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

Earth made of rock. Wind, rain, heat, etc. erodes rock. Sand is little rock bits. Sand mixes with minerals (which are just little pieces of different kinds of rock bits) and become dirt.