1409. Abrasion : 1 - Mutual rubbing of particles of sediment in flowing water as well as in the channel bed as a result of which these particles tend to decrease in size. Note - Sorting occurs with a change of the sediment carrying capacity of the stream. Whenever the tractive force of a stream decreases due to any reason, the coarser particles of sediment normally carried by the stream cease to move and get deposited in the river bed. On the other hand, abrasion refers to the diminishing of particle size of sediment due to rubbing, grinding or crushing of particles against each other or the river bed. 2 - See 6427. |