Have you ever thought about what we humans would leave behind as a mark of our existence?
What would the future anthropologist, paleontologists or geologists find left of us in 40 million years?
This is of course assuming the planet remains the same and doesn’t become a burning fireball of gas.
So…. geologists study stratigraphic layers in a rock and each layer can usually be directed to a specific Period, Epoch, or Era like the Jurassic or Holocene through fossils or dating. (There’s a photo attached of what the layers look like).