Use the simplified rock-cycle model shown. The rock cycle does not have a fixed starting point, and rocks can change types over time.
One arrow on a student's rock-cycle diagram is labeled: "Sedimentary rock → Magma (Cooling)." What is the best correction based on the model?
- Replace "Cooling" with "Melting." (correct answer)
- Reverse the arrow so it points from magma to sedimentary rock and keep "Cooling."
- Replace "Cooling" with "Compaction."
- No correction is needed because cooling turns any rock into magma.
Explanation: The skill of understanding rock formation requires correctly matching processes to their outcomes in the rock cycle. Rock type is determined by formation process - cooling creates igneous rock from magma, while melting creates magma from existing rocks. The rock cycle demonstrates multiple pathways, but each arrow represents a specific process with a particular direction and outcome. To check diagram accuracy, verify that each process arrow points in the correct direction and is labeled with the appropriate transformation. A critical misconception is confusing opposite processes like melting and cooling, or reversing the direction of transformations. Rocks change through specific processes over millions of years, each with its own cause and effect. The rock cycle operates continuously, but the processes must be accurately represented to understand how rocks actually transform.