with snow cover, although it's usually about 3x that).
Greenland is not completely covered in ice; there are some very sizeable areas in the southwest that are green. There are even Greenlandic "forests" (although they're not much to write home about ;) ). Now, yes, there was an element of propaganda in the choice of name for Greenland. But it's not totally off base in terms of the places where people settled.
Musk needs a safer hobby than Twitter. Fire juggling? Cage fighting? Solo hot air balloon trips?
the denser metals such as Cu, Pt, Ni, Ag, and Au should have started to stratify over 4B years. Therefore, what we need is a really big straw, about 4000mi/6400km long to stick into the earth's core and pump out all the those valuable metals. The straw will probably need to be made of graphite and/or carbon nanotubes to handle the heat. On the plus side, it may be a diamond when we remove it.
Think of the side benefits. We can pump iron and transuranic wastes in to replace what we're drawing out. The transuranic wastes will help keep the core hot, and they should stay there for a long time. So, we get valuable metals and we get rid of some nuclear waste at the same time.
So, where do I apply for a grant to start research and drilling?
make imaginary.friends COUNT=100 VISIBLE=false
There be gold in that there core! Stake a claim and start a digging! Yea Haw we're gonna strick it rich.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
"Element 79" by Fred Hoyle
So what would happen if a large meteorite of pure gold landed in, say, England?
American's are Gold diggers, There be gold in them there hills!
Iceland was significantly more green at the time of settlement though - before it got deforested and the consequent erosion of most of the topsoil. The interior always was desert, iirc. A magnificent place, by the way.
Ubi solitudinem faciunt, pacem appellant.
So Terry Pratchett was bang on the money again?
The Fifth Elephant :-)
It says in the Quran 57:25 , http://quran.com/57/25
More explanation on the verse. http://www.harunyahya.com/miracles_of_the_quran_p1_04.php#10
True, over 1/3rd of Iceland used to be forested before human settlement. Well, as much as you can call Icelandic forests "forests" ;) But as you note, the interior was always desert, plus the glaciers were still giant rivers of ice back then, they still got their winter snows, etc. A funny thing, now with the introduction of the lupine/lúpína, some places in Iceland that were never able to be colonized before due to too hostile of a climate, like some of the sands in the northeast, are now being colonized. So in that way, the country is actually getting greener.
Yeah, isn't Iceland such an incredible place? Too good for this Earth. A couple weeks ago I took the time to translate my resume into Icelandic, for obvious purposes. ;) Veistu einhver sem (th)arft** forritara? ;)
** -- Dang Slashdot doesn't let me type thorns :P
Musk needs a safer hobby than Twitter. Fire juggling? Cage fighting? Solo hot air balloon trips?
Can we have some more gold?