The crust has a few tectonically stable regions that have never slid into the mantle. This is where we’ve found rocks that date all the way back to 2-3 billion-ish years. We call them geologic shields.
Our current activities would leave chemical markers in these regions that would be detectable for a very, very long time, and could come from no known natural process.
Otherwise you’re right, everything else eventually slides into the mantle and gets turned back into magma over a long enough timeframe.
To be fair, the effect of stuff being cycled back into the mantle doesn’t destroy every human artifact regardless, given that some of our constructs aren’t even on earth. Though I’m not sure that the odds of anyone actually finding one of our space probes is that high, the solar system is a big place after all.
The crust has a few tectonically stable regions that have never slid into the mantle. This is where we’ve found rocks that date all the way back to 2-3 billion-ish years. We call them geologic shields.
Our current activities would leave chemical markers in these regions that would be detectable for a very, very long time, and could come from no known natural process.
Otherwise you’re right, everything else eventually slides into the mantle and gets turned back into magma over a long enough timeframe.
To be fair, the effect of stuff being cycled back into the mantle doesn’t destroy every human artifact regardless, given that some of our constructs aren’t even on earth. Though I’m not sure that the odds of anyone actually finding one of our space probes is that high, the solar system is a big place after all.