Weathering is the breaking down of rock into smaller pieces (sediment). Physical weathering occurs when the forces of nature break down rocks without chemically altering the original rock (we smashed one with a hammer today!)
We took sugar cubes and physically weathered them today by shaking 6 of them in a cup and removing one every hundred shakes. Wow did the shape change! We were left with some rather sweet sediment!
 |
| Sweet weathered "rocks" changed shape and size as weathering time increased! |
Chemical weathering alters the composition with a chemical reaction making the substance become something different. Think rusty iron, or acid rain and limestone.
Then, we chemically weathered "limestone" (Tums tablets) with "acid rain" (vinegar) while comparing the weathering rate of still water and moving water (courtesy of eye dropper squirting!)
Erosion is the picking up or physical removable of rock particles by an agent (wind, water, glaciers, even us!) Erosion moves sediment from one place to another. Next time you kick a rock you are an agent of erosion. Secret agent (of erosion) name "Rock Kicker."
Our last experiment showed the whole process! We weathered a line of Tums tablets by squirting water down a plastic tub on them. The water broke down the tablets (weathering) and carried the sediment (erosion) and deposited it in the cracks of the tub and the bottom (deposition.) Wow, Tums really taught us a lot about science with the bonus classroom "air freshener" that smelled rather fruity!
 |
| Weathering, eroding, and depositing "limestone"-Tums |
We even used motions that represented weathering, erosion, and deposition. Perhaps it will become a new dance craze!
Here is a video from the studyjams at scholastic.com with some good content about weathering and erosion. What kind of super hero would deposition be?
http://studyjams.scholastic.com/studyjams/jams/science/rocks-minerals-landforms/weathering-and-erosion.htm
No comments:
Post a Comment