[Johnny555]

Its a reasonable question - what human made artifacts would survive for hundreds of millions of years? Would concrete and steel buildings still be intact after hundreds of millions of years of erosion and weathering? Would objects in a 5 story deep basement be intact? Would even something we placed on the moon be visible after a 500 million years of micrometeorite impacts?

[halfcat]

Erosion would happen, but also icebergs would wipe out anything like buildings during the next ice age. And eventually subduction would consume the existing earth’s surface into the inner molten layer, leaving behind zero trace, but that might take hundreds of millions of years.

[Gare]

Cratons don't get subducted, that's a common misconception.

https://en.wikipedia.org/wiki/Craton

[halfcat]

Interesting! Thank you. So craton areas, say, near the equator where icebergs may not reach, could possibly contain remnants from indefinitely old civilizations?