Cascades to Coast

What's the difference between mudstone and siltstone?

Mud and silt are made up of pieces of weather rock. Mud is a smaller piece and contains more clay while silt is silt sized pieces. Mudstone is composed mostly of mud sized particles and siltstone is made of larger pieces of silt.

Sand = 2.0 to 0.02 mm, Silt = 0.02 to 0.002 mm, Clay/mud = <0.002 mm