| LAYERING: 1 |
 | When streams run rapidly, as they do after a storm or when snow melts, much sediment is picked up and transported. When the velocity of the water subsides, as it does when it enters a lake or the ocean, the sediment is deposited. Notice how the water in this lake is cloudy with sediment. |
 | Each pulse of rapidly running water transports another batch of sediment. With time, the sediment accumulates layer by layer. |
 | Here we see hills and valleys made of layered rocks. How may these rocks be related to sediment deposited on the floor of a lake or the ocean? |
 | Here's an explanation: - First, sediment is deposited in the ocean. With time, the layers of sediment turn to rock.
- Next, the whole area is uplifted well above sea level. The ocean water drains elsewhere.
- As soon as the sedimentary rocks are exposed, they begin to erode, forming hills and valleys.
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