Hannah is comparing a rock from a riverbed and a rock from deep underground. One is very smooth, and the other has very rough edges. Explain why each rock was probably found in that location.

2 answers

What has happened continuously to the rock in the riverbed? What has happened to the rock from deep underground?
Think about what the river would do to the rock. Scroll down to continue.

Erosion. If the rock was eroded, it would be smooth. In the cave, erosion can't occur. So it would be a rough rock. I hope that helps you.