Tuesday, January 17, 2012

Weathering

We have been plugging away with our large landform unit. As we wait for the Foss Kits to show up I have been busy teaching weathering. As we move away from weathering onto erosion I wanted to show what we have done so far. Here is what we have done in science in the past two weeks (not including the GLAD component which I will make a separate post on later):


Weathering Experiment: I took some different rocks from my yard (pebbles and decorative rocks bought at Home Depot) and placed them in a glass baby food jar. Then I had the students fill the jars with water and shake at 15 second intervals. Over time the decorative rock broke away and what looked like sand sediment appeared. We were able to weather our own rocks!
The murky water is actually weathered sediment
A student's experiment write up
Sand Observation: My son has a sand collection from different beaches around the world. We have sand from Japan, Thailand, Honduras, Mexico, Caribbean, and local beaches as well. You would be amazed how all sand looks different! In pairs students got two samples to compare. Then I had students infer why the two samples would look so differently. They had more difficulty with this than I expected. However, after some discussion we realized that different rocks could be one reason for the difference in appearance, and also the how long they had been weathered may also be a factor.
Looking at differences
Sand Samples
Students comparison notes and inferences

Chemical/Physical Weathering Picture Sort: After watching my PowerPoint on the different types of both physical and chemical weathering, that highlight some characteristics to watch for, we inferred from pictures what type of weathering each image was.  For example, honeycomb appearance tells us salt-wedging has occurred. It was fun to guess which type of weathering each image was. To take it a step further, if a student could tell me the EXACT name of weathering that was happening they got a Super Scientist award (more on that in another post).

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