Clastic sedimentary rocks form by weathering processes which break down rocks into pebble, sand, or clay particles by exposure to wind, ice, and water. Clastic and nonclastic sedimentary rocks are the only members of the rock family that contain fossils as well as indicators of the climate (ripple marks, mudcracks and raindrops) that was present when the rock was formed.
Clastic sedimentary rocks are named according to the grain size of the sediment particles.
