For thousands, even millions of years, little
pieces of our earth have been eroded--broken down and worn away
by wind and water. These little bits of our earth are washed downstream where they settle
to the bottom of the rivers, lakes, and oceans. Layer after layer of eroded earth is
deposited on top of each. These layers are pressed down more and more through time, until
the bottom layers slowly turn into rock.
For examples of sedimentary rocks, take a look at these:
