Bump.

"Even without carbon 14 dating, geologists can study those layers and give a (very rough) estimate about how much time transpired between the most recent known dinosaur fossils and the oldest known human ones."

The geologists haven't been around to watch the transformations of the earth as they occured. How can we be sure that their theories on how these processes occur really be true? Aren't their theories based, at least in part, on carbon dating of the contents of the various layers of earth?

I am curious to know more about the basis of the geological methods of fossil dating, if you (or someone else) can provide a layperson's summary.