Deposition occurs when river current slows, causing sediment to be dropped. Which statement is true?

• A. It increases erosion downstream.
• B. It dissolves minerals in the water.
• C. It causes sediment to be dropped, forming landforms like deltas.
• D. It turns sediment into gas.

Answer: (C)

Deposition happens when the flowing water loses energy and can no longer carry its sediment. As velocity drops, the river’s capacity to transport sediment decreases, so particles settle out and accumulate. At a river’s mouth, these deposits build outward into the standing body of water, forming landforms like deltas. So the idea that deposition causes sediment to be dropped, creating deltas and similar features, is the correct description of what happens.

The other statements don’t fit deposition: erosion downstream would require ongoing energy to wear away material, which isn’t what happens during deposition; dissolving minerals is a chemical process, not sediment deposition; turning sediment into gas isn’t a natural river process.