These pebbles were deposited in a stream that once flowed over this area in Indiana, USA thousands of years ago.
Click on image for full size
Courtesy of Bruce Molnia, Terra Photographics
Click on image for full size
Courtesy of Bruce Molnia, Terra Photographics
Step 3: Sediments Settling Down!
When water or wind loses energy and slows down, sediment can no longer be carried in it. The particles fall through the water or air and form a blanket of sediment on the bottom of a river, a lake, ocean, or on the surface of the land.
Settling out of the wind or water depends on the size of the sediment. Larger pieces will settle more quickly than smaller ones. The opposite is true as well, so it takes more energy to move larger sediment through the water or air than small sediment.
The process of settling down is called deposition. How does deposition happen?
Try this experiment and find out!
- Add a handful or two of sediment to a jar that includes particles of different sizes such as pebbles, sand and mud.
- Fill the jar with water and seal the lid on top.
- Shake the jar and watch the pebbles and dirt fill the water.
- Let the jar sit still for a few minutes. What has been deposited on the bottom of the jar? Are any of the small particles still in the water? (The heaviest items fall out of the water more quickly than the small ones once you stop shaking the jar.)
Last modified August 25, 2003 by Lisa Gardiner.
