[Rockhounds] How cities will fossilise

[Kreigh Tomaszewski]

But while a building might not be designed to stand tall for millennia,
that does not mean it will lack a geological legacy. According to Jan
Zalasiewicz, emeritus professor of palaeobiology at the University of
Leicester, it is "a quite reasonable, even prosaic, geological prediction"
that a megacity will leave a fossil. I asked him how he could be so
certain. "As a geologist, you’d almost put the question the other way
around," he replied. "How can you prevent this?"

It’s a matter, he says, of durability, abundance, and location. The main
components of a modern city have their origins in geology and are
therefore, in their different ways, highly durable. The majority of the
world’s iron ore formed nearly two billion years ago. The sand, gravel, and
quartz in concrete are among the most resilient substances on Earth. These
hard-wearing materials once existed in natural deposits. But where before
it was only water, gravity, or tectonic activity that moved them, now it’s
a combination of human initiative and hydrocarbon fuels.


https://www.bbc.com/future/article/20210505-how-cities-will-fossilise