Here's why:

* Erosion: Erosion is the process of wearing away and transporting rock and soil. While erosion plays a role in creating the conditions for a spit to form, it's not the primary force behind its creation.

* Deposition: Deposition is the process of dropping sediments that have been transported by wind, water, or ice. Spits are formed when longshore drift (the movement of sediment along the coastline) carries sand and other materials and deposits them at a point where the coastline changes direction.

How it works:

1. Longshore drift: Waves approach the shore at an angle, carrying sediment along the coastline.

2. Change in direction: When the coastline changes direction (e.g., a bend in the coast), the longshore drift continues to move sediment but is now directed outward, away from the coast.

3. Deposition: The sediment is deposited in the water, building up over time and forming a spit.

Let me know if you'd like more details about the process of spit formation!