> But imagine if civilization had ended 500 years ago, or even a thousand. There would be absolutely nothing to show for it in a couple hundred million years ti

> But imagine if civilization had ended 500 years ago, or even a thousand. There would be absolutely nothing to show for it in a couple hundred million years time. I think some stone artifacts (cities, pyramids, roads) would still be identifiable in some cases. Excavation would be needed, of course. Similarly, some of our concrete, glass and non-ferrous metal construction should survive a long, long time.