Deltas

Deltas

1. These are composed of fine sediment which is deposited when a river loses energy and competence as it flows into an area of slow moving water such as a lake or sea

   • When freshwater and seawater meet an electric charge is produced which causes clay particles to coagulate and to settle on the seabed

2. Arculate delta

   • Curving shoreline
   • Many tributaries break away from the main channel causing the river to braid
   • Longshore drift keeps the delta smooth in shape
   • River Nile

3. Cuspate delta

   • Pointed like a cup or tooth
   • Shaped by regular but opposing sea currents
   • River Tiber, Italy

4. Bird foot delta

   • Where the river has many distributaries bounded by sediment
   • Mississippi
   • These extend out to sea like the claw's of a bird's foot