Sediments are
derived from the weathering of older rocks.
After sediment is weathered
from older rocks, it undergoes erosion: it is first transported
(chiefly by running water in the form of streams) to a basin, or
low-lying area, and then it is deposited in layers.
Sedimentary rocks
form when sediments lithify, or turn into rock. Common sedimentary
rocks: shale (lithified mud), sandstone (lithified
sand), and conglomerate (lithified pebbles).
Weathering and erosion
are accelerated wherever uplift of the land surface occurs.
Some rocks have been uplifted several miles, e.g., marine strata
on Mt. Everest.