1. deposites
   1. bottomset
      1. fine particles
      2. out to sea
      3. advance of delta
   2. doreset
      1. coarser materials
      2. inclined layers
         1. over
         2. bottomset
      3. causes delta
         1. advance
         2. seaward
   3. topset
      1. landward margins
      2. fine particles
         1. clay
         2. silt
         3. mud
      3. continuous with flood plain
2. Why
   1. river approaches sea
      1. slows down
      2. ability to carry material reduced
      3. load is deposited
   2. factors
      1. large amount of sediment
      2. shallow coastal waters
      3. low wave energy
   3. causes distributaries
      1. smaller channels