Eli5 Where does the dirt come from?

Question

When looking at a geological timescale, typically ‘the deeper you dig, the older stuff gets’, right?
So, where does this buildup of new sediment come from?
I understand we’re talking about very large timeframes here, but I still dont really get it.

In: 19

Answer 1

Dirt is poop. Human eats apple, makes poop. Fly eats poop, makes fly poop. Bacteria eats fly poop, makes dirt.