Many human artifacts don't need to be fossilized and could be preserved for millions of years (e.g. a gold ring, a stone bracelet, concrete). Also humans delib

Many human artifacts don't need to be fossilized and could be preserved for millions of years (e.g. a gold ring, a stone bracelet, concrete). Also humans deliberately bury their dead (and lots of other stuff), which in some cases might help with fossilization and preservation. If humanity were wiped out tomorrow, I think it would leave plenty of traces that could be found and understood in millions of years by a later civilization with paleontologists are as active as ours. It's just that those traces would be relatively small and/or buried, like human fossils with jewelry and caissons (with geometric iron oxide deposits from the rebar!) from the foundations of large buildings. No monuments or cities, but enough to indicate that we were here and had technology.