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from the where-the-mother-lode-gives-birth? dept.
Geologists identify deep-earth structures that may signal hidden metal lodes
If the world is to maintain a sustainable economy and fend off the worst effects of climate change, at least one industry will soon have to ramp up dramatically: the mining of metals needed to create a vast infrastructure for renewable power generation, storage, transmission and usage. The problem is, demand for such metals is likely to far outstrip currently both known deposits and the existing technology used to find more ore bodies.
Now, in a new study, scientists have discovered previously unrecognized structural lines 100 miles or more down in the earth that appear to signal the locations of giant deposits of copper, lead, zinc and other vital metals lying close enough to the surface to be mined, but too far down to be found using current exploration methods. The discovery could greatly narrow down search areas, and reduce the footprint of future mines, the authors say. The study appears this week in the journal Nature Geoscience.
[...] The study found that 85 percent of all known base-metal deposits hosted in sediments-and 100 percent of all "giant" deposits (those holding more than 10 million tons of metal)-lie above deeply buried lines girdling the planet that mark the edges of ancient continents. Specifically, the deposits lie along boundaries where the earth's lithosphere-the rigid outermost cladding of the planet, comprising the crust and upper mantle-thins out to about 170 kilometers below the surface.
Up to now, all such deposits have been found pretty much at the surface, and their locations have seemed to be somewhat random. Most discoveries have been made basically by geologists combing the ground and whacking at rocks with hammers. Geophysical exploration methods using gravity and other parameters to find buried ore bodies have entered in recent decades, but the results have been underwhelming. The new study presents geologists with a new, high-tech treasure map telling them where to look.
Journal Reference:
Mark J. Hoggard, Karol Czarnota, Fred D. Richards, et al. Global distribution of sediment-hosted metals controlled by craton edge stability, Nature Geoscience (DOI: 10.1038/s41561-020-0593-2)
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(Score: 4, Informative) by VLM on Thursday July 02 2020, @08:27PM (2 children)
My understanding of the metal biz is tangential related to the energy biz that I invest in and I do actually know about.
However. From what I do understand WRT all the people freaking out about the gold reserve being 100 miles down. The way it SEEMS to work for sedimentary metals like gold, is gold comes out of lava or other eroded gold containing rocks thrust to the surface, and washes into the downstream river bed curves naturally which eventually accumulate concentrated nuggets of gold.
We're pretty talented at finding subsurface ancient riverbeds. Trust me, they aren't ALL a mile downriver of gold-containing ancient lava rocks. But, if we somehow knew where deep crust reserves of gold existed, we could predict that "in the recent million years" or WTF gold-enriched lava had squirted out around there or predictably nearby, then we already know there's an ancient riverbed 100 feet below the surface a mile downriver of the gold-lava, so, go dig up those river gravels that are only 100 feet down.
Mind you its a waste of time to dig up ALL the river gravel thats 100 feet down, thats a metric shit ton of almost entirely gold-free gravel. Most of the earth has not been dug up, despite some people's peculiar ideas.
I don't think anyone is ambitious enough to dig 100 miles down, and the river bends naturally concentrate heavy gold to maybe higher concentration than the stuff 100 miles down anyway! So even if you could dig 100 miles down you might get more gold per ton from the river bend a mile downstream and 100 feet below the surface.
At least as I understand geology of metal mining. Oil geology is more interesting. Permeability discussions all day long.
(Score: 1, Interesting) by Anonymous Coward on Thursday July 02 2020, @08:59PM (1 child)
Looking purely at gold (and silver) contents per ton of material, landfills have higher concentrations than most active gold/silver mines. Makes one wonder when a company is going to start mining landfills.
(Score: 2) by VLM on Monday July 06 2020, @06:08PM
Sorry for the late response, but some tailings piles have been reprocessed multiple times as extraction technology has improved, LOL, so its not impossible.
My guess is the oversight of re-disposal of "fresh" trash would be more expensive than digging up new ore. You could throw out cans of paint in the old days but they'd shit a brick at the cost of proper disposal if it was unearthed from a landfill.
I guess one way to make sure leaking landfills don't contaminate the earth would be to dig them up before they leak, regardless of disposal cost.