BirAdam was referring specifically to ADVANCED CIVILIZATIONS. People who build cities (latin civitas). Many of them, in many places, including places where stuf

BirAdam was referring specifically to ADVANCED CIVILIZATIONS. People who build cities (latin civitas). Many of them, in many places, including places where stuff stays put for millions of years. Mines, quarries, tunnels and canal excavations don't get wiped away. Debris on the ocean floor doesn't get wiped away. We're not talking about people living in mud huts who only eat fruit, haven't discovered fire, and leave no archeological traces; likewise we're not talking about hyperintelligent dolphins who went extinct, or aliens that landed briefly 4 billion years ago on a continent that got subducted. If you want to talk about the non-discoverability of something that isn't an advanced civilization, go ahead, split that hair. The next ice age we have is not going to remove any of Canada's open pit mines. https://en.m.wikipedia.org/wiki/List_of_open-pit_mines https://en.m.wikipedia.org/wiki/List_of_open-pit_mines