[TeMPOraL]

Indeed. Also, in line with SI_Rob's parallel comment here[0], it's worth pondering what does it bury those ores under. Answer: it's bodies. Piles and piles and piles of dead bodies, covering the resources or even becoming them (e.g. limestone). Hell, the soil - the most important, life-giving resource we need to survive - is itself made of rock mixed with lots of dead bodies.

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[0] - https://news.ycombinator.com/item?id=40744826

[shiroiushi]

Sure, the soil and other things are literally made of the corpses of earlier lifeforms, but that still qualifies as "recycling". I'm just addressing the fact that not everything is actually "recycled" in this way, and is simply buried, similar to a human landfill, although for nature and asteroids, the stuff wasn't used by the biosphere in the first place so it isn't exactly "garbage" in the normal sense.

Stuff like lead (Pb), for instance, isn't useful to the biosphere as far as I know, and is actively harmful to lifeforms in fact. It came from asteroid impacts to my knowledge, and was buried in the ground before humans dug it up and extracted it from ore, yielding the lead pollution we have today.

[TeMPOraL]

I view stuff like lead less as something that biosphere couldn't figure out how to recycle yet, so it sequesters and buries it - but by the nature of how life works, if some random mutation would make lead useful as a building block (like many, many other elements are), the biosphere would happily suck all the lead back up and spread it.

The pattern I see here is that over time, the biosphere makes everything it finds useful diffuse, present everywhere in low concentrations; everything else, it sequesters and stashes in high concentration in few places. So not unlike what our industry is doing, just with different materials.