Do mountains last forever? This was the questions students in our class have been investigating over the last 2 days.

Students explored how solid rock breaks apart into smaller pieces through a process called weathering. We learned terms like ‘root wedging’ and ‘ice wedging’ and how the cracks in rocks allows for seeds and water to get trapped inside, eventually causing the crack to widen and crack the rock into smaller pieces.

Students modeled the process of weathering that occurs when rocks tumble and crash into each other using sugar cubes in a container. Each group of students shook a container of sugar cubes approximately 200 times and more!

We hypothesized what we thought our sugar cubes would look like after shaking the containers. We drew pictures and recorded observations as we worked through many trials of shaking. We took turns with our partner so we both had turns shaking the sugar cubes.

Take a look at what happened after the sugar cubes were taken out of the container! (One of the sugar cubes was left out as a comparison). Do you notice how the edges of the sugar cube became smoothed out and the cube turned into a sphere?

This is what happens when rocks tumble down hills and mountains. With wet weather and when you add friction, rocks eventually will break down into smaller pieces and may show smoother surfaces at the bottoms of mountains. See below.

What do you wonder about rocks? Have you ever found a really smooth rock and wondered how it became smooth? What is the most interesting rock you’ve found?