From Wikipedia：
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion,and is subsequently transported by the action of wind,water,or ice,and/or by the force of gravity acting on the particle itself.
sedimentation 主要侧重于沉淀,是指由于风化和侵蚀等作用,剥离出的物质在各种搬运作用力下聚集到起来.
Deposition is the geological process by which sediments,soil,and rocks are added to a landform or land mass.Fluids such as wind and water,as well as sediment flowing via gravity,transport previously eroded sediment,which,at the loss of enough kinetic energy in the fluid,is deposited,building up layers of sediment.
deposition 更侧重于沉积,是个地质的变化过程,主要指沉淀的物质sediments经过长期的化学作用,形成的地质上的沉积相态.