Deposition — Science definition
The settling and dropping of transported sediment when the agent carrying it — water, wind, or ice — loses energy and slows down.
Where it is taught
- Weathering, Erosion & Deposition — Rocks, Landscapes & Water, Earth & Space Science, Grade 9
In use
Weathering breaks or changes rock where it is; erosion transports the products; deposition occurs when transport capacity falls.
Weathering, Erosion & Deposition
Questions using deposition
Problem 1
Explain why deposition happens where a fast river meets a calm lake or ocean, rather than somewhere in the middle of the river's fast-flowing course.
Answer and explanation
Deposition happens when a carrying agent loses energy and can no longer hold its sediment load. A fast-flowing river has plenty of energy to keep sediment moving, but when it enters a calm lake or ocean it slows down sharply, loses that energy, and drops its sediment, often building a delta right at the river's mouth.