How Rocks Form Practice Test

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

Model (arrows show possible changes):

Magma/Lava --(cooling)--> Igneous Rock

Igneous Rock --(weathering & erosion)--> Sediments --(compaction)--> Sedimentary Rock

Sedimentary Rock --(heat & pressure)--> Metamorphic Rock

Metamorphic Rock --(melting)--> Magma/Lava

(Also: Igneous Rock --(heat & pressure)--> Metamorphic Rock)

A student finds a rock that formed when melted material cooled and hardened after a volcanic eruption. According to the model, which process formed this rock?

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?