AFOQT Practice Test

Which rock type forms from cooling lava or magma?

1. Sedimentary rock

2. Igneous rock

3. Metamorphic rock

4. Intrusive rock

The correct answer is: Igneous rock

The correct answer is igneous rock, which forms from the cooling and solidification of lava or magma. When magma rises from beneath the Earth's surface and cools slowly, it creates intrusive igneous rocks, such as granite. Conversely, when lava cools quickly on the Earth's surface, it forms extrusive igneous rocks, like basalt. The definition highlights the fundamental process of rock formation in relation to temperature and cooling periods, making igneous rock unique among the types mentioned. Sedimentary rocks, on the other hand, form from the accumulation and compaction of sediment, while metamorphic rocks are produced from existing rocks that undergo transformation due to heat and pressure. Intrusive rock is a term that describes a specific type of igneous rock that cools slowly beneath the surface. However, the broader category that encompasses all rocks formed from cooled lava or magma is igneous rock.