Rates of erosion by attrition are affected by the rocks shape, lithology, and the energy of impact, therefore, softer rocks are more susceptible to attrition erosion. As attrition and breakage occur on a bedrock it becomes suspended: down-stream of a river or waterway the bedload increases due to attrition.
Rates of wearing away are affected by the rock's shape, material, and the force of collision, making softer rocks more susceptible to erosion. As rocks break down in situ, they become suspended: as they move downstream, the amount of sediment carried by a river or waterway increases due to the breakdown.