How Rocks Form Practice Test

Use the simplified rock-cycle model below (it does not have a fixed starting point, and rocks can change types over time).

Model (arrows show possible pathways):

• Magma/Lava --cooling--> Igneous rock
• Igneous rock --weathering & erosion--> Sediments --compaction--> Sedimentary rock
• Sedimentary rock --heat & pressure--> Metamorphic rock
• Metamorphic rock --melting--> Magma/Lava (Other arrows shown: Igneous rock --heat & pressure--> Metamorphic rock; Any rock --weathering & erosion--> Sediments)

A student finds a rock that formed when melted material cooled and solidified. According to the model, which process formed that rock?

A student drew a rock-cycle connection on a simplified model that already includes these correct arrows:

• Magma/Lava --cooling--> Igneous rock
• Any rock --weathering & erosion--> Sediments --compaction--> Sedimentary rock
• Sedimentary rock --heat & pressure--> Metamorphic rock
• Metamorphic rock --melting--> Magma/Lava (There is no fixed starting point; rocks can change types over time.)

Which added arrow is incorrect based on the processes in the model?